Quantitative Threonine Requirement of the Weanling Pig

Abstract

Semi-purified diets containing corn and appropriate supplements of essential amino acids and other nutrients have been used to determine the threonine requirement of the weanling pig. When the diet contained 0.2, 0.4, 0.5, 0.6, or 0.7 percent L-threonine maximum gain and feed efficiency were realized with the 0.4 percent level. This value represents 3.0 percent of the crude protein. The high quality of the protein in the corn-amino acid rations was shown by a protein efficiency of 3.1 pounds of gain per pound of crude protein. When the proper amounts and balance of essential amino acids were supplied, weanling pigs (weight 25 lb.) grew at a normal rate at a level of 13.2 percent crude protein in the diet.