Effects of dietary fish oil replacement by cottonseed oil on growth performance and fatty acid composition of rainbow trout (Oncorhynchus mykiss)

Authors : Müjde GÜLER, Mustafa YILDIZ

Pages : 157-167

View : 15 | Download : 7

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :The aim of the present study was to determine the effects of replacing fish oil insert ignore into journalissuearticles values(FO); with cottonseed oil insert ignore into journalissuearticles values(CSO);, as an alternative plant lipid source in diets for rainbow trout insert ignore into journalissuearticles values(89.3 ± 1.1 g mean individual weight);, on the growth and fatty acid composition of fish. As a control diet, 5 experimental diets were formulated with pure FO and with partial or complete insert ignore into journalissuearticles values(25%, 50%, 75%, or 100% CSO, respectively); replacement of FO with CSO. The fish were fed 2% of their body weight per day for 60 days at an average water temperature of 10.2 °C. At the end of the feeding trial, the highest growth and the lowest FCR insert ignore into journalissuearticles values(1.28); were obtained in fish fed the CSO50 diet. The fillet lipid concentrations and fatty acid composition of the fish were significantly affected by the experimental diets. Fish fed the FO and CSO25 diets contained significantly lower lipid levels insert ignore into journalissuearticles values(6.8% and 6.5%, respectively); than those fed the 3 other diets. The viscerosomatic index insert ignore into journalissuearticles values(VSI); and hepatosomatic index insert ignore into journalissuearticles values(HSI); values increased with increasing cottonseed oil percentages in the diets. Fillet fatty acid composition reflected dietary fatty acid composition. The n-6 polyunsaturated fatty acid insert ignore into journalissuearticles values(PUFA); concentration increased with increasing cottonseed oil levels in the diets. In contrast, the n-3 PUFA levels decreased with increasing cottonseed oil levels in the diets. The highest level of eicosapentaenoic acid insert ignore into journalissuearticles values(EPA); and docosahexaenoic acid insert ignore into journalissuearticles values(DHA); concentrations were recorded in fish fed the FO diet and the lowest in those fed the CSO100 diet. Based on the results of growth performance and fatty acid composition of the experimental fish in the present study, it can be concluded that the 50% concentration of cottonseed oil performed best among the diets tested in the experiment.
Keywords : Key words Nutrition, cottonseed oil, fatty acids, growth, rainbow trout