Effects of algae supplementation in high-energy dietary on fatty acid composition and the expression of genes involved in lipid metabolism in Hu sheep managed under intensive finishing system

This study aims to investigate the effect of algae supplementation in high-energy diet (HE diet) on lipid metabolism of intensive feeding sheep. The lambs were assigned to two groups and received a standard diet (ST diet, 8.40 MJ/kg) or a HE diet (9.70 MJ/kg) based on corn, wheat bran, soybean meal. Each group was divided into two subgroups: control and algae supplement (3%, DM basis). The body fat, serum cholesterol, and oleic acid in the liver and muscle increased in lambs receiving the HE diet. However, after supplementing the microalgae (Schizochytrium sp.) in the HE diet, these parameters were all reduced. In addition, EPA, DHA and CLA cis-9, trans-11 in muscle and liver increased. Algae supplementation also altered the expression of lipid metabolism related genes, including up-regulated FADS2, ELOVL2, SCD, CPT1 alpha and SREBF-1, and down-regulated PPAR alpha and PPAR gamma. In conclusion, algae supplementation in ST and HE diets increased n-3PUFA and improved metabolic disorder caused by the HE diet.