Calcium 2-hydroxy-4-(methylthio)butanoate is primarily used in animal nutrition as a source of methionine, an essential amino acid. It is commonly added to poultry, swine, and cattle feed to promote growth, improve feed efficiency, and enhance overall animal health. The compound is particularly beneficial in diets that are deficient in natural methionine, ensuring optimal protein synthesis and metabolic functions. Additionally, it supports muscle development, feathering in poultry, and milk production in dairy cattle. Its stability and bioavailability make it a reliable supplement in various feed formulations.