The effect of proanthocyanidins on the physiological state of the sterlet Acipenser ruthenus (Linnaeus, 1758) and the antioxidant activity of compound feed

The effect of grape seed extract (GSE), containing 95% proanthocyanidins, on the physiological state of sterlet grown in conditions of closed water supply system is investigated. Additionally, the changes in the antioxidant activity of compound feed with the introduction of GSE (in dry and water-dissolved) after 1, 3 and 24 hours are analyzed. It is established that the greatest total amount of water-soluble antioxidants (TAWSA) is observed in the Russian compound feed with introduction of water solution of GSE (95% proanthocyanidins). The introduction of 50 mg of GSE per 1 kg of compound feed for 63 days promotes changes in the biochemical parameters of blood and organs of the experimental sterlet group. The total amount of water-soluble antioxidants in the liver increases by 25% (p < 0.05) compared to the control group. There is a tendency to increase the level of total protein (0.05 ≤ p ≤ 0.1), increase in albumin level by 36.47% (p ≤ 0.01) and the alkaline phosphatase enzyme activity by 25.45% (p ≤ 0.01) in serum. There is also a significant decrease in glucose levels in the experimental group of 60.22% (p < 0.01). There are no differences in the chemical and mineral composition of meat (p ≥ 0.1). It is assumed that in sterlet of the experimental group metabolism is intensified and oxidative processes in the liver are reduced. It is proposed to use GSE containing 95% proanthocyanidins in a dosage of 50 mg/kg as an additive in compound feed for juvenile sterlet to prevent oxidative stress and stimulate metabolic processes in the body.