Regulatory Role of Amino Acids in Pigs Fed on Protein-restricted Diets

The high inclusion of dietary protein and the imbalance of amino acid (AA) composition in animal husbandry result in inefficient utilization of protein resources and increased nitrogen excretion. Therefore, an efficient approach to alleviate the nitrogen excretion and increase the utilization of protein resources is to formulate the AA-balance protein-restricted diet with crystalline AA supplementation. Nowadays, it is essential to thoroughly understand the regulatory mechanisms of AAs on body metabolism and their vital roles in protein-restricted diets. Besides, an establishment of the amino acid balanced protein-restricted diet system is beneficial for the maintenance of healthy environment and sustainable animal husbandry. This review focused on the recent advances on functional roles of AAs and development of a protein-restricted diet system in animal husbandry.