Effectiveness of biologically active substances added to sturgeon feeds

The purpose of this research was to study the effect of the vitamin‐mineral complex E‐selenium and the probiotic preparation Bacell when added to industrial feed on the fish‐breeding‐biological and physiological‐ biochemical parameters of juvenile sterlet‐beluga hybrids when reared in cages. The duration of the experiment was 45 days. In experimental option 1, the fish were fed with basic compound feed with the addition of E‐selenium (300 μg selenium/kg of feed), in experimental option 2, the fish were fed with basic compound feed with the addition of E‐selenium (300 μg selenium/kg of feed) and the Bacell preparation (0.2 % by weight of dry food). The control variant was fed with basic feed. The absolute increase in the experimental variants was 13.0–25.0 % higher than in the control. Hematological parameters varied – in some cases with a high degree of significance. In particular, hemoglobin increased by 5.6–13 %, blood serum protein by 0.42–12.6 %, cholesterol by 9.8–16.3 % in the experimental variants and by 70.5 % in the control, due to the presence of a high degree of stress in control fish. At the same time, in fish experiments the effects of stress factors were suppressed by antioxidants. Preventive doses of microelements, vitamins and probiotics reduce and stabilise peroxide processes and contribute to the maintenance of good physiological condition of fish kept in artificial conditions.