Effect of Dietary Inorganic Copper on Growth Performance and Some Hematological Indices of Siberian Sturgeon Acipenser baerii Juveniles

Abstract This research work was conducted to evaluate the effect of dietary copper (Cu) levels on growth performance, feed utilization, and some hematological parameters of juvenile Siberian Sturgeon Acipenser baerii. Five semipurified diets containing 0, 3, 6, 12, and 24 mg Cu/kg in the form of copper sulfate pentahydrate (CuSO4·5H2O) were formulated to provide the actual dietary copper values of 1.8, 5.7, 10.1, 15.9, and 28.3 mg Cu/kg diet, respectively. The obtained results exhibited a significant improvement in the final weight, protein efficiency ratio, daily growth coefficient, and hepatosomatic index with increasing dietary copper levels up to 10.1 mg/kg diet, while the feed conversion ratio significantly decreased. Also, erythrocyte count, hemoglobin, and hematocrit values increased with increasing levels of dietary copper, but no steady trend was observed in mean corpuscular hemoglobin changes. Furthermore, the neutrophils were significantly increased with enhancing the copper level in the fish diet, while the lymphocytes declined. Findings of the current research illustrate that an appropriate dietary copper level is required for improvement of growth performance, oxygen transfer capability, and white blood cell proliferation. Based on the broken-line regression analysis of leukocyte count and monocyte percentage, the optimum dietary copper supplementation was estimated to be 10.63 and 10.36 mg Cu/kg diet, respectively.