Morphometric parameters of sterlet when using probiotic compositions

The paper presents the results of a production experiment on juvenile sterlet (Acipenser ruthenus L. 1758), conducted at the fi sh farm Novaya Akvakultura LLC in the Tyumen Region in a closed water supply system. The aim of our work was to assess the eff ect of probiotic compositions on the dynamics and balance of morphometric parameters of juvenile sterlet in a closed water supply system. Probiotics of various microbiological compositions were added to the diet of juvenile sterlet in the experimental groups at a rate of 0.5 g per 1 kg of feed. A hydrochemical study revealed a decrease in organic pollution of water in the experimental pools. The biochemical oxygen demand (BOD5) index in the control was 2.8 mg/dm3, in the experimental group № 1 — 2.0 mg/dm3, in the experimental group № 2 — 2.4 mg/dm3. It was found that the use of probiotic compositions in the diet of young sterlet reduces the variability of morphometric features, indicating a more homogeneous reared juveniles; causes a high interrelation of linear features (head length, body length, anteanal distance) in juveniles aged 82 and 97 days. The inclusion of probiotic organisms in the diet ensured an increase in the absolute growth rate of juveniles in the experimental groups by 23.29% and 22.14% compared to the control. The group that received the probiotic “Bacifolin A” with the main diet showed the highest results in terms of economic eff ect and fi sh productivity relative to the group that received “Basulifor A”.