Growth performance, physiological parameters, and transcript levels of lipid metabolism-related genes in hybrid yellow catfish (Tachysurus fulvidraco ♀ × Pseudobagrus vachellii ♂) fed diets containing Siberian ginseng

In high-density aquaculture, fish health can suffer because of excessive feeding, which causes fatty liver disease. Siberian ginseng ( Acanthopanax senticosus ) has been used as a feed additive to promote animal growth, immunity, and lipid metabolism. In this study, we explored the effects of A . senticosus on the physiology of hybrid yellow catfish ( Tachysurus fulvidraco ♀ × Pseudobagrus vachellii ♂ ). A control group and five groups fed diets containing A . senticosus (0.5, 1, 2, 4, and 8 g A . senticosus /kg feed) were established and maintained for 8 weeks. Dietary supplementation with A . senticosus at 4 g/kg promoted growth of the hybrid yellow catfish. Serum total cholesterol (TC) and triacylglycerol (TG) levels at 2 g/kg A . senticosus (TC: 1.31 mmol/L; TG: 1.08 mmol/L) were significantly lower than in the control group (TC: 1.51 mmol/L; TG: 1.41 mmol/L), and 4 g/kg A . senticosus (17.20 μmol/g tissue) reduced the liver TG level compared with the control group (21.36 μmol/g tissue) ( P <0.05). Comparative transcriptomic analysis of liver tissue between the control group and the group showing optimum growth (4 g/kg A . senticosus ) revealed 820 differentially expressed genes and 44 significantly enriched pathways, especially lipid metabolism pathways such as unsaturated fatty acid and fatty acid metabolism. The transcript levels of five lipid metabolism-related genes were determined by quantitative real-time PCR. The results showed that 2–4 g/kg A . senticosus supplementation reduced the FADS2 , ELOVL2 , CYP24a , and PLPP3 transcript levels and 4 g/kg A . senticosus increased the DIO2 transcript level ( P <0.05), leading to altered synthesis of TG and thyroxine and reduced fat deposition in the liver. Our results show that dietary A . senticosus affects the regulation of fat metabolism and promotes the growth of hybrid yellow catfish. A . senticosus is a healthy feed additive, and the appropriate dietary supplementation rate is 2–4 g/kg.