Efficacy of using sunflower meal as an ingredient, and partial fishmeal-replacer, in practical feed formulated for stinging catfish (Heteropneustes fossilis)

This study was conducted to determine the growth performance, body composition, and haematological profile of Heteropneustes fossilis in response to the replacement of fish meal (FM) by sunflower meal (SFM). The experiment was conducted in a completely randomized design (CRD) with five treatments and three replications. The fish (initial average body weight of 2.42 ± 0.01 g) were reared in 15 glass aquaria (40 fish/aquarium) with a 150-L water capacity. Five isoproteic (35%) diets were prepared by replacing FM protein with SFM protein at a rate of 0% (T₀), 10% (T₁₀), 20% (T₂₀), 30% (T₃₀), and 40% (T₄₀). Fish were fed with experimental diet twice a day (9.00 and 16.00), 7 days a week for 8 weeks. Fish were sampled at the end of the experimental period of 8 weeks. At the end of the rearing period, the highest weight gain (6.25 ± 0.11g), % weight gain (163.32%), and specific growth rate (1.61 ± 0.03%/day) were observed in the control (T₀) treatment, but the difference was not significant (p > 0.05) with T₁₀ and T₂₀ treatments. However, all the growth factors were decreased with the further inclusion level of SFM in replacement of FM, and the lowest growth performance was observed in T₄₀ treatment. The protein efficiency ratio (PER) and feed conversion ratio (FCR) followed the same pattern as the growth parameters. It was found that the whole-body proximate composition of fish was also affected significantly (p < 0.05). Haematological parameters significantly (P < 0.05) altered at 30% and 40% levels of replacement of FM with SFM. Based on these results, it can be concluded that 20% FM protein can be substituted with SFM protein in the diet of H. fossilis without compromising growth performance, feed utilization, chemical composition, and haematological status. However, according to polynomial regression analysis, the optimum level of replacement of FM protein with SFM protein was determined to be 14.3% in the diet of H. fossilis.