Tilapia (Oreochromis niloticus) previously reared on a commercial feed were fed three experimental diets with added 60g kg-1 of soybean (SO), linseed (LO) or fish oils (FO), for 6weeks. The final bodyweight (week 6) of fish was significantly lower when feeding the vegetable oils. At 0, 2, 4 and 6weeks, fillet, liver, visceral fat, testis and ovary triacylglycerols (TAG) and phospholipids (PL) were analysed for their fatty acid (FA) composition. The simple FA dilution model has been successfully applied to describe the incorporation of numerous dietary FAs into both tissue TAGs and PLs. Fillet PL FAs reacted more sensitively on the FAs of the SO and LO diets, when compared to the TAGs. Alterations of the hepatic TAG and PL fractions were minor and less predictable. Testicular PLs have been found to preferentially accumulate n3 FAs, in particular docosahexaenoic acid (DHA) (C22:6 n3). In contrast, ovarian TAGs showed a predominant accretion of oleic acid by the FO diet. The increased dietary unsaturation index (SO, FO) was found to augment hepatic in vivo lipid peroxidation, as assessed by the tissue malondialdehyde concentrations.
ASJC Scopus subject areas
- Aquatic Science