Hepatic lipolysis in broiler chickens with different fat deposition during embryonic development

The aim of this study was to explore the hepatic lipolysis in broiler chickens with different fat deposition during embryonic development. The mRNA expression of CPT-1 (carmitine palmtoyltransferase-1), PPARalpha (peroxisome proliferator-activated receptor alpha) and LPL (lipoprotein lipase) genes were determined using Real time RT-PCR. The start of incubation was called day 1 (E1) and after hatching called day 1 (H1). On incubation days 9 (E9), 14 (E14) and 19 (E19) as well as at hatching (H1), samples of liver were collected. Blood samples were obtained during days 14 (E14) and 19 (E19) of embryonic development and at hatching. This study showed that serum TG (triglycerol) decreased and TC (total cholesterol) and NEFA (non-estered fatty acid) increased during embryonic development. The expression of CPT-1, PPARalpha and LPL genes exhibited different developmental changes. For example, little LPL gene was expressed at hatching and PPARalpha gene expression peaked before hatching. However, CPT-1 gene exhibited no significance during the embryonic development. Our results showed that expression of these genes in Arbor Acres (AA) broilers was significantly higher than that in San Huang (SH) broilers. Therefore, this study suggested that hepatic lipolysis in broiler chickens exhibited developmental changes during embryogenesis and breed difference which may be one of the factors in the fat deposition difference between fat line and lean line broilers during embryonic development.