The Amino Acid Content of Fresh and Stored Shell Eggs. III. Methionine, Cystine, and Lysine Contents of Eggs From Hens Fed Diets Differing in Percentage of these Amino Acids

THE extent to which differences in the amino acid content of the hen’s diet will be reflected in the amino acid content of the eggs produced is not clear. Csonka and Titus (1942) and Csonka, Denton, and Ringel (1947) have presented evidence that eggs from hens fed high protein diets with casein as the source of supplemental protein contain more methionine, cystine, arginine, and tyrosine than eggs from hens fed low protein diets or high protein diets with soybean oil meal as the source of supplemental protein. No higher methionine content resulted from supplementing the diet with DL-methionine. Differences in the amount of an amino acid in whole eggs might result from differences in (1) the amount of protein per egg, (2) the proportions of the constituent amino acids in the egg proteins, or (3) the relative amounts of the different proteins in the egg. Csonka et al. (1947) observed . . .