L-Methionine is a sulfur-containing essential L-amino acid that is important in many body functions. Methionine is a dietary indispensable amino acid required for normal growth and development of humans, other mammals, and avian species. In addition to being a substrate for protein synthesis, it is an intermediate in transmethylation reactions, serving as the major methyl group donor.It must be obtained from diet and food sources since it is unable to be biosynthesized in the body. 

Methionine is an important amino acid species in animal feed. Adding methionine is an indispensable additive in animal feed, which can help animals grow rapidly in a short time and save about 40% of feed. Especially in feed poultry feed, methionine is the first limiting amino acid. Methionine deficiency in livestock can lead to growth retardation, weight loss, decreased kidney function, muscle atrophy, and degeneration of fur. In the feed industry, the demand for methionine is very large, especially for various amino acids in nutritional feed additives, methionine accounts for 60%, lysine accounts for 30%, and other amino acids account for about 10%.