Temporal effect of change in diet composition on plasma estradiol and thyroxine concentrations and hepatic lipogenesis in laying hens.
Temporal effects of feeding isocaloric and isonitrogenous diets with and without 10% menhaden fish meal (FM) on plasma estradiol and thyroxine concentrations, hepatic fatty acid synthetase and hepatic lipid content were investigated. Hepatic fatty acid synthetase activity and lipid content were significantly increased at 7 days and 14 days, respectively, after feeding the corn-soybean meal (CS) diet. Plasma thyroxine concentration was significantly reduced at 3 days after feeding the FM diet. Plasma estradiol concentration was immediately and gradually elevated after feeding the CS diet and reduced after changing from the CS to the FM diet. A significant positive correlation was observed between plasma estradiol, but not plasma thyroxine, and hepatic fatty acid synthetase activity. These findings suggest that tissue estradiol concentration responds early to dietary changes followed by stimulated hepatic lipogenesis, and steatosis in laying hens.
D000818:Animals; D002645:Chickens / Q000378:metabolism*; D004044:Dietary Proteins / Q000008:administration & dosage; D004958:Estradiol / Q000097:blood*; D064429:Fatty Acid Synthases / Q000378:metabolism; D005260:Female; D005396:Fish Products; D050356:Lipid Metabolism; D008099:Liver / Q000201:enzymology / Q000378:metabolism*; D013974:Thyroxine / Q000097:blood*; D013997:Time Factors
D004044:Dietary Proteins; D004958:Estradiol; D064429:Fatty Acid Synthases; D013974:Thyroxine