Effect of different level of lipids and carbohydrates on growth indices of Benni juvenile (B.sharpeyi)

A study was undertaken to determine the effects of various dietary carbohydrate to lipid ratios on growth indices, feed performance and body composition of benni (Barbus sharpeyi) juveniles. Nine iso-nitrogenous (25% crude protein) and iso-caloric (3.5 kcal/g digestible energy) semipurified diets with varying carbohydrate to lipid (CHO L) ratios (0.8 to 8.8 g/g) were tested for 8 weeks with three replicates. Each replicate was stocked with 20 fish (initial mean weight 16.47 ± 0.25 g) that were fed to satiation thrice daily. Twenty seven flow-through fiberglass tanks of 300 L capacity with a flow rate of 1.5 L min-1 were used for rearing the fish. Maximum weight gain (WG), weight gain rate (WGR), specific growth rate (SGR), feed conversion ratio (FCR), feed efficiency ratio (FER), protein efficiency ratio (PER), apparent net protein utilization (ANPU) and fulton,s condition factor (K) were observed in fish fed a 44% carbohydrate and 9% lipid diet, corresponding to a CHO/L ratio of 4.8. Whole body moisture, crude protein and ash content of fish fed varying CHO:L diets did not show any significant differences among treatments (P>0.05), But whole body lipid content of fish decreased (P<0.05) as dietary CHO/L ratio increased. The hepatosomatic and viscerosomatic indices (HSI and VSI) decreased (P<0.05) as dietary CHO:L ratio increased and maximum values were observed in diet with highest amount of lipid. The results of the present study indicated that the optimal dietary CHO/L ratio for a optimal growth and feeding performance of Barbus sharpeyi juvenile, ranged between 3.8 and 4.8.

Iranian Fisheries Science Research Institute

Published