Effects of Dietary Tannins’ Supplementation on Growth Performance, Rumen Fermentation, and Enteric Methane Emissions in Beef Cattle: A Meta-Analysis

The environmental sustainability of beef production is a significant concern within the food system. Tannins (TANs) can be used to minimize impact ruminant because they improve ruminal fermentation and ruminants’ lifetime performances mitigate methane (CH4) emissions. objective this study was evaluate effects dietary supplementation with TANs as sustainable natural alternative reduce on growth performance, rumen fermentation, enteric CH4 emissions, nitrogen (N) use efficiency cattle through meta-analysis. A comprehensive search studies published in scientific journals that investigated TANs’ variables interest performed using Scopus, Web Science, PubMed databases. data analyzed were extracted from 32 peer-reviewed publications. assessed random-effects statistical models examine standardized mean difference (SMD) between treatments control (non-TANs). heterogeneity explored by meta-regression subgroup analysis for covariates significant. did not affect weight gain, feed consumption, efficiency, or N (p > 0.05). However, it reduced concentration ammonia (SMD = −0.508, p < 0.001), emissions per day −0.474, 0.01) unit dry matter intake −0.408, 0.01), urinary excretion −0.338, 0.05), digestibility −0.589, 0.001). Ruminal propionate 0.250) butyrate 0.198) concentrations fecal 0.860) improved response In conclusion, possible mitigation strategy without affecting rate. addition, shift may beneficial environment preservation, induces more harmful than N. Therefore, addition tannins diet could production.