Effects of diets containing β‐glucan on survival, growth performance, haematological, immunity and biochemical parameters of rainbow trout (Oncorhynchus mykiss) fingerlings

摘要

Abstract This study aimed to investigate the effect of β‐glucan in rainbow trout's diet on survival, growth performance, haematological, immunity and biochemical parameters. Rainbow trout (Oncorhynchus mykiss) with an average weight of 6.33 ± 0.09 were stocked in 30 fibreglass tanks with a volume of 200 L. Four treatments including control group (0), 0.05, 0.1 and 0.2 of β‐glucan were considered for 8 weeks. The results showed that the survival and growth performance of rainbow trout in the control group were at the lowest level and showed a significant difference (p < 0.05) with other treatments. The highest percentage of haematocrit (47.9), white blood cell count and neutrophil percentage (35.2) was observed in the treatment with 0.2 β‐glucan. Also, the highest lysosomal activity (59.7 units’ ml−1), IgM (54.7 mg dl−1), C3 and C4 was obtained in 0.2 β‐glucan treatment. Biochemical parameters indicated improvement in treatments fed with 0.1 and 0.2 β‐glucan. In conclusion, the present study suggested that 0.2 β‐glucan in the diet of rainbow trout improves growth performance, survival, haematological, immunity and biochemical parameters.