Effect of dietary vitamin E on growth, muscle composition, hematological and immunological parameters of sub-yearling beluga Huso huso L

Abstract

This study was designed to determine the effect of dietary vitamin E on growth, some hematological and immunological parameters and muscle proximate analysis of beluga Huso huso. Experimental fish were fed practical diets supplemented with 0, 25, 50, 100, 200 and 400 mg Dl-all-rac-α-tocopherol acetate kg diet −1 for 8 weeks. 360 fish (mean initial weight 49.7 ± 0.1 g) were distributed into eighteen 785 L circular concrete tanks and each diet was fed to triplicate groups of fish. At the end of experiment (8 weeks), growth parameters such as final weight (FW), weight gain (WG), total length (TL), feed conversion ratio (FCR), specific growth rate (SGR), protein efficiency ratio (PER), condition factor (CF), hepatosomatic index (HSI), muscle composition, and some physiological indicators, including hematological and immunological parameters, such as hematocrit (Hct), total leukocyte count (WBC), lymphocyte, neutrophil, eosinophil and monocyte, cortisol, glucose, erythrocyte fragility, lysozyme and complement activity were determined. FW, WG, SGR, PER and CF in fish fed unsupplemented vitamin E were significantly lower than those fish fed the other five diets. However FW and PER in fish fed control diet had not significant differences with fish fed at 400 mg kg −1. FCR were significantly higher in fish fed control diet than other groups. TL and survival rate had no significant differences among fish groups. HSI in fish fed 0 and 25 mg vitamin E kg diet −1 were significantly lower than the other treatments. Muscle composition analysis showed no significant differences among the treatments. Erythrocyte fragility, Hct, WBC, lymphocyte, neutrophil, eosinophil and monocyte, lysozyme and complement activities were not significant. Also cortisol and glucose concentrations had not significant differences between treatments. Results indicated that vitamin E had no significantly effect on muscle proximate analysis, hematological and immunological parameters of sub-yearling beluga but has a direct effect on growth performance of beluga sturgeon and this vitamin is an essential nutrient required for normal growth in this species.