Overall assessment of antimicrobial peptides in broiler chickens: A meta-analysis

Antimicrobial peptides (AMPs) are considered promising alternatives to traditional antibiotics for promoting growth and reducing disease incidence in livestock. However, the effects of AMP additives on broiler chickens remain uncertain. Here, we performed a meta-analysis of 43 studies published from January 2000 to January 2024 to evaluate the effects of AMPs on growth performance, intestinal morphology, and immune organ development in broiler chickens. Our findings indicate that the addition of AMPs significantly improved the average daily gain and feed conversion ratio (FCR), along with notable effects on the overall average daily feed intake (ADFI) (P < 0.05). AMPs enhanced small intestinal morphology by increasing the villus height and the villus height to crypt depth ratio (P < 0.05) without decreasing crypt depth. Furthermore, the addition of AMPs promoted immune system development by increasing the weights of the thymus and spleen during the starter period (P < 0.05). Notably, AMPs outperformed conventional antibiotics in improving the ADFI and jejunal villus height (P < 0.05), demonstrating comparable efficacy in improving the FCR (P > 0.05). Our meta-analysis suggests that AMPs can serve as effective alternatives to antibiotics in broiler chickens.