DIETARY LIPID SOURCES FOR GIBEL CARP CARASSIUS AURATUS GIBELIO: GROWTH PERFORMANCE, TISSUE COMPOSITION AND MUSCLE FATTY ACID PROFILES

A 12-week growth trial was conducted with juvenile gibel carp (Carassius auratus gibelio) to evaluate their ability by utilize different dietary lipids. Ten diets were supplemented with 8% of either fish oil (FO), coconut oil (CNO), corn oil (CO), linseed oil (LO), soybean oil (SO), rapeseed oil (RO), 1∶1 fish oil-coconut oil (FCNO), 1∶1 fish oil-corn oil (FCO), 1∶1 fish oil-linseed oil (FLO) or 1∶1∶1∶1 fish-coconut-corn-linseed oil mixture (MIX). Each diet was fed to triplicate groups of fish (initial weight: 3.53 g, 30 ini.) in a recirculation system at (241)℃.Weight gain were the highest in SO and CNO group, followed RO and the lowest in FO, CO and LO group, when used as a single lipid source. Compared to total replacement of fish oil, coconut oil, corn oil or linseed oil substitute 50% fish oil led to a higher weight gain, respectively. Neither the plasma biochemistry nor the lipid and moisture contents in different tissues of gibel carp showed significant difference between groups (P0.05). Fatty acid composition of muscle in fish generally reflected the composition of the diet. Fish fed CO and SO had higher 20:4n-6, while relative higher 20:5n-3 and 22:6n-3 was detected in fish fed LO. These results suggested that gibel carp had ability to desaturate and elongate 18:2n-6 and 18:3n-3 to highly unsaturated fatty acid. In conclusion, soybean oil, coconut oil and rapeseed oil were good alternative lipid sources for gibel carp.