Effects of dietary cobalt chloride and vitamin C on growth performance, some hematological and biochemical indices in Siberian sturgeon (Acipenser baerii)

In this study, the effects of cobalt chloride (CoCl2) with two levels of 2 and 4 mg/kg and vitamin C with two levels of 200 and 800 mg/kg diet and their combined levels in 9 treatments and each treatment with 3 repelications on 270 Siberian sturgeon (Acipenser baerii) with an initial average weight of 11.51±0.29 g were evaluated for 12 weeks. Based on the results, the mean final weight and length of the fish in 4 mg/kg CoCl2 were significantly higher than the control group (p<0.05). There was no significant difference in the weight gain, body weight gain and food conversion ratio between the treatments and the control group (p>0.05). The results of blood and biochemical indices showed that the highest number of red and white blood cells was observed in the treatments of 2 mg/kg CoCl2+200 and 800 mg/kg vitamin C, respectively. The highest percentage of neutrophils was observed in 800 mg/kg vitamin C treatment, which showed a significant difference with treatments 2 CoCl2, 800 C+4 CoCl2, 800 C+2 CoCl2, 200 C+4 CoCl2 and control (p<0.05). There was a significant difference in the percentage of lymphocytes in 800 mg/kg vitamin C and 800 mg/kg vitamin C + 2 mg/kg CoCl2 treatments compared to the control group (p<0.05). The lowest percentage of monocytes was in the control group (p<0.05). The highest percentage of eosinophils was found in 800 mg/kg vitamin C and 800 mg/kg vitamin C + 2 mg/kg CoCl2 treatments compared to the control group and other treatments (p<0.05). The highest amount of triglyceride and cholesterol was observed in the concentrations of 200 mg/kg vitamin C+4 mg/kg CoCl2 and 4 mg/kg CoCl2, respectively (p<0.05). The results showed that the use of vitamin C and cobalt chloride separately and in combination in the desired weight range had significant effects on growth parameters during the culture period. The effect of vitamin C on some growth and blood indices was higher compared to cobalt chloride. The positive effects of combined treatments were more than individual treatments in most indices. Finally, the diet containing 200 mg/kg vitamin C+4 mg/kg CoCl2 was considered suitable for growth of juvenile Siberian sturgeon.