The effects of multi-enzyme and betaine on growth performance, body composition haemato-immunological parameters and expression of growth-related genes in beluga (Huso huso)

Abstract

The present study investigated the effect of apsozyme and betaine on growth performance, carcass composition, haemato-immunological parameters, and expression of growth hormone (GH) and insulin-like growth factor 1 (IGF1) encoding genes in beluga sturgeon (Huso huso). Fish (31.5 ± 0.5 g) were fed with different levels of multi-enzyme (i.e., 0, 250, and 500 mg) and attractant (i.e., 0.5%, 1.0%, and 1.5%). The results obtained from this study indicated that no significant difference was detected in weight gain, specific growth rate (SGR), feed conversion ratio (FCR), and growth-related genes expression with an increase in betaine in experimental treatments (P > 0.05). However, an increase in apsozyme from 250 mg to 500 mg without betaine resulted in significant elevations in weight gain, SGR, FCR, and growth-related gene expression (P < 0.05). The highest growth performance (weight gain, SGR, and FCR) and growth-related gene expression were observed in combined treatments (i.e., 500 mg apsozyme +1.0% and 1.5% betaine) (P < 0.05). No significant difference was detected in carcass composition in different treatments (P > 0.05). Also, the blood biochemical factors including glucose, and hepatic enzymes, i.e., alkaline phosphatase (ALP), alanine aminotransferase (ALT), and aspartate aminotransferase (AST), were not found significantly different (P > 0.05), whereas significant increases were observed in protein, albumin, and lysozyme with increased apsozyme in the diet in combined treatments (P < 0.05). Overall, it is concluded that apsozyme and betaine together could positively affect growth performance parameters, growth-related genes, and haemato-immunological parameters in H. huso.