Total replacement of fish meal and large portion of fish oil by plant sources without decrease in growth performance and feed utilization in rainbow trout fingerlings (Oncorhynchus mykiss) diet

The present study was performed to examine the effect of replacing fish meal and fish oil with plant sources on growth performance and feed utilization of rainbow trout fingerlings. Nine hundred fish with average weight of 6 ± 0.5 g were distributed into 18 (300 L) tanks (5 fish tank-1) and cultured for 60 days using experimental diets. The control diet contained only fish meal and fish oil as the primary sources of protein and lipid, while the 5 remaining diets each contained 80% canola, linseed, sanflower and safflower oil blend (30:30:30:10% respectively) as the primary lipid source and 0, 40, 60, 80 and 100 percent replacement of fish meal with plant protein sources. The Results showed that 100% fish meal replacement with plant protein and 80% replacement of fish oil (final weight: 54.9± 0.2 gr) did not have any significant effect on growth indices and feed utilization compared to the control group (final weight: 58.0± 1.9 gr) (P>0.05). However, growth parameter and feed utilization in group fed with 80% vegetable oil did not exhibited any significant difference compared to the control group (P>0.05).