L-Threonine is used mainly in premixtures and pig feed, but also in poultry feed. it is the second limiting amino acid for pigs after Lysine and improves zootechnical performance and reduces nitrogen waste. CAS No. 72-19-5 Synonyms:2-Amino-3-HydroxybutyricacidMolecular  Formula:C4H9NO3  Molecular weight:119.12 Method of production: Produced by microbial fermentation. Packing:25kg/bag750kg/bag1,000kg/bag.