Effects of dietary Chinese herbal medicines mixture on growth performance, digestive enzyme activity and serum biochemical parameters of European eel, Anguilla anguilla

Abstract

A feeding trial was conducted to investigate the effects of Chinese herbal medicines mixture (CHMM) on growth performance, digestive enzyme activity and serum biochemical parameters of European eels, Anguilla anguilla (initial weight 6.19±0.09 g). Diets with different supplementation of CHMM (0, 2.5, 5, 7.5, 10, 12.5 g/kg) were given to eels for 42 days. Results showed: eels fed with 5–12.5 g/kg CHMM were observed an improvement in growth performance, where the weight gain (WG) and specific growth rate (SGR) were significantly enhanced. Eels fed with 5–12.5 g/kg CHMM presented a higher activity of enteric trypsin (TRS) (P<0.05). Meanwhile, an enhancement of amylase activity was observed in eels fed with 10 g/kg CHMM (P<0.05). Eels fed with 10 g/kg CHMM was observed a marked improvement in body protein content. The total superoxide dismutase activity (T-SOD) had a significant improvement among all experimental groups compared with the control group, and the lysozyme activity (LZM) was also enhanced by dietary 5 and 7.5 g/kg CHMM addition (P<0.05). For determine the optimal addition of CHMM, WG, SGR, TRS, body protein content, T-SOD and LZM were choose to carry out regression analysis. Regression analysis results show, 7.422, 7.343, 9.156, 9.085, 4.465 and 7.282 g/kg CHMM are the optimal addition for those parameters, respectively. In conclusion, dietary CHMM could improve the growth performance, enteric trypsin activity, body protein content, non-specific immunity and antioxidant capacity of eels, and the recommended supplementation of CHMM for European eels is about 9 g/kg.

Keywords

• European eel
• Trypsin
• Body composition
• Total superoxide dismutase
• Lysozyme