Benefits of tannin added to concentrate diets fed to ruminants and monogastric livestock
- John R. Caradus1*corresponding author
- Grasslanz Technology Ltd, Hamilton, New Zealand
Abstract
Additives and supplements are often added to concentrate and conserved feeds for both ruminants and monogastrics to maximise feed efficiency, optimise animal health, bridge nutrient deficiencies, and improve economic returns. This may include incorporating polyphenols, such as tannins, extracted from natural plant by-products (e.g., grape pomace or extracts from wattle, quebracho and chestnut trees) to improve animal performance, biohydrogenation processes, quality and quantity of milk and meat, and to reduce methanogenesis. The focus is solely on the use of tannins as an additive—obtained from either extracts or natural variants of feedstuff containing higher amounts of these compounds —and the use of tannins as an additive directly from forages. A review of 72 studies where extracts of, or plants containing, tannins were added to concentrate or conserved feeds for ruminant animals indicated that 63% of cattle/cow studies and 54% of sheep/goat studies confirmed positive benefits. Reasons why benefits were not observed include using the ‘wrong’ type or concentration of tannin, the negation of tannin effects by other compounds in the extract, an unsuitable combination of tannin type and concentrate, or the developmental status of the ruminant. However, assuming this practice continues, this raises the question of whether tannin expression in the main ingredient of concentrate or conserved, feed such as maize or soybean, would be beneficial. For monogastrics, 20 studies for each poultry and swine were reviewed. The inclusion of tannins in feed for poultry provided little nutritional benefit reduced infection where coccidiosis severity due to microbial infection was measured. Tannin extracts fed to pigs produced variable results, ranging from no appreciable influence at low levels to a negative impact on the nutritive value of feed, although in some cases, animal health was improved. In conclusion, inclusion of tannin extracts appears to provide more benefit for ruminants than monogastrics, particularly poultry. The most likely benefits for ruminants fed tannin-containing diets are reduced methane emissions and improved gut health through an anthelmintic effect.
Keywords
1 Introduction
Conserved feeds and concentrate diets for both ruminants and monogastrics often have a range of additives included to provide environmental, animal health and, resulting product quality benefits (Tedeschi et al., 2011; Pimentel et al., 2022; Firkins and Mitchell, 2023; Life Rainbow Biotech, 2024; Cargill, 2026a). These may include natural products that could replace synthetic growth promoters and antibiotics (Franz et al., 2010; Placha et al., 2022). Low-quality forages and high grain diets require dietary supplementation with essential polyunsaturated fatty acids and antioxidants to extend shelf life of resulting meat cuts (Ponnampalam et al., 2024). Polyphenol compounds are increasingly used in USA feed mill products as natural, antioxidant-rich alternatives to synthetic additives, aimed at improving livestock health, growth performance, and meat quality (Mahfuz et al., 2021; Dunshea, 2022). As an example, Proviox™ 50 is a polyphenol-based solution that uses a plant-derived antioxidant blend designed to manage oxidative stress in livestock (Feed Additive, 2024; Cargill, 2026b). Proviox 50 contains a mixture of onion extract (quercetin and flavonols) and grape seed extract (catechins, flavonols, procyanidins, and anthocyanidins) (Hilbert et al., 2015). Another example, Phenofeed contains hydroxytyrosol, tyrosol, verbascoside derived from olive-based co-products (Di Meo et al., 2023), and Silvafeed®ATX contains vescalagin, quercetin, gallic acid extracted from chestnut (Panciroli, 2016). Used in feed, these polyphenols enhance immune response, support gut health, and improve product quality in swine, rabbits and poultry, often serving as a replacement for synthetic antioxidants (Abd El Azeem et al., 2021; Wu et al., 2025). Polyphenols such as tannins, provide anti-inflammatory, antibacterial, and antioxidant effects, resulting in reduced lipoperoxidation in animal products (meat and milk) (Gessner et al., 2016; Cutrim and Cortez, 2018; Pizzi, 2021; Serra et al., 2021; Bešlo et al., 2023; Sun et al., 2024; Muzzo and Provenza, 2026).
Ionophores such as monensin, lasalocid, laidlomycin, salinomycin and narasin, are often added to concentrate feeds for cattle to improve feed efficiency, promote weight gain, reduce bloat, and/or prevent coccidiosis (Duffield and Bagg, 2000; McGuffey et al., 2001; Callaway et al., 2003; Babandi et al., 2020; Marques and Cooke, 2021; Seema et al., 2025). In the USA about 90% of cattle in feedlots are fed ionophores (VanValin, 2024). Essentially ionophores are antibiotics that target specific bacteria that produce acetate in the rumen allowing the more energy efficient propionate-producing bacteria to dominate (Felix, 2024) resulting in reduced methanogenesis (Prusty et al., 2024) but notably does not affect nitrogen levels in urine (Rezaei Ahvanooei et al., 2024). Most jurisdictions allow the use of ionophores in ruminant and monogastric feed with global regulatory frameworks converging on classifying ionophores as non-antibiotic feed additives, with minor exceptions for therapeutic purposes. Regulatory compliance primarily involves navigating label claims, exports to European Union, and ensuring alignment with Maximum Residue Levels (EU, 2003). Ionophores are on a small list of in-feed antibiotics not considered medically important to human medicine by the World Health Organization (British Poultry Council, 2019). The risk to human health associated with the use of ionophores for control of coccidiosis in poultry because antibiotic resistance remains extremely low and is unquantified (Simjee and Tice, 2023). Some concerns have been raised about potential risks of ionophores, which have been identified in manure, runoff, and agricultural soils, moving into terrestrial and aquatic ecosystems, with studies revealing potentially hazardous effects even at low concentrations (Watanabe et al., 2008; Alam et al., 2025). However, tannins may provide an effective and natural alternative to ionophores by improving feed efficiency and performance metrics as demonstrated in weaned calves (Rigby, 2021) and lambs (Ibrahim and Hassen, 2022; Ibrahim, 2024).
The use of antimicrobials as growth-promoting factors, as distinguished from therapeutic and pro-phylactic use of antibiotics that are administrated at higher doses over short periods of time, has been banned in some jurisdictions (e.g. European Union (EU, 2003)) (Redondo et al., 2014). The removal of antibiotics from animal feed has raised concerns about the welfare and productivity of animals, particularly monogastrics, and has resulted in a drive to seek alternative options. This led to reviews of the efficacy of enzymes, acids, pre- and probiotics and herbs with phytochemical properties, organic acids or etheric oils (Huyghebaert et al., 2011; Sethiya, 2016; Kalia et al., 2022; Thirumeignanam et al., 2024) but seeking a consensus has been challenging (Lillehoj et al., 2018). Plant extracts have been identified and with a particular focus on tannins as natural antimicrobial chemistry although there is a critical need to determine the appropriate dosages of supplemental tannins for their potential implementation (Choi and Kim, 2020). However, even recently the view that “there does not appear to be an alternative product that can entirely replace antibiotics as a growth promoter in animal feed for poultry and swine production” (Rahman et al., 2022) still resonates. Yet others have concluded that “the use of tannins in commercial flocks of broiler chickens for replacing antibiotics while maintaining performance, suggesting that this type of additive is a promising alternative for the implementation of antimicrobial use free programmes” (Viso et al., 2025).
Tannins are polyphenolic compounds found in many plants affording protection against insect predation (Feeny, 1970; Moilanen and Salminen, 2008; Furlan et al., 2010; Barbehenn and Constabel, 2011). They have also been traditionally considered to be both unpalatable and anti-nutritional for monogastrics (Treviño et al., 1992; Jansman, 1993; de Lange et al., 2000; Smulikowska et al., 2001; Bhat et al., 2013; Redondo et al., 2014) but also with grazing ruminant animals (Kumar and Singh, 1984; Tadele, 2015), and certainly above certain concentrations (5 to 9% of dry matter) that appears likely (Makkar, 1993; Seresinhe and Pathirana, 2003; Ammar et al., 2011; Choi and Kim, 2020). However, their effects are complex and can vary depending on the type, concentration, and context of their use (Mueller-Harvey, 2006). While high concentrations of tannins can indeed reduce feed intake and nutrient absorption (Barry, 1985; Addisu, 2016), moderate levels may offer certain benefits, such as being antimicrobial, anti-parasitic, antiviral, antioxidant, anti-inflammatory, and immunomodulating as well as improving protein utilisation and reducing methane emissions in ruminants (Min et al., 2019; Pandey et al., 2022; Camarda et al., 2026; Ng’ambi, 2026). Indeed “tannins are considered valid alternatives to the conventional feed ingredients and as antipathogenic molecules, which can be used as an alternative ingredient” (Hassan et al., 2020). This dual nature of tannins necessitates a more considered understanding of their role in animal nutrition. A meta-analysis of 27 studies on the impact of including tannins in beef and dairy cattle diets determined that tannins reduced ammonia nitrogen concentration and methane production in the rumen (Brutti et al., 2023). They also concluded that “the best strategy to achieve these positive results includes the use of an integration between hydrolysable and condensed tannins due to the synergy between these two phenolic structures”. Another review indicated that “treating cereals with tannic acid might be a promising method to shift the site of starch digestion from the rumen to the intestines, thus reducing the incidence of rumen fermentation disorders” (Humer and Zebeli, 2017).
Tannins come in many forms, although there are two main categories recognised, i.e., hydrolysable tannins and condensed tannins (Mora et al., 2022). Hydrolysable tannins have a polyol core (commonly D-glucose), which is esterified with phenolic acids (mainly gallic or hexahydroxy diphenic acid) (Haslam, 1989; Pizzi, 2008; Bule et al., 2020). Condensed tannins are oligomeric or polymeric flavonoids consisting of flavan-3-ol units that include catechin, epicatechin, gallocatechin and epigallocatechin (Porter, 1989; Pizzi, 2008; Bule et al., 2020; Favari et al., 2020). These can form complexes with each other (Bedran-Russo et al., 2014; Fraga-Corral et al., 2021), and a third type of tannin referred to as phlorotannins can be found in marine algae (Bule et al., 2020). Tannins consumed by ruminants are either hydrolysable or condensed tannins, or mixtures of both. However, most studies have focused on the benefits and risks associated with the consumption of condensed tannins (Mueller-Harvey et al., 2019; Waghorn, 2008). As a result, there is limited evidence of the benefits of hydrolysable tannins on both the animal and the environment. Some studies have considered hydrolysable tannins toxic to livestock and can cause death if consumed in large quantities (Makkar, 2003), while other studies have indicated that hydrolysable tannins may reduce enteric methane emissions (Śliwiński et al., 2002b; Hassanat and Benchaar, 2013; Jayanegara et al., 2015; Aboagye et al., 2018; Aboagye and Beauchemin, 2019; Stewart et al., 2019; Loza et al., 2021). Hydrolysable tannins also have a lethal anthelmintic effect on gastrointestinal nematodes such as Haemonchus contortus (Engström et al., 2016; Acevedo-Ramirez et al., 2019) and have been noted as having less adverse effect on digestibility than condensed tannins (Jayanegara et al., 2015).
For ruminants grazing pastures in situ some forages containing condensed tannins have been shown to benefit both the animal (e.g., improved milk production and composition, positive changes to meat production, composition and taste, reduced bloat, improved antioxidant effects) and the environment (e.g., reduced methane and nitrous oxide emissions) (Waghorn et al., 1997; Woodward et al., 2004; Puchala et al., 2005; Min et al., 2003; Waghorn, 2008; Attia et al., 2016; Vasta et al., 2019). There is considerable evidence for the control of or tolerance towards gastrointestinal parasites in both ruminants and monogastrics including coccidiosis caused by Eimeria species in poultry through consumption of moderate levels of tannins (Athanasiadou et al., 2000; Molan et al., 2000a, b; Min and Hart, 2003; Hoste et al., 2006; Waghorn, 2008; Wang et al., 2008; Kaleem et al., 2014; Hoste et al., 2016; Tonda et al., 2018; Choi and Kim, 2020). However, for animals fed indoors with concentrates or conserved feed any inclusion of tannins is most often through being added as a supplement. A meta-analysis of 30 experiments comprising 171 treatments observed inconsistent effects of low-level supplemental tannin effects on ruminal methane, with greater mitigation of ruminal methane observed with forage-based diets (Jayanegara et al., 2012).
A review (Mueller-Harvey, 2006) of the effects of tannins from 35 different plant sources showed that 23 provided significant benefit in terms of either improved environmental outcomes (e.g., movement of nitrogen from urine to faeces and lowered methane emissions), increased dry matter intake with higher growth rates and milk yields, anthelmintic effects, improved reproductive performance, and/or reduced bloat. For the 23 showing some benefit 21 of these used plants containing condensed tannins, with the other two being from plants containing a mix of hydrolysable and condensed tannins. The other 12 tannin sources resulted in mixed outcomes or negative/toxic impacts. This included the two plants sources providing hydrolysable tannins and 5 of the 7 plant sources containing a mix of hydrolysable and condensed tannins. Differences in chemical structures (degree of polymerisation, procyanidins to propdelphinidins, stereochemistry and carbon-to-carbon bonding) and concentrations of tannins, and type of diets can influence the benefits or otherwise of tannins (Patra and Saxena, 2011; Mueller-Harvey et al., 2019). The source of tannins for use as a supplement for ruminant concentrate feed can be very variable and include condensed tannins and/or hydrolysable tannins at varying concentrations (Besharati et al., 2022). Condensed tannins are also known to lessen the drop in ruminal pH and reduced the inflammatory state of cows fed a high grain diet resulting in induced subacute ruminal acidosis (Olagaray and Bradford, 2019).
A significant part of conserved feed can constitute maize and soybean, neither naturally containing tannins to any degree – less than 0.2% of dry matter (Adegbusi et al., 2022). However, if that opportunity (i.e. condensed tannins expressed in maize and/or soybean) was available, how would that positively or negatively affect animal productivity, health and welfare of ruminants and monogastrics fed concentrated or conserved feed? Recently it has been shown that introducing a Sorghum bicolor transcription factor (SbTT2) specifically regulating condensed tannin biosynthesis into a maize inbred deficient in anthocyanin biosynthesis appears to activate both anthocyanin and condensed tannin biosynthesis pathways (Lu et al., 2023; Dixon and Lu, 2025).
The aim here is to explicitly identify the benefits of, or risks associated with varying tannins and concentrations of them for use as supplements in concentrate feed. The focus will be solely on the use of tannins as an additive either obtained from plant extracts and/or natural variants of feedstuff containing higher amounts of these compounds and does not include the use of tannins as an additive directly from forages. This should provide guidance as to whether intrinsic condensed tannin expression in maize and soybean would be worth pursuing or not. This is not an exhaustive review of the benefits and concerns about inclusion of tannins in animal diets but rather a review of studies that have incorporated tannin in concentrate feed diets and their impact on ruminant and monogastric domestic animals grown as a protein and energy source for human consumption. Reviews on the impacts and benefits of forages or pasture plants containing tannins, particularly condensed tannins, when provided to ruminants are manifold (Mueller-Harvey, 2006; Serrano et al., 2009; Piluzza et al., 2014; Mueller-Harvey et al., 2019; Olagaray and Bradford, 2019; Vasta et al., 2019; Kelln et al., 2021; Besharati et al., 2022; Al Rharad et al., 2025).
2 Use of tannin extracts in concentrate and conserved feed diets for ruminants
A literature search using Google Scholar, with no time period limit, was undertaken using the keywords ‘tannin’, ‘concentrate’, and ‘supplementary feed’ to identify studies testing the impacts of adding tannins to feed on animal performance, biohydrogenation processes, milk and meat quality and quantity, and methanogenesis reduction. Google Scholar was used as a result of a systematic comparison of 252 subject categories, which concluded that Google Scholar citation data is essentially a superset of Web of Science and Scopus, with substantial extra coverage (Martín-Martín et al., 2018). A total of 72 studies were identified where tannin extracts or plants containing tannins were added to concentrate feed for ruminant animals (Table 1). Of these 70 were in vivo studies and 2 in vitro, and 53 (74%) were with condensed tannins added, 11 (15%) with hydrolysable tannins, and 8 (11%) with a mixture of condensed and hydrolysable tannin added. The impact of tannin added to concentrate feed for each study described in Table 1 was classified as either positive, mixed, or negative. Those categorised as positive improved animal performance through at least one of the following - reducing biohydrogenation, nitrogen movement away from urine, improved quality and quantity of milk and meat, improved animal health, or reduced methanogenesis and caused no significant negative effects on animal performance or health. Those categorised as negative failed to show significant positive effects on animal performance while demonstrating predominantly negative impacts. Those described as providing mixed results had either minimal impact or both positive and negative impacts on animal performance factors.
Table 1. Effects of tannins added as a supplement into the diet of concentrate feed fed to ruminants. A positive rating - ✓- indicates improved animal performance through at least one of reducing biohydrogenation, nitrogen movement away from urine, improved quality and quantity of milk and meat, improved animal health, or reduced methanogenesis and caused no significant negative effects on animal performance or health. A negative rating - X – indicates that adding tannin failed to show significant positive effects on animal performance while demonstrating predominantly negative impacts. Those described as providing mixed results - (✓) - had either minimal impact or both positive and negative impacts on animal performance factors.
| Tannin type, source and concentration | Basal feed type | Ruminant type | Benefit of tannins | Limitations | Recommendation | Reference | Rating |
|---|---|---|---|---|---|---|---|
| Condensed tannins (CT) | |||||||
| Quebracho (Schinopsis spp.) extract. [0.25% and 1.5% CT of DM] | Lucerne (Medicago sativa): barley (Hordeum vulgare) silages (50:50; dry matter basis) with a crude protein content of 17.1% | Steers – in vivo | Decreased ruminal ammonia concentration | Tannin levels possibly too low to be effective. No effect on rumen pH, total volatile fatty acid concentration, proportions of acetate and propionate, total protozoa populations, and methane production | Aboagye et al., 2018 | X | |
| 3 trials involving quebracho (Schinopsis spp.) extract (trials 1 and 2), with or without Lespedeza added (trial 3) -at a rate of 100 g/lamb quebracho extract | Trial 1- cracked maize, wheat middlings,soybean meal and hulls, cottonseed hulls, lucerne pellets, molasses, minerals.Trial 2 – maize and soybean mealTrial 3 - Lucerne | Trials 1 and 2 - Lambs – in vivoTrial 3- kids – in vivo | Faecal oocyst count increased in control lambs and were reduced in lambs fedquebracho or quebracho and lespedeza | Clinical signs (dag and fecal scores) were essentially the same between dietary groups; supplementary CT led to a reduction in serum concentrations of cobalt, molybdenum and selenium, | No specific recommendation provided but expressed concern about CT impact on production and health of the animal during long-term feeding | Acharya et al., 2020 | (✓) |
| Black wattle (Acacia mearnsii) - 0, 0.5, 1.0, 1.5, and 2.0 g CT/kg of diet dry matter. | Mix of Tifton-85 hay, ground maize (Zea mays), soybean (Glycine max) meal, mineral mix | Cattle – Jersey steers - in vivo | Reduced the molar proportion of acetate | Did not affect the ruminal protozoal population, which might be related to the low doses used. | CT extracts from A. mearnsii are not recommended for improving nutrient utilization in steers at the tested levels. | Avila et al., 2020 | X |
| Quebracho (Schinopsis lorentzii) extract. [0, 1% and 2% CT of DM] | Barley silage, barley grain, soybean meal, maize meal, minerals | Cattle – in vivo | No effect on body weight, average daily gain, or nutrient intakes. No effect on methane emission or dry matter digestibility, but apparent digestibility of crude protein decreased linearly | Feeding up to 2% of the dietary DM as quebracho tannin extract failed to reduce enteric methane emissions from growing cattle | Beauchemin et al., 2007 | X | |
| Tamarind (Tamarindus indica) seed husk (approx. 40% CT҂) – 0, 2.5 and 7.5% of feed offered | Maize, rice (Oryza sativa) bran, wheat (Triticum aestivum) bran, groundnut (Arachis hypogaea) cake, molasses minerals | Cows – in vivo | Reduce urine N and increased faeces N; significantly higher milk protein content at 7.5% level | DM intake, milk yield, milk fat, solid not fat and lactose were not significantly affected | Tannin at low concentration (7.5% level of tamarind) has beneficial effect on the performance of lactating cows | Bhatta et al., 2000 | ✓ |
| Black wattle (Acacia mearnsii) – 2.23% CT in DM | Barley, wheat bran, dehydrated lucerne hay, soybean meal, molasses and mineral-vitamin premix | Lambs – in vivo | Dramatic decrease in meat of Enterobacteriaceae population - Gram-negative, rod-shaped bacteria common to intestinal tracts | Tannin extract supplementation is a promising dietary strategy to preserve lamb meat quality | Biondi et al., 2019 | ✓ | |
| Grape (Vitis vinifera) pomace - 0, 5, 10, 15 and 20% GP/kg DM | Lucerne meal, soybean hulls, maize bran, wheat and oat (Avena sativa) bran, maize meal, molasses | Lambs – in vivo | 20% GP/kg-diet finished lamb meat had the highest antioxidant activity and the lowest total viable bacterial counts, lipid and protein oxidation values | 20% GP/kg DM in lamb diets improved meat shelf-life without negatively affecting sensory quality | Chikwanha et al., 2019 | ✓ | |
| Mimosa (Acacia farnesiana) pods at 100, 200 and 300 g/kg DM | Lucerne hay and grain | Dairy goat – in vivo | Pods inclusion increased the presence of bioactive compounds and the antioxidant activity of milk and diminished the cholesterol content in milk. | No clear effects of feeding treatment were observed to modify the fatty acid profile of goat’s milk | Delgadillo-Puga et al., 2019 | ✓ | |
| Bengal fig (Ficus bengalensis) leaves [0% and 1.5% tannin in DM] | Rice bran, maize grain, mustard (Brassica spp.) cake and minerals | Cows – in vivo | Increased milk fat and lowered serum urea concentration | Positive impact evident on milk production and antioxidant status when fed Ficus leaves | Dey and De, 2014 | ✓ | |
| Quebracho (Schinopsis spp.) extract [CT 3% of dietary DM] | Lucerne hay, maize silage, barley, beet (Beta vulgaris) pulp, canola (Brassica napus) meal, wheat middlings, minerals | Cows – in vivo | Decreased ruminal ammonia-N and milk urea N concentrations, indicating that less ruminal N was lost as ammonia, less N excretion into urine but more into faeces | Decreased intakes of dry matter, but digestibility of dry matter and nutrients were not affected, yields of milk and milk component were not influenced | Dietary use of CT may alter ruminal metabolism and nitrogen excretion into urine | Dschaak et al., 2011 | (✓) |
| Quebracho (Schinopsis spp.) extract. [0, 0.5, and 1.0% CT on DM basis] | Steam-flaked maize–based finishing diet (14.4% CP and NEg 1.47 Mcal/kg). | Beef steers; in vivo | Faecal N excretion linearly increased with inclusion of CT in first 34 days | Urinary nitrogen excretion was not different, but urinary nitrogen as a proportion of total nitrogen excretion linearly decreased in first 34 days | Growth performance, gas emissions, and energetic losses were not affected by the inclusion CT in a steam-flaked corn–based finishing diet. | Ebert et al., 2017 | (✓) |
| Acacia aroma and Larrea divaricata leaves – both at 125 g/kg DM [0.56% and 0.17% CT, respectively] | Lucerne hay, maize and soybean meal | Goats – in vivo | Positive effect of incorporation in the diet of goats in oxidative stability of the meat but cannot be ascribed to the presence in meat of antioxidant compounds. | No differences were found in meat colour due to nutritional treatment. Meat antioxidant activity and ultimate pH values were not affected by CT inclusion. | Inclusion of Acacia aroma and Larrea divaricata leaves in goat diet enhanced meat oxidative stability. | Garcia et al., 2019 | (✓) |
| Black wattle (Acacia mearnsii) extract. [CT concentrations of 0, 2.03, 6.19 and 10.2 g/kg DM] | Rapeseed (Brasicca napus) meal, maize grain, wheat grain, vegetable fat, minerals | Sheep – in vivo | Organic matter digestibility decreased. | CT from A. mearnsii to rations of sheep reduced nutrient digestibility at much lower levels than previously reported for CT from other forage sources | Gerlach et al., 2018 | X | |
| Black wattle (Acacia mearnsii) – extract at 0, 10, 30 or 50 g/kg DM. [720 g/kg of tannin in the extract] | Bermuda grass (Cynodon spp). Tifton-85 hay, ground maize, soybean meal and oil, mineral mix | Young bulls – in vivo | Reduced ruminal biohydrogenation and improved the polyunsaturated fatty acid content of salted and sun-dried meat | Did not influence most of the physicochemical characteristics, fatty acids and nutraceutical compounds | Salted and sun-dried meat with the inclusion of CTs was considered the best tasting by consumers. | Gesteira et al., 2019 | ✓ |
| Grape (Vitis vinifera) peel and seed used, aqueous extraction. [6.5% CT of DM] | Meadow hay, concentrate, barley (43 %), beet pulp (40 %), soybean meal (12 %) and molasses | Sheep – in vivo | Enhanced the plasma total antioxidant status | Digestive processes in ruminants do not inhibit the antioxidant properties of polyphenols | Gladine et al., 2007 | (✓) | |
| Black wattle (Acacia mearnsii) extract. [Dosed to cows at 0, 163, 326 g CT per day] | Ryegrass (Lolium spp.) pasture supplemented with 5 kg d-1 cracked triticale grain | Cows – in vivo | Low and high CT supplementation reduced methane emissions by 14% and 29%. Percentage of nitrogen in urine was reduced | Milk production and energy digestibility was reduced particularly at high CT level | Dairy producers would be reluctant to adopt feeding practices that compromise profitability | Grainger et al., 2009 | (✓) |
| Carob (Ceratonia siliqua) fruit pulp – 0, 24 and 35% of feed | Barley, lucerne, soybean meal, wheat bran | Male lambs – in vivo | Carob pulp increased the n-3 polyunsaturated fatty acids and decreased the concentration of saturated fatty acids in muscle | Including carob pulp up to 35% in concentrate-based diet could be a feasible strategy to improve lamb meat quality traits | Gravador et al., 2015 | ✓ | |
| Grape (Vitis vinifera) seed extract and grape pomace - 50 mg grape seed extract per kg; 5% dried red grape pomace per kg | Barley, soybean, molasses, mineral premix | Male lambs – in vivo | Grape pomace decreased lipid oxidation by about 20% | Vitamin E was more effective in preventing sensory spoilage than grape pomace | Grape pomace as feed in lamb diets could be adopted as a strategy to reduce feeding cost | Guerra-Rivas et al., 2016 | (✓) |
| Quebracho (Schinopsis spp.) extract – containing 76% CT. Added as 0, 28, 83 and 166 g/kg DM | Lucerne hay, barley straw and Erica arborea | Ewes – in vivo | 28 g/kg DM did not produce adverse effects; 83 g/kg DM impacted in situ crude protein disappearance and cumulative gas production | Signs of toxicity at 166g/kg DM | Effect of quebracho CTs on ruminal fermentation activity was dependent on the dose and the substrate incubated | Hervas et al., 2003 | (✓) |
| Unencapsulated and encapsulated Mimosa (Acacia tannin) tannins [tannin at 20 g/kg DM] | Total mixed ration – soybean meal, maize, lucerne hay, Eragrostis hay, minerals | Ram lambs – in vivo | Increased intake of DM; increased faecal nitrogen excretion; reduced methane emissions; | Tannin could mitigate enteric methane while enhancing nutrient intake when supplemented at 20 g/kg DM of feed | Ibrahim and Hassan, 2022 | ✓ | |
| Grape (Vitis vinifora) seed extract – 2.5% of DM. [2.09% CT] | 90% dehydrated lucerne and 10% wheat bran | Lambs – in vivo | Inclusion of grape seed extract protected the meat against lipid oxidation and did not change the sensory properties of meat. | Did not improve the meat colour stability | Might be a good approach to reduce the meat deterioration induced by lipid oxidation in ruminant meat | Jerónimo et al., 2012 | ✓ |
| Tannin-rich peanut (Arachis hypogaea) skin/testa (PS)* - 0, 25, 50, or 75% tannin-rich peanut skin [3.9, 7.8, and 11.7% CT, respectively] | Cracked maize, soybean meal, soybean hull, molasses, minerals | Male goats – in vivo | Loin chops from goats fed 75% PS had better colour; 50% PS fed goats had a higher fat content | Supplementing peanut skin can slightly alter the fatty acid profile of edible tissues in meat goats. | Kafle et al., 2021 | ✓ | |
| Black wattle (Acacia mearnsii) – [2.5% CT extract] | High protein diets containing maize dried distiller’s grains and solubles, a barley-based diet that contained 91% concentrate and 9% silage | Beef heifers - in vivo | Total N output, however, feeding CT decreased the excretion of total urinary N and urea N in urine by 17 and 21%, | Reduction of N digestibility reflected the protein binding effects of CT | Supplementation of CT in high protein diets fed to feedlot cattle reduced urinary N and increased the capture of N in manure to potentially lessen the loss of N as ammonia | Koenig et al., 2018 | ✓ |
| Quebracho (Schinopsis spp.) extract – 14.9g CT/ kg DM | High-grain diet – maize, sorghum hay, cottonseed (Gossypium hirsutum) hulls and meal, minerals | Steers – in vivo | No effect of tannin on animal performance, ruminal fermentation parameters, in vitro methane producing activity, or carcass and non-carcass traits | Tannin supplementation may be a viable option in finishing beef cattle if bactericidal efficacy is established | Krueger et al., 2010 | (✓) | |
| High tannin sorghum (Sorghum bicolor) grain – [1.73 to 3.46% CT of DM] | Maize grain | Steers – in vivo | Increased plasma cortisol | Increased rate of discoloration of meat after aerobic display | Larraín et al., 2008 | X | |
| Grape (Vitis vinifora) seed extract [0.74% CTs of DM] | Forage, concentrate, dried sugar beet pulp | Dairy sheep and goats – in vivo | Supplemented goats had higher urinary phenol concentrations. Goats have coping mechanisms like a higher salivary tannin-binding capacity than sheep | Phenol concentrations increased in blood (+10% and 17% in weeks 5 and 11, respectively) and in milk (+32% in week 5) | Leparmarai et al., 2019 | (✓) | |
| Quebracho (Schinopsis spp.) – 75% CT as 10% of concentrate. [7.5% CT] | Concentrate - 300 g/head of concentrate to ewes fed either pasture or hay | Single bearing ewes – in vivo | Improved meat appearance and reduced lipid oxidation | Quebracho is recommended to be fed to dams because it improves colour and extends the meat shelf life of the suckling lamb | Lobón et al., 2017 | ✓ | |
| Quebracho (Schinopsis spp.) – 6.4% tannins | Barley, lucerne hay, soybean meal and vitamin/mineral premix | Lambs – in vivo | No phenolic compounds were found in lamb tissues. Liver and the plasma displayed a greater antioxidant capacity | Profisetinidin tannins seem not to be degraded or absorbed in the gastrointestinal tract, but they induced antioxidant effects in animal tissues | López-Andrés et al., 2013 | ✓ | |
| Quebracho (Schinopsis lorentzii) [4% tannin in DM] | Barley and soybean meal and lucerne hay | Lamb – in vivo | Positive effects on haem pigment concentration and metmyoglobin formation, and higher muscle antioxidant capacity | Quebracho tannins improved meat colour stability of fresh lamb during extended refrigerated storage. | Luciano et al., 2009; Luciano et al., 2011 | ✓ | |
| Quebracho trees (Schinopsis lorentzii) - 0.3, 0.6 and 0.9 % of quebracho extract in the diet; extract was 64% tannin | Silage (75%) and hay (5%), plus ground maize, soybean meal, minerals, | Male lambs – in vivo | Addition of tannin stimulated the immune system | Did not affect intake, feed conversion, or growth in lambs | Addition of 0.3% of quebracho in the diet improved lamb body condition score and health after weaning | Lucianer et al., 2019 | (✓) |
| Quebracho (Schinopsis spp.) extract. [1g CT/ 10kg body weight daily] | Soybean meal | Steers - in vivo | In the presence of soybean meal, the addition of CT increased the flux of rumen undegradable protein and metabolisable protein and improved the ratio of metabolisable to crude protein. | No difference in pH, volatile fatty acids, and ruminal ammonia with the addition of CT | CT in beef cattle diets with high level of concentrate and soybean meal has positive effects on crude protein utilization, decreasing digestion rate and ruminal digestibility of crude protein and consequently increasing the levels of metabolisable protein | Mezzomo et al., 2011 | ✓ |
| Tannin-rich peanut (Arachis hypogaea) skin/ testa (PS)* ¥ - [PS at 0, 5, 10, 15, and 20% as-fed at 15% WDGS] or [WDGS at 0, 10, 20, 30, and 40% as-fed with and without 15% PS inclusion] | Steam-flaked maize (52%), and wet-distiller’s grains plus solubles (WDGS) (40%) made up of wet maize gluten, cotton-seed meal, chopped maize stalks, and mineral/ vitamin premix | In vitro - 50 mL of ruminal fluid (pH 5.8), 40 mL of artificial saliva (pH 6.8), and 6 g of mixed diets after a maximum of 24 h of incubation | Production of CH4 was reduced, ruminal lactate, succinate, and acetate/ propionate ratio tended to be less. Bacteroidetes, total methanogens, Methanobrevibacter sp. AbM4, and total protozoa were less. | Associative effect of tannin-rich PS and WDGS, which suppressed methanogenesis both directly and indirectly by modifying populations of ruminal methanogens. | Min et al., 2019 | ✓ | |
| Grape (Vitis vinifora) seed - 10, 20 and 40 mg CT/kg BW/day | Maize and millet straw, maize, soybean meal, cottonseed meal, wheat bran and minerals | Ram lambs – in vivo | Levels of 10 and 20 mg/kg BW/day improved growth performance. | Grape seed CTs linearly increased antioxidative enzyme activities of muscle and improved liver function of lambs. | Mu et al., 2020 | ✓ | |
| Dietary red wine (Vitis vinifora) extract (RWE) - 900 mg extract/kg feed | Barley + concentrate (maize meal, barley, wheat, soybean meal, sunflower (Helianthus annuus) meal) supplemented with extruded linseed and deodorized fish oil | Lambs – in vivo | Improved n-6/n-3 ratio of fatty acids in meat | Dietary RWE did not enhance the oxidative stability or sensory attributes of lamb meat | Lack of an effect of red wine extract on oxidative stability of lamb meat could arise from the use of a low dose | Muíño et al., 2014 | (✓) |
| Quebracho tannin (Schinopsis spp.) extract fed at 0%, 1.5%, 3%, and 4.5% of dry matter (DM); quebracho extract contained 77.99% total condensed tannins (CT) | Cottonseed hulls, cracked maize, lucerne pellets, Bermuda grass hay, molasses and minerals | Decreased urinary N, increased faecal N, decreased methane emissions, increased total volatile fatty acid levels with increased levels of CT added; quebracho atnnin provided up to 4.5% of dry matter intake (about 3.51% of CT, on Dm basis) does not affect N and energy retention | Significant discrepancies among studies feeding CT to cattle require more investigation of effects on animals at varying growth stages within diverse production settings if results are to be applied in non-research settings | Norris et al., 2020 | ✓ | ||
| Acacia mearnsii - tannin extract (Tanac, Brazil)- 0, 0.14, 0.29, 0.43% tannin | Maize silage, lucerne hay, whole cottonseeds, maize grain, citrus pulp, soybean meal and minerals | Cows – in vivo | Tendency for the ratio of acetate to propionate to be linearly increased with tannin; linear decreases in milk urea N, urine N and plasma urea N | Tannin up to 0.43% of DM did not affect DM intake and lactation performance; a tendency to reduce urine N excretion | Oliveira et al., 2023 | ✓ | |
| Black wattle (Acacia mearnsii) - tannin extract tested were 9, 18 or 27 g/kg of total dietary DM. | Oat (Avena strigosa) plus concentrate, in a proportion of 0.55:0.45 | Steers – in vivo | Tannin extract linearly reduced the total-tract digestibility of N compounds, as well as the urinary N excretion, and linearly increased the faecal N excretion, N retention and the efficiency of N utilization by steers. | Dietary inclusion of Acacia mearnsii tannin extract up to a level of 18 g/kg DM decreased the urinary N excretion and improved the amino acid supply in steers fed fresh-frozen oat forage plus concentrate | Orlandi et al., 2015 | ✓ | |
| Black wattle (Acacia mearnsii) tannin extract – containing 69% tannin at 3.8 g/kg DM of diet [0.26% tannin] | Tifton 85 hay (Cynodon dactylon) ad libitum plus concentrate – 50:50. | Male sheep – in vivo | Tannin level was not high enough to negatively impact the feed intake, digestibility, faecal and urinary excretion and retention of N | Tannin did not impact the nutrients supply and N use by sheep fed with a tropical grass-based diet. | Orlandi et al., 2020 | X | |
| White fig (Ficus infectoria) and guava (Psidium guajava) leaves – [0, 1, 1.5 and 2.0% CT] | Basal diet of wheat straw and oat hay offered ad libitum | Lambs – in vivo | Supplementation significantly improved the antioxidant status and cell mediated immune response and reduced faecal egg counts of Haemonchus contortus | Dietary supplementation of CT (1-2%) improved the erythrocytic antioxidant status and immune response, and reduced faecal egg counts in lambs | Pathak et al., 2017 | ✓ | |
| Quebracho (Schinopsis balansae) tannins extract [0, 1, 2, 3, and 4% of DM] | Low-quality chopped Pennisetum purpureum grass | Heifers – in vivo | Molar proportion of propionate increased linearly for treatments with 3 and 4% quebracho extract; total methane production decreased linearly as quebracho extract increased in the diet | Quebracho extract at 2 or 3% of DM ration can decrease methane production up to 29 and 41%, respectively, without compromising feed intake and nutrients digestibility | Piñeiro-Vázquez et al., 2018 | ✓ | |
| Carob (Ceratonia siliqua) fruit pulp – 20% of diet | Commercially pelleted diet | Male lambs – in vivo | Higher conversion index (2.68 and 3.22kg DM per kg weight gain respectively for control and carob diets | Carcasses are similar and unable to be distinguished between by sensory panelists | Priolo et al., 1998 | (✓) | |
| Carob (Ceratonia siliqua) fruit pulp – 56% of diet [2.5% tannin as DM in diet] | Conventional maize-based diet | Lambs – in vivo | Lower growth rates and poorer feed efficiencies; lower carcass yield and had less fat, and the meat had a higher ultimate pH and poorer quality | CTs from carob pulp were detrimental to feed digestibility and lamb performance | Priolo et al., 2000 | X | |
| Quebracho (Schinopsis lorentzii) [0%, and 0.6% on DM basis] | Steam-flaked maize diet (65%); distillers dried grains plus solubles (15%); sugar cane (Saccharum officinarum) bagasse (10%) | Steers – in vivo | Increased (6.5%) weight gain, gain efficiency (5.5%), and tended to increase dietary net energy (3.2%) | Tannin supplementation promotes greater dry matter intake, and hence, average daily gain of steers during the finishing feedlot phase. | Rivera-Méndez et al., 2017 | ✓ | |
| Grape (Vitis vinifora) residue silage - 0, 50, 75 and 100 g/kg DM | Maize silage, soybean meal, maize grain, wheat bran, soybean oil, minerals | Cows – in vivo | Grape silage residue may have led cows to deposit less body fat; at 100 g/kg produced milk with the highest oxidative stability | Total tract apparent digestibility DM, crude protein, acid detergent fiber and neutral detergent fiber decreased linearly with higher proportions of grape residue | Possible to improve milk fat quality by feeding cows with grape residue silage as shown by enhanced antioxidant activity | Santos et al., 2014 | ✓ |
| Black wattle (Acacia mearnsii) - tannin extract – 141 g extract/kg DM | Maize silage | Bulls – in vivo | No effect on biohydrogenation intermediates and fat quality traits | Not effective in improving carcass fat properties of maize-silage fed bulls | Staerfl et al., 2011 | X | |
| Birdsfoot trefoil (Lotus corniculatus) or sainfoin (Onobrychis viciifolia) hay – [0.6 and 2.5 % CT on DM] | Birdsfoot trefoil or sainfoin hay | Cows and heifers – in vivo | Excreted less urinary urea N (g/d) and showed lower concentrations of blood urea N; reduced CH4 emissions | Tannin-containing hays have the potential to reduce urinary urea N excretion, increase N retention, and reduce enteric CH4 emissions from beef cattle | Stewart et al., 2019 | ✓ | |
| Grape (Vitis vinifora) pomace - 150 g/kg DM | Wheat bran and straw, maize, lucerne, molasses, canola | Steers – in vivo | Higher meat colour values and fewer coliform counts; increased antioxidant activity | Grape pomace could be a better natural preservative than citrus pulp when included in beef cattle finishing diets | Tayengwa et al., 2020 | ✓ | |
| Black wattle (Acacia mearnsii) – extract was 4% of DM fed; 26g/d intake; approx. 2.3% of diet | Barley, wheat bran, lucerne, soybean meal, molasses minerals | Male lambs – in vivo | Did not affect animal feed intake; | No effect on any of the main groups of fatty acids and the peroxidability index | Effects of tannins on animals’ metabolism and product quality may depend on the basal diet and metabolic status of animals. | Valenti et al., 2019 | (✓) |
| Quebracho (Schinopsis lorentzii) powder, providing 4.0% of dietary DM as tannins. | Comparison of concentrate-based diet with fresh herbage (vetch (Vicia spp.)). Pelleted concentrate of barley (551 g/kg), lucerne hay (300 g/kg), soybean meal (130 g/kg), and mineral premix (19 g/kg). | Male lambs – in vivo | Reduced the concentration of stearic acid (−49%) and increased the concentration of vaccenic acid (+97%) in ruminal fluid from concentrate-fed lambs; reduced the accumulation of saturated fatty acids in blood | The correct dietary concentration of tannins should be carefully chosen to avoid negative effects on DMI and animal performance. | Results confirm, in vivo, that tannins reduce ruminal biohydrogenation, as previously reported in vitro. CT supplementation could be a useful strategy to increase rumenic acid and reduce the saturated fatty acids in ruminant meats. | Vasta et al., 2009 | ✓ |
| Wine (Vitis vinifora) grape pomace – 5% or 10% of dry matter | Total mixed ration containing 2.7% (on a DM basis) of linseed (Linum usitatissimum) oil, forage and concentrate, at a 40:60 ratio | Ewes and suckling lambs – in vivo | Lambs from ewes fed grape pomace and vitamin E showed lower metmyoglobin percentage, lower lipid oxidation and improved scores on sensory perception | Grape pomace (5%) was just as effective as vitamin E in preventing spoilage during retail storage. | Vieira et al., 2021 | ✓ | |
| Peanut (Arachis hypogaea) skins (testa)¥ - 0, 8, 16, or 24% of dry matter | Total mixed ration – maize silage, lucerne silage, ground maize, soybean meal and hulls, minerals | Cows – in vivo | Increased dry matter intake and milk yields; ruminal ammonia and urinary N declined | Milk protein percentage declined as peanut skin content of the diet increased | Peanut skins can be used in diets for lactating cows up to 16% of diet | West et al., 1993 | ✓ |
| Wine (Vitis vinifora) grape pomace – diet 0%, 5% and 10% WGP | Maize, soybean meal, wheat bran, oil cake of linseed, naked oat straw and potato (Solanum tuberosum) rattan. | Lamb – in vivo | 10% dietary WGP increased body weight, average daily gain, and reduced the feed to gain ratio | WGP can be used as a feed ingredient in lamb production to relieve oxidative stress, and improve feed efficiency and meat tenderness, | Zhao et al., 2018 | ✓ | |
| Grain sorghum (Sorghum bicolor) – [0.82 to 2.45% CT of DM] | Finely ground maize grain substituted with levels of finely ground sorghum grain | Male lambs – in vivo | Faecal egg count of Haemonchus contortus decreased with increased proportion of sorghum in diet | DM intake decreased with increased level of sorghum grain but did not affect average daily weight gain | Including grain sorghum protected lambs against H. contortus infection and improved meat colour | Zhong et al., 2016 | ✓ |
| Hydrolysable tannins (HT) | |||||||
| Tara (Ceesalpina spinosa) – 2.23% CT in DM | Barley, wheat bran, dehydrated lucerne hay, soybean meal, molasses and mineral-vitamin premix | Lambs – in vivo | Dramatic decrease in meat of Enterobacteriaceae population; lowered total trans-18:1 fatty acid | Tannin extract supplementation is a promising dietary strategy to preserve lamb meat quality | Biondi et al., 2019 | ✓ | |
| Chestnut (Castanea sativa) extract - 20.8 g·kg-1 DM (2% tannin) | Soybean meal | Lambs – in vivo | No impact on voluntary intake, feed conversion, daily gain or length of fattening period | Longer duration experiments needed to check for toxicity effects | Frutos et al., 2004b | (✓) | |
| Dietary tannic acid - 0.15% of DM in the in vitro experiment and 0.20% of DM in the animal feeding experiment | Whole maize silage, wheat bran, corn, soybean meal, beer residue, cottonseed meal, minerals | Cattle – in vitro and in vivo | Tendency to reduce methane concentration of ferment; suppressed relative abundance of Methanosphaera and Methanobacteriaceae; significantly improved average daily gain (+0.15 kg/d), dressing percent (+1.30%), net meat percentage | Dietary supplementation of tannic acid could improve the growth and slaughter performance and health status of beef cattle | He et al., 2023 | ✓ | |
| Chestnut (Castanea spp.) extract – 14.9g CT/ kg DM | High-grain diet – maize, sorghum hay, cottonseed hulls and meal, minerals | Steers – in vivo | No effect of tannin on animal performance, ruminal fermentation parameters, in vitro methane producing activity, or carcass and non-carcass traits | Tannin supplementation may be a viable option in finishing beef cattle if bactericidal efficacy is established | Krueger et al., 2010 | (✓) | |
| Chestnut (Castanea sativa) [0% and 0.6% hydrolysable tannin] | Steam-flaked maize diet (65%); distillers dried grains plus solubles (15%); sugar cane bagasse (10%) | Steers – in vivo | Inclusion of 0.6% of tannin in diet tended to increase average daily gain (6.8%); DM intake was greater (2.4%) | Tannin supplementation promotes greater dry matter intake, and hence, average daily gain of steers during the finishing feedlot phase. | Rivera-Méndez et al., 2017 | ✓ | |
| Chestnut (Castanea sativa) wood extract. 0.5 and 2.5 g tannins/kg) | Grass silage, barley grain, grass hay) with a low crude protein content | Dairy cow - fermenter rumen simulation technique (Rusitec) – in vitro | High HT doses reduced ammonia levels by 21% relative to the control. | No differences in CH4 or H2 production or H2 balance; although 16% decrease in CH4 mmol/g fermented organic matter with high HT versus control. | Ruminal N metabolism effects were observed only at doses exceeding those recommended by the manufacturers. | Śliwiński et al., 2002a | (✓) |
| Chestnut (Castanea sativa) wood extract. 1 and 2 g/kg DM, equivalent to 7.5 and 15 g/kg CP, respectively | 1:1 (air-dry basis) chopped hay and the respective concentrate, provided in meal form and offered together with the hay after thorough mixing | Lambs – in vivo | A weak trend for reduced urine N losses (relative to N intake and N excretion) and low ammonia release from the stored excreta with the high tannin dose | Low dose of the tannin-rich extract significantly increased methane release by 33% relative to the negative control | Śliwiński et al., 2002b | X | |
| Chestnut (Castanea sativa) wood extract. 4.9 g/kg DM – 0.49% tannin) | Soybean meal | Cows – in vivo | Less urinary and milk urea N excretion - N emissions from 8-weeks stored manure were lower | For mitigation of ammonia emission | Śliwiński et al., 2004 | ✓ | |
| Small burnet (Sanguisorba minor) hay – HT 4.5% of DM | Small burnet hay | Cows and heifers – in vivo | Excreted less urinary urea N (g/d) and showed lower concentrations of blood urea N; reduced methane emissions | Digestibility of crude protein was reduced for cows and heifers | tannin-containing hays have the potential to reduce urinary urea N excretion, increase N retention, and reduce enteric CH4 emissions from beef cattle | Stewart et al., 2019 | ✓ |
| Chestnut (Castanea sativa) (hydrolysable ellagitannins) or tara (Cesalpinia spinosa) (hydrolysable gallotannins) – extract was 4% of DM fed; 26g/d intake; approx. 2.3% of diet | Barley, wheat bran, lucerne, soybean meal, molasses minerals | Male lambs – in vivo | Tara tannin diet increased the concentration of γ-tocopherol in muscle and tended to increase that of α-tocopherol | No effect on any of the main groups of fatty acids and the peroxidability index. Chestnut tannin reduced growth rate, final weight, carcass weight and feed intake. | Effects of tannins on animals’ metabolism and product quality may depend on the basal diet and metabolic status of animals. | Valenti et al., 2019 | (✓) |
| Chestnut (Castanea sativa) – 110g/kg (1.1% tannin) | Hay made from Arrhenatherum elatius (30%), Dactylis glomerata (13%), Festuca pratensis (6%), Trifolium repens and Trifolium pratense (23%) | Sheep and goats – in vivo | Decreased DM and organic matter apparent digestibility; ruminal microbial synthesis unaffected | Did not disturb rumen degradation of cell walls or ruminal microbial synthesis. | Zimmer and Cordesse, 1996 | X | |
| Condensed and hydrolysable tannins mixture | |||||||
| Quebracho (Schinopsis lorentzii) and chestnut (Castenea spp.) mix. [Tannin levels were 0.125% or 0.75% of each type] | Lucerne: barley silage (50:50; dry matter basis) with a crude protein content of 17.1% | Steers – in vivo | Decreased ruminal ammonia concentration | Tannin levels possibly too low to be effective. No effect on rumen pH, total volatile fatty acid concentration, proportions of acetate and propionate, and total protozoa populations. | Combination of HT and CT at a concentration of 1.5% dietary DM also tended to decrease CH4 emissions without negatively affecting performance. | Aboagye et al., 2018 | (✓) |
| One-third chestnut (Castanea sativa) tannin extract and two-thirds quebracho (Schinopsis lorentzii) tannin extract – fed at 0, 0.45, 0.90 and 1.80% of diet DM | Lucerne and maize silage, cottonseed, rice hulls and minerals | Lactating Holstein cows – in vivo | 0.45% tannin extract in the diet lowered urinary N excretion | Had detrimental effects on DM intake, milk protein content, milk protein yield, and nutrient digestibility | Quebracho and chestnut tannin extract at 0.45% of diet DM may be adequate to reduce excretion of environmental labile urinary N with a small effect on animal performance | Aguerre et al., 2016 | (✓) |
| Red quebracho (Schinopsis lorentzii) or chestnut (Castanea sativa) [1.6% tannin of DM] | Barley, maize, wheat bran, soybean meal, beet pulp, and minerals | Ewes – in vivo | Increased milk rumenic acid and reduced vaccenic acid biohydrogenation at the rumen level | Dietary integration with tannins improves sheep milk quality. Condensed tannins are more effective than hydrolysable tannins. | Buccioni et al., 2017 | ✓ | |
| Mix of one-third chestnut wood (Castanea sativa) tannins extract and two-thirds quebracho (Schinopsis lorentzii) tannins extract by weight. | Lucerne hay, maize grain, soybean meal and minerals | Holstein cows – in vivo | Modified rumen microbiota composition, reducing fiber and starch degrading bacteria, while favouring Ruminococcaceae and other members of phylum Firmicutes; a reduction of methanogenic archaea occurred in tannin supplemented animals | Relation between tannins impact on rumen microbiota and alteration of rumen fermentation parameters associated with bovine performance needs further assessment | Díaz Carrasco et al., 2017 | ✓ | |
| Labdanum (Cistus ladanifer)† – 50, 100 and 200 g/kg DM [0.27, 0.69 and 1.56% tannins, respectively] | Maize, wheat, soybean meal, lucerne, minerals | Lambs – in vivo | Labdanum improves the colour and lipid oxidative stability of lamb's meat. Inclusion in the diet increased meat flavour. Muscle resistance to lipid oxidation was enhanced and α-tocopherol content increased, reducing meat lipid oxidation | 200 g/kg DM of labdanum in lamb's diet, when associated to lipid supplied, is probably close to the physiologic tolerance of rumen ecosystem | Labdanum can partly replace the forage component in lamb diets without compromising growth performance if diets are kept isoenergetic and isoproteic. Labdanum has a protective effect against lipid oxidation through increasing α-tocopherol concentration in the muscle. | Francisco et al., 2015; Jerónimo et al., 2020 | ✓ |
| Labdanum (Cistus ladanifer)† – 25% of DM [2.09% tannins] | Dehydrated lucerne (90%), wheat bran (10%) | Lambs – in vivo | Inclusion of labdanum protected the meat against lipid oxidation and did not change the sensory properties of meat. | Did not improve the meat colour stability | Might be a good approach to reduce the meat deterioration induced by lipid oxidation in ruminant meat | Jerónimo et al., 2012 | ✓ |
| Pine bark (Pinus taeda) – 13% tannin of dry matter | Lucerne pellet, molasses, and mineral mixtures | Male goats – in vivo | None specified | No significant differences were found in carcass yield | Pine bark such a by-product of the timber industry, can be used as a post-weaning diet. | Lee et al., 2017 | (✓) |
| Blend of 0.3% condensed (quebracho)and 0.3% hydrolysable (chestnut) tannin | Steam-flaked maize diet (65%); distillers dried grains plus solubles (15%); sugar cane bagasse (10%) | Steers – in vivo | Inclusion of 0.6% of tannin in diet tended to increase average daily gain (6.8%); DM intake was greater (7.1%) | Although the 50:50 blend of CT and HT resulted in a greater DMI there was no further enhanced gain in weight | Tannin supplementation promotes greater dry matter intake, and hence, average daily gain of steers during the finishing feedlot phase. | Rivera-Méndez et al., 2017 | ✓ |
҂ Sinchaiyakit et al., 2011.
* Along with condensed tannins, peanut skins are rich in catechin, epicatechin, resveratrol, and phenolic acids.
¥ Mature, red peanut skins contain about 17% by weight of procyanidins (Karchesy and Hemingway, 1986).
† Labdanum also known as rockrose, a Mediterranean tanniferous shrub (Cistus ladanifer).
The types of tannins used in these feeding studies were often not well described but based on their source could be categorised as either condensed tannin or hydrolysable tannins. The structural differences amongst tannins which can have molecular weights ranging from 500 to more than 3000 (Hassanpour et al., 2011) lead to varied applications and biological activities which are also moderated by concentration level of the tannin in the feed. However, an essential characteristic of both types of tannins is their ability to bind proteins and to a lesser extent, polysaccharides (Patra and Saxena, 2011; Naumann et al., 2013). They also can have properties associated with being an antioxidant, anti-inflammatory, and/or anti-microbial depending on their chemistry (Koleckar et al., 2008; Mal and Pal, 2021). Based on their chemistry condensed tannins can be categorised by (a) the ratio of procyanidin/prodelphinidin building blocks; (b) cis/trans ratios; (c) mean degree of polymerisation (i.e., the degree to which small molecules called monomers join to form a long chain molecule called a polymer) which can range from 6 to 39; (d) percentage galloylation (galloyl groups increase the ability to bind to and precipitate proteins) which can range from 0 to 75%; and (e) ratio of soluble to insoluble tannins (Naumann et al., 2018; Zeller, 2019). Understanding the impact of these chemical differences on the measured benefits and risks associated with the consumption of tannin compounds is required to ensure benefits are maximised.
An extensive review of tannins from tradition and ancient vegetables, fodder plants, and vegetal industry co-products in ruminant nutrition showed that animal performance is related to both tannin type and concentration supplied (Besharati et al., 2022). However, almost all of the studies listed in Tables 1, 2 do not provide any commentary on the actual chemistry of the tannin used in the concentrate feed. For many of these studies the incorporation of tannin containing extracts or products was about how to utilise an agro-industrial waste product not about the beneficial properties of tannin per se. Inconsistent effects of tannins in ruminant and monogastric nutrition can be due to different chemical composition or type of the tannin (Rodriguez et al., 2014), the amount or concentration administered, the animal species involved and the background diet to which tannins are added (Patra and Saxena, 2011). Others have concluded that “some effects of tannins cannot be easily generalised but may strictly depend on their specific characteristics and on conditions inherent to the basal diet and the metabolic status of the animals” (Valenti et al., 2019).
Table 2. Effects of tannins added as a supplement into the diet of concentrate feed fed to monogastrics – (a) poultry and (b) pigs.
| Tannin type (highlighted where known), source and concentration | Impact if tannin | Recommendation or conclusion | Reference | Rating |
|---|---|---|---|---|
| (a) Poultry | ||||
| Maize-wheat-soybean basal diet supplemented with one of three tannin-based products – at 0.3% or 0.13% of diet; analysis if products showed complex mix of compounds with some containing condensed or hydrolysable tannins | Tannin-treated broilers suffered from a reduction in feed consumption and weight gain and reduction in the caecal microbial diversity and short-chain fatty acid producer bacteria | Reduced caecal microbial diversity and short-chain fatty acid producer bacteria related to the depressed performance of tannin-fed chickens | Brugaletta et al., 2020 | (✓) |
| Incorporation of chestnut tannins (0, 500 or 2, 000 mg/kg) in basal diets of maize/soybean or wheat, palm oil, and rapeseed meal; hydrolysable tannins | Tannin dose of 500 mg/kg had no effect on performance, but diets containing 2, 000 mg/kg chestnut tannins lowered broiler performance in grower and finisher phase; tannins positively affected meat quality | Effects on intestinal development and health may indicate that the use of chestnut tannins tomodulate absorptive capacity | Buyse et al., 2021 | X |
| Basal sorghum (Sorghum bicolor) grains of high and low tannin contents with either 0.1% or 1.0% tannic acid added to a basal diet; mix of condensed and hydrolysable tannins | Raising the tannic acid or plant tannin level of a ration depressed feed intake and had a toxic effect | Conner et al., 1969 | X | |
| Ground mesquite (Prosopis juliflora) pods which contain tannin used in 0 to 30% of total feed ration; pods contain low levels of condensed tannins (Makkar et al., 1990) | Body weight change and feed conversion ratio was not impacted; egg yolk colour which was greater 30% inclusion, but egg mass was lower | Up to 20% inclusion of ground P. juliflora pods is recommended based on the performance of the birds | Girma et al., 2011 | (✓) |
| Sorghum grains with low (0.28% catechin equivalent) or high (1.36% catechin equivalent); condensed tannin | Significant reduction in weight gain and feed intake of broiler chicks | High tannin containing sorghum not recommended | Hassan et al., 2003 | X |
| High tannin red sorghum (23 g tannin/kg) or reconstituted red sorghum (16 g tannin/kg) in combination with a maize-soybean based diet; condensed tannin | Concentration of tannins remained 3·6 to 15·5 g/kg in raw and 2·5 to 10·8 g/kg in reconstituted sorghum-based diets and had no appreciable influence on nutrient utilisation, blood chemicals and enzymes and gross pathological changes | Feeding of reconstituted sorghum-based diets to broiler chickens is recommended; however, feeding raw red sorghum exhibited greater immuno-responsiveness than their reconstituted counterparts | Kumar et al., 2007 | (✓) |
| High tannin sorghum grain compared with same soaked in wood ash slurry or wood ash extract (which effectively reduced the tannin level); condensed tannin | Significant improvement in growth rate of chicks that were fed on diets that contained treated sorghum diluted with wood ash | Treatment of high tannin sorghum with wood ash extract improves its nutritive value | Kyarisiima et al., 2004 | X |
| Reconstituted low tannin sorghum grain and compared with maize diet; condensed tannin | Body weight was higher with the maize diets than with the untreated sorghum diets, and lowest with the reconstituted grain diets. | Reconstitution of the sorghum was found to eliminate the tannin content of the low-tannin sorghum | Madacsi et al., 1988 | X |
| White (low tannin), brown and red (high tannin) sorghum feed as part of a maize/soybean meal diet; condensed tannin | Dry matter and energy metabolised with red and brown sorghum were significantly less than for the white; inverse relationship between tannin and nitrogen-corrected apparent metabolisable energy | Sorghum with lighter seed coat colour contained less tannin and were superior in nutritional values than those of darker colour | Mandal et al., 2006 | X |
| High-tannin (2.95% catechin equivalent (CE)) sorghum treated (0.36% CE) or not treated (1.94% CE) with wood ash extract; condensed tannin | Performance of broiler chicks fed on the high-tannin sorghum soaked in wood ash extract or water was equal to that of broilers fed on the low-tannin diet | Soaking of high-tannin sorghums in wood ash extract improved their feeding value | Mohammed and Ali, 1988 | X |
| White, brown and red seed coat sorghum with tannin contents ranging from 0.16 to 0.77%; condensed tannin | Dry matter digestion and amino acid availability increased as the tannin content decreased | Sorghum seed coat colour is not a reliable indicator of nutritional quality | Nelson et al., 1975 | X |
| Low tannin sorghum in combination with maize at 0, 50 and 100%; condensed tannin | No difference in egg weights, amounts of protein, fat, Vitamin E and Vitamin A; egg yolks increased in lightness and reduced in hue with increasing sorghum | Low tannin sorghum can replace maize as a source of energy in chicken feeds with no adverse effects on the quality of the eggs | Ochieng et al., 2018 | (✓) |
| Low tannin levels (5%) in sorghum variety mixed with maize in varying proportions; condensed tannin | Diet of 100% sorghum had undetectable level of unsaturated fatty acids and highest cholesterol and vitamin E content in meat | Partial substitution of maize with low tannin sorghum can improve the nutritional value of broiler meat | Ochieng et al., 2020 | (✓) |
| Sorghum cultivars with varying condensed tannin levels | Correlation between tannin intake and percentage of abdominal fat in both sexes was positive and significant, but body weight reduced at high tannin levels | Broiler chicks could tolerate up to 2.6 g tannin/kg above which their performance was reduced | Pour-Reza and Edriss, 1997 | (✓) |
| Compared bird resistant (related to tannin content) sorghum (BR64), intermediate bird resistant sorghum (NK300) or diets containing a bird susceptible sorghum (RS610) or maize; condensed tannin | Chicks fed sorghum BR64 exhibited poorer growth and feed conversion | High condensed tannin containing sorghum not recommended | Rostagno et al., 1973 | X |
| Red, yellow and white sorghum varying in condensed tannin content (1.84%, 0.57%, 0.32% respectively) used in a maize based diet | Body weight gain was lowered when incorporating sorghum in maize diet; energy metabolisation was lower and feed conversion reduced by red sorghum diets. | High tannin red sorghum use should be limited; relatively low tannin containing yellow and white sorghum can be incorporated in broiler diets up to 75% of maize. | Sannamani et al., 2010. | X |
| Peas (Pisum sativum) from cultivars of differing flower colour and tannin content - Seeds of coloured-flowered cultivars are rich in condensed tannins | Tannin reduced protein digestibility and apparent metabolisable energy value in chickens | Lowering the tannin content should be included in breeding programmes of new cultivars of pea | Smulikowska et al., 2001 | X |
| Tannic acid extract (100 mg/kg of diet) added to a maize/soybean meal diet; hydrolysable tannin | Oocysts per gram of excreta in broilers infected with Eimeria spp. was lowest for feed with tannic acid extract | Supplementation of tannic acid with coccidiosis vaccination is a potential alternative strategy to address coccidiosis in broiler chickens | Tonda et al., 2018 | ✓ |
| Reconstituted faba beans with high, medium or low condensed tannin contents (means of 9.9, 5.8 and 1.3 g/kg, respectively) | Both apparent metabolisable energy content and total tract apparent protein digestibility were lower for the high- than for the low-tannin diet | Results confirm the nutritional advantages of faba bean varieties free of tannins | Vilariño et al., 2009 | X |
| Tannin extracts from chestnut oak, quebracho, and wattle bark along with tannic acid combined with a grain diet; mix of hydrolysable and condensed tannins | 0.5% dietary tannic acid caused a depression in the growth of chickens; a level of 5% tannic acid caused chick mortality of about 70% | Tannic acid reduced the metabolisable energy of diets, depressed the nitrogen retention by chicks | Vohra et al., 1966 | X |
| (b) Pigs/Swine | ||||
| Two levels (0.25% and 0.5%) of water-soluble chestnut hydrolysable tannin were added to the diet | Apparent digestibility of both dietary dry matter and nitrogen decreased with level 0.5% tannin | A concentration of 250g tannin per 100kg mixed feed does not appreciably influence the animals’ performance | Antongiovanni et al., 2007 | (✓) |
| Tannin incorporation (1, 2, 3, and 4% sweet chestnut extract rich in hydrolysable tannins) | Tannin had no effect on chemical and amino acid composition as well as fatty acid profile in adipose tissue, and only slightly on carcass value; skatole concentration in fat tissue declined after 2–4% administration | Lower skatole accumulation (associated with boar taint) in adipose tissue may be a positive benefit of tannin supplementation but increasing some saturated fatty acids is undesirable | Bahelka et al., 2021 | (✓) |
| Diets supplemented with 0, 15 or 30 g/kg (T30) of hydrolysable tannin | Feed efficiency but not daily gain and daily feed intake was lower when tannin included | Up to 3% hydrolysable tannin in a finisher diet of male pigs has only a marginal impact on growth performance, carcass characteristics and meat quality | Bee et al., 2017 | (✓) |
| Diet supplemented with 1%, 2% and 3% of hydrolysable tannin-rich extract | Tannin increased villus height, villus perimeter and mucosal thickness and in large intestine reduced mitosis and apoptosis | Hydrolysable tannins had no unfavourable effects on small intestine morphology but may alter cell debris production in the large intestine, reducing intestinal skatole production | Bilić-Šobot et al., 2016 | (✓) |
| Two levels of carob (Ceratonia siliqua) pulp (0% vs. 20%) added to a grain-based diet; both condensed and hydrolysable tannins[unlike other tannin-rich sources, carob pulp is characterised by its high sugar content] | Inclusion of 20% carob pulp is possible without affecting overall performance though it reduces nutrient apparent digestibility and may increase feeding cost | Replacing barley, with up to 200 g carob/kg in the diet is feasible without affecting productive performance, metabolic status, behaviour, and health measurements | Bottegal et al., 2024 | (✓) |
| Four sorghums ranging widely in tannin content (0.83 to 3.40 mg catechin/100mg DM), and yellow corn were evaluated; condensed tannin | Digestibility of dry matter, gross energy and N was higher for low tannin diet; performance was similar for animals fed the low tannin sorghums and those fed corn | Low tannin diets are recommended | Cousins et al., 1981 | (✓) |
| Sorghum hybrids with low and high condensed tannin compared with maize | Dry matter digestibility lower with high tannin diet | Tannins negatively affected sorghum nutritive value, which is compounded by high kafirins (storage proteins) | De Souza et al., 2023 | X |
| Dietary addition at 0.15, 0.30 or 0.53% of a supplement containing 75% of chestnut (Castanea sativa) hydrolysable tannins | Tannin addition (at 1.5–5.3 g/kg) does not modify digestibility, metabolic use of nutrients and performance of heavy pigs, but reduces urine volumes of animals | Condensed tannin cannot be considered anti-nutritional when included at the levels used in this study | Galassi et al., 2019 | (✓) |
| Sorghum grain of low (0.32%) and medium (0.94%) condensed tannin content | Medium tannin sorghum in pig diets had no significant adverse effect on growth, back fat thickness or feed conversion efficiency | Sorghum grain with up to 0.94% tannic can be used as the main or sole grain diet without adverse effect on growth or back fat thickness | Kondos and Foale, 1983 | (✓) |
| Diets were supplemented with 125, 250, 500 and 1000 mg tannic acid/kg; hydrolysable tannin | Increase in tannin concentration reduced average daily gain, feed efficiency, faecal coliform count and tended to reduce feed intake | Inclusion of tannic acid had a negative impact on performance, haematological indices and plasma iron status of pigs | Lee et al., 2010 | X |
| Chestnut (Castanea sativa) meal replaced 0, 5, 10 and 15% of dry matter with basal diet of grains; hydrolysable tannin | Dry matter and crude protein intakes were highest in 10% supplementation of chestnut meal | Considering feed intake and digestibility, supplementation of chestnut meal at 5% for pig fed is proposed | Lee et al., 2016 | (✓) |
| High-moisture sorghum silage grain with high (0.08% of DM) and low (0.01%) condensed tannin contents compared with high (1.17%) and low (0.48%) dried sorghum grain and a maize grain diet | No treatment effects observed on average daily feed intake and average daily weight gain | Sorghum silage can replace maize or sorghum dry grains in diets of weanling pigs with no adverse effects on growth performance | Lopes et al., 2017 | (✓) |
| Dietary tara (Tara spinosa) containing hydrolysable tannins fed at 10g/kg in a basal diet | No differences in growth performance and carcass traits were observed, but tannin lowered meat cholesterol and delayed lipid oxidation in meat | Including hydrolysable tannins may reduce lipid oxidation in meat | Menci et al., 2024 | (✓) |
| High and low condensed tannin sorghum | Diets containing high-tannin grain sorghum had lower energy, crude protein and dry matter digestibility than did diets containing low-tannin grain | Low-tannin grain sorghum is recommended | Myer et al., 1986 | X |
| Three low-tannin white sorghum cultivars and three high-tannin red sorghum cultivars compared with a maize diet; condensed tannin | Digestible and metabolisable energy and apparent total tract digestibility were all lower for red sorghum than for maize, but values for maize were lower than those obtained for white sorghum | Low-tannin white sorghum varieties are superior to high-tannin red sorghum for pigs | Pan et al., 2019 | X |
| 30% or 60% sorghum grain in partial or total replacement of maize grain; condensed tannin | No differences in growth performance or apparent digestibility of gross energy between treatments over the whole period; pigs fed sorghum had higher contents of urea nitrogen | Low-tannin sorghum could be an alternative energy source in diets for pigs without adverse effects on growth performance | Pan et al., 2021 | (✓) |
| Low (0.5 to 4.2g/kg) and high (15.9 to 47.6 g/kg) condensed tannin containing sorghum grain compared with a maize starch diet | Apparent digestibility and hindgut disappearance of gross energy and crude protein were negatively correlated with condensed tannins and total phenolics in sorghum grain | Condensed tannins in sorghum grain may impede nutrient digestibility in the foregut and hindgut | Pan et al., 2022 | X |
| Soybean diet was supplemented at 0, 5, 10, and 15% with sainfoin (Onobrychis viciifolia) meal; condensed tannin | C18:3n-3 fatty acids and long-chain homologs increased in the backfat and intramuscular fat when sainfoin in diet | Sainfoin can be included at up to 15% in the diet to replace 7% of soybean in a diet for pig finishing without negative impacts | Seoni et al., 2021 | (✓) |
| Basal diet with added organic and inorganic acids and chestnut tannin extrcat - basal diet with 0.3% additive containing 0.15% hydrolysable tannin | While diet with acids and tannin did not improve the growth performance of pigs there were no deleterious effects on selected blood parameters | Beneficial effects of adding acids and tannin in diets could not be excluded | Štukelj et al., 2010 | (✓) |
| Basal diet with 0.15% condensed tannin | 0.15% tannin increased the average daily gain and average daily feed intake of weaned piglets and decreased diarrhoea incidence | 0.15% tannin could improve growth performance, digestibility, and intestinal function of weaned piglets | Xu et al., 2022 | ✓ |
A positive rating - ✓- indicates improved animal performance through at least one of reducing biohydrogenation, nitrogen movement away from urine, improved quality and quantity of milk and meat, improved animal health, or reduced methanogenesis and caused no significant negative effects on animal performance or health. A negative rating - X – indicates that adding tannin failed to show significant positive effects on animal performance while demonstrating predominantly negative impacts. Those described as providing mixed results - (✓) - had either minimal impact or both positive and negative impacts on animal performance factors.
Bold values indicate where the tannin type is known.
Across all tannin types 41 (57%) of the studies showed significant benefits to adding tannins toconserved feed, 21 (29%) showed mixed effects and 10 (14%) showed negative effects. Thesepercentages changed little among the different tannin types. Cattle/cows were used in 32 andlambs/sheep/goats were used in 38 of the in vivo studies. Cattle/cow studiesdemonstrated both a slightly higher percentage of benefits (63%) and negative (19%) effects toadding tannins to conserved feed compared with sheep/goat studies (54% and 11%, respectively). Anextensive review examining the effect of polyphenol plant extracts added to the diet of ruminantspecies also concluded that results can be mixed and conflicting (Formato et al., 2022a). They reviewed 43 studies with essentially one thirdindicating a negative effect (<5% milk production), one third a negligible effect, and one thirda positive effect (>5% milk production) on milk yield. They concluded that the benefits ofpolyphenols as additives to concentrate feeds “strongly depends on the animal species and itsphysiological state, the plant source, the type and dose of polyphenols experimentally applied, aswell as their synergistic effects with other coexisting compounds.” These concerns also applyto the reviewed studies (Table 1) which vary considerably in animal species, tannin source, supplementation level, experimental design, and measured parameters.
In a meta-analysis of 97 studies with just sheep and/or goats fed tannin containing feed, as either being added to concentrated or from forage, it was concluded that tannin fed to small ruminants improved dry matter intake, but did not affect crude protein intake, animal productivity and antioxidative status (Al Rharad et al., 2025). Tannin in the diet increased nitrogen intake and faecal nitrogen concentration, and decreased urinary nitrogen and blood urea nitrogen concentrations, but had no significant effect on retained nitrogen. Fatty acid profile of meat was improved through increased polyunsaturated fatty acid percentage content by inclusion of tannin in the diet (Al Rharad et al., 2025). Others have concluded that “the effect of tannins on the fatty acid profile in milk and meat is dependent on the composition of the diet and the dose of tannins included therein” (Jerónimo et al., 2016).
While maize was mentioned as a feed constituent of 34 studies (47%) in Table 1, in almost all cases it was a constituent and combined with a range of other feeds or additives meaning it is not possible to determine definitely the effect of tannin being added to maize in improving increased animal production, improved product quality and animal health benefits. However, the prevalence of use of maize in feed indicates that if tannin expression is achieved in maize, it will have potential role in feedlot fed animals. This will however require numerous in vivo feeding trials to confirm.
2.1 Understanding the positive commentaries on use of tannins in concentrate feed for ruminants
Presence of tannin in diets at less than 4% has been considered advantageous to ruminants as it acts as a natural protein protectant and therefore reduces the degradation of protein by forming tannin protein complex in the rumen and subsequently enhances the amino acids availability in lower gut and thereby increases the rumen bypass protein (Kushwaha et al., 2011; Salami et al., 2018). However, condensed tannin concentrations between 0.5 to 1% in feed have been considered adequate to “reduce bloat risk, increase ruminal undegradable protein, reduce enteric methane production, and benefit anthelmintic activity” Kelln et al., 2021). Tannin reduces proteolysis of forage protein in the rumen, reduces rumen and plasma ammonia concentrations, reduces blood plasma concentration and increases the net absorption of essential amino acids especially branched chain amino acids from the small intestine, improves milk production and reproduction performance in cows (Kushwaha et al., 2011). Supplementation of concentrate diets with condensed tannin can ameliorate feedlot bloat which can be a common digestive disorder in fattening ruminant animals (Wang et al., 2023a). High-concentrate diet supplemented with tannin improves the ruminal fermentation of lambs resulting in improved average daily weight gain, feed efficiency, and crude protein digestibility and decreased ammonia-nitrogen content (Lin et al., 2024). Additionally, tannin supplementation contributed to improved immunity and antioxidant capacity of fattening lambs decreasing Escherichia coli and Salmonella counts in the faeces (Lin et al., 2024). Including non-edible foods by-products containing condensed tannin has been shown to be an effective alternative energy source which can also mitigate the environmental impacts of nitrogen excretion (Fonseca et al., 2024). Adding tannins to ruminant feed has been demonstrated as an effective means of mitigating methane emission from cattle (Yang et al., 2017; Orzuna-Orzuna et al., 2021) and sheep (Liu et al., 2011).
2.2 Understanding the negative commentaries on use of tannins in concentrate feed for ruminants
A meta-analysis of 70 papers comprised of 348 dietary treatments (from both in vivo and in situ studies) (Yanza et al., 2021)) revealed that an increased level of tannin extract inclusion in the diet lowered ruminant intake, digestibility, and production performance. The evidence also showed that an increased level of tannin concentration decreased animal nitrogen utilisation where most of rumen bypass protein was not absorbed well in the small intestine and directly excreted in the faeces. Hydrolysable tannin extract was considered more favourable to maintain nutrient intake, digestibility, and production performance and to mitigate methane production particularly when supplemented at low (<1%) to moderate (~3%) levels than condensed tannin (Yanza et al., 2021). Much of the negative commentary on the use of condensed tannins relates to reduced feed intake (Kumar and Singh, 1984; Makkar, 2003; Bhat et al., 2013; Nawab et al., 2020).
2.3 Explaining inconsistent commentaries on use of tannins in concentrate feed for ruminants
Negative effects of tannins were noted for extracts from quebracho, Acaciamearnsii, high tannin sorghum grain, carob and Castanea sativa, but in allcases, there were one or more studies showing benefits of tannins from extracts from these sources(Table 1). The variability on responses to and commentary to including tannins in concentrate feeds for ruminants may include:
- Levels of tannin either too low or too high to deliver a beneficial effect: High concentrations of tannins (>5%) reduce voluntary feed intake and nutrient digestibility, whereas low to moderate concentrations may improve the digestive utilisation of feed mainly due to a reduction in protein degradation in the rumen and a subsequent increase in amino acid flow to the small intestine (Frutos et al., 2004a; Bhat et al., 2013). While it is acknowledged that condensed tannins can protect protein in the rumen and allow improved uptake of protein in the abomasum, it is important to ensure that the concentration of tannins added to the concentrate is at a level that is not toxic to animals (Besharati et al., 2022). Condensed or hydrolysable tannins at levels at or below 4% of supplemental feed display specific antimicrobial activity against methanogens and protozoa without compromising ruminal fermentation in a long-term feeding trial (Kushwaha et al., 2011; Salami et al., 2018). Other studies have indicated for hydrolysable tannins that doses of less than 2% would be optimal for enhancing protein digestion and increasing the types of beneficial bacteria in the rumen, while doses above 6% should be avoided (Sun et al., 2025). The European Food Safety Authority (EFSA, 2022) has assessed the safety and the efficacy of red quebracho extract (which contains about 80% condensed tannin) using the principles laid down in Regulation (EC) No.429/2008 (EUR-Lex, 2008) and defined them as safe up to levels of 1, 580 mg/kg for cattle for fattening and other growing ruminants such as sheep, goats, and 1, 030 mg/kg for dairy cows and other dairy ruminants. These levels are low with 1, 000 mg/kg being equivalent to 0.1%.
- The ‘wrong’ type of and/or poorly defined tannins were used and/or the tannin extract is not pure: The inconsistent antioxidant effect of tannins added to concentrate feeds can be influenced by the type of tannin used (Tao et al., 2019; Soldado et al., 2021). It has also been observed that “extraction technique massively affects the chemistry of an extract, and the use of different extraction techniques or even just different extractants can lead to extracts that are not comparable in terms of bioactivity” (Formato et al., 2022a). Additionally, other compounds associated with the tannin containing material can be either synergistic or antagonistic toward the response observed (Formato et al., 2022a).
- The combination of tannin type and concentrate used was inappropriate: Inconsistent antioxidant effect of dietary condensed tannin sources in ruminants may be due to tannin chemical structure and concentration in the diets, composition of basal diet, presence of pro-oxidant and antioxidant compounds, or other uncontrolled factors that might create a different balance between antioxidant and pro-oxidant agents (Tao et al., 2019; Soldado et al., 2021). Tannin concentrations in feed below 1% while unlikely to have any negative side effects are also unlikely have any positive benefit or impact (Antongiovanni et al., 2007; Schilling et al., 2022). Getting the balance established between tannin concentration and degree of benefit is critical. Having said that in Table 1, 53 studies had a maximum tannin level above 1% and 16 studies had a maximum tannin level at or below 1%. For those studies with above 1% tannin 62% showed a positive benefit of tannins with 14% a negative effect, while for those with 1% or less tannin 41% showed a positive benefit of tannins with 18% a negative effect. Tannins sourced from different plants can also protect protein from degradation differently (Arisya et al., 2019).
- Developmental status of the ruminant: It has been observed that feeding ewes tannin containing feed while suckling lambs provides lambs with improved meat quality parameters such as colour, lipid oxidation, and fatty acid profile compared to lambs being fed the tannin feed themselves (Lobón et al., 2017).
In some studies, the presence of tannin-degrading bacteria in the rumen may nullify the expected effects of tannins (Lofti, 2020). Tannin-degrading microorganisms appear to be particularly active against hydrolysable tannins (Goel et al., 2005). This is due to the action of the enzyme tannase (tannin acyl hydrolase, EC 3.1.1.20) which is produced by a group of microorganisms, such as fungi, yeast and bacteria (Lekha and Lonsane, 1997).
3 Effect of tannins in concentrate feed for monogastrics
A Google Scholar literature review, with no time period limit, using keywords’ tannin content’ and ‘poultry feed’ was used to determine the effects of tannins added as a supplement into the diet of concentrate feed fed to poultry (Table 2a). The first 20 suitable studies from the literature search (as a random sample) were included. Most of these studies compare diets including sorghum grain which varies in tannin content depending on cultivar or where inclusion of tannin containing extracts appears to be largely motivated by reducing feed costs and bulking up other feed sources and/or using agro-industrial by-products (e.g. extracts from chestnut bark (Castanea sativa) and quebracho (Schinopsis spp.), or carob (Ceratonia siliqua) pulp) rather than providing direct benefit (Lee et al., 2016; Caprarulo et al., 2021; Rodríguez-Solana et al., 2021; Yang et al., 2021; Brunetti et al., 2022). The general impression from the 20 studies reviewed (Table 1a) is that inclusion of tannins provides little nutritional benefit for poultry. However, in studies where coccidiosis severity due to microbial infection was measured a benefit of incorporating tannin in the diet of poultry was observed (Tonda et al., 2018; Choi et al., 2022; Zhang et al., 2024; Galamatis et al., 2025). Similarly, polyphenols, including tannins, have been shown to decrease Campylobacter colonisation of poultry which can lead to the foodborne disease campylobacteriosis of humans (Redondo et al., 2014).
Despite the widely held views that tannins are antinutritional (Butler, 1992; Etuk et al., 2012; Medugu et al., 2012; Redondo et al., 2014; Razzaq et al., 2024), causing growth depression (Chang and Fuller, 1964) and should be avoided in feed for monogastrics, there are drivers starting to reverse this attitude. Firstly, increasing feed prices of common conventional ingredients has resulted in investigations to identify substitutes, and some do contain tannins (Achilonu et al., 2018; Hassan et al., 2020; Malenica et al., 2023). Secondly, antibiotics used in feed to promote growth have been linked to residues in meat causing resistance to some bacteria in humans (Dutta et al., 2019; Shahid et al., 2021; Arsène et al., 2022; Redwan Haque et al., 2023). And thirdly, tannins have been accepted as providing health benefits, particularly the control of zoonotic pathogens such as Salmonella (Huang et al., 2018) and Eimeria tenella infection Wang et al., 2008). The benefits of tannins in the diet of poultry have been profiled in a review which concluded that “even though tannins can act as feed additives, their inclusion level will depend on the source, age and species of poultry” (Hassan et al., 2020). However, as word of caution for growing chicks (rather than laying hens) it has been noted that with just 1% tannic acid added to the basal diet resulted in a highly significant growth depression (Chang and Fuller, 1964). They observed the same depression with consumption of grain sorghum containing condensed tannin at about 1.3% through inducing a choline and/or methionine deficiency which was completely alleviated by providing high levels of these nutrients in the diet. This led to the breeding of low tannin containing sorghum grain which was deemed suitable for use as the only cereal component of commercial poultry diets (Gualtieri and Rapaccini, 1990). Referring to the European Food Safety Authority (EFSA, 2022) assessment for the safety and the efficacy of red quebracho extract (which contains about 80% condensed tannin) the following levels were considered safe - 720 mg/kg for piglets, 860 mg/kg for pigs for fattening, and 400 mg/kg for poultry.
A Google Scholar literature review, with no time period limit, using keywords’ tannin content’ and ‘pig or swine feed’ was used to determine the effects of tannins added as a supplement into the diet of concentrate feed fed to pigs (Table 2b). The first 20 suitable studies from the literature search (as a random sample) were included. Interest in incorporating organic acids, botanicals, probiotics and tannin into diets for pigs has been largely driven by abolition of using in-feed antibiotics or chemotherapeutics as growth promoters (Štukelj et al., 2010). Tannin impact on pigs is variable ranging from no appreciable influence at low levels (less than 1%) through to negatively affecting nutritive value of feed, but in some cases possibly improved animal health (Table 2b). A review of the influence of dietary incorporation of grape by-products which can contain flavonoids, phenolic acids, tannins on pork-quality traits showed that feeding pigs with grape pomace and grape seeds has a positive impact on fatty acid profile and reduces, in general, the susceptibility of pork meat to oxidation (Alfaia et al., 2022; Ospina-Romero et al., 2024). Feeding chestnut (Castanea sativa) tannin (i.e., hydrolysable tannin) to pigs resulted in improved growth mainly through reducing harmful Escherichia coli and Campylobacter spp. and by increasing counts of beneficial lactic acid bacteria (Brus et al., 2013). A review of the use of hydrolysable and condensed tannins in pig nutrition indicated that they could be beneficial through enhancing productivity and animal health and therefore should be considered as feed additives (Caprarulo et al., 2021). A more recent review investigating the impact of various grape-derived polyphenols on the antioxidant system and inflammation in pigs, chicken, and cattle demonstrated that “grape by-products can effectively reduce oxidative stress and inflammation in pigs and chickens, often leading to improved performance” (Eder et al., 2025). Interestingly, they concluded that for cattle “fewer studies have been conducted, and the results regarding oxidative stress and inflammation are less consistent.”
A review of 31 studies where tannins (from chestnut (Castanea sativa), grape (Vitis vinifera) seed and pomace, tannic acid, mimosa (Acacia spp.), or red quebracho (Schinopsis lorentzii)) containing diets were fed to monogastric animals (chickens or pigs) and while anti-bacterial and anti-parasitic activity was expected based on in vitro trials, the observed in vivo effects varied greatly (Huang et al., 2018). For monogastrics in general it has been concluded that tannins as polyphenols are “biologically active compounds improve the quality of animal products and contribute to animal health and performance” (Lipiński et al., 2017). At levels between 0.05% and 0.5% hydrolysable tannins have the potential to improve antibacterial, antioxidant and digestive properties that could enhance growth rate and gut health actions that reduce inflammation (Razzaq et al., 2024). A recent review on the incorporation of condensed and hydrolysable tannins concluded that “tannins may promote growth performance and intestinal health, but they may have some negative effects” and this depends very much on their type and dosage rate (Zhao et al., 2026). There has been commentary that some hydrolysable tannins have far less impact on growth rates and feed intake in grower and finisher pigs than condensed tannins (Bee et al., 2017; Antongiovanni et al., 2007; Stukelj et al., 2010). Nutritional characterisation based on level of feed intake and digestibility of tannin rich chestnut has recommended supplementation of chestnut meal at 5% for pig feed (Lee et al., 2016).
4 Mechanisms underlying the reported responses
The documented benefits (predominantly in, but occasionally in Table 1) resulting from consuming tannins can be categorised as improving:
- Environmental outcomes from reduced nitrogen in urine leading to reduced nitrous oxide emissions and nitrogen leaching and reduced methane emissions.
- Product quality through increased antioxidant activity in meat and milk, increased proportion of polyunsaturated fatty acids, reduced presence of gram-negative bacteria and increased meat flavour.
- Animal health through a stimulated immune system and reduced faecal egg counts.
- Animal production leading to increased animal liveweight gain and milk production.
Tannins can cause these effects through a range of mechanisms including:
- Protection of consumed protein from rumen microbes such that undegraded protein moves into the abomasum for uptake by the ruminant as amino acids (Waghorn et al., 1990);
- A direct effect on methanogenic microbes in the rumen through inhibiting their enzymatic activity (Caetano et al., 2019);
- An indirect inhibition of methanogenic microbes through reducing the availability of nutrients (Naumann et al., 2017);
- Acting as a proton scavenger (Naumann et al., 2017);
- Inhibiting the biohydrogenation of unsaturated fatty acids (Vasta et al., 2019);
- Anthelmintic properties mediated indirectly through effects on protein and mineral metabolism or directly through effects on nematode viability (Kahn and Diaz-Hernandez, 2000; Molan et al., 2000a, 2000, 2002);
- Reduction in number of Escherichia coli and coliform bacteria in small intestine of young chickens (Jamroz et al., 2009);
- Prebiotic effects in the gut, together with antioxidant and anti-inflammatory effects (Girard and Bee, 2020); and/or
- Acting as alternative dietary antioxidants for ruminants (Soldado et al., 2021).
The most commonly used condensed tannins in the feed studies came from wattle species (Acacia spp.), quebracho (Schinopsis spp.) and grape (Vitis vinifera); and hydrolysable tannins came predominantly from chestnut (Castanea sativa). To demonstrate the difference in tannin chemistry depending on source it has been noted that tannin extract from wattle is soluble in cold water and does not require sulphitation for complete extraction, whereas tannin extracted from quebracho is not even soluble with hot water due largely to the absence of robinetinidol extender units (Venter et al., 2012). Robinetinidol has one more aromatic hydroxyl ion than fisetinidol which increases water solubility via hydrogen bonding. Documented benefits of tannin extracts from wattle, quebracho, grape and chestnut are summarised in Table 3. These include antioxidant, anti-bacterial, anti-fungal and anti-inflammatory effects as well as reduced methane emissions and reduced gastrointestinal parasites. However, achieving these benefits will be dependent upon the tannin compound(s) used, their concentration in the feed and the type of ruminant animal consuming the feed.
Table 3. Examples of documentation of beneficial effects of tannin from four plants-based sources (wattle (Acacia spp.) quebracho (Schinopsis spp.), grape (Vitis vinifera), and chestnut (Castanea sativa)) when fed to ruminants – these effects are moderated by concentration of tannin supplied and makeup of concentrate feed used.
| Trait | Tannin source and type | |||
|---|---|---|---|---|
| Wattle | Quebracho | Grape | Chestnut | |
| Predominantly condensed tannin | Hydrolysable tannin | |||
| Antioxidant (slowing cellular and molecular damage) | Ogawa and Yazaki, 2018 | López-Andrés et al., 2013; Cardullo et al., 2020 | Olejar et al., 2016; Saratale et al., 2021; Krasteva et al., 2023; Ma et al., 2024 | Prodanović et al., 2023; Wang et al., 2023b; Gao et al., 2024; Sun et al., 2025 |
| Anti-bacterial | Ogawa and Yazaki, 2018; Salami et al., 2018 | Patra et al., 2012; Cremonesi et al., 2025† | Saratale et al., 2021; Krasteva et al., 2023; Ma et al., 2024 | Bonelli et al., 2021; Prapaiwong et al., 2021 and 2023; Sun et al., 2025 |
| Anti-fungal | Tascioglu et al., 2013; Timotheo and Lauer, 2017 | Tascioglu et al., 2013; Cremonesi et al., 2025 | Li et al., 2017 | Esposito et al., 2019҂ |
| Anti-protozoal | Salami et al., 2018 | Salawu et al., 1999; Cremonesi et al., 2025† | Abarghuei et al., 2010; Foikland et al., 2016 | Salami et al., 2018 |
| Anti- inflammatory | Xiong et al., 2016; Ogawa and Yazaki, 2018 | Ogawa and Yazaki, 2018 | Urkmez and Biricik, 2022 | Prodanović et al., 2024; Sun et al., 2025 |
| Reduced methane emissions and/or urinary nitrogen | Carulla et al., 2005; Hassanat and Benchaar, 2013; Salami et al., 2018 | Hassanat and Benchaar, 2013; Piñeiro-Vázquez et al., 2018; Cremonesi et al., 2025 | Khiaosa-Ard et al., 2015; Suescun-Ospina et al., 2022 | Hassanat and Benchaar, 2013; Salami et al., 2018; Formato et al., 2022b; Prodanović et al., 2025; Van Mullem et al., 2025 |
| Reduced gastro-intestinal parasites | Minho et al., 2008 | Athanasiadou et al., 2001;Fraquelli et al., 2015 | Mena et al., 2025a, b | Bonelli et al., 2018 |
† while a reduction was observed for some species of fungi and protozoa, there was also an increase for some others.
҂ Fungicidal effect observed using in vitro studies.
A recently published meta-analysis of 43 studies on the effects of condensed tannins from quebracho and hydrolysable tannins from chestnut as functional feed additives on the growth performance of beef cattle concluded that the benefits of tannin extracts appear to be a context-dependent rather than a universal growth promoter, and responses did not necessarily require doses near the model-derived optimum (i.e., at approximately 0.30% of dietary dry matter) to be effective (Lee and Tedeschi, 2026). In summary, this meta-analysis demonstrated the complexities of obtaining benefits from incorporating tannins into concentrate feeds and the need to better “refine dosing strategies, better characterise tannin extract chemistry, and evaluate environmental outcomes in dedicated studies”.
5 Concluding comments
In certain circumstances tannins in ruminant feed can significantly benefit animal growth and health, and product quality, but for this to be successfully achieved account needs to be made of tannin chemistry, concentration and combinatorial effects with the concentrate feed used. While it has been considered that ensuring tannins levels in feed are below 4% to provide the optimal balance between benefits and negative outcomes that can only be definitively determined through in vivo trials as tannin sources vary in terms of chemistry and their interactions with other feed sources and animal categories involved. Indeed, condensed tannin concentrations between 0.5 and 1% have been considered adequate to provide nutritional benefits for ruminants. Tannins may also have a beneficial role in the diet of monogastrics despite an established view that they are antinutritional. Indeed, the dual nature of tannins in terms of providing both positive and negative effects highlights their complex role in animal nutrition and health. However, many studies exploring the benefits or risks of tannin extracts when used in animal diets fail to adequately define the type of tannin used, their concentration when added to feed. It still remains to be seen if delivering condensed tannin as a trait in the major feed source (e.g., maize and/or soybean) of concentrate feed, would provide similar benefits or risks as has been achieved by adding supplements containing polyphenols. However, if that opportunity can be achieved it could result in simplified concentrate feed formulation. To provide confidence for those who may seek to use maize expressing condensed tannins, monitoring animal safety and nutritional effects through in vivo feeding trials will be required along with determining stability of tannin expression and understanding consumer acceptance concerns. In addition, regulatory requirements for use of gene edited technologies to allow expression of tannins in major row crops will need to be negotiated in respective jurisdictions.
Generative AI statement
The author(s) declared that generative AI was not used in the creation of this manuscript.
Any alternative text (alt text) provided alongside figures in this article has been generated by Frontiers with the support of artificial intelligence and reasonable efforts have been made to ensure accuracy, including review by the authors wherever possible. If you identify any issues, please contact us.
Publisher’s note
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.
Footnotes
Edited by: Serkan Ates, Oregon State University, United States
Reviewed by: Alfredo Sánchez-Villarreal, Colegio de Postgraduados (COLPOS), Mexico
Harun Kutay, Çukurova University, Türkiye
Statements
- Conflict of interest
JC is employed by Grasslanz Technology Ltd which has invested in introducing a Sorghum bicolor transcription factor SbTT2 specifically regulating condensed tannin biosynthesis into a maize inbred deficient in anthocyanin biosynthesis to activate both anthocyanin and condensed tannin biosynthesis pathways.
- Funding
The author(s) declared that financial support was not received for this work and/or its publication.
- Author contributions
JC: Conceptualization, Writing – original draft, Writing – review & editing.
References
- Abarghuei M. J., Rouzbehan Y., Alipour D. (2010). The influence of the grape pomace on the ruminal parameters of sheep. Livestock. Sci. 132, 73 – 79. doi: doi:10.1016/j.livsci.2010.05.002
- Abd El-Azeem N. M., Magied A., Abdel-Mawla L. F., Abd El-Razik T. M. (2021). Effect of hydrolysable tannin and grape seed extract supplementation on growth performance, antioxidative status and immune response of growing rabbits during summer season. Egypt. Poult. Sci. J. 41, 45 – 62. doi: doi:10.21608/epsj.2021.159930
- Aboagye I. A., Beauchemin K. A. (2019). Potential of molecular weight and structure of tannins to reduce methane emissions from ruminants: a review. Anim. (Basel). 9, 856. doi: doi:10.3390/ani9110856
- Aboagye I. A., Oba M., Castillo A. R., Koenig K. M., Iwaasa A. D., Beauchemin K. A. (2018). Effects of hydrolysable tannin with or without condensed tannin on methane emissions, nitrogen use, and performance of beef cattle fed a high forage diet. J. Anim. Sci. 96, 5276 – 5286. doi: doi:10.1093/jas/sky352
- Acevedo-Ramirez P., Hallal-Calleros C., Flores-Perez I., Alba-Hurtado F., Mendoza-Garfias M. B., Castro Del Campo N.. (2019). Anthelmintic effect and tissue alterations induced in vitro by hydrolysable tannins on the adult stage of the gastrointestinal nematode Haemonchus contortus. Vet. Parasitol. 266, 1 – 6. doi: doi:10.1016/j.vetpar.2018.12.008
- Acharya M., Burke J. M., Miller J. E., Terrill T. H., Wood E. L., Muir J. P. (2020). Quebracho tannins aid in the control of Eimeria spp. and gastrointestinal nematodes in lambs and goat kids. Veterin. Parasitol. 288, 109295. doi: doi:10.1016/j.vetpar.2020.109295
- Achilonu M., Shale K., Arthur G., Naidoo K., Mbatha M. (2018). Phytochemical benefits of agroresidues as alternative nutritive dietary resource for pig and poultry farming. J. Chem. 2018, 1035071. doi: doi:10.1155/2018/1035071
- Addisu S. (2016). Effect of dietary tannin source feeds on ruminal fermentation and production of cattle; a review. Online J. Anim. Feed. Res. 6, 45 – 56. Available online at: https://ojafr.com/main/attachments/article/120/Online%20J.%20Anim.%20Feed%20Res.,%206(2)%2045-56,%202016.pdf (Accessed April 25, 2026).
- Adegbusi H. S., Ismail A., Mohd Esa N., Azuan Mat Daud Z. (2022). Application of Folin-Ciocalteau colorimetric method in the determination of total tannin in maize and soybean food products. Int. Food. Res. J. 29, 1110 – 1119. doi: doi:10.47836/ifrj.29.5.13
- Aguerre M. J., Capozzolo M. C., Lencioni P., Cabral C., Wattiaux M. A. (2016). Effect of quebracho-chestnut tannin extracts at 2 dietary crude protein levels on performance, rumen fermentation, and nitrogen partitioning in dairy cows. J. Dairy. Sci. 99, 4476 – 4486. doi: doi:10.3168/jds.2015-10745
- Alam M., Basir M. S., Sultan M. B., Murshed M., Hossain S., Anik A. H. (2025). Ecological footprint of ionophores in livestock production: Environmental pathways and effects. Water Environ. Res. 97, e70052. doi: doi:10.1002/wer.70052
- Alfaia C. M., Costa M. M., Lopes P. A., Pestana J. M., Prates J. A. M. (2022). Use of grape by-products to enhance meat quality and nutritional value in monogastrics. Foods 11, 2754. doi: doi:10.3390/foods11182754
- Al Rharad A., El Aayadi S., Avril C., Souradjou A., Sow F., Camara Y.. (2025). Meta-analysis of dietary tannins in small ruminant diets: Effects on growth performance, serum metabolites, antioxidant status, ruminal fermentation, meat quality, and fatty acid profile. Anim. 15, 596. doi: doi:10.3390/ani15040596
- Ammar H., López S., Salem A. Z., Bodas R., González J. S. (2011). Effect of saliva from sheep that have ingested quebracho tannins on the in vitro rumen fermentation activity to digest tannin-containing shrubs. Anim. Feed. Sci. Technol. 163, 77 – 83. doi: doi:10.1016/j.anifeedsci.2010.10.007
- Antongiovanni M., Minieri S., Petacchi F. (2007). Effect of tannin supplementation on nitrogen digestibility and retention in growing pigs. Ital. J. Anim. Sci. 6, 245 – 247. doi: doi:10.4081/IJAS.2007.1S.245
- Arisya W., Ridwan R., Ridla M., Jayanegara A. (2019). Tannin treatment for protecting feed protein degradation in the rumen in vitro. J. Phys. Conf. Ser. 1360, 12022. doi: doi:10.1088/1742-6596/1360/1/012022
- Arsène M. M. J., Davares A. K. L., Viktorovna P. I., Andreevna S. L., Sarra S., Khelifi I.. (2022). The public health issue of antibiotic residues in food and feed: Causes, consequences, and potential solutions. Vet. World. 15, 662 – 671. doi: doi:10.14202/vetworld.2022.662-671
- Athanasiadou S., Kyriazakis I., Jackson F., Coop R. L. (2000). Consequences of long-term feeding with condensed tannins on sheep parasitised with Trichostrongylus colubriformis. Int. J. Parasitol. 30, 1025 – 1033. doi: doi:10.1016/S0020-7519(00)00083-7
- Athanasiadou S., Kyriazakis I., Jackson F., Coop R. (2001). Direct anthelmintic effects of condensed tannins towards different gastrointestinal nematodes of sheep: in vitro and in vivo studies. Vet. Parasitol. 99, 205 – 219. doi: doi:10.1016/S0304-4017(01)00467-8
- Attia M. F. A., El-Din A. N. M. N., El-Zarkouny S. Z., El-Zaiat H. M. (2016). impact of quebracho tannins supplementation on productive and reproductive efficiency of dairy cows. J. Anim. Sci. 6, 269 – 288. doi: doi:10.4236/ojas.2016.64032
- Avila A. S., Zambom M. A., Faccenda A., Fischer M. L., Anschau F. A., Venturini T.. (2020). Effects of Black Wattle (Acacia mearnsii) condensed tannins on intake, protozoa population, ruminal fermentation, and nutrient digestibility in Jersey steers. Anim. 10, 1011. doi: doi:10.3390/ani10061011
- Babandi B., Ashiru R. M., Baba M., Gumel I. A., Umar Z., Baso M. U.. (2020). The roles of ionophores in ruminant animal nutrition: A Review. IOSR. J. Agric. Vet. Sci. 13, 46 – 51. Available online at: https://www.iosrjournals.org/iosr-javs/papers/Vol13-issue10/Series-1/G1310014651.pdf (Accessed April 23, 2026).
- Bahelka I., Bučko O., Fľak P. (2021). Can hydrolysable tannins in diet of entire male pigs affect carcass, pork quality traits, amino and fatty acid profiles, and boar taint, skatole and and rostenone levels ? Anim. 11, 896. doi: doi:10.3390/ani11030896
- Barbehenn R. V., Constabel C. P. (2011). Tannins in plant–herbivore interactions. Phytochemistry. 72, 1551 – 1565. doi: doi:10.1016/j.phytochem.2011.01.040
- Barry T. N. (1985). The role of condensed tannins in the nutritional value of Lotus pedunculatus for sheep. 3. Rates of body and wool growth. Brit. J. Nutr. 54, 211 – 217. doi: doi:10.1079/BJN19850106
- Beauchemin K. A., McGinn S. M., Martinez T. F., McAllister T. A. (2007). Use of condensed tannin extract from quebracho trees to reduce methane emissions from cattle. J. Anim. Sci. 85, 1990 – 1996. doi: doi:10.2527/jas.2006-686
- Bedran-Russo A. K., Pauli G. F., Chen S.-N., McAlpine J., Castellan C. S., Phansalkar R. S.. (2014). Dentin biomodification: strategies, renewable resources and clinical applications. Dent. Mater. 30, 62 – 76. doi: doi:10.1016/j.dental.2013.10.012
- Bee G., Silacci P., Ampuero-Kragten S., Čandek-Potokar M., Wealleans A. L., Litten-Brown J.. (2017). Hydrolysable tannin-based diet rich in gallotannins has a minimal impact on pig performance but significantly reduces salivary and bulbourethral gland size. Anim. 11, 1617 – 1625. doi: doi:10.1017/S1751731116002597
- Besharati M., Maggiolino A., Palangi V., Kaya A., Jabbar M., Eseceli H.. (2022). Tannin in ruminant nutrition: Review. Molecules 27, 8273. doi: doi:10.3390/molecules27238273
- Bešlo D., Golubić N., Rastija V., Agić D., Karnaš M., Šubarić D.. (2023). Antioxidant activity, metabolism, and bioavailability of polyphenols in the diet of animals. Antioxidants 12, 1141. doi: doi:10.3390/antiox12061141
- Bhat T. K., Kannan A., Singh B., Sharma O. P. (2013). Value addition of feed and fodder by alleviating the antinutritional effects of tannins. Agric. Res. 2, 189 – 206. doi: doi:10.1007/S40003-013-0066-6
- Bhatta R., Krishnamoorthy U., Mohammed F. (2000). Effect of feeding tamarind (Tamarindus indica) seed husk as a source of tannin on dry matter intake, digestibility of nutrients and production performance of crossbred dairy cows in mid-lactation. Anim. Feed. Sci. Technol. 83, 67 – 74. doi: doi:10.1016/S0377-8401(99)00118-2
- Bilić-Šobot D., Kubale V., Škrlep M., Čandek-Potokar M., Prevolnik Povše M., Fazarinc G.. (2016). Effect of hydrolysable tannins on intestinal morphology, proliferation and apoptosis in entire male pigs. Arch. Anim. Nutr. 70, 378 – 385. doi: doi:10.1080/1745039X.2016.1206735
- Biondi L., Randazzo C. L., Russo N., Pino A., Natalello A., Van Hoorde K.. (2019). Dietary supplementation of tannin-extracts to lambs: Effects on meat fatty acids composition and stability and on microbial characteristics. Foods 8, 469. doi: doi:10.3390/foods8100469
- Bonelli F., Turini L., Paganelli A., Conte G., Meucci V., Sgorbini M.. (2021). Evaluation of oral administration of chestnut tannins in preventing calf diarrhoea. Ital. J. Anim. Sci. 20, 640 – 649. doi: doi:10.1080/1828051X.2021.1906166
- Bonelli F., Turini L., Sarri G., Serra A., Buccioni A., Mele M. (2018). Oral administration of chestnut tannins to reduce the duration of neonatal calf diarrhea. BMC Veterin. Res. 14, 227. doi: doi:10.1186/s12917-018-1549-2
- Bottegal D. N., Latorre M.Á., Lobón S., Verdú M., Álvarez-Rodríguez J. (2024). Fattening pigs with tannin-rich source (Ceratonia siliqua L.) and high doses of vitamin E: Effects on growth performance, economics, digestibility, physiology, and behaviour. Anim. 14, 1855. doi: doi:10.3390/ani14131855
- British Poultry Council (2019). Everything you want to know about ionophore use. Available online at: https://britishpoultry.org.uk/why-do-poultry-meat-farmers-use-ionophores-antiparasitics/#:~:text=The%20World%20Health,risk%20to%20humans (Accessed April 23, 2026).
- Brugaletta G., Luise D., De Cesare A., Zampiga M., Laghi L., Trevisi P.. (2020). Insights into the mode of action of tannin-based feed additives in broiler chickens: looking for connections with the plasma metabolome and caecal microbiota. Ital. J. Anim. Sci. 19, 1349 – 1362. doi: doi:10.1080/1828051X.2020.1842813
- Brunetti L., Leuci R., Colonna M. A., Carrieri R., Celentano F. E., Bozzo G.. (2022). Food industry byproducts as starting material for innovative, green feed formulation: A sustainable alternative for poultry feeding. Molecules 27, 4735. doi: doi:10.3390/molecules27154735
- Brus M., Dolinsek J., CenCic A., Skorjanc D. (2013). Effect of chestnut (Castanea sativa Mill.) wood tannins and organic acids on growth performance and faecal microbiota of pigs from 23 to 127 days of age. Bulgarian. J. Agric. Sci. 19, 841 – 847. Available online at: http://www.agrojournal.org/19/04-35.pdf (Accessed April 23, 2026).
- Brutti D. D., Canozzi M. E. A., Sartori E. D., Colombatto D., Barcellos J. O. J. (2023). Effects of the use of tannins on the ruminal fermentation of cattle: A meta-analysis and meta-regression. Anim. Feed. Sci. Techn. 306, 115806. doi: doi:10.1016/j.anifeedsci.2023.115806
- Buccioni A., Pauselli M., Minieri S., Roscini V., Mannelli F., Rapaccini S.. (2017). Chestnut or quebracho tannins in the diet of grazing ewes supplemented with soybean oil: Effects on animal performances, blood parameters and fatty acid composition of plasma and milk lipids. Small. Rumin. Res. 153, 23 – 30. doi: doi:10.1016/j.smallrumres.2017.05.006
- Bule M., Khan F., Nisar M. F., Niaz K., Nabavi S., Saeedi M.. (2020). Tannins (hydrolysable tannins, condensed tannins, phlorotannins, flavono-ellagitannins). Recent Adv. Natural Prod. Anal. 2020, 132 – 146.
- Butler L. G. (1992). “ Antinutritional effects of condensed and hydrolyzable tannins,” in Plant Polyphenols. Basic Life Sciences, vol. 59. Eds. Hemingway R. W., Laks P. E. (Springer, Boston, MA), 693 – 708. doi: doi:10.1007/978-1-4615-3476-1_40
- Buyse K., Delezie E., Goethals L., Van Noten N., Ducatelle R., Janssens G. P.. (2021). Chestnut tannins in broiler diets: performance, nutrient digestibility, and meat quality. Poultry. Sci. 100, 101479. doi: doi:10.1016/j.psj.2021.101479
- Caetano M., Wilkes M. J., Pitchford W. S., Lee S. J., Hynd P. I. (2019). Effect of ensiled crimped grape marc on energy intake, performance and gas emissions of beef cattle. Anim. Feed. Sci. Technol. 247, 166 – 172. doi: doi:10.1016/j.anifeedsci.2018.10.007
- Callaway T. R., Edrington T. S., Rychlik J. L., Genovese K. J., Poole T. L., Jung Y. S.. (2003). Ionophores: their use as ruminant growth promotants and impact on food safety. Curr. Issues Intestinal. Microbiol. 4, 43 – 51.
- Camarda L., Budriesi R., Corazza I., Frosini M., Marzetti C., Mattioli L. B. (2026). Antioxidant and health-related effects of tannins: From agri-food by-products to human and animal health. Antioxidants 15, 104. doi: doi:10.3390/antiox15010104
- Caprarulo V., Giromini C., Rossi L. (2021). Chestnut and quebracho tannins in pig nutrition: The effects on performance and intestinal health. Anim. 15, 100064. doi: doi:10.1016/j.animal.2020.100064
- Cardullo N., Muccilli V., Cunsolo V., Tringali C. (2020). Mass spectrometry and 1H-NMR study of Schinopsis lorentzii (quebracho) tannins as a source of hypoglycemic and antioxidant principles. Molecules 25, 3257. doi: doi:10.3390/MOLECULES25143257
- Cargill (2026 a). Animal Nutrition. Available online at: https://www.cargill.com/animal-nutrition (Accessed April 20, 2026).
- Cargill (2026 b). Boost Antioxidants. Reduce Feed Costs. Proviox™. Available online at: https://www.cargill.com/animal-nutrition/products/proviox-50#:~:text=Proviox%E2%84%A2%2050%20is%20made,and%20dairy)%2C%20and%20aqua (Accessed April 21, 2026).
- Carulla J. E., Kreuzer M., Machmüller A., Hess H. D. (2005). Supplementation of Acacia mearnsii tannins decreases methanogenesis and urinary nitrogen in forage-fed sheep. Aust. J. Agric. Res. 56, 961 – 970. doi: doi:10.1071/AR05022
- Chang S. I., Fuller H. L. (1964). Effect of tannin content of grain sorghums on their feeding value for growing chicks. Poult. Sci. 43, 30 – 33. doi: doi:10.3382/ps.0430030
- Chikwanha O. C., Moelich E., Gouws P., Muchenje V., Nolte J. V. E., Dugan M. E. R.. (2019). Effects of feeding increasing levels of grape (Vitis vinifera Cv. Pinotage) pomace on lamb shelf-life and eating quality. Meat. Sci. 157, 107887. doi: doi:10.1016/j.meatsci.2019.107887
- Choi J., Kim W. K. (2020). Dietary application of tannins as a potential mitigation strategy for current challenges in poultry production: A review. Anim. 10, 2389. doi: doi:10.3390/ani10122389
- Choi J., Tompkins Y. H., Teng P.-Y., Gogal R. M. Jr., Kim W. K. (2022). Effects of tannic acid supplementation on growth performance, oocyst shedding, and gut health of in broilers infected with Eimeria maxima. Anim. 12, 1378. doi: doi:10.3390/ani12111378
- Connor J., Hurwood I., Burton H., Fuelling D. (1969). Some nutritional aspects of feeding sorghum grain of high tannin content to growing chickens. Aust. J. Exptal. Agric. Anim. Husb. 9, 497 – 501. doi: doi:10.1071/EA9690497
- Cousins B. W., Tanksley T. D. Jr., Knabe D. A., Zebrowska T. (1981). Nutrient digestibility and performance of pigs fed sorghums varying in tannin concentration. J. Anim. Sci. 53, 1524 – 1537. doi: doi:10.2527/jas1982.5361524x
- Cremonesi P., Severgnini M., Battelli M., Monistero V., Penati M., Gazzonis A. L.. (2025). Reducing enteric methane emission in dairy goats: impact of dietary inclusions of quebracho tannin extract on ruminal microbiota. Front. Microbiol. 16, 1595924. doi: doi:10.3389/fmicb.2025.1595924
- Cutrim C. S., Cortez M. A. S. (2018). A review on polyphenols: Classification, beneficial effects and their application in dairy products. Int. J. Dairy. Technol. 71, 564 – 578. doi: doi:10.1111/1471-0307.12515
- de Lange C. F., Nyachoti C. M., Verstegen M. W. (2000). “ The significance of antinutritional factors in feedstuffs for monogastric animals,” in Feed Evaluation – Principles and Practice. Leiden, The Netherlands: Wageningen Academic Eds. Moughan P. J., Verstegen M. W. A., Visser-Reyneveld M. I., 169 – 188. doi: doi:10.1163/9789004683846_013
- Delgadillo-Puga C., Cuchillo-Hilario M., León-Ortiz L., Ramírez-Rodríguez A., Cabiddu A., Navarro-Ocaña A.. (2019). Goats’ feeding supplementation with Acacia farnesiana pods and their relationship with milk composition: Fatty acids, polyphenols, and antioxidant activity. Anim. 9, 515. doi: doi:10.3390/ani9080515
- De Souza T. C. R., Árres I.E.Á., Gómez-Soto J. G., García K. E., Rodríguez E. R., Mariscal-Landín G. (2023). Effect of tannins and kafirins on the nitrogen and energy balance and performance of pigs. Anim. Prod. Sci. 63, 1188 – 1195. doi: doi:10.1071/AN22058
- Dey A., De P. S. (2014). Influence of condensed tannins from Ficus Bengalensis leaves on feed utilization, milk production and antioxidant status of crossbred cows. Asian-Australasian. J. Anim. Sci. 27, 342 – 348. doi: doi:10.5713/ajas.2013.13295
- Díaz Carrasco J. M., Cabral C., Redondo L. M., Pin Viso N. D., Colombatto D., Farber M. D.. (2017). Impact of chestnut and quebracho tannins on rumen microbiota of bovines. Biomed. Res. Internat. 2017, 9610810. doi: doi:10.1155/2017/9610810
- Di Meo M. C., Salzano A., Zotti T., Palladino A., Giaquinto D., Maruccio L.. (2023). Plasma fatty acid profile in Italian Holstein-Friesian dairy cows supplemented with natural polyphenols from the olive plant Olea Europaea L. Vet. Anim. Sci. 21, 100298. doi: doi:10.1016/j.vas.2023.100298
- Dixon R., Lu N. (2025). Methods and compositions for engineering condensed tannins in maize (University of North Texas). Available online at: https://www.goveda.com/patent/WO-2025207520-A1 (Accessed May 7, 2026).
- Dschaak C. M., Williams C. M., Holt M. S., Eun J. S., Young A. J., Min B. R. (2011). Effects of supplementing condensed tannin extract on intake, digestion, ruminal fermentation, and milk production of lactating dairy cows. J. Dairy. Sci. 94, 2508 – 2519. doi: doi:10.3168/jds.2010-3818
- Duffield T. F., Bagg R. N. (2000). Use of ionophores in lactating dairy cattle: A review. Can. Vet. J. 41, 388 – 394. Available online at: https://pubmed.ncbi.nlm.nih.gov/10816832/ (Accessed May 7, 2026).
- Dunshea F. R. (2022). 352 Awardee Talk: Opportunities for antioxidants and plant-derived polyphenols to improve ruminant health and productivity. J. Anim. Sci. 100, 160 – 161. doi: doi:10.1093/jas/skac247.298
- Dutta T. K., Yadav S. K., Chatterjee A. (2019). Antibiotics as feed additives for livestock: Human health concerns. Indian J. Anim. Health 58, 121 – 136. doi: doi:10.36062/ijah.58.2SPL.2019.121-136
- Ebert P. J., Bailey E. A., Shreck A. L., Jennings J. S., Cole N. A. (2017). Effect of condensed tannin extract supplementation on growth performance, nitrogen balance, gas emissions, and energetic losses of beef steers. J. Anim. Sci. 95, 1345 – 1355. doi: doi:10.2527/jas.2016.0341
- Eder K., Ringseis R., Gessner D. K. (2025). Effects of grape by-products on oxidative stress and inflammation in farm animals: An overview of studies performed in pigs, chickens, and cattle. Anim. 15, 1536. doi: doi:10.3390/ani15111536
- EFSA (2022). Safety and efficacy of a feed additive consisting of an extract of condensed tannins from Schinopsis balansae Engl. and Schinopsis lorentzii (Griseb.) Engl. (red quebracho extract) for use in all animal species (FEFANA asbl). EFSA. J. 20, 7699 – 7619. doi: doi:10.2903/j.efsa.2022.7699
- Engström M. T., Karonen M., Ahern J. R., Baert N., Payré B., Hoste H.. (2016). Chemical structures of plant hydrolyzable tannins reveal their in vitro activity against egg hatching and motility of Haemonchus contortus nematodes. J. Agric. Food. Chem. 64, 840 – 851. doi: doi:10.1021/acs.jafc.5b05691
- Esposito T., Celano R., Pane C., Piccinelli A. L., Sansone F., Picerno P.. (2019). Chestnut (Castanea sativa Miller.) burs extracts and functional compounds: UHPLC-UV-HRMS profiling, antioxidant activity, and inhibitory effects on phytopathogenic fungi. Molecules 24, 302. doi: doi:10.3390/molecules24020302
- Etuk E. B., Okeudo N. J., Esonu B. O., Udedibie A. B. I. (2012). Antinutritional factors in sorghum: chemistry, mode of action and effects on livestock and poultry. Online J. Anim. Feed. Res. 2, 113 – 119. Available online at: https://ojafr.com/main/attachments/article/85/OJAFR,%20B23,%20113-119,%202012.pdf (Accessed April 25, 2026).
- EU (2003). Regulation (EC) No 1831/2003 of the European parliament and of the council of 22 September 2003 on additives for use in animal nutrition. Available online at: https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX%3A02003R1831-20210327 (Accessed April 23, 2026).
- EUR-Lex (2008). Commission Regulation (EC) No 429/2008 of 25 April 2008 on detailed rules for the implementation of Regulation (EC) No1831/2003 of the European Parliament and of the Council as regards the preparation and the presentation of applications and the assessment and the authorisation of feed additives. OJ L 133, 22.5.2008, p. 1. Available online at: https://eur-lex.europa.eu/eli/reg/2008/429/oj/eng (Accessed August 4, 2026).
- Favari C., Mena P., Curti C., Del Rio D., Angelino D. (2020). “ Flavan-3-ols: catechins and proanthocyanidins,” in Dietary Polyphenols: Their Metabolism and Health Effects. Hoboken, New Jersey, USA: John Wiley & Sons. Inc Eds. Tomás-Barberán F. A., González-Sarrías A., García-Villalba R., 283 – 317. doi: doi:10.1002/9781119563754.ch8
- Feed Additive (2024). Boost antioxidants and reduce feed costs. Available online at: https://www.feedandadditive.com/boost-antioxidants-and-reduce-feed-costs/#:~:text=To%20combat%20oxidative%20stress%2C%20antioxidants,and%20suitable%20for%20multiple%20species (Accessed April 21, 2026).
- Feeny P. (1970). Seasonal changes in oak leaf tannins and nutrients as a cause of spring feeding by winter moth caterpillars. Ecology 51, 565 – 581. doi: doi:10.2307/1934037
- Felix T. L. (2024). Ionophores: A technology to improve cattle efficiency. In: Pennstate Extension. Available online at: https://extension.psu.edu/ionophores-a-technology-to-improve-cattle-efficiency (Accessed April 23, 2026).
- Firkins J. L., Mitchell K. E. (2023). Invited review: Rumen modifiers in today's dairy rations. J. Dairy. Sci. 106, 3053 – 3071. doi: doi:10.3168/jds.2022-22644
- Foiklang S., Wanapat M., Norrapoke T. (2016). Effect of grape pomace powder, mangosteen peel powder and monensin on nutrient digestibility, rumen fermentation, nitrogen balance and microbial protein synthesis in dairy steers. Asian-Australas. J. Anim. Sci. 29, 1416 – 1423. doi: doi:10.5713/ajas.15.0689
- Fonseca N. V., da Silva Cardoso A., Granja-Salcedo Y. T., Siniscalchi D., Camargo K. D., Dornellas I. A.. (2024). Effects of condensed tannin-enriched alternative energy feedstuff supplementation on performance, nitrogen utilization, and rumen microbial diversity in grazing beef cattle. Livestock. Sci. 287, 105529. doi: doi:10.1016/j.livsci.2024.10552
- Formato M., Cimmino G., Brahmi-Chendouh N., Piccolella S., Pacifico S. (2022 a). Polyphenols for livestock feed: Sustainable perspectives for animal husbandry ? Molecules 27, 7752. doi: doi:10.3390/molecules27227752
- Formato M., Vastolo A., Piccolella S., Calabrò S., Cutrignelli M. I., Zidorn C.. (2022 b). Castanea sativa Mill. Leaf: UHPLC-HR MS/MS analysis and effects on in vitro rumen fermentation and methanogenesis. Molecules 27, 8662. doi: doi:10.3390/molecules27248662
- Fraga-Corral M., Otero P., Cassani L., Echave J., Garcia-Oliveira P., Carpena M.. (2021). Traditional applications of tannin rich extracts supported by scientific data: Chemical composition, bioavailability and bioaccessibility. Foods 10, 251. doi: doi:10.3390/foods10020251
- Francisco A., Dentinho M. T., Alves S. P., Portugal P. V., Fernandes F., Sengo S.. (2015). Growth performance, carcass and meat quality of lambs supplemented with increasing levels of a tanniferous bush (Cistus ladanifer L.) and vegetable oils. Meat. Sci. 100, 275 – 282. doi: doi:10.1016/j.meatsci.2014.10.014
- Franz C., Baser K. H. C., Windisch W. (2010). Essential oils and aromatic plants in animal feeding - a European perspective. A review. Flavour. Fragr. J. 25, 327 – 340. doi: doi:10.1002/ffj.1967
- Fraquelli C., Zanzani S. A., Gazzonis A. L., Rizzi R., Manfredi M. T. (2015). Effects of condensed tannin on natural coccidian infection in goat kids. Small. Rumin. Res. 126, 19 – 24. doi: doi:10.1016/j.smallrumres.2015.01.019
- Frutos P., Hervás G., Giráldez F. J., Mantecón Á.R. (2004 a). Review. Tannins and ruminant nutrition. Spanish. J. Agric. Res. 2, 191 – 202. doi: doi:10.5424/SJAR/2004022-73
- Frutos P., Raso M., Hervas G., Mantecon A. R., Perez V., Giraldez F. J. (2004 b). Is there any detrimental effect when a chestnut hydrolysable tannin extract is included in the diet of finishing lambs ? Anim. Res. 53, 127 – 136. doi: doi:10.1051/animres:2004001
- Furlan C. M., Motta L. B., dos Santos D. Y. A. C. (2010). “ Tannins: What do they represent in plant life ?,” in Tannins - Types, Foods Containing, and Nutrition. Ed. Petridis G. K. (Nova Science Publishers, Inc, Brazil), 13.
- Galamatis D., Panitsidis I., Mantzios T., Sioutas G., Stylianaki I., Papadopoulos E.. (2025). Assessment of a natural phytobiotic mixture as feed additive for broiler chicken: Studies on animal performance, gut health, and antioxidant status after experimental infection with Eimeria spp. Poultry 4, 4. doi: doi:10.3390/poultry4010004
- Galassi G., Mason F., Rapetti L., Crovetto G. M., Spanghero M. (2019). Digestibility and metabolic utilisation of diets containing chestnut tannins and their effects on growth and slaughter traits of heavy pigs. Ital. J. Anim. Sci. 18, 746 – 753. doi: doi:10.1080/1828051X.2019.1570361
- Gao C., Qi M., Zhou Y. (2024). Chestnut tannin extract modulates growth performance and fatty acid composition in finishing Tan lambs by regulating blood antioxidant capacity, rumen fermentation, and biohydrogenation. BMC Vet. Res. 20, 23. doi: doi:10.1186/s12917-023-03870-3
- García E. M., López A., Zimerman M., Hernández O., Arroquy J. I., Nazareno M. A. (2019). Enhanced oxidative stability of meat by including tannin-rich leaves of woody plants in goat diet. Asian-Australasian. J. Anim. Sci. 32, 1439 – 1447. doi: doi:10.5713/ajas.18.0537
- Gerlach K., Pries M., Südekum K. H. (2018). Effect of condensed tannin supplementation on in vivo nutrient digestibilities and energy values of concentrates in sheep. Small. Ruminant. Res. 161, 57 – 62. doi: doi:10.1016/j.smallrumres.2018.01.017
- Gessner D. K., Ringseis R., Eder K. (2016). Potential of plant polyphenols to combat oxidative stress and inflammatory processes in farm animals. J. Anim. Physiol. Anim. Nutr. 101, 605 – 628. doi: doi:10.1111/jpn.12579
- Gesteira S. M., Oliveira R. L., Trajano J., Ribeiro C., de Sousa Costa E. I., Ribeiro R. D. X.. (2019). Fatty acid profile, physicochemical composition and sensorial attributes of salted and sun-dried meat from young Nellore bulls supplemented with condensed tannins. PloS One 14, e0219581. doi: doi:10.1371/journal.pone.0216047
- Girard M., Bee G. (2020). Invited review: Tannins as a potential alternative to antibiotics to prevent coliform diarrhoea in weaned pigs. Animal 14, 95 – 107. doi: doi:10.1017/S1751731119002143
- Girma M., Urge M., Animut G. (2011). Ground Prosopis juliflora pod as feed ingredient in poultry diet: effects on laying performance and egg quality. Intern. J. Poultry. Sci. 10, 879 – 885. doi: doi:10.3923/ijps.2011.879.885
- Gladine C., Rock E., Morand C., Bauchart D., Durand D. (2007). Bioavailability and antioxidant capacity of plant extracts rich in polyphenols, given as a single acute dose, in sheep made highly susceptible to lipoperoxidation. Br. J. Nutr. 98, 691 – 701. doi: doi:10.1017/S0007114507742666
- Goel G., Puniya A. K., Aguilar C. N., Singh K. (2005). Interaction of gut microflora with tannins in feeds. Naturwissenschaften 92, 497 – 503. doi: doi:10.1007/s00114-005-0040-7
- Grainger C., Clarke T., Auldist M. J., Beauchemin K. A., McGinn S. M., Waghorn G. C.. (2009). Potential use of Acacia mearnsii condensed tannins to reduce methane emissions and nitrogen excretion from grazing dairy cows. Can. J. Anim. Sci. 89, 241 – 251. doi: doi:10.4141/CJAS08110
- Gravador R. S., Luciano G., Jongberg S., Bognanno M., Scerra M., Andersen M. L.. (2015). Fatty acids and oxidative stability of meat from lambs fed carob-containing diets. Food Chem. 182, 27 – 34. doi: doi:10.1016/j.foodchem.2015.02.094
- Gualtieri M., Rapaccini S. (1990). Sorghum grain in poultry feeding. World’s. Poultry. Sci. J. 46, 46 – 254. doi: doi:10.1079/WPS19900024
- Guerra-Rivas C., Vieira C., Rubio B., Martínez B., Gallardo B., Mantecón A. R.. (2016). Effects of grape pomace in growing lamb diets compared with vitamin E and grape seed extract on meat shelf life. Meat. Sci. 116, 221 – 229. doi: doi:10.1016/j.meatsci.2016.02.022
- Haslam E. (1989). “ Gallic acid derivatives and hydrolysable tannins,” in Natural Products of Woody Plants: Chemicals Extraneous to the Lignocellulosic Cell Wall. Ed. Rowe J. W. (Springer Berlin Heidelberg, Berlin, Heidelberg), 399 – 438. doi: doi:10.1007/978-3-642-74075-6_13
- Hassan I., Elzubeir E., El Tinay A. (2003). Growth and apparent absorption of minerals in broiler chicks fed diets with low or high tannin contents. Trop. Anim. Health Prod. 35, 189 – 196. doi: doi:10.1023/A:1022833820757
- Hassan Z. M., Manyelo T. G., Selaledi L., Mabelebele M. (2020). The effects of tannins in monogastric animals with special reference to alternative feed ingredients. Molecules 25, 4680. doi: doi:10.3390/molecules25204680
- Hassanat F., Benchaar C. (2013). Assessment of the effect of condensed (acacia and quebracho) and hydrolysable (chestnut and valonea) tannins on rumen fermentation and methane production in vitro. J. Sci. Food Agric. 93, 332 – 339. doi: doi:10.1002/jsfa.5763
- Hassanpour S., Maheri-Sis N., Eshratkhah B., Mehmandar F. B. (2011). “ Plants and secondary metabolites (Tannins): A Review,” in Intern. J. Forest, Soil, Erosion, vol. 1., 47 – 53.
- He T., Yi G., Li J., Wu Z., Guo Y., Sun F.. (2023). Dietary supplementation of tannic acid promotes performance of beef cattle via alleviating liver lipid peroxidation and improving glucose metabolism and rumen fermentation. Antioxidants 12, 1774. doi: doi:10.3390/antiox12091774
- Hervas G., Frutos P., Giraldez F. J., Mantecon A. R., del Pino M. (2003). Effect of different doses of quebracho tannins extract on rumen fermentation in ewes. Anim. Feed. Sci. Technol. 109, 65 – 78. doi: doi:10.1016/S0377-8401(03)00208-6
- Hilbert M., van de Linde I., Lechevestrier Y., Koedijk R. M. (2015). “ Меthod of feeding an animal,” in International Publication Number: WO 2015/184311 A2. Available online at: https://patentimages.storage.googleapis.com/ca/69/ab/30959997f01a0c/WO2015184311A2.pdf (Accessed May 7, 2026).
- Hoste H., Jackson F., Athanasiadou S., Thamsborg S. M., Hoskin S. O. (2006). The effects of tannin-rich plants on parasitic nematodes in ruminants. Trends Parasitol. 22, 253 – 261. doi: doi:10.1016/j.pt.2006.04.004
- Hoste H., Torres-Acosta J. F. J., Quijada J., Chan-Perez I., Dakheel M. M., Kommuru D. S.. (2016). Interactions between nutrition and infections with Haemonchus contortus and related gastrointestinal nematodes in small ruminants. Adv. Parasitol. 93, 239 – 351. doi: doi:10.1016/bs.apar.2016.02.025
- Huang Q., Liu X., Zhao G., Hu T., Wang Y. (2018). Potential and challenges of tannins as an alternative to in-feed antibiotics for farm animal production. Anim. Nutr. 4, 137 – 150. doi: doi:10.1016/j.aninu.2017.09.004
- Humer E., Zebeli Q. (2017). Grains in ruminant feeding and potentials to enhance their nutritive and health value by chemical processing. Anim. Feed. Sci. Technol. 226, 133 – 151. doi: doi:10.1016/j.anifeedsci.2017.02.005
- Huyghebaert G., Ducatelle R., Van Immerseel F. (2011). An update on alternatives to antimicrobial growth promoters for broilers. Vet. J. 187, 182 – 188. doi: doi:10.1016/j.tvjl.2010.03.003
- Ibrahim S. L. (2024). “ Use of lipid encapsulated tannin to replace ionophore in mitigating enteric methane emission and manipulating dietary protein bypass in SA mutton merino sheep,” in Doctor of philosophy in animal science (University of Pretoria, South Africa). Available online at: https://www.proquest.com/openview/39966d61bc69fd64c7310c65fcdcf763/1?pq-origsite=gscholar&cbl=2026366&diss=y (Accessed May 7, 2026).
- Ibrahim S. L., Hassen A. (2022). Effect of non-encapsulated and encapsulated mimosa (Acacia mearnsii) tannins on growth performance, nutrient digestibility, methane and rumen fermentation of South African mutton Merino ram lambs. Anim. Feed. Sci. Technol. 294, 115502. doi: doi:10.1016/j.anifeedsci.2022.115502
- Jamroz D., Wiliczkiewicz A., Skorupińska J., Orda J., Kuryszko J., Tschirch H. (2009). Effect of sweet chestnut tannin (SCT) on the performance, microbial status of intestine and histological characteristics of intestine wall in chickens. Brit. Poultry. Sci. 50, 687 – 699. doi: doi:10.1080/00071660903191059
- Jansman A. J. M. (1993). Tannins in feedstuffs for simple-stomached animals. Nutr. Res. Rev. 6, 209 – 236. doi: doi:10.1079/NRR19930013
- Jayanegara A., Goel G., Makkar H. P. S., Becker K. (2015). Divergence between purified hydrolysable and condensed tannin effects on methane emission, rumen fermentation and microbial population in vitro. Anim. Feed. Sci. Technol. 209, 60 – 68. doi: doi:10.1016/j.anifeedsci.2015.08.002
- Jayanegara A., Leiber F., Kreuzer M. (2012). Meta-analysis of the relationship between dietary tannin level and methane formation in ruminants from in vivo and in vitro experiments. J. Anim. Physiol. Anim. Nutr. 96, 365 – 375. doi: doi:10.1111/j.1439-0396.2011.01172
- Jerónimo E., Alfaia C. M. M., Alves S. P., Dentinho M. T. P., Prates J. A. M., Vasta V.. (2012). Effect of dietary grape seed extract and Cistus ladanifer L. in combination with vegetable oil supplementation on lamb meat quality. Meat. Sci. 92, 841 – 847. doi: doi:10.1016/j.meatsci.2012.07.011
- Jerónimo E., Pinheiro C., Lamy E., Dentinho M. T., Sales-Baptista E., Lopes O.. (2016). “ Tannins in ruminant nutrition: Impact on animal performance and quality of edible products,” in Tannins: Biochemistry, Food Sources and Nutritional Properties. Ed. Combs C. A. (Nova Science Publishers, Hauppauge, NY, USA), 121 – 168. Available online at: http://hdl.handle.net/10174/19651 (Accessed April 21, 2026).
- Jerónimo E., Soldado D., Sengo S., Francisco A., Fernandes F., Portugal A. P. V.. (2020). Increasing the -tocopherol content and lipid oxidative stability of meat through dietary Cistus ladanifer L. in lamb fed increasing levels of polyunsaturated fatty acid rich vegetable oils. Meat. Sci. 164, 108092. doi: doi:10.1016/j.meatsci.2020.108092
- Kafle D., Lee J. H., Min B. R., Kouakou B. (2021). Carcass and meat quality of goats supplemented with tannin-rich peanut skin. J. Agric. Food Res. 5, 100159. doi: doi:10.1016/j.jafr.2021.100159
- Kahn L. P., Diaz-Hernandez A. (2000). “ Tannins with anthelmintic properties,” in Tannins in livestock and human nutrition. Canberra, Australia: ACIAR - Australian Centre for International Agricultural Research, Australian Government. Ed. Brooker J. D., 130 – 139. Aciar Proceedings No. 92.
- Kaleem Q. M., Akhtar M., Awais M. M., Saleem M., Zafar M., Iqbal Z.. (2014). Studies on Emblica officinalis derived tannins for their immunostimulatory and protective activities against coccidiosis in industrial broiler chickens. Sci. World J. 2014, 378473. doi: doi:10.1155/2014/378473
- Kalia V. C., Shim W. Y., Patel S. K., Gong C., Lee J. K. (2022). Recent developments in antimicrobial growth promoters in chicken health: Opportunities and challenges. Sci. Total. Environ. 834, 155300. doi: doi:10.1016/j.scitotenv.2022.155300
- Karchesy J. J., Hemingway R. W. (1986). Condensed tannins:(4. beta. fwdarw. 8; 2. beta. fwdarw. O. fwdarw. 7)-linked procyanidins in Arachis hypogea L. J. Agric. Food. Chem. 34, 966 – 970. doi: doi:10.1021/jf00072a009
- Kelln B. M., Penner G. B., Acharya S. N., McAllister T. A., Lardner H. A. (2021). Impact of condensed tannin-containing legumes on ruminal fermentation, nutrition, and performance in ruminants: a review. Can. J. Anim. Sci. 101, 210 – 223. doi: doi:10.1139/cjas-2020-0096
- Khiaosa-Ard R., Metzler-Zebeli B. U., Ahmed S., Muro-Reyes A., Deckardt K., Chizzola R.. (2015). Fortification of dried distillers grains plus solubles with grape seed meal in the diet modulates methane mitigation and rumen microbiota in Rusitec. J. Dairy. Sci. 98, 2611 – 2626. doi: doi:10.3168/jds.2014-8751
- Koenig K. M., Beauchemin K. A. (2018). Effect of feeding condensed tannins in high protein finishing diets containing corn distillers grains on ruminal fermentation, nutrient digestibility, and route of nitrogen excretion in beef cattle. J. Anim. Sci. 96, 4398 – 4413. doi: doi:10.1093/JAS/SKY273
- Koleckar V., Kubikova K., Rehakova Z., Kuca K., Jun D., Jahodar L.. (2008). Condensed and hydrolysable tannins as antioxidants influencing the health. Mini-Rev. Med. Chem. 8, 436 – 447. doi: doi:10.2174/138955708784223486
- Kondos A. C., Foale M. A. (1983). Comparison of the nutritional value of low and medium tannin sorghum grains for pigs. Anim. Feed. Sci. Technol. 8, 85 – 95. doi: doi:10.1016/0377-8401(83)90089-5
- Krasteva D., Ivanov Y., Chengolova Z., Godjevargova T. (2023). Antimicrobial potential, antioxidant activity, and phenolic content of grape seed extracts from four grape varieties. Microorganisms 11, 395. doi: doi:10.3390/microorganisms11020395
- Krueger W. K., Gutierrez-Bañuelos H., Carstens G. E., Min B. R., Pinchak W. E., Gomez R. R.. (2010). Effects of dietary tannin source on performance, feed efficiency, ruminal fermentation, and carcass and non-carcass traits in steers fed a high-grain diet. Anim. Feed. Sci. Technol. 159, 1 – 9. doi: doi:10.1016/j.anifeedsci.2010.05.003
- Kumar V., Elangovan A. V., Mandal A. B., Tyagi P. K., Bhanja S. K., Dash B. B. (2007). Effects of feeding raw or reconstituted high tannin red sorghum on nutrient utilisation and certain welfare parameters of broiler chickens. Brit. Poultry. Sci. 48, 198 – 208. doi: doi:10.1080/0007166070125108
- Kumar R., Singh M. (1984). Tannins – their adverse role in ruminant nutrition. J. Agric. Food Chem. 32, 447 – 453. Available online at: https://pubs.acs.org/doi/pdf/10.1021/jf00123a006 (Accessed April 25, 2026).
- Kushwaha R. B., Rai S. N., Singh A. K., Chandra G., Vaidya M. M., Sharma V.. (2011). Tanniniferous feed resources in dairy animals: a review. Agric. Rev. 32, 267 – 275. Available online at: https://arccjournals.com/journal/agricultural-reviews/ARCC912 (Accessed May 7, 2026).
- Kyarisiima C. C., Okot M. W., Svihus B. (2004). “ Use of wood ash in the treatment of high tannin sorghum for poultry feeding,” in Sth. Afr. J. Anim. Sci, vol. 34., 110 – 115. Available online at: https://hdl.handle.net/10520/EJC94364 (Accessed May 7, 2026).
- Larraín R. E., Schaefer D. M., Richards M. P., Reed J. D. (2008). Finishing steers with diets based on corn, high-tannin sorghum or a mix of both: Color and lipid oxidation in beef. Meat. Sci. 79, 656 – 665. doi: doi:10.1016/j.meatsci.2007.10.032
- Lee H. J., Choi I. H., Kim D. H., Amanullah S. M., Kim S. C. (2016). Nutritional characterization of tannin rich chestnut (Castanea) and its meal for pig. J. Appl. Anim. Res. 44, 258 – 262. doi: doi:10.1080/09712119.2015.1031779
- Lee J. H., Min B. R., Lemma B. B. (2017). Quality characteristics of goat meat as influenced by condensed tannins-containing pine bark. Small. Rumin. Res. 146, 28 – 32. doi: doi:10.1016/j.smallrumres.2016.11.009
- Lee S. H., Shinde P. L., Choi J. Y., Kwon I. K., Lee J. K., Pak S. I.. (2010). Effects of tannic acid supplementation on growth performance, blood hematology, iron status and faecal microflora in weanling pigs. Livestock. Sci. 131, 281 – 286. doi: doi:10.1016/j.livsci.2010.04.013
- Lee M., Tedeschi L. O. (2026). The impact of supplementing quebracho and chestnut tannin extracts on the growth performance in growing and finishing beef cattle: a meta-analytical assessment. J. Anim. Sci. 104, skag082. doi: doi:10.1093/jas/skag082
- Lekha P. K., Lonsane B. K. (1997). Production and application of tannin acyl hydrolase: state of the art. Adv. Appl. Microbiol. 44, 215 – 260. doi: doi:10.1016/S0065-2164(08)70463-5
- Leparmarai P. T., Sinz S., Kunz C., Liesegang A., Ortmann S., Kreuzer M.. (2019). Transfer of total phenols from a grapeseed-supplemented diet to dairy sheep and goat milk, and effects on performance and milk quality. J. Anim. Sci. 97, 1840 – 1851. doi: doi:10.1093/jas/skz046
- Li P., Shen Y., You M., Zhang Y., Yan J., Li D.. (2017). Effect of grape pomace on fermentation quality and aerobic stability of sweet sorghum silage. Anim. Sci. J. 88, 1523 – 1530. doi: doi:10.1111/asj.12791
- Life Rainbow Biotech (2024). What are Feed Additives and How do They Benefit Livestock ? Available online at: https://en.engormix.com/poultry-industry/poultry-nutrition-other-additives/what-are-feed-additives_a55005/ (Accessed April 21, 2026).
- Lillehoj H., Liu Y., Calsamiglia S., Fernandez-Miyakawa M. E., Chi F., Cravens R. L.. (2018). Phytochemicals as antibiotic alternatives to promote growth and enhance host health. Vet. Res. 49, 76. doi: doi:10.1186/s13567-018-0562-6
- Lin L., Lu Y., Wang W., Luo W., Li T., Cao G.. (2024). The influence of high-concentrate diet supplemented with tannin on growth performance, rumen fermentation, and antioxidant ability of fattening lambs. Anim. 14, 2471. doi: doi:10.3390/ani14172471
- Lipiński K., Mazur M., Antoszkiewicz Z., Purwin C. (2017). Polyphenols in monogastric nutrition–a review. Ann. Anim. Sci. 17, 41 – 58. doi: doi:10.1515/aoas-2016-0042
- Liu H., Vaddella V., Zhou D. (2011). Effects of chestnut tannins and coconut oil on growth performance, methane emission, ruminal fermentation, and microbial populations in sheep. J. Dairy. Sci. 94, 6069 – 6077. doi: doi:10.3168/jds.2011-4508
- Lobón S., Sanz A., Blanco M., Ripoll G., Joy M. (2017). The type of forage and condensed tannins in dams’ diet: Influence on meat shelf life of their suckling lambs. Small. Rumin. Res. 154, 115 – 122. doi: doi:10.1016/j.smallrumres.2017.08.005
- Lopes A. B., Tse M. L., Silva A. M., Trindade M. A., Pereira C. S., Saleh M. A.. (2017). High-moisture sorghum grain silage with low-and high-tannin contents for weanling piglets. Ciec. Rural 47, e20151255. doi: doi:10.1590/0103-8478cr20151255
- López-Andrés P., Luciano G., Vasta V., Gibson T. M., Biondi L., Priolo A.. (2013). Dietary quebracho tannins are not absorbed, but increase the antioxidant capacity of liver and plasma in sheep. Brit. J. Nutr. 110, 632 – 639. doi: doi:10.1017/S0007114512005703
- Lotfi R. (2020). A commentary on methodological aspects of hydrolysable tannins metabolism in ruminant: a perspective view. Lett. Appl. Microbiol. 71, 466 – 478. doi: doi:10.1111/lam.13346
- Loza C., Verma S., Wolffram S., Susenbeth A., Blank R., Taube F.. (2021). Assessing the potential of diverse forage mixtures to reduce enteric methane emissions in vitro. Anim. 11, 1126. doi: doi:10.3390/ani11041126
- Lu N., Jun J. H., Li Y., Dixon R. A. (2023). An unconventional proanthocyanidin pathway in maize. Nat. Comms. 14, 4349. doi: doi:10.1038/s41467-023-40014-5
- Lucianer E., Da Silva A. S., Cazarotto C. J., Alba D. F., Griss L. G., Zampar A.. (2019). Addition of tannin in lamb diets after weaning: impact on performance and hematological and biochemical variables. Acta Scientiae. Veterinariae. 47, 1709. doi: doi:10.22456/1679-9216.98310
- Luciano G., Monahan F. J., Vasta V., Biondi L., Lanza M., Priolo A. (2009). Dietary tannins improve lamb meat colour stability. Meat. Sci. 81, 120 – 126. doi: doi:10.1016/j.meatsci.2008.07.006
- Luciano G., Vasta V., Monahan F. J., López-Andrés P., Biondi L., Lanza M.. (2011). Antioxidant status, colour stability and myoglobin resistance to oxidation of Longissimus dorsi muscle from lambs fed a tannin-containing diet. Food Chem. 124, 1036 – 1042. doi: doi:10.1016/j.foodchem.2010.07.070
- Ma J., Li T., Lin L., Lu Y., Chen X., Li S.. (2024). Effects of grape seed extract supplementation on the growth performance, nutrients digestion and immunity of weaned lambs. Front. Vet. Sci. 11, 1402637. doi: doi:10.3389/fvets.2024.1402637
- Madacsi J. P., Parrish F. W., McNaughton J. L. (1988). Treatment of low-tannin sorghum grain for broiler feed. Anim. Feed. Sci. Technol. 20, 69 – 78. doi: doi:10.1016/0377-8401(88)90128-9
- Mahfuz S., Shang Q., Piao X. (2021). Phenolic compounds as natural feed additives in poultry and swine diets: a review. J. Anim. Sci. Biotech. 12, 48. doi: doi:10.1186/s40104-021-00565-3
- Makkar H. P. S. (1993). “ Antinutritional factors in foods for livestock,” in Animal Production in Developing Countries. Brit. Soc. Anim. Prod. Occ. Publ, Cambridge, UK: British Society of Animal Production. vol. 16., 69 – 85. doi: doi:10.1017/S0263967X00031086
- Makkar H. P. S. (2003). Effects and fate of tannins in ruminant animals, adaptation to tannins, and strategies to overcome detrimental effects of feeding tannin-rich feeds. Small. Ruminant. Res. 49, 241 – 256. doi: doi:10.1016/S0921-4488(03)00142-1
- Makkar H. P. S., Singh B., Negi S. S. (1990). Tannin levels and their degree of polymerisation and specific activity in some agro-industrial by-products. Biol. Wastes. 31, 137 – 144. doi: doi:10.1016/0269-7483(90)90167-Q
- Mal S., Pal D. (2021). “ Tannins and polyphenols extracted from natural plants and their versatile application,” in Bioactive Natural Products for Pharmaceutical Applications. Advanced Structured Materials, vol. 140. Eds. Pal D., Nayak A. K. (Springer, Cham). doi: doi:10.1007/978-3-030-54027-2_21
- Malenica D., Kass M., Bhat R. (2023). Sustainable management and valorization of agri-food industrial wastes and by-products as animal feed: For ruminants, non-ruminants and as poultry feed. Sustainability 15, 117. doi: doi:10.3390/su15010117
- Mandal A. B., Tyagi P. K., Elangovan A. V., Tyagi P. K., Kaur S., Johri A. K. (2006). Comparative apparent metabolisable energy values of high, medium and low tannin varieties of sorghum in cockerel, Guinea fowl and quail. Brit. Poultry. Sci. 47, 336 – 345. doi: doi:10.1080/00071660600741875
- Marques R. D., Cooke R. F. (2021). Effects of ionophores on ruminal function of beef cattle. Animals 11, 2871. doi: doi:10.3390/ani11102871
- Martín-Martín A., Orduna-Malea E., Thelwall M., López-Cózar E. D. (2018). Google Scholar, Web of Science, and Scopus: A systematic comparison of citations in 252 subject categories. J. Informetrics. 12, 1160 – 1177. doi: doi:10.1016/j.joi.2018.09.002
- McGuffey R. K., Richardson L. F., Wilkinson J. I. (2001). Ionophores for dairy cattle: Current status and future outlook. J. Dairy. Sci. 84, E194 – E203. doi: doi:10.3168/jds.S0022-0302(01)70218-4
- Medugu C. I., Saleh B., Igwebuike J. U., Ndirmbita R. L. (2012). Strategies to improve the utilization of tannin-rich feed materials by poultry. Int. J. Poultry. Sci. 11, 417 – 423. doi: doi:10.3923/ijps.2012.417.423
- Mena M. O., Trevise G. G. D. O., Bassetto C. C., Pinchao W. H. P., Louvandini H., Soutello R. V. G. D.. (2025 a). Effect of grape pomace inclusion in the diet of ewes naturally infected with gastrointestinal nematodes during lactation. Pathogens 14, 560. doi: doi:10.3390/pathogens14060560
- Mena M. O., Trevise G. G. O., Silva T. N. R., Moellmann V. M., Bassetto C. C., Gatti B. S.. (2025 b). Evaluation of grape pomace supplementation in lamb diets to mitigate Haemonchus contortus infection. Agric. 15, 341. doi: doi:10.3390/agriculture15030341
- Menci R., Luciano G., Natalello A., Priolo A., Mangano F., Biondi L.. (2024). Performance and meat quality in pigs fed hydrolysable tannins from Tara spinosa. Meat. Sci. 207, 109364. doi: doi:10.1016/j.meatsci.2023.109364
- Mezzomo R., Paulino P. V. R., Detmann E., Valadares Filho S. C., Paulino M. F., Monnerat J. S.. (2011). Influence of condensed tannin on intake, digestibility, and efficiency of protein utilization in beef steers fed high concentrate diet. Livestock. Sci. 141, 1 – 11. doi: doi:10.1016/J.LIVSCI.2011.04.004
- Min B., Barry T. N., Attwood G. T., McNabb W. C. (2003). The effect of condensed tannins on the nutrition and health of ruminants fed fresh temperate forages: a review. Anim. Feed. Sci. Technol. 106, 3 – 19. doi: doi:10.1016/S0377-8401(03)00041-5
- Min B. R., Castleberry L., Allen H., Parker D., Waldrip H., Brauer D.. (2019). Associative effects of wet distiller’s grains plus solubles and tannin-rich peanut skin supplementation on in vitro rumen fermentation, greenhouse gas emissions, and microbial changes. J. Anim. Sci. 97, 4668 – 4681. doi: doi:10.1093/jas/skz317
- Min B. R., Hart S. P. (2003). Tannins for suppression of internal parasites. J. Anim. Sci. 81, E102 – E109. doi: doi:10.2527/2003.8114_suppl_2E102x
- Minho A. P., Bueno I. C. D. S., Gennari S. M., Jackson F., Abdalla A. L. (2008). In vitro effect of condensed tannin extract from acacia (Acacia mearnsii) on gastrointestinal nematodes of sheep. Rev. Bras. Parasitol. Veterin. 17, 144 – 148.
- Mohammed T. A., Ali O. M. (1988). Effect of wood ash extract treatment on the feeding value and utilization of high-tannin sorghums by broiler chicks. Anim. Feed. Sci. Technol. 22, 131 – 136. doi: doi:10.1016/0377-8401(88)90080-6
- Moilanen J., Salminen J. (2008). Ecologically neglected tannins and their biologically relevant activity: chemical structures of plant ellagitannins reveal their in vitro oxidative activity at high pH. Chemoecology 18, 73 – 83. doi: doi:10.1007/s00049-007-0395-7
- Molan A. L., Hoskin S. O., Barry T. N., McNabb W. C. (2000 a). The effect of condensed tannins extracted from four forages on deer lungworm gastrointestinal nematode larval viability. Vet. Rec. 147, 44 – 48. doi: doi:10.1136/vr.147.2.44
- Molan A. L., Waghorn G. C., McNabb W. C. (2002). Effect of condensed tannins on egg hatching and larval development of Trichostrongylus colubriformis in vitro. Veterin. Rec. 150, 65 – 69. doi: doi:10.1136/vr.150.3.65
- Molan A. L., Waghorn G. C., Min B. R., McNabb W. C. (2000 b). The effect of condensed tannins from seven herbages on Trichostrongylus colubriformis larval migration in vitro. Folia Parasitologica. 47, 39 – 44. doi: doi:10.14411/fp.2000.007
- Mora J., Pott D. M., Osorio S., Vallarino J. G. (2022). Regulation of plant tannin synthesis in crop species. Front. Genet. 13, 870976. doi: doi:10.3389/fgene.2022.870976
- Mu C., Yang W., Wang P., Zhao J., Hao X., Zhang J. (2020). Effects of high-concentrate diet supplemented with grape seed proanthocyanidins on growth performance, liver function, meat quality, and antioxidant activity in finishing lambs. Anim. Feed. Sci. Technol. 266, 114518. doi: doi:10.1016/j.anifeedsci.2020.114518
- Mueller-Harvey I. (2006). Unravelling the conundrum of tannins in animal nutrition and health. J. Sci. Food. Agr. 86, 2010 – 2037. doi: doi:10.1002/jsfa.2577
- Mueller-Harvey I., Bee G., Dohme-Meier F., Hoste H., Karonen M., Kölliker R.. (2019). Benefits of condensed tannins in forage legumes fed to ruminants: importance of structure, concentration and diet composition. Invited review. Crop Sci. 59, 861 – 885. doi: doi:10.2135/cropsci2017.06.0369
- Muíño I., Apeleo E., de la Fuente J., Pérez-Santaescolástica C., Rivas-Cañedo A., Pérez C.. (2014). Effect of dietary supplementation with red wine extract or vitamin E, in combination with linseed and fish oil, on lamb meat quality. Meat. Sci. 98, 116 – 123. doi: doi:10.1016/j.meatsci.2014.05.009
- Muzzo B. I., Provenza F. D. (2026). Phytochemically rich food-system by-products in ruminant diets: Nutritional and health benefits from animals to humans within a circular bioeconomy. Rec. Progr. Nutr. 6, 4. doi: doi:10.21926/rpn.2602004
- Myer R. O., Gorbet D. W., Combs G. E. (1986). Nutritive value of high- and low-tannin grain sorghums harvested and stored in the high-moisture state for growing-finishing swine. J. Anim. Sci. 62, 1290 – 1297. doi: doi:10.2527/jas1986.6251290x
- Naumann H. D., Muir J. P., Lambert B. D., Tedeschi L. O., Kothmann M. M. (2013). Condensed tannins in the ruminant environment: a perspective on biological activity. J. Agric. Sci. 1, 8 – 20.
- Naumann H., Sepela R., Rezaire A., Masih S. E., Zeller W. E., Reinhardt L.. (2018). Relationships between structures of condensed tannins from Texas legumes and methane production during in vitro rumen digestion. Molecules 23, 2123. doi: doi:10.3390/molecules23092123
- Naumann H. D., Tedeschi L. O., Zeller W. E., Huntley N. F. (2017). The role of condensed tannins in ruminant animal production: advances, limitations and future directions. Rev. Bras. Zootec. 46, 929 – 949. doi: doi:10.1590/S1806-92902017001200009
- Nawab A., Tang S., Gao W., Li G., Xiao M., An L.. (2020). Tannin supplementation in animal feeding; mitigation strategies to overcome the toxic effects of tannins on animal health: A review. J. Agric. Sci. 12, 217 – 230. doi: doi:10.5539/jas.v12n4p217
- Nelson T. S., Stephenson E. L., Burgos A., Floyd J., York J. O. (1975). Effect of tannin content and dry matter digestion on energy utilization and average amino acid availability of hybrid sorghum grains. Poultry. Sci. 54, 1620 – 1623. doi: doi:10.3382/ps.0541620
- Ng’ambi W. J. (2026). “ A Review of opportunities and limitations of the potential use of tannins to reduce methane production in ruminants,” in Ruminant Science - Research and Innovation [Working Title]. Ed. Babinszky L. (London, UK: IntechOpen). doi: doi:10.5772/intechopen.1015050
- Norris A. B., Crossland W. L., Tedeschi L. O., Foster J. L., Muir J. P., Pinchak W. E.. (2020). Inclusion of quebracho tannin extract in a high-roughage cattle diet alters digestibility, nitrogen balance, and energy partitioning. J. Anim. Sci. 98, skaa047. doi: doi:10.1093/jas/skaa047
- Ochieng B. A., Owino W. O., Kinyuru J. N., Mburu J. N., Gicheha M. G. (2020). Effect of low tannin sorghum based feeds on broiler meat nutritional quality. J. Agric. Food Res. 2, 100078. doi: doi:10.1016/j.jafr.2020.100078
- Ochieng B. A., Owino W. O., Kinyuru J. N., Mburu J. N., Gicheha M. G., Kabuage L. (2018). Effect of low tannin sorghum based feed on physical and nutritional quality of layer chicken eggs. J. Food. Res. 7, 94 – 106. doi: doi:10.5539/jfr.v7n4p94
- Ogawa S., Yazaki Y. (2018). Tannins from Acacia mearnsii De Wild. Bark: Tannin determination and biological activities. Molecules 23, 837. doi: doi:10.3390/molecules23040837
- Olagaray K. E., Bradford B. J. (2019). Plant flavonoids to improve productivity of ruminants – A review. Anim. Feed. Sci. Technol. 251, 21 – 36. doi: doi:10.1016/j.anifeedsci.2019.02.004
- Olejar K. J., Ray S., Kilmartin P. A. (2016). Enhanced antioxidant activity of polyolefin films integrated with grape tannins. J. Sci. Food Agric. 96, 2825 – 2831. doi: doi:10.1002/jsfa.7450
- Oliveira L. N., Pereira M. A. N., Oliveira C. D. S., Oliveira C. C., Silva R. B., Pereira R. A. N.. (2023). Effect of low dietary concentrations of Acacia mearnsii tannin extract on chewing, ruminal fermentation, digestibility, nitrogen partition, and performance of dairy cows. J. Dairy. Sci. 106, 3203 – 3216. doi: doi:10.3168/jds.2022-22521
- Orlandi T., Kozloski G. V., Alves T. P., Mesquita F. R., Ávila S. C. (2015). Digestibility, ruminal fermentation and duodenal flux of amino acids in steers fed grass forage plus concentrate containing increasing levels of Acacia mearnsii tannin extract. Anim. Feed. Sci. Technol. 210, 37 – 45. doi: doi:10.1016/j.anifeedsci.2015.09.012
- Orlandi T., Pozo C. A., Mezzomo M. P., Kozloski G. V. (2020). Acacia mearnsii tannin extract as a feed additive: impact on feed intake, digestibility and nitrogen excretion by sheep fed a tropical grass-based diet. Ciencia. Rural 50, 16. doi: doi:10.1590/0103-8478CR20200095
- Orzuna-Orzuna J. F., Dorantes-Iturbide G., Lara-Bueno A., Mendoza-Martínez G. D., Miranda-Romero L. A., Hernández-García P. A. (2021). Effects of dietary tannins’ Supplementation on growth performance, rumen fermentation, and enteric methane emissions in beef cattle: A meta-analysis. Sustainability 13, 7410. doi: doi:10.3390/su13137410
- Ospina-Romero M. A., González-Ríos H., Barrera-Silva M.Á., Valenzuela-Melendres M., Martínez-Téllez M.Á., Pinelli-Saavedra A. (2024). “ Winemaking by-products and grape polyphenols extracts as phytogenic feed additives in pork production. Review,” in Revista Mexicana De Ciencias Pecuarias, 15, 669 – 699. doi: doi:10.22319/rmcp.v15i3.6479
- Pan L., An D., Zhu W. (2021). Low-tannin sorghum grain could be used as an alternative to corn in diet for nursery pigs. J. Anim. Physiol. Anim. Nutr. 105, 890 – 897. doi: doi:10.1111/jpn.13523
- Pan L., Li W., Gu X. M., Zhu W. Y. (2022). Comparative ileal digestibility of gross energy and amino acids in low and high tannin sorghum fed to growing pigs. Anim. Feed. Sci. Technol. 292, 115419. doi: doi:10.1016/j.anifeedsci.2022.115419
- Pan L., Ma X., Hu J., Liu L., Yuan M., Liu L.. (2019). Low-tannin white sorghum contains more digestible and metabolisable energy than high-tannin red sorghum if fed to growing pigs. Anim. Prod. Sci. 59, 524 – 530. doi: doi:10.1071/AN17245
- Panciroli (2016). Silvafeed® ATX: How to Improve FCR during High Temperatures Season. Available online at: https://en.engormix.com/feed-machinery/feed-additives/silvafeed-atx-how-improve_a39750/ (Accessed April 21, 2026).
- Pandey A., Nayak S., Khare A., Sharma R., Chourasiya A., Reddy B. V.. (2022). Perspectives in the use of tannins in animal production and health: a review. J. Livestock. Sci. 13, 113 – 119. doi: doi:10.33259/jlivestsci.2022.112-119
- Pathak A. K. P., Dutta N., Pattanaik A. K., Sharma K., Banerjee P. S., Goswami T. K. (2017). The effect of condensed tannin supplementation through Ficus infectoria and Psidium guajava leaf meal mixture on erythrocytic antioxidant status, immune response and gastrointestinal nematodes in lambs (Ovis aries). Veterinarski. Arhiv. 87, 139 – 156. Available online at: https://hrcak.srce.hr/178590 (Accessed May 7, 2026).
- Patra A. K., Min B. R., Saxena J. (2012). “ Dietary tannins on microbial ecology of the gastrointestinal tract in ruminants,” in Dietary Phytochemicals and Microbes. Ed. Patra A. (Springer, Dordrecht), 237 – 262. doi: doi:10.1007/978-94-007-3926-0_8
- Patra A. K., Saxena J. (2011). Exploitation of dietary tannins to improve rumen metabolism and ruminant nutrition. J. Sci. Food Agric. 91, 24 – 37. doi: doi:10.1002/jsfa.4152
- Piluzza G., Sulas L., Bullitta S. (2014). Tannins in forage plants and their role in animal husbandry and environmental sustainability: a review. Grass. Forage. Sci. 69, 32 – 48. doi: doi:10.1111/gfs.12053
- Pimentel P. R. S., Brant L. M. D. S., Lima A. O., Cotrim D. C., Nascimento T. V. C., Oliveira R. L. (2022). How can nutritional additives modify ruminant nutrition ? Rev. La. Facultad Cienc. Agrarias. Universidad. Nacional. Cuyo. 54, 175 – 189. doi: doi:10.48162/rev.39.076
- Piñeiro-Vázquez A. T., Jiménez-Ferrer G., Alayon-Gamboa J. A., Chay-Canul A. J., Ayala-Burgos A. J., Aguilar-Pérez C. F.. (2018). Effects of quebracho tannin extract on intake, digestibility, rumen fermentation, and methane production in crossbred heifers fed low-quality tropical grass. Trop. Anim. Health Prod. 50, 29 – 36. doi: doi:10.1007/s11250-017-1396-3
- Pizzi A. (2008). “ Chapter 8 - tannins: major sources, properties and applications,” in Monomers, Polymers and Composites From Renewable Resources. Eds. Belgacem M. N., Gandini A. (London: Elsevier), 179 – 199. doi: doi:10.1016/B978-0-08-045316-3.00008-9
- Pizzi A. (2021). Tannins medical / pharmacological and related applications: A critical review. Sustain. Chem. Pharm. 22, 100481. doi: doi:10.1016/j.scp.2021.100481
- Placha I., Gai F., Pogány Simonová M. (2022). Editorial: Natural feed additives in animal nutrition-Their potential as functional feed. Front. Vet. Sci. 9, 1062724. doi: doi:10.3389/fvets.2022.1062724
- Ponnampalam E. N., Kearns M., Kiani A., Santhiravel S., Vahmani P., Prache S.. (2024). Enrichment of ruminant meats with health enhancing fatty acids and antioxidants: feed-based effects on nutritional value and human health aspects – invited review. Front. Anim. Sci. 5, 1329346. doi: doi:10.3389/fanim.2024.1329346
- Porter L. J. (1989). “ Condensed tannins,” in Natural Products of Woody Plants. Springer Series in Wood Science. Ed. Rowe J. W. (Springer, Berlin, Heidelberg). doi: doi:10.1007/978-3-642-74075-6_18
- Pour‐Reza J., Edriss M. A. (1997). Effects of dietary sorghum of different tannin concentrations and tallow supplementation on the performance of broiler chicks. Brit. Poultry. Sci. 38, 512 – 517. doi: doi:10.1080/00071669708418030
- Prapaiwong T., Srakaew W., Poolthajit S., Wachirapakorn C., Jarassaeng C. (2023). Effects of Chestnut hydrolysable tannin on intake, digestibility, rumen fermentation, milk production and somatic cell count in crossbred dairy cows. Vet. Sci. 10, 269. doi: doi:10.3390/vetsci10040269
- Prapaiwong T., Srakaew W., Wachirapakorn C., Jarassaeng C. (2021). Effects of hydrolyzable tannin extract obtained from sweet chestnut wood (Castanea sativa Mill.) against bacteria causing subclinical mastitis in Thai Friesian dairy cows. Vet. World 14, 2427 – 2433. doi: doi:10.14202/vetworld.2021.2427-2433
- Priolo A., Lanza M., Biondi L., Pappalardo P., Young O. A. (1998). Effect of partially replacing dietary barley with 20% carob pulp on post-weaning growth, and carcass and meat characteristics of Comisana lambs. Meat. Sci. 50, 355 – 363. doi: doi:10.1016/S0309-1740(98)00041-2
- Priolo A., Waghorn G. C., Lanza M., Biondi L., Pennisi P. (2000). Polyethylene glycol as a means for reducing the impact of condensed tannins in carob pulp: effects on lamb growth performance and meat quality. J. Anim. Sci. 78, 810 – 816. doi: doi:10.2527/2000.784810x
- Prodanović R., Bošnjaković D., Djordjevic A., Simeunović P., Arsić S., Mitrović A.. (2025). Effects of chestnut tannin extract on enteric methane emissions, blood metabolites and lactation performance in mid-lactation cows. Anim. 15, 2238. doi: doi:10.3390/ani15152238
- Prodanović R., Nedić S., Bošnjaković D., Nedić S., Jovanović L., Arsić S.. (2024). Chestnut tannin supplementation can improve immune response and kidney function in prepartum dairy cows. J. Anim. Feed. Sci. 33, 185 – 192. doi: doi:10.22358/jafs/174065/2023
- Prodanović R., Nedić S., Vujanac I., Bojkovski J., Nedić S., Jovanović L.. (2023). Dietary supplementation of chestnut tannins in prepartum dairy cows improves antioxidant defense mechanisms interacting with thyroid status. Metabolites 13, 334. doi: doi:10.3390/metabo13030334
- Prusty S., Mahesh M. S., Sheel R., Swain P. S., Madhusoodan A. P., Thakur N.. (2024). “ Ionophoric additives to augment performance outcomes and economics in ruminants,” in Feed Additives and Supplements for Ruminants (Springer Nature Singapore, Singapore), 479 – 493. Available online at: https://link.springer.com/chapter/10.1007/978-981-97-0794-2_22 (Accessed May 7, 2026).
- Puchala R., Min B. R., Goetsch A. L., Sahlu T. (2005). The effect of condensed tannin-containing forage on methane emission by goats. J. Anim. Sci. 83, 182 – 186. doi: doi:10.2527/2005.831182x
- Rahman M. R. T., Fliss I., Biron E. (2022). Insights into the development and uses of alternatives to antibiotic growth promoters in poultry and swine production. Antibiotics 11, 766. doi: doi:10.3390/antibiotics11060766
- Razzaq S., Khan K. T., Sadia A., Kanza K. S., Imran M. (2024). “ Tannins as a dietary additive in animal feed,” in Complementary and Alternative Medicine: Feed Additives. Eds. Abbas R. Z., Akhtar T., Asrar R., Khan A. M. A., Saeed Z. (Unique Scientific Publishers, Faisalabad, Pakistan), 316 – 325. Chapter 28. doi: doi:10.47278/book.CAM/2024.324
- Redondo L. M., Chacana P. A., Dominguez J. E., Miyakawa M. E. D. F. (2014). Perspectives in the use of tannins as alternative to antimicrobial growth promoter factors in poultry. Front. Microbiol. 5, 118. doi: doi:10.3389/fmicb.2014.00118
- Redwan Haque A., Sarker M., Das R., Azad M. A. K., Hasan M. M. (2023). A review on antibiotic residue in foodstuffs from animal source: global health risk and alternatives. Intern. J. Environ. Anal. Chem. 103, 3704 – 3721. doi: doi:10.1080/03067319.2021.1912334
- Rezaei Ahvanooei M. R., Norouzian M. A., Piray A. H., Vahmani P., Ghaffari M. H. (2024). Effects of monensin supplementation on rumen fermentation, methane emissions, nitrogen balance, and metabolic responses of dairy cows: A systematic review and dose-response meta-analysis. J. Dairy. Sci. 107, 607 – 624. doi: doi:10.3168/jds.2023-23441
- Rigby L. B. (2021). “ Effects of probiotics and tannins on growth performance, gastrointestinal tract fermentation, and measures of Eimeria species in cattle,” in A thesis submitted to the Department of Animal Science and the University of Wyoming in partial fulfilment of the requirements for the degree of Master of Science in animal and veterinary science (University of Wyoming, Department of Animal Science). Available online at: https://www.proquest.com/openview/9533d48f5cfa8757fa562a3427733a9c/1?pq-origsite=gscholar&cbl=18750&diss=y (Accessed August 4, 2026).
- Rivera-Méndez C., Plascencia A., Torrentera N., Zinn R. A. (2017). Effect of level and source of supplemental tannin on growth performance of steers during the late finishing phase. J. Appl. Anim. Res. 45, 199 – 203. doi: doi:10.1080/09712119.2016.1141776
- Rodríguez R., de la Fuente G., Gómez S., Fondevila M. (2014). Biological effect of tannins from different vegetal origin on microbial and fermentation traits in vitro. J. Anim. Prod. Sci. 54, 1039 – 1046. doi: doi:10.1071/AN13045
- Rodríguez-Solana R., Romano A., Moreno-Rojas J. M. (2021). Carob pulp: A nutritional and functional by-product. Processes 9, 1146. doi: doi:10.3390/pr9071146
- Rostagno H. S., Featherston W. R., Rogler J. C. (1973). Studies on the nutritional value of sorghum grains with varying tannin contents for chicks: 1. Growth studies. Poultry. Sci. 52, 765 – 772. doi: doi:10.3382/ps.0520765
- Salami S. A., Valenti B., Bella M., O'Grady M. N., Luciano G., Kerry J. P.. (2018). Characterisation of the ruminal fermentation and microbiome in lambs supplemented with hydrolysable and condensed tannins. FEMS Microbiol. Ecol. 94, fiy061. doi: doi:10.1093/femsec/fiy061
- Salawu M. B., Acamovic T., Stewart C. S., Hoveli F. (1999). Effects of feeding quebracho tannin diets, with or without a dietary modifier, on rumen function in sheep. Anim. Sci. 69, 265 – 274. doi: doi:10.1017/S1357729800051298
- Sannamani P., Tyagi P. K., Tyagi P. K., Sastry V. R. B., Elangovan A. V., Mandal A. B. (2010). Feeding value of high and low tannin sorghum as broiler feed. Ind. J. Poultry. Sci. 45, 35 – 41. Available online at: https://Indianjournals.com/article/ijps-45-1-009 (Accessed April 21, 2026).
- Santos N. W., Santos G. T. D., Silva-Kazama D. C., Grande P. A., Pintro P. M., de Marchi F. E.. (2014). Production, composition and antioxidants in milk of dairy cows fed diets containing soybean oil and grape residue silage. Livestock. Sci. 159, 37 – 45. doi: doi:10.1016/j.livsci.2013.11.015
- Saratale R. G., Saratale G. D., Ahn S., Shin H.-S. (2021). Grape pomace extracted tannin for green synthesis of silver nanoparticles: assessment of their antidiabetic, antioxidant potential and antimicrobial activity. Polymers 13, 4355. doi: doi:10.3390/polym13244355
- Schilling A. K., Newman L. K., Kutz M. B., Clark S. M., Thompson L. R., Stackhouse-Lawson K. R. (2022). PSIII-1 Impact of low levels of tannin supplementation on enteric methane emissions and performance in organic dairy heifers. (Abstract). J. Anim. Sci. 100, 247. doi: doi:10.1093/jas/skac247.446
- Seema S. Z., Uddin M., Tamanna S. N., Esha K. A., Al-Noman K. M., Hoque S. A.. (2025). Potential of ionophores as A feed additive for sustainable beef cattle production. J. Appl. Vet. Sci. 10, 35 – 46. doi: doi:10.21608/javs.2025.348090.1508
- Seoni E., Battacone G., Kragten S. A., Dohme-Meier F., Bee G. (2021). Impact of increasing levels of condensed tannins from sainfoin in the grower–finisher diets of entire male pigs on growth performance, carcass characteristics, and meat quality. Anim. 15, 100110. doi: doi:10.1016/j.animal.2020.100110
- Seresinhe T., Pathirana K. K. (2003). Forage tannins in ruminant nutrition. Trop. Agric. Res. Ext. 6, 29 – 43. doi: doi:10.4038/tare.v6i0.5437
- Serra V., Salvatori G., Pastorelli G. (2021). Dietary polyphenol supplementation in food producing animals: effects on the quality of derived products. Anim. 11, 401. doi: doi:10.3390/ani11020401
- Serrano J., Puupponen‐Pimiä R., Dauer A., Aura A. M., Saura‐Calixto F. (2009). Tannins: current knowledge of food sources, intake, bioavailability and biological effects. Mol. Nutr. Food. Res. 53, S310 – S329. doi: doi:10.1002/mnfr.200900039
- Sethiya N. K. (2016). Review on natural growth promoters available for improving gut health of poultry: An alternative to antibiotic growth promoters. Asian J. Poult. Sci. 10, 1 – 29. doi: doi:10.3923/ajpsaj.2016.1.29
- Shahid A., Ali M. A., Muzammil S., Aslam B., Shahid M., Saqalein M.. (2021). Antibiotic residues in food chains; impact on the environment and human health: a review. Appl. Ecol. Environ. Res. 19, 3959 – 3977. doi: doi:10.15666/aeer/1905_39593977
- Simjee S., Tice G. (2023). The risk-benefit balance of resistance to ionophores in Enterococcus faecium and Enterococcus faecalis for ionophore coccidiostats in broiler chickens. J. Antimicrob. Chemotherapy 78, 2121 – 2130. doi: doi:10.1093/jac/dkad183
- Sinchaiyakit P., Ezure Y., Sriprang S., Pongbangpho S., Povichit N., Suttajit M. (2011). Tannins of tamarind seed husk: preparation, structural characterization, and antioxidant activities. Natural Prod. Comms. 6, 829 – 834. doi: doi:10.1177/1934578X11006006
- Sliwinski B. J., Kreuzer M., Sutter F., Machmuller A., Weststein H. R. (2004). Performance, body nitrogen conversion and nitrogen emission from manure of dairy cows fed diets supplemented with different plant extracts. J. Anim. Feed. Sci. 13, 73 – 91. doi: doi:10.22358/jafs/67390/2004
- Sliwinski B. J., Kreuzer M., Wettstein H. R., Machmuller A. (2002 b). Rumen fermentation and nitrogen balance of lambs fed diets containing plant extracts rich in tannins and saponins, and associated emissions of nitrogen and methane. Arch. Anim. Nutr. 56, 379 – 392. doi: doi:10.1080/00039420215633
- Sliwinski B. J., Soliva C. R., Machmuller A., Kreuzer M. (2002 a). Efficacy of plant extracts rich in secondary constituents to modify rumen fermentation. Anim. Feed. Sci. Technol. 101, 101 – 114. doi: doi:10.1016/S0377-8401(02)00139-6
- Smulikowska S., Pastuszewska B., Swiech E., Ochtabinska A., Mieczkowska A., Nguyen V. C.. (2001). Tannin content affects negatively nutritive value of pea for monogastrics. J. Anim. Feed. Sci. 10, 511 – 523. Available online at: https://www.jafs.com.pl/pdf-68004-6770?filename=Tannin (Accessed April 21, 2026).
- Soldado D., Bessa R. J. B., Jerónimo E. (2021). Condensed Tannins as antioxidants in ruminants—Effectiveness and action mechanisms to improve animal antioxidant status and oxidative stability of products. Anim. 11, 3243. doi: doi:10.3390/ani11113243
- Staerfl S. M., Soliva C. R., Leiber F., Kreuzer M. (2011). Fatty acid profile and oxidative stability of the perirenal fat of bulls fattened on grass silage and maize silage supplemented with tannins, garlic, maca and lupines. Meat. Sci. 89, 98 – 104. doi: doi:10.1016/j.meatsci.2011.04.006
- Stewart E. K., Beauchemin K. A., Dai X., MacAdam J. W., Christensen R., Villalba J. J. (2019). Effect of tannin-containing hays on enteric methane emissions and nitrogen partitioning in beef cattle. J. Anim. Sci. 97, 3286 – 3297. doi: doi:10.1093/JAS/SKZ206
- Štukelj M., Valenčak Z., Krsnik M., Svete A. (2010). The effect of the combination of acids and tannin in diet on the performance and selected biochemical, haematological and antioxidant enzyme parameters in grower pigs. Acta Vet. Scand. 52, 19. doi: doi:10.1186/1751-0147-52-19
- Suescun-Ospina S. T., Vera N., Astudillo R., Yunda C., Williams P., Allende R.. (2022). Effects of País grape marc inclusion in high and low forage diets: ruminal fermentation, methane production and volatile fatty acids. Ital. J. Anim. Sci. 21, 924 – 933. doi: doi:10.1080/1828051X.2022.2076620
- Sun S., Liu Z., Lin M., Gao N., Wang X. (2024). Polyphenols in health and food processing: antibacterial, anti-inflammatory, and antioxidant insights. Front. Nutr. 11, 1456730. doi: doi:10.3389/fnut.2024.1456730
- Sun M., Liu P., Xing Y., Zhang M., Yu Y., Wang W.. (2025). Effects of chestnut tannin on nutrient digestibility, ruminal protease enzymes, and ruminal microbial community composition of sheep. Fermentation 11, 302. doi: doi:10.3390/fermentation11060302
- Tadele Y. (2015). Important anti-nutritional substances and inherent toxicants of feeds. Food. Sci. Qual. Manage. 36, 40 – 47.
- Tao W., Zhang Y., Shen X., Cao Y., Shi J., Ye X.. (2019). Rethinking the mechanism of the health benefits of proanthocyanidins: Absorption, metabolism, and interaction with gut microbiota. Compr. Rev. Food. Sci. Food. Saf. 18, 971 – 985. doi: doi:10.1111/1541-4337.12444
- Tascioglu C., Yalcin M., Sen S., Akcay C. (2013). Antifungal properties of some plant extracts used as wood preservatives. Internat. Biodeteriorat. Biodegrad. 85, 23 – 28. doi: doi:10.1016/j.ibiod.2013.06.004
- Tayengwa T., Chikwanha O. C., Gouws P., Dugan M. E. R., Mutsvangwa T., Mapiye C. (2020). Dietary citrus pulp and grape pomace as potential natural preservatives for extending beef shelf life. Meat. Sci. 162, 108029. doi: doi:10.1016/j.meatsci.2019.108029
- Tedeschi L. O., Callaway T. R., Muir J. P., Anderson R. C. (2011). Potential environmental benefits of feed additives and other strategies for ruminant production. Rev. Bras. Zootecnia 40, 291 – 309. Available online at: https://search.nal.usda.gov/discovery/delivery/01NAL_INST:MAIN/12280813870007426 (Accessed April 21, 2026).
- Thirumeignanam D., Chellapandian M., Arulnathan N., Parthiban S., Kumar V., Vijayakumar M. P.. (2024). Evaluation of natural antimicrobial substances blend as a replacement for antibiotic growth promoters in broiler chickens: enhancing growth and managing intestinal bacterial diseases. Curr. Microbiol. 81, 55. doi: doi:10.1007/s00284-023-03573-w
- Timotheo C. A., Lauer C. M. Jr. (2017). Toxicity of vegetable tannin extract from Acacia mearnsii in Saccharomyces cerevisiae. Int. J. Environ. Sci. Technol. 15, 659 – 664. doi: doi:10.1007/s13762-017-1430-z
- Tonda R., Rubach J., Lumpkins B., Mathis G., Poss M. (2018). Effects of tannic acid extract on performance and intestinal health of broiler chickens following coccidiosis vaccination and/or a mixed-species Eimeria challenge. Poult. Sci. 97, 3031 – 3042. doi: doi:10.3382/ps/pey158
- Treviño J., Ortiz L., Centeno C. (1992). Effect of tannins from faba beans (Vicia faba) on the digestion of starch by growing chicks. Anim. Feed. Sci. Technol. 37, 345 – 349. doi: doi:10.1016/0377-8401(92)90017-Z
- Urkmez E., Biricik H. (2022). Grape seed extract supplementation in heat-stressed preweaning dairy calves: I. Effects on antioxidant status, inflammatory response, hematological and physiological parameters. Anim. Feed. Sci. Technol. 292, 115421. doi: doi:10.1016/j.anifeedsci.2022.115421
- Valenti B., Natalello A., Vasta V., Campidonico L., Roscini V., Mattioli S.. (2019). Effect of different dietary tannin extracts on lamb growth performances and meat oxidative stability: Comparison between mimosa, chestnut and tara. Animal 13, 435 – 443. doi: doi:10.1017/S1751731118001556
- Van Mullem J., Jeyanathan J., Peiren N., Vermeir P., Valckx J., Govaerts W.. (2025). Screening of and mechanistic insights into the enteric methane mitigation potential of European native and non-native forage trees, shrubs, and herbs using in vitro batch culture. Grass. Forage. Sci. 80, e70001. doi: doi:10.1111/gfs.70001
- VanValin K. (2024). Are growth promoting technologies becoming a lost art for the cow-calf sector ? In: Ohio BEEF Cattle Letter. A Publication of the Ohio State University Extension Beef Team. Available online at: https://u.osu.edu/beef/2024/12/11/are-growth-promoting-technologies-becoming-a-lost-art-for-the-cow-calf-sector/ (Accessed April 23, 2026).
- Vasta V., Daghio M., Cappucci A., Buccioni A., Serra A., Viti C.. (2019). Invited review: Plant polyphenols and rumen microbiota responsible for fatty acid biohydrogenation, fiber digestion, and methane emission: Experimental evidence and methodological approaches. J. Dairy. Sci. 102, 3781 – 3804. doi: doi:10.3168/jds.2018-14985
- Vasta V., Mele M., Serra A., Scerra M., Luciano G., Lanza M.. (2009). Metabolic fate of fatty acids involved in ruminal biohydrogenation in sheep fed concentrate or herbage with or without tannins. J. Anim. Sci. 87, 2674 – 2684. doi: doi:10.2527/jas.2008-1761
- Venter P. B., Sisa M., Van Der Merwe M. J., Bonnet S. L., Van Der Westhuizen J. H. (2012). Analysis of commercial proanthocyanidins. Part 1: The chemical composition of quebracho (Schinopsis lorentzii and Schinopsis balansae) heartwood extract. Phytochem. 73, 95 – 105. doi: doi:10.1016/j.phytochem.2011.10.006
- Vieira C., Guerra-Rivas C., Martínez B., Rubio B., Manso T. (2021). Effects of grape pomace supplementation on the diet of lactating ewes as compared to vitamin E on the meat shelf life of suckling lambs. Meat. Sci. 184, 108666. doi: doi:10.1016/j.meatsci.2021.108666
- Vilariño M., Métayer J. P., Crépon K., Duc G. (2009). Effects of varying vicine, convicine and tannin contents of faba bean seeds (Vicia faba L.) on nutritional values for broiler chicken. Anim. Feed. Sci. Technol. 150, 114 – 121. doi: doi:10.1016/j.anifeedsci.2008.08.001
- Viso N. P., Redondo E., Redondo L., Carrasco J. D., Farber M., Miyakawa M. F. (2025). Could tannins be the right dietary alternative for replacing antibiotics as growth promoters in broiler chicken production? A comprehensive microbiota shift assessment in a commercial farm. Poult. Sci. 104, 105260. doi: doi:10.1016/j.psj.2025.105260
- Vohra P., Kratzer F. H., Joslyn M. A. (1966). The growth depressing and toxic effects of tannins to chicks. Poultry. Sci. 45, 135 – 142. doi: doi:10.3382/ps.0450135
- Waghorn G. C. (2008). Beneficial and detrimental effects of dietary condensed tannins for sustainable sheep and goat production - Progress and challenges. Anim. Feed. Sci. Technol. 147, 116 – 139. doi: doi:10.1016/j.anifeedsci.2007.09.013
- Waghorn G. C., Jones W. T., Shelton I. D., McNabb W. C. (1990). Condensed tannins and the nutritive value of herbage. Proc. NZ Grassl. Assoc. 51, 171 – 176. doi: doi:10.33584/jnzg.1990.51.1894
- Waghorn G. C., Reed J. D., Ndlovu L. R. (1997). “ Condensed tannins and herbivore nutrition,” in Proceedings of the XVIII International Grassland Congress, vol. 3. Eds. Buchanan-Smith J. G., Bailey L. D., McCaughey P. (Winnipeg and Saskatoon, Canada: International Grassland Congress), 153 – 166. (Accessed April 23 2026).
- Wang Z., Guo L., Ding X., Li F., Xu H., Li S.. (2023 b). Supplementation of chestnut tannins in diets can improve meat quality and antioxidative capability in Hu lambs. Meat. Sci. 206, 109342. doi: doi:10.1016/j.meatsci.2023.109342
- Wang M. L., Suo X., Gu J. H., Zhang W. W., Fang Q., Wang X. (2008). Influence of grape seed proanthocyanidin extract in broiler chickens: effect on chicken coccidiosis and antioxidant status. Poult. Sci. 87, 2273 – 2280. doi: doi:10.3382/ps.2008-00077
- Wang Y., Wang L., Wang Z., Xue B., Peng Q., Hu R.. (2023 a). Recent advances in research in the rumen bloat of ruminant animals fed high-concentrate diets. Front. Vet. Sci. 10, 1142965. doi: doi:10.3389/fvets.2023.1142965
- Watanabe N., Harter T. H., Bergamaschi B. A. (2008). Environmental occurrence and shallow ground water detection of the antibiotic monensin from dairy farms. J. Environ. Qual. 37, S-78 – S-85. doi: doi:10.2134/jeq2007.0371
- West J. W., Hill G. M., Utley P. R. (1993). Peanut skins as a feed ingredient for lactating dairy cows. J. Dairy. Sci. 76, 590 – 599. doi: doi:10.3168/jds.S0022-0302(93)77379-8
- Woodward S. L., Waghorn G. C., Laboyrie P. (2004). Condensed tannins in birdsfoot trefoil (Lotus corniculatus) reduced methane emissions from dairy cows. Proc. NZ Soc Anim. Prod 64, 160 – 164. Available online at: https://www.nzsap.org/proceedings/2004/condensed-tannins-birdsfoot-trefoil-lotus-corniculatus-reduce-methane-emissions (Accessed May 7, 2026).
- Wu S., Liu Z., Pourazad P., Zhou X., Wouters W., Aubert T.. (2025). Onion extract and grape seed powder as antioxidants to improve growth: Evidence from studies with oxidative stressed intestinal and liver cells as well as growing broilers. JSFA Rep. 5, 400 – 413. doi: doi:10.1002/jsf2.70017
- Xiong J., Grace M. H., Esposito D., Wang F., Lila M. A. (2016). Phytochemical characterization and anti-inflammatory properties of Acacia mearnsii leaves. Nat. Prod. Comms. 1, 1934578X1601100524. doi: doi:10.1177/1934578X16011005
- Xu T., Ma X., Zhou X., Qian M., Yang Z., Cao P.. (2022). Coated tannin supplementation improves growth performance, nutrients digestibility, and intestinal function in weaned piglets. J. Anim. Sci. 100, skac088. doi: doi:10.1093/jas/skac088
- Yang K., Qing Y., Yu Q., Tang X., Chen G., Fang R.. (2021). By-product feeds: Current understanding and future perspectives. Agric. 1, 207. doi: doi:10.3390/agriculture11030207
- Yang K., Wei C., Zhao G. Y., Xu Z. W., Lin S. X. (2017). Effects of dietary supplementing tannic acid in the ration of beef cattle on rumen fermentation, methane emission, microbial flora and nutrient digestibility. J. Anim. Physiol. Anim. Nutr. 101, 302 – 310. doi: doi:10.1111/jpn.12531
- Yanza Y. R., Fitri A., Suwignyo B., Elfahmi, Hidayatik N., Kumalasari N. R.. (2021). The utilisation of tannin extract as a dietary additive in ruminant nutrition: A meta-analysis. Anim. 11, 3317. doi: doi:10.3390/ani11113317
- Zeller W. E. (2019). Activity, purification, and analysis of condensed tannins: current state of affairs and future endeavours. Crop Sci. 59, 886 – 904. doi: doi:10.2135/cropsci2018.05.0323
- Zhang Z., Xu P., Liu C., Chen J., Ren B., Du E.. (2024). Effect of tannic acid on antioxidant function, immunity, and intestinal barrier of broilers co-infected with coccidia and Clostridium perfringens. Anim. 14, 955. doi: doi:10.3390/ani14060955
- Zhao Z., Cheng Z., Ji Y., Nie W. (2026). Research progress of tannins and poultry intestinal health. Brit. Poultry. Sci. 67, 463 – 468. doi: doi:10.1080/00071668.2025.2559003
- Zhao J. X., Li Q., Zhang R. X., Liu W. Z., Ren Y. S., Zhang C. X.. (2018). Effect of dietary grape pomace on growth performance, meat quality and antioxidant activity in ram lambs. Anim. Feed. Sci. Technol. 236, 76 – 85. doi: doi:10.1016/j.anifeedsci.2017.12.004
- Zhong R. Z., Fang Y., Wang Y. Q., Sun H. X., Zhou D. W. (2016). Effects of substituting finely ground sorghum for finely ground corn on feed digestion and meat quality in lambs infected with Haemonchus contortus. Anim. Feed. Sci. Technol. 211, 31 – 40. doi: doi:10.1016/j.anifeedsci.2015.08.007
- Zimmer N., Cordesse R. (1996). Digestibility and ruminal digestion of non-nitrogenous compounds in adult sheep and goats: effects of chestnut tannins. Anim. Feed. Sci. Technol. 61, 259 – 273. doi: doi:10.1016/0377-8401(95)00940-X
Citation
Caradus, J. R. (2026). Benefits of tannin added to concentrate diets fed to ruminants and monogastric livestock. Frontiers in Animal Science, Volume 7. https://doi.org/
- Received
- Accepted
- Published
- Volume
- 7 - 2026
Copyright
Copyright © 2026 Caradus.
License: https://creativecommons.org/licenses/by/4.0/
*Correspondence: John R. Caradus
Article metrics
- Views
- 0
- Downloads
- 0
- Citations
- 0
- Shares
- 0