EN
Nutritional support is important for optimum health in fish as it provides the building blocks of innate defense mechanisms and thus protection against infectious diseases. In the present study, we determined the influence of β-glucan (Leiber ®Beta-S) delivered with food on the nonspecific humoral defense mechanisms in fingerling carp. The fish weighed 15-17 g. Four tanks in a recirculation system were stocked with 100 fish each. The water temperature was 20-22°C. The fish were fed daily with commercial pellets containing β-glucan (Leiber ®Beta-S) at doses of 100, 200, and 400 mg per kg of pellets. The feed was prepared by the carp protocol used at the Inland Fisheries Institute. The control group was fed glucan-free pellets. On days 14 and 30 of the experiment, blood was drawn from 10 fish from each group and the nonspecific humoral defense mechanism parameters were examined. The results showed that β -glucan (Leiber ®Beta-S) at doses of 100, 200, and 400 mg per kg of pellets increased the myeloperoxidase activity in blood leukocytes and lysozyme activity in the serum. Total protein and immunoglobulin (Ig) levels were also increased in the serum. The optimal stimulating effect was observed following 30 days of application at a dose of 200 mg of β-glucan (Leiber ®Beta-S) on kg of pellets in fingerling carp.