Effect of Dietary Sulfate on Growth and Serum Amino Acid Concentrations in Chicks

The effects of dietary sulfate on growth and the chemical components of the serum and liver in chicks were investigated. DL-Methionine or sodium sulfate was added to a semi-purified diet containing isolated soybean protein as the sole protein source. Chicks were fed the diet from hatching to 28 days of age. No significant differenc in body weight was observed between chicks fed diets supplemented with 0.44% methionine and with 0.22% methionine plus 0.22% sodium sulfate. However, the body weight of chicks fed a diet with 0.44% sodium sulfate alone was about 60% of that of chicks given diets supplemented with methionine. The addition of a higher level (0.88%) of sulfate did not improve the weight gain. When dietary methionine was decreased or sulfate addition was increased, the total nitrogen contents of the serum and liver showed a tendency to decrease and total lipid contents tended to increase. The contents of liver glycogen and blood sugar were not affected by supplementation of methionine or sulfate. When dietary methionine was decreased or dietary sulfate was increased, the patterns of change in serum free amino acids could be divided into 3 types: (1) methionine, cystine, aspartic acid, leucine, tyrosine, histidine and arginine were decreased, (2) threonine, serine, glycine and lysine were increased, and (3) glutamic acid, praline, alanine, valine, isoleucine, phenylalanine and ornithine remained constant. The activity of liver glutamateoxaloacetate transaminase was increased with decreasing dietary methionine or with increasing addition of sulfate, but that of glutamate-pyruvate transaminase was unchanged.