Fatty acid profile of fillet, liver and mesenteric fat in tilapia (Oreochromis niloticus) fed vegetable oil supplementation in the finishing period of fattening

Abstract. Tilapia (Oreochromis niloticus) previously reared on a commercial feed were shifted to 3 experimental diets with added 5 % of soybean, linseed oil or fish oils, for 42 days as a finishing diet, according to literature recommendations. Fillet, liver and mesenteric fat total lipid fatty acid composition was determined and evaluated taking health and dietary recommendations into consideration. It was found that dietary vegetable oil fatty acids are effectively incorporated into tilapia hepatic and muscular total lipids, but have no pronounced effect on further fatty acid metabolism, in particular on the n-3 fatty acids. Liver was found to sensitively indicate elevated dietary lipid intake, as proven by its higher, most probably endogenous palmitate synthesis. Based on our results the application of vegetable oils to partially substitute fish oil for tilapia can be recommended in relation to the most important dietary lipid quality indicators.