Effect of dietary β-carotene supplementation on growth and antioxidant capability of female swimming crab Portunus trituberculatus

Dietary supplementation with synthetic β-carotene was investigated in this study to assess its impact on gonad development, antioxidant status, color parameters, and carotenoid composition in adult female swimming crab (Portunus trituberculatus). Four diets, designated as Diet 1 to 4, were formulated to contain 3.07, 53.78, 103.23, and 205.22 mg/kg dry diets of synthetic β-carotene. The findings revealed the following: (1) No significant differences in body weights or feed utilization were observed, indicating that β-carotene did not significantly enhance the growth of adult P. trituberculatus. (2) The inclusion of 50–100 mg/kg β-carotene in the diets led to improvements in antioxidant capacity indicators (T-AOC, MDA) and immune-related parameters (AKP, ACP) in both hepatopancreas and hemolymph. (3) Notably, the redness of ovaries and hepatopancreas increased significantly with higher dietary β-carotene supplementation for color enhancement. In conclusion, incorporating β-carotene into the diet enhanced the antioxidative capability, nonspecific immunity, and tissue carotenoid contents in adult female P. trituberculatus, and the optimal level of dietary synthetic β-carotene supplementation for adult female P. trituberculatus was suggested to be around 100 mg/kg.