Complexity of a Chick Growth Response to Egg Yolk, Animal Fat and Fish Solubles Additions to the Diet

Abstract

IN VITAMIN B12 assay investigations, Lillie et al. (1954) and Denton et al. (1954a) have reported that fresh egg yolk additions to the diet resulted in marked gains of chicks that were several times greater than those encountered for chicks fed levels of vitamin B12 maintained within the standard curve. On the basis of their findings, these data appear at variance with the B12 values for egg yolk previously reported by Milligan et al. (1952). Subsequently, Denton et al. (1954b) reported that egg yolk, lard or fish solubles additions to the ration resulted in weight gains of 18, 6, or 9%, respectively, over the basal diet which was adequately fortified with the known nutrients including vitamin B12. The studies comprising this report are intended to show the complexity of the growth response of chicks to dried egg yolk additions in the presence of tallow and/or fish solubles. EXPERIMENTAL PROCEDURE Day-old …