Effect of different concentrations of canola oil in diets on body chemical composition and growth performance of nile tilapia (Oreochromis niloticus, Linnaeus 1758)

The study was conducted in order to investigate the effect of supplementing various concentrations of canola oil on the growth performance and body chemical composition of Nile tilapia (Oreochromis niloticus, Linnaeus 1758). In the present study, five different experimental diets were used. Control group was fed 100% fish oil (FO) while other groups in triplicate, each of 25 fish, weighing 10 g each on the average were fed varying concentrations of canola oil viz., 25% (CO25), 50% (CO50), 75% (CO75) and 100% (CO100). There was no significant difference among the groups in terms of their growth performance at the end of the experiment (60 days). The better feed utilization was observed for the FO group (P0.05). The highest protein content in whole body was determined for CO50 and the lowest lipid content was determined for the CO75 group. Total saturated fatty acid (SFA) content was the highest in CO75 (33.51%). The monounsaturated fatty acid (MUFA) level was higher in canola-fed groups than in FO. The total n-3 polyunsaturated fatty acid (PUFA) level was higher in FO (11.21%) than that in the canola-fed groups (between 6.26% and 8.27%). The ratio of n-3/n-6 was highest in FO group (2.16), and in all groups it was greater than 1. Our findings confirmed that there was no adverse effect of canola oil on growth performance of Nile tilapia. Furthermore the whole body fatty acid composition was balanced in the canola-fed groups. Copyright 2015 Zoological Society of Pakistan