Limiting amino acids in milo for the growing pig.

Abstract

Three growth trials and two nitrogen retention trials were conducted to determine the limiting amino acids in milo for growing pigs. Lysine supplementation of a basal milo diet resulted in a marked improvement in daily gain, feed efficiency and nitrogen retention. The addition of threonine increased daily gain and improved feed efficiency when added to diets containing supplemental lysine or lysine and methionine. Similarly, nitrogen retention was increased with the addition of threonine to the basal diet supplemented with lysine. Supplementing the basal diet with methionine in presence of lysine gave no beneficial response in two trials and depressed performance in another. The addition of isoleucine in the presence of lysine, threonine and methionine improved daily gains and feed efficiency. No beneficial response was obtained by the addition of non-essential amino acids (glycine and glutamic acid) in the presence of all other amino acids studied. These data confirm that lysine is the first-limiting amino acid in milo protein for the growing pig. The results demonstrate that threonine is the second-limiting amino acid in milo protein for the growing pig and that methionine is not third-limiting. Additionally, these data suggest that isoleucine may be the third-limiting amino acid in milo protein for the growing pig.