Effects of dietary Lactobacillus brevis 47f on growth performance, hematological and histological parameters of juvenile sterlet (Acipenser ruthenus)

In this work, a study was conducted on the possibility of using the probiotic strain Lactobacillus brevis 47f in feeds for juvenile sterlet ( Acipenser ruthenus ). The preservation of lactobacilli in manufactured feeds and the survival rate of the strain on the mucous surface of the intestines of fish were established. In a long-term experiment (60 days), an increase in the number of lymphocytes in the blood was revealed, as well as a change in histomorphometric parameters: the number of lamina propria lymphocytes, the number of goblet cells. There was a significant decrease in the feed coefficient, as well as an increase in sterlet biomass in the experimental group, probably associated with a change in protein metabolism – an increase in the level of total protein, albumin, globulin in blood serum. The conducted studies have shown the possibility of using a number of histomorphometric data to assess the reaction of the gastrointestinal tract in sturgeon fish to feed with a probiotic strain. The results obtained suggest that the probiotic strain L. brevis 47f is promising for use in aquaculture.