Substitution of soybean oil with linseed oil on growth performance, fatty acid profile and texture attributes in large Nile tilapia, Oreochromis niloticus reared under cold suboptimal temperature

Abstract

This study evaluated the effects of substituting soybean oil (SO) by linseed oil (LO) on growth performance, fatty acid profile and flesh quality in large Nile tilapia, Oreochromis niloticus reared under cold suboptimal temperature. Fish (initial weight 1035.4 ± 10.5 g) were used in a completely randomized design with a 2 × 2 factorial arrangement, two oil sources (SO or LO) at two levels (15 or 30 g/kg) and four replicates of 12 fish. The fish were hand-fed until apparent satiety for seven weeks. The interaction between the oil source led to improved daily weight gain in the fish that were fed LO at 30 g/kg when compared with those on other diets. Fish fed LO exhibited higher fillet yield and n-3/n-6 PUFA ratio in the fillet compared with SO. Fish offered oil at 30 g/kg showed enhanced feed conversion ratio and fillet with higher lipids content coupled with decreased hardness than that fed oil at 15 g/kg. Fillet water loss, pH and colour were unaffected by diets. Together, LO at 30 g/kg optimized the growth performance and the n-3/n-6 PUFA ratio without showing any adverse effects on fillet quality in large Nile tilapia reared under suboptimal temperature.