Studies on Avian Fat Composition: 2. The Selective Utilization of Fatty Acids by the Chick Embryo

Abstract

THE fat of the yolk of the avian egg serves as an energy source for the developing embryo, and the fact that its composition can be materially influenced by certain nutritional factors may be significant in embryonic nutrition according to Cruickshank (1934).It has been shown that polyunsaturated acids are essential nutrients in the growth of chicks (Reiser, 1950b, c). The fatty acids contained in the egg yolk of hens on low-fat or fat-free diets tend to be more saturated than the egg yolks of hens on a diet containing fat. However, the egg yolk fat from hens on the fat-free diet never becomes completely devoid of unsaturated acids as was shown by Reiser (1950a) and Feigenbaum and Fisher (1959). Thus the synthesis of the unsaturated acids from nonfat precursors suggests that the unsaturated acids might possibly be essential for embryo development. Information was acquired very early on the fat…