Influence of the Level of Vitamins in the Diet on the Concentration of Free Amino Acids in the Plasma of Chicks

Abstract

The influence of the amount of a vitamin in the diet on the free amino acid content of the blood plasma of chicks was investigated. The plasma of chicks receiving two basal diets, which were adequate in all the vitamins required by the chick, was assayed for free arginine, lysine, methionine, tryptophan and valine by microbiological procedures. Plasma from chicks receiving diets low in pyridoxine, pantothenic acid, riboflavin, niacin, choline and vitamin B₁₂, respectively, was assayed also for these amino acids. Chicks receiving the different basal diets grew at about the same rate, but the concentration of amino acids in the plasma was different. The soybean meal diet (diet 2) contained a smaller amount of the amino acids than the semisynthetic diet (diet 1) but plasma from the chicks which received the soybean meal diet contained twice as much arginine and significantly more tryptophan than that from those receiving the semisynthetic diet. When the diet was low in pyridoxine and pantothenic acid, the concentration of arginine, methionine and tryptophan in the plasma was increased. When it was low in riboflavin, the concentration of methionine, tryptophan and valine increased. When it was low in niacin, the concentration of arginine and lysine decreased. When it was low in vitamin B₁₂, the concentration of all 5 of the amino acids was decreased. These effects were analyzed statistically and found to be highly significant.