The impact of supplementing quebracho and chestnut tannin extracts on the growth performance in growing and finishing beef cattle: A meta-analytical assessment

Lay Summary This study examined whether tannin extracts (natural compounds derived from quebracho and chestnut trees) can help beef cattle grow more efficiently. Tannins are known to interact with dietary proteins, sometimes reducing waste and improving nutrient use, but past research has yielded mixed results. To get a clearer picture, the authors combined data from 43 studies involving over 22,000 cattle. They found that supplementing with tannins improved weight gain, but the effect was not a simple case of “more is better.” Instead, the analysis identified an optimal inclusion level, with the greatest benefits observed when tannins were included at approximately 0.30% of dietary dry matter. Importantly, the animals did not eat more feed, indicating that the improvement came from using nutrients more efficiently rather than simply eating more. The study also showed that responses to dietary tannins were more frequently positive when the diet was low in protein or when fed together with monensin, a common feed additive. Tannin extracts are considered growth promoters, but they may offer additional benefits under certain feeding conditions.