Physiology, Endocrinology, and Reproduction I

The present study was conducted to investigate the variation in the lipid profile between Egyptian breed Fayoumi and commercial strain ISA-Brown. Forty 32-wk-old ISA-Brown and thirty-five 36-wk-old Fayoumi were housed individually in separated layer cages in opensystem housing. Four weeks later, Body weight was recorded and egg weight, number, and composition were measured. In addition, lipid profile was estimated in serum and liver in Fayoumi and ISA-Brown. ISA-brown was higher in body weight, egg weight and egg number by 29%, 37%, and 24% respectively compared with Fayoumi. The difference in egg weight mainly due to albumin weight, but there was no significant difference in yolk weight. Even though the concentration of serum HDL and liver cholesterol, and the activity of liver HMG-coreductase were significantly higher in ISA-Brown by 50%, 100%, and 40% respectively compared with Fayoumi, there were no significance differences in serum triglyceride, serum total lipid, serum LDL, serum cholesterol, yolk cholesterol, and liver total lipid. On the other hand, plasma progesterone and estradiol concentrations were significantly higher in Fayoumi by 27% and 60% respectively compared with ISABrown. The results of the current investigation indicate that the lipid profile in Fayoumi native breed and Isa-Brown commercial hybrid could help to understand not only the mechanisms that regulate differences in gene expression, but also how genes interact.