An evaluation on taurine addition in the diet of juvenile sea cucumber (Apostichopus japonicus): Growth, biochemical profiles and immunity genes expression

A 60-day feeding trial was conducted to evaluate the effects of dietary taurine (Tau) levels on the growth, biochemical profiles and related immune gene expression of sea cucumbers (Apostichopus japonicus). A total of 225 sea cucumbers (initial body weights 0.79 +/- 0.05 g) were randomly stocked into 5 groups (three tanks per group) and received one of the following diets: Each diet was supplemented with 0 g/kg (T0), 5 g/kg (T0.1), 10 g/kg (T0.5), 20 g/kg (T1) or 50 g/kg (T2) Tau. The sea cucumber weight gain rate, specific growth rate, feed efficiency and crude protein content increased in Tau-supplemented groups compared with T0 group. The body wall total amino acids and total essential amino acids in Tau-supplemented groups were significantly lower than in T0 group while the Tau contents were significantly higher. The acid phosphatase, alkaline phosphatase and complement 3 values were significantly increased in T0.5/T1. Meanwhile, total superoxide dismutase activities in T0.1, T0.5 and T1 were significantly higher than T0 group. The intestinal ATP synthase, Aj-p105, Aj-lys and AjTRX gene expression levels were significantly increased in Tau supplementation groups than in T0 group. And Tau optimum content in the diet of juvenile sea cucumber was determined as 3 g/kg of the dry diet.

Automated summary

This study found that dietary supplementation of taurine in sea cucumbers can promote growth and increase protein content, while significantly affecting the expression levels of related immune genes. The optimal taurine content in the diet of juvenile sea cucumbers was determined to be 3g/kg of the dry diet.