مطالعه امکانتنظیم جیرهغذاییعاری از پودر ماهی در تغذیه ماهی قزل آلای رنگین کمان

Background:there is the possibility of using some plant protein sources such ascottonseed mealandcanolamealandanimal proteinsourcessuch aspoultry by-product meal as a substitute forfish mealin formulating rainbow trout (oncorhynchus mykiss) diets.objectives:the current study was conducted to investigate the possibility of formulating fish meal-free diets for rainbow trout considering growth performance, carcass traitsand carcass chemical composition.methods:fourexperimentaldietssimilarin terms of digestible energy and crude protein were formulated to meet thenutrientrequirementsrecommended bynrc (1999).diet 1 (control diet) was based on 50% fish meal and diets 2, 3 and 4 had 24.66%, 16.14% and 0% fish meal, respectively.the fish fed four experimental diets in a completely randomized design with four replications of four treatments in 60 days in 16 pools. water flow rate was 2 litersper secondwith thevolume ofone cubic meter. nine hundred sixty rainbowtrouts weighing approximately150 ± 9gwere used. with increasingsubstitution offish mealwithplant and animalprotein sourcesfrom0 to100%,no significant difference was observed in specific growth rate and feed conversion ratio of fish. average weight and carcass efficiency along with viscera weight and viscera index showed no significant differences between diets. increasing substitution of fish meal with animal and plant protein sources from 0 to 100% showed significant reduction in liver weight and liver index (p < 0.05). replacing fish meal with plant and animal protein sources had no effect on average amount of protein and carcass fat.results: it was concluded that poultry by-product meal along with cottonseed meal and canola meal can replace fish meal up to 100% in rainbow trout feeds without having any significant differencein growth performance, carcass traits and carcass chemical composition of rainbow trout.