Aims: The breeding of Huso huso is a relatively new industry in Iran. The aim of this study was to investigate the effect of different levels of choline on growth factors, carcass composition, and haematological-biochemical parameters in juvenile beluga (Huso huso).
Materials and Methods: In this experimental study, 150 Huso huso in control, Cho₂, Cho₄, Cho₆, and Cho₈ treatments consisting of 0, 2, 4, 6, and 8g/kg^-1 choline of food with 3 replicates per treatment were fed for 12 weeks to evaluate growth performance, carcass composition, and some haematological and serological parameters. The data were analysed by analysis of one way variance and Duncan test, using SPSS 24 software.
Findings: The final weight, weight gain, specific growth rate index, protein efficiency ratio, obesity coefficient, and feed conversion ratio of fish fed with diet containing appropriate levels of choline (2-4g/kg^-1) were significantly better than fish fed with other diets. The highest growth and food efficiency was observed in fish fed with Cho₄. With increasing choline in fish diet, body fat and protein concentrations significantly increased, but carcass moisture decreased. Also, addition of 2-4g/kg^-1 choline to diet caused a significant difference in the mean number of red and white cells, the activity of liver enzymes (alanine aminotransferase and aspartate aminotransferase), albumin, and total blood protein compared with control treatment.
Conclusion: In order to achieve the best growth and optimal carcass composition of juvenile beluga, the most suitable amount of choline is 2-4g/kg^-1 in the fish diet.