THE IMPACT OF DIETARY ORGANIC FOOD ON THE HAEMATOLOGICAL PARAMETERS, BODY COMPOSITION AND GROWTH OF SILVER CARP RAISED IN RECIRCULATING AQUACULTURE SYSTEM

Abstract

The effects of different dietary doses of organic selenium (Se) on the growth, body composition, and haematological parameters of silver carp were evaluated in a feeding experiment. The basal diet was supplemented with selenium at levels of 0.0, 0.5, 1, and 2 mgkg⁻¹. A total of 25 fish were randomly stocked into 500 L tanks using Recirculating Aquaculture System (RAS) technology and fed for ten weeks. Fish fed diets containing 0.5 mgkg⁻¹, 1 mgkg⁻¹, and 2 mgkg⁻¹ Se showed significantly higher weight gain, final body weight, and specific growth rate (p<0.05). The lowest growth values were observed in fish fed the basal diet. Survival rate was similar among all treatment groups, and no significant difference was observed in feed intake (p>0.05). Whole-body composition analysis revealed that fish fed 1 mgkg⁻¹ Se had significantly higher body moisture and protein levels on a dry weight basis (p<0.05). Fish receiving 2 mgkg⁻¹ Se had the highest fibre content, while those fed 0.5 mgkg⁻¹ had significantly higher ash content. Dietary selenium had no significant effect on fat content. Whole-body selenium concentrations increased significantly (p<0.05) with increasing dietary Se levels. Haematological data indicated that fish fed 0.5 mgkg⁻¹ and basal diets exhibited significantly higher haemoglobin and red blood cell counts (p<0.05). White blood cell counts were higher in fish fed basal and 2 mgkg⁻¹ diets, whereas lymphocyte percentages were higher in fish fed basal and 0.5 mgkg⁻¹ diets (p<0.05). Overall, the study concludes that dietary selenium supplementation benefits silver carp. Supplementation with organic selenium, particularly at 0.5–1 mgkg⁻¹, improved growth performance, whole-body protein content, selenium deposition, and certain haematological indicators. Therefore, the optimal dietary selenium level for silver carp is suggested to be between 0.5 and 1 mgkg⁻¹.