Promois encapsulated L-Tryptophan is one of the essential amino acids and the fourth limiting amino acid in animals diets, which means it could not be synthesized by the body, in addition, dietary supply through feed materials is usually insufficient.  

The deficiency of L-Tryptophan was generally characterized as decreased feed intake and efficiency, and a slow growth rate. Considering L-Tryptophan playing a key role in growth performance and feed efficiency, it is recommended to add L-Tryptophan in diet to achieve the optimal amino acid balance and fulfil the digestible tryptophan requirement of animals, especially piglets, sows and poultry etc.