Effect of Glutamic Acid and Antiacids on Chick Bioassay of Protein Quality of Fish Meals

IN A study of dietary factors affecting a 3-week chick bioassay of fish meal quality, Miller and Kifer (1970) indicated that the method responded to the quality as well as to the quantity of the dietary protein. Chicks fed an aged fish meal as the sole source of protein were very sensitive to a detrimental excessive addition (2.59%) of glycine and also to small additions of methionine and lysine. Nevertheless, the addition of 0.36% arginine to the aged fish meal gave a 9% increase in growth. Ousterhout and Snyder (1962), by adding 5% glutamic acid as a “stress” factor to a 15% protein diet, containing fish meal as a sole source protein, demonstrated that the sulfur amino acids (methionine and cystine) were the first limiting in those fish meals which gave very poor growth. Hegsted (1944), Klain et al. (1958), Fisher et al. (1960), Dean and Scott (1965), and many…