Ross Hamilton Darling International

Publish Date: March 25, 2010

Pigs of all ages and stages of the life cycle require amino acids to enable them for normal body function. Amino acids are the structural units of protein. During digestion, dietary protein is broken down into amino acids and peptides (more than one amino acid linked together). The amino acids and peptides are then absorbed into the body and are used to build new proteins, such as muscle, which is composed of about 21 different amino acids. Thus, pigs require amino acids, not crude protein. Diets must be balanced with respect to a desirable level and ratio of the 10 essential amino acids; they must also contain adequate amounts of amino acids required by pigs for maintenance, growth, reproduction, and lactation. Those 10 essential amino acids for swine are arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. Two other amino acids (cysteine and tyrosine) are semi-essential since both can be synthesized if adequate amounts of methionine and phenylalanine are present for cysteine and tyrosine, respectively. The other nine amino acids (aspartic acid, asparagines, glutamic acid, glutamine, glycine, alanine, proline, hydroxyproline and serine) are considered nonessential because they can be synthesized at sufficient rates if an adequate amount of non-specific protein is present in the diet. [3, 9, 10, 11]