The Methionine Requirement of the Laying Hen

IN AN effort to design a ration deficient in methionine, but adequate in all other nutrients, it was decided to use peanut meal as the source of protein for a study of the methionine requirement of the laying hen. In addition to methionine, the available figures on the amino acid content of peanut meal indicates that lysine and tryptophan might also be low (Lyman et al., 1947). All rations were, therefore, supplemented with both of these amino acids. In previous studies by Ingram et al. (1950), it was shown that lysine and tryptophan deficient rations did not affect the amino acid composition of the egg, while on the other hand, Csonka et al. (1947) have reported that the methionine and cystine content of the egg could be modified by the diet fed the hen. In order to determine if a methionine deficiency would affect the composition of the egg, it . . .