Evaluation of the optimum dietary iron level and its immunomodulatory effects on juvenile Chinese mitten crab, Eriocheir sinensis

Abstract This study evaluated the effects of dietary iron levels on growth, antioxidant status and non-specific immunity in juvenile Chinese mitten crab (Eriocheir sinensis). A 56-day feeding trial containing six experimental diets supplemented with six iron levels (0, 30, 60, 120, 240, 480 mg/kg) was conducted. The crabs fed the 177 mg/kg iron diet had significantly higher weight gain and specific growth rate and lower feed conversion ratio compared with those fed the 64 and 508 mg/kg iron diets. A positive correlation was observed between the iron content in the whole body and hepatopancreas with dietary iron supplementation. The catalase activities, total antioxidant capacity, superoxide dismutase and glutathione peroxidase in the hepatopancreas were significantly increased in 89–177 mg/kg iron diets. In addition, the non-specific immunity of the crabs was also improved with the increasing level of dietary iron supplementation (P