Effect of dietary β-carotene supplementation on growth and antioxidant capability of pre-adult male Chinese mitten crab, Eriocheir sinensis

Abstract

β-carotene has been shown to be beneficial for the color formulation, survival, antioxidation, immunity and stress resistance of many crustaceans. This study was conducted to investigate the effects of dietary supplementation of synthetic β-carotene on growth, antioxidant status, high pH resistance, color parameters, and carotenoids composition of pre-adult Chinese mitten crab Eriocheir sinensis. Three diets were formulated to contain 3.06, 52.40 and 103.59 mg/kg dry diets of synthetic β-carotene (defined as Diet 1 - 3). The results showed that: (1) There were no marked differences in body weights or feed utilization, suggesting that β-carotene was not particularly efficient in enhancing the growth of pre-adult E. sinensis. (2) Indicators of antioxidant capacity (T-AOC, MDA) and immunity (AKP, ACP) both got improved in the hepatopancreas and hemolymph with the supplementation of 50–100 mg/kg β-carotene in the diets. (3) The stress test with high pH indicated Diet 1 treatment had the highest mortality among all treatments, and the lowest mortality was found in Diet 3 treatment. (4) For color enhancement, the redness of the carapace and hepatopancreas increased significantly with the increase of dietary β-carotene supplementation at Day 30. Combined, the inclusion of β-carotene in the diet could enhance the antioxidative capability, non-specific immunity, stress resistance to high pH and tissue carotenoid contents, and the optimal level of dietary synthetic β-carotene supplementation was suggested to be around 50 mg/kg for pre-adult male E. sinensis.