Abstract: Branched-chain amino acids (BCAA) play important roles in poultry growth, production performance, immune function and intestinal health. They are involved in key processes such as organ development, immune response, muscle protein turnover and gene regulation. However, an excess, deficiency or imbalance of a single BCAA can affect poultry protein synthesis and intestinal health. Therefore, maintaining a balanced ratio of BCAA is critical for poultry performance. Although the NRC (1994) provides recommended amounts of BCAA for broilers, laying hens, and breeders, there are variations in BCAA requirements among poultry breeds, dietary protein levels, and growth stages. Meanwhile, the ban on antibiotic growth promoters and the challenges of multiple diseases in poultry farming necessitate a re-evaluation of the recommended levels of BCAA intake. Additionally, more research is needed to explore the mechanisms of action of BCAA in maintaining intestinal integrity and regulating gut microbial composition and enhancing protein turnover efficiency in the body. This review aims to describe the nutritional and physiological roles of BCAA in poultry, as well as their effects on production and health. And also provides BCAA requirements for different broiler breeds (broilers, laying hens and breeders) under various feeding conditions. These recommendations aim to provide theoretical references for the recommended levels of BCAA in low-protein diets for poultry.

Key words: poultry, branched-chain amino acids, productive performance, immune function, intestinal health