Effects of dietary peptide intake on growth, energy budget, body composition and non-specific immunity of the sea cucumber Apostichopus japonicus (Selenka)

In this study, a 60-day feeding trial was conducted to determine the effects of feed supplementating the feed of Apostichopus japonicus with peptides on its growth, energy budget, body composition and immune responses. Sea cucumbers were fed with five experimental diets supplemented with different proportions of peptides: 0 (D1), 12.5 (D2), 25 (D3), 37.5 (D4) and 50 (D5) g/kg in basal diet. Our results suggested that specific growth rate (SGR) and ratio of viscera to body wall (RVBW) of sea cucumbers fed with D4 were significantly improved. Relative to D1, ingestion rate (IR) and faeces production rate (FPR) for D3 and D4 were reduced considerably. Notably, the energy intake increased when peptide level increased from 0 to 50 g/kg. Meanwhile, the energy deposited for growth increased, and the energy loss decreased when peptide level increased from 0 to 37.5 g/kg. The sea cucumbers in D4 had the highest level of crude fat and lowest crude ash. The activities of immunoenzyme, such as SOD, CAT, T-AOC, ACP and AKP, increased with peptide increase. Results suggested that supplementation of the feed with 25-37.5 g/kg peptides could significantly improve the growth performance, body composition and immune capacity of Apostichopus japonicus.

Automated summary

The study found that supplementing the feed of Apostichopus japonicus with 25-37.5 g/kg peptides significantly improved its growth performance, body composition, and immune capacity.