Meta-analysis of the Effects of Chinese Herbal Additives on the Production Performance, Immune Function and Meat Quality of Sheep

Background: This meta-analysis systematically evaluates the effects of Chinese herbal additives on production performance, immune function and meat quality in sheep to support their application in ruminant nutrition. Methods: A total of 13 studies, comprising 37 controlled trials, were included in the analysis. The overall effect size was assessed by forest plots and meta-analysis was conducted to identify sources of heterogeneity, perform sensitivity analysis and evaluate publication bias by funnel plots. Result: Dietary supplementation with Chinese herbal additives significantly increased average daily gain (ADG) and average daily feed intake (ADFI) (P less than 0.05) and reduced the feed-to-gain ratio (F/G) (P less than 0.05). Immunological analysis showed that serum IgA and IgM levels were elevated (P less than 0.05). For meat quality parameters, the additives increased cooking yield and pH (P less than 0.05) and decreased shear force (P less than 0.05) with no significant effect on drip loss (P greater than 0.05). Funnel plot analysis revealed minimal publication bias and sensitivity analysis confirmed the robustness and reliability of the results. These findings suggested that Chinese herbal additives contributed to enhanced production performance, immune function and meat quality in sheep. Further research should validate these findings through more controlled feeding trials, while exploring the active ingredients and mechanisms of action of Chinese herbal additives.