Year: 2026
Type: article
Abstract: The L-arginine is essential amino acid for birds because they have limited ability to produce enough endogenous L-arginine. In addition to its role in protein synthesis, arginine serves as a precursor of polyamines, creatine, proline, other bioactive metabolites, and nitric oxide, which are involved in growth, immune function, antioxidant defense, integrity of the intestine, reproduction, and cell signaling. The purpose of this review was to critically appraise the present understanding on the metabolism, physiological role and application of l-arginine supplementation to the nutrition of various types of poultry especially broiler chickens, laying hens, breeder flocks and Japanese quail. Therefore, experimental studies have shown that providing sufficient levels of arginine in the diet is crucial for optimum growth performance, feed efficiency, skeletal muscle development, reproductive performance and immune competence. These beneficial effects are most clearly demonstrated when nutrients are added at times of high growth rate, heat stress, oxidative stress, immune challenge, or when dietary arginine is low. However, excessive supplementation beyond the physiological requirement does not always result in an increase in productive performance and can influence the amino acid balance, especially when the level is increased with lysine. Recent studies in molecular biology have shown that arginine affects several signaling pathways such as nitric oxide synthase, mechanistic target of rapamycin (mTOR), phosphoinositide 3-kinase/protein kinase B (PI3K/Akt), and polyamine biosynthesis, which in turn impact nutrient utilization, intestinal development, cellular proliferation, and stress adaptation. Further, emerging evidence indicates that arginine regulates gut microbiota and gut host–microbe interaction, which opens the possibilities for gut health and disease resistance. However, this is achieved while there is great variation within published studies ranging from species of birds, genotype, age, diet, environmental factors and experimental design. Future studies should combine transcriptomics, proteomics, metabolomics and microbiome studies with standardized dose-response studies to clarify precise nutritional recommendations for various poultry production systems. In conclusion, L-arginine is not just an amino acid that is essential to poultry but a multifunctional nutritional regulator that has considerable potential to enhance poultry health, welfare and productivity when fed at the correct dietary level.
Institutions: University of Kirkuk, Al-Qalam University
Language: English
Subfield: Animal Science and Zoology
Domain: Life Sciences
SDG: Zero hunger
Open Access status: diamond
OpenAlex ID: W7225360267