Changes of Estradiol and Lipid Concentrations in Serum and Liver Fatty Acid of Maturing Hen and Cockerel

Abstract

Changes of the estradiol and lipid concentrations in hen serum, and those in the fatty acids of hen and cockerel livers were studied during the maturing period. The concentrations of estradiol and lipid in serum reached a maximum level a few days before the onset of laying, and then fell. A marked increase in oleate, and decreases in stearate and arachidonate were observed in both the liver and serum lipids of the hen when reaching laying. The fatty acid compositions of the serum and liver of the hen at 145 and 167 days of age were close to those of yolk lipid. In the cockerel, high contents of stearate and arachidonate and a low content of oleate were observed, and the fatty acid composition did not change appreciably with age. On estrogenization of the male chick, the fatty acid cmposition of the liver lipid was similar to that of the laying hen liver. The ratio of the unsaturated fatty acid/saturated fatty acid in the liver of hen increased when reaching laying, the value at 167 days old being close to that of yolk lipid. This ratio in the liver lipid of cockerel did not change significantly throughout the experimental period.