Effect of different vegetable oils on the body composition of pikeperch (Sander lucioperca (L.)) under intensive culture conditions

Abstract

The aim of this study was to evaluate the effects of the different vegetable oils on the body composition of pikeperch (Sander lucioperca (L.)). Fish of 27.88±7.97 g body weight and 135.83±11.99 mm (mean±SD; n=60) standard body length were introduced into 65 L aquaria, working in a recirculation system. Three experimental diets containing different vegetable oils were fed. Basic feed (60 g kg^-1 lipid content) was complemented with vegetable oils (soybean oil (So), rapeseed oil (Ra), and sunflower oil (Su)) that resulted 110 g kg^-1 crude fat content, in average. Body composition and the fillet fatty acid profile were determined at the end of the 6 weeks experimental period. Control group fed on the basic feed had significantly lower dry matter and lipid content than fish consuming oil complemented feeds. Fatty acid profile of the fish fillets changed according to the lipid composition of the experimental diets. The proportion of palmitic acid (C16:0) decreased, while the ratio of oleic acid (C18:1n-9) has increased significantly in the fish fillets in group Ra compared to the control group. The ratio of linoleic acid (C18:2n-6; feed Ra) and α-linolenic acid (C18:3n-3; feed Ra and So) showed also significant increases while the level of arachidonic acid (C20:4n-6) decreased significantly in all of the treated groups. The ratio of DPA (C22:5n-3) changed in groups Ra and Su significantly. The ratio of n3 fatty acids was found to be the highest in the Su group while group So had the highest n6 levels. Rapeseed oil induced the highest n9 fatty acid ratio in the fish fillet. As compared to the initial value all of the treatments produced a decreased n3/n6 values.