사료 지질원이 메기 Silurus asotus의 성장 및 체조성에 미치는 영향

Abstract

This study investigated the effects of dietary lipid sources on growth performance and body composition of juvenile far eastern catfish, Silurus asotus. Three replicate groups of fish (average weight 3.6 g) were fed with one of the following experimental diets containing 10% beef tallow (BT), 5% BT plus 5% corn oil (CO), 5% BT plus 5% linseed oil (LO), or 5% BT plus 5% squid liver oil (SO) as the lipid source for 5 weeks. No significant difference was observed in the survival among groups. The weight gain of fish fed the LO (high in 18:3n-3) and SO (high in n-3 highly unsaturated fatty acid) diets was significantly higher than that of the fish fed the CO (high in 18:2n-6) and BT diets (P<0.05). The feed efficiency of fish fed LO and SO diets was significantly higher than that of the fish fed the BT diet (P<0.05), but not significantly different from that of the fish fed the CO diet. The protein efficiency ratio of fish fed the SO diet was significantly higher than that of fish fed the CO and BT diets (P<0.05), but not significantly different from that of fish fed the LO diet. The 18:1n-9 of whole-body polar lipid fraction in fish fed the BT diet increased compared to that of fish fed the other diets. Fish fed the CO and LO diets had significantly higher contents of 18:2n-6 and 20:4n-6, and 18:3n-3, than the fish fed the other diets in polar and non-polar lipid fractions, respectively (P<0.05). Significantly higher contents of 20:5n-3 and 22:6n-3 were observed in the whole-body polar lipid fraction of fish fed the SO diet compared with fish fed the other diets (P<0.05). The study results indicate that linseed oil and squid liver oil containing n-3 fatty acids are good dietary lipid sources for the growth of far eastern catfish.