Effect of Dietary Fish Oil Replacement by Grapeseed Oil on Growth Performance, Body Composition and Lipase Activity of Rainbow Trout (Oncorhynchus mykiss)

In this study, the replacement effect of dietary fish oil with grapeseed oil was assessed on growth performance, body composition and lipase activity of rainbow trout (Oncorhynchus mykiss) (40±2 g mean individual weight) over a period of 60 days. At the beginning of trial, 5 experimental diets were formulated with fish oil as control (A) and diets with 25% (B), 50% (C), 75% (D) and 100% (E) grapeseed oil, respectively. At the end of feeding trial, growth performance, body composition and lipase activity from pyloric caeca and intestine were measured. The findings showed the significant differences in parameters of WG, HIS, VSI, FCR, moisture and crude protein among experimental diets (P>0.05). The parameters of SGR, CF, crude fat and ash had no significant differences among experimental diets (P0.05). Based on the results of growth performance, body composition, lipase activity and broken line data analysis was revealed that the diet containing 50% grapeseed oil (C) could be appropriate for rainbow trout growth.