Amino acids play a very large role in the life of organisms, because all protein substances are built from amino acids. Many plants and bacteria can synthesize all the amino acids they need from simple inorganic compounds. Most amino acids are synthesized in the human and animal body from ordinary nitrogen-free metabolic products and assimilable nitrogen. However, 8 amino acids (lysine, methionine, threonine, valine, isoleucine, leucine, tryptophan and phenylalanine) are essential, i.e. cannot be synthesized in the body of animals and humans, and must be delivered with food.

With a lack of these amino acids (usually tryptophan, lysine, methionine) or in the absence of at least one of them in food synthesis of proteins and many other biologically important substances necessary for life.

Agricultural diets. animals must contain all the amino acids necessary for the body, especially essential ones, therefore, when organizing feeding, they began to take into account in feed not only the total amount of protein, as was the case before, but also an essential amino acid. The diets of pigs and poultry must be balanced in terms of amino acid content. For this purpose, feed is selected that complement each other in terms of amino acid composition, and synthetic amino acids produced by the industry are used.

Synthetic amino acids are fed in a mixture with concentrates; it is more expedient to add them to industrial mixed feed.