Effects of dietary chenodeoxycholic acid on growth performance, body composition and related gene expression in large yellow croaker (Larimichthys crocea) fed diets with high replacement of fish oil with soybean oil

摘要

An experiment was conducted to determine the effects of dietary chenodeoxycholic acid (CDCA) on the growth performance, body composition and lipid deposition of juvenile large yellow croaker (Larimichthys crocea) (initial weight, 10.03 +/- 0.02 g) fed a soybean oil diet. The practical diet with 6% soybean oil (SO) was used as the control, and a fish oil (FO) diet was designed with 6% fish oil. On the basis of the soybean oil diet, 300 mg and 900 mg/kg (CDCA) were added, respectively. After 10-week growth trial, results showed that survival rate (SR) and condition factor (CF) were not significantly different among dietary treatments. Compared with the FO group, final weight (FW) and weight gain rates (WGR) in the SO group significantly decreased while the groups with the supplementation of CDCA show significantly better growth performance than the SO group and FO group. The lipid content of liver was significantly increased by the replacement of FO with SO but decreased with the increase of the supplementation of CDCA. The activity of lipoprotein lipase was significantly higher in fish fed the diet with 900 mg/kg CDCA supplementation. The expression of PPARa decreased while the expression of SREBP-1 increased significantly in fish fed the SO diet compared with fish fed the FO diet. Meanwhile, dietary 900 mg/kg CDCA significantly upregulated the expression of PPARa and FXR while the expression of SREBP-1 was decreased by the supplementation of CDCA. The results suggested that the supplementation of CDCA could improve the growth performance and lipid deposition of liver in large yellow croaker which were negatively affected by the replacement of dietary fish oil with soybean oil.