Lower ω-6/ω-3 Polyunsaturated Fatty Acid Ratios Decrease Fat Deposition by Inhibiting Fat Synthesis in Gosling.

The objective of the current study was to investigate the effects of dietary omega-6/omega-3 polyunsaturated fatty acid (PUFA) ratios on lipid metabolism in goslings. One hundred and sixty 21-day-old Yangzhou geese of similar weight were randomly divided into 4 groups. They were fed different PUFA-supplemented diets (the 4 diets had omega-6/omega-3 PUFA ratios of 12: 1, 9: 1, 6: 1, or 3: 1). The geese were slaughtered and samples of liver and muscle were collected at day 70. The activities and the gene expression of enzymes involved in lipid metabolism were measured. The results show that the activities of acetyl coenzyme A carboxylase (ACC), malic enzyme (ME), and fatty acid synthase (FAS) were lower (p<0.05), but the activities of hepatic lipase (HL) and lipoprotein lipase (LPL) were higher (p<0.05), in the liver and the muscle from the 3: 1 and 6: 1 groups compared with those in the 9: 1 and 12: 1 groups. Expression of the genes for FAS (p<0.01), ME (p<0.01) and ACC (p<0.05) were higher in the muscle of groups fed diets with higher omega-6/omega-3 PUFA ratios. Additionally, in situ hybridization tests showed that the expression intensities of the high density lipoprotein (HDL-R) gene in the 12: 1 and 9: 1 groups were significantly lower (p<0.01) than that of the 3: 1 group in the muscle of goslings. In conclusion, diets containing lower omega-6/omega-3 PUFA ratios (3: 1 or 6: 1) could decrease fat deposition by inhibiting fat synthesis in goslings.