Interactive Effects of Vitamin C and E Supplementation on Growth, Fatty Acid Composition, and Lipid Peroxidation of Sea Cucumber, Apostichopus japonicus, Fed with Dietary Oxidized Fish Oil

A feeding trial was conducted to determine the interactive effects of vitamin C (ascorbic acid, AsA) and E (alpha-tocopherol, alpha-Toc) supplementation with dietary oxidized fish oil (OFO) on the growth performance, whole-body AsA, and alpha-Toc concentrations and fatty acid composition of juvenile sea cucumber. In a 9-wk feeding trial, juveniles (average weight: 0.6+/-0.1 g) were cultured in twenty-four 50-L tanks (30 juveniles per tank) in triplicate, and fed with eight test diets containing two levels of OFO (8.9 and 156.9meq/kg) with varying levels of vitamin C (500 and 1000mg AsA equivalents/kg diet) and E (100 and 200mg alpha-Toc equivalents/kg diet) supplementation, respectively. Body weight gain of sea cucumber was significantly reduced by dietary OFO, while mortality and whole-body thiobarbituric acid-reactive substances value were increased significantly. Increasing dietary vitamin C and E levels significantly increased whole-body alpha-Toc and AsA concentrations, respectively. A high level of vitamin E combined with OFO led to consumption of AsA. Even with supplementation of a large dose of vitamin C and/or E in diets, growth performance could not be improved, probably due to the high levels of vitamins in the control diets.