Effect of fish oil replacement by poultry waste oil in feeds on growth parameters, chemical composition and fatty acid profile of rainbow trout (Oncorhynchus mykiss)

The present study aimed to investigate the effects of dietary fish oil replacement by poultry fat on growth performance and fillet quality, Oncorhynchus mykiss. Three diets were used in this experiment, containing different percentages of poultry fat (0% (D1), 50% (D2) and 100% (D3) replacement with fish oil. The fish were reared as three treatments; the fish fed D1 diet; the fish fed D2 diet; the fish fed D3 diet. No significant effects were observed in growth performance among the treatments. There were no significant differences in fillet moisture, fat, protein, and ash contents among the treatments. Fillet fatty acid compositions reflected those of the diets. Increase in dietary poultry fat content led to decrease in ω-3 fatty acids, eicosapentaenoic acid and docosahexaenoic acid, and increase in ω-6 fatty acids and mono unsaturated fatty acids. In conclusion, full replacement of fish oil with poultry fat had no detrimental effects on fish growth performance, but leads to decline in the fish fillet ω-3 fatty acids.