Lack of Sulfur Amino Acid Sparing Effect with Ammonium Sulfate and Sodium Sulfate in Laying Hen Diets

An experiment was carried out to evaluate the effectiveness of ammonium sulfate and sodium sulfate additions to low-methionine diets for laying hens. In the first series, a 14% protein diet was fed at 0.45, 0.50, 0.55 and 0.60% total dietary sulfur amino acid levels. There were no significant differences in egg production rates, egg weight or feed conversions which could be attributed to the sulfate supplements. Regression analyses of methionine plus cystine intakes vs. egg yields produced highly significant correlation coefficients. Slope-ratio analyses of the two series indicated that the effect of methionine supplementation on egg yield was reduced by 12% in the presence of dietary ammonium sulfate. Similar analyses of plasma levels of sulfur amino acids suggest that the methionine supplements were 11% less effective for this criterion in the presence of dietary ammonium sulfate. The feeding of sodium sulfate did not reduce the dietary levels of sulfur amino acids required for optimum performance.