Threonine is an essential amino acid that cannot be synthesised by animals and is generally regarded as the third limiting amino acid in pig and poultry diets, after lysine and methionine. It plays a key role in protein synthesis, immunoglobulin production, and the maintenance and repair of the intestinal mucosa. As an important structural component of mucins and immunoglobulins, threonine supports mucin production by intestinal goblet cells, helping maintain intestinal barrier integrity and supporting the gut’s natural defence against pathogens and digestive disturbances.

In low-protein diet formulations, adequate threonine supplementation allows the inclusion of soybean meal and dietary crude protein levels to be reduced while maintaining or supporting growth performance and feed efficiency. More efficient nitrogen utilisation can also reduce nitrogen excretion and contribute to more environmentally sustainable animal production.

Feed-grade threonine is primarily supplemented in the form of L-threonine (≥98.5% purity). It is one of the most widely used amino acid feed additives worldwide, following lysine and methionine in global usage, and is extensively used in diets for piglets, growing-finishing pigs, sows, and meat poultry.