Effect of fermentation of herbal products on growth performance, breast meat quality, and intestinal morphology of broiler chickens: a meta-analysis

Although it has widely been applied in human applications for therapeutic purposes, the use of fermented herbal products to improve growth performance in broiler chickens is still disputable. This study aimed to compare the effectiveness of fermented versus unfermented herbal products in improving the growth performance, breast meat quality, and small intestinal morphology of broiler chickens and to determine the optimal conditions according to meta-analysis and response surface methodology. The database was developed based on 23 articles comprising 123 data points collected in 2023. The metadata was analysed using OpenMEE and R, with the inclusion of fermented herbal products as fixed factors and individual studies as random factors. The optimal dosage was determined using response surface methodology (RSM). A significant difference (p