Ability of the Chick to Utilize D- and Excess L-Indispensable Amino Acid Nitrogen in the Synthesis of Dispensable Amino Acids

Publisher Website
Google Scholar
Abstract
Studies were conducted on the ability of the chick to utilize D- and excess L-indispensable amino acid nitrogen for the synthesis of dispensable amino acids. A purified type of diet containing only the essential amino acids was used in these studies. Growth, feed efficiency, nitrogen retention and plasma amino acid concentrations were the criteria used to determine the extent to which the D- or excess L-indispensable amino acid nitrogen was utilized. The nitrogen from D- and excess L-indispensable amino acids was shown to be utilized by the chick for the synthesis of dispensable amino acids. Growth of chicks fed diets containing D- or excess L-indispensable amino acids indicated that the two sources of nitrogen were utilized equally well. Feed efficiency and nitrogen retention data, however, indicated that the nitrogen from L-indispensable amino acids may have been somewhat more efficiently utilized than the nitrogen from D-indispensable amino acids. Marked increases in the concentrations of dispensable amino acids of plasma were observed as a result of the addition of D- or excess L-indispensable amino acids to the diet. The data do not permit any conclusion as to whether the intestinal microflora played a part in this utilization.
Keywords