effecTs in differenT dieTs

T ryptophan is an essential amino acid in pigs, which means that the diet is the only way to supply tryptophan to the animal. Tryptophan is after lysine, methionine plus cysteine and threonine the fourth limiting amino acid in cereal-based diets for piglets and growing pigs under practical conditions. It is, like the other essential amino acids, an important substrate for protein synthesis in the body. When the supply of tryptophan via the diet (relative to the other essential amino acids) is limiting, protein synthesis is compromised and performance is decreased.