Effect of Dietary Amino Acid Level, Folic Acid, Glycine, and Serine on Chick Performance and Blood Parameters

Abstract

Studies of the interrelationships between dietary amino acid level, folic acid, glycine, and serine in chicks fed crystalline amino acid diets indicated that a folic acid deficiency exerted a greater detrimental effect on chick growth than did a deficiency of glycine and serine. The increased chick growth observed when a folic acid deficient diet containing normal levels of amino acids was supplemented with glycine and serine suggested that these amino acids were exerting a folic acid sparing effect. A similar sparing effect was not noted when the diet contained a high level of dietary amino acids which resulted in increased uric acid synthesis. Blood hemoglobin levels appeared to be influenced by a combination of factors including dietary folic acid and glycine levels and possibly growth rate of the chicks. Plasma glycine and serine concentrations were closely associated with the presence or absence of these amino acids in the diet and the level of the other amino acids in the diet. Within groups receiving the same level of dietary glycine and serine, lower plasma glycine was associated with higher levels of plasma uric acid.