Effects of Replacing Fish Meal With Poultry By- Product Meal on Growth Performance and Carcass Quality in Rainbow Trout (Oncorhynchus mykiss.) Feeding

A fish meal based - diet was formulated for rainbow trout (Oncorhynchus mykiss) to evaluate the potential replacing of fish meal with poultry by-product meal in levels of 0, 20, 40, 60 percent. Four experimental diets associated with a commercial diet (as control) were fed to 780 rainbow trout with initial body weight average of 87.8± 5.7 gr in a 90-day feeding trial as completely randomized design in 15 experimental pools. The results showed that body length, specific growth rate, weight gain and feed conversion ratio were not significantly different among experimental diets and control one. Feed intake was decreased significantly (P< 0.05) in diet with replacing level of 60 % in comparison to fish meal based diet, 0 % of replacing. The 0, 20 and 40 % of replacing fish meal with poultry – by product meal did not influence rainbow trout dressing percentage but replacing level of 60 % significantly decreased (P< 0.05) the dressing percentage in comparison to fish meal based diet, 0 % of replacing. The dressing percentage were not significantly different among experimental diets in replacing levels of 0, 20, 40 percent fish meal with poultry by-product meal and control diet. In all replacing levels of fish meal with poultry by-product meal, body chemical compounds particularly protein content of rainbow trout were not affected compared to control group. As a whole in this study, feeding common commercial diet did not indicate any benefits in comparison to fish meal and poultry by-product meal based diets. The results of this research showed that fish meal can be replaced with poultry by-product meal up to 60 % in rainbow trout diet.