Effects of Arginine or Serine on the Requirement for Glycine by the Chick

Abstract

Six experiments were conducted to determine the effect of arginine or serine in the diet on the response of the chick to supplementary glycine. With 24% casein diets, growth was improved by additional glycine when zero or 0.4% L-arginine was added to the diet but not when 0.8 or 1.2% was added. No response to glycine was observed when 35% casein or 26.2% of an amino acid mixture was used, regard-less of the arginine level. However, when serine was omitted from the amino acid mixture, glycine was needed for maximal growth. In addition, serine improved growth when glycine was omitted from the amino acid mixture. Under these conditions there was no limitation of glycine-serine interconversion in the chick.