Effects of dietary oil sources on growth performance, apparent digestibility and body composition of Carassius auratus gibelio.

The objective of this study was to determine the impact of dietary lipid sources on growth,body composition and apparent digestibility of Carassius auratus gibelio[initial weight: ( 6. 04 ± 0. 05) g]. 5 experimental diets were formulated to contain 4% lipid originated from fish oil,soybean oil,lard,peanut oil and mixed oil( fish oil:soybean oil:lard,3:4:3) ,respectively. The feeding trial lasted for 60 days. Weight gain and protein efficiency ratio( PER) of fish fed mixed oil was significantly( P 0. 05) higher than that of fish fed fish oil and lard,but not different from that of other groups. No significant difference was found among all treatments in specific growth rate( SGR) and feed conversion ratio ( FCR) . Mesenteric length/ length of fish fed soybean oil was significantly ( P 0. 05) higher than that of fish fed fish oil and lard. Hepatosomatic index( HSI) of fish fed lard was significantly( P 0. 05) higher than that of fish fed fish oil. However,visceralsomatic index( VSI) of fish fed lard was significantly( P 0. 05) higher than that of fish fed mixed oil. However,no significant difference was observed among all treatments in muscle moisture,protein, lipid,ash and phosphorus content. Liver lipid content of fish fed lard was significantly( P 0. 05) higher than that of fish fed fish oil and peanut oil,and liver protein content of fish fed fish oil and soybean oil were significantly ( P 0. 05 ) higher than that of fish fed lard and peanut oil. Apparent protein and lipid digestibility of fish fed lard were significantly( P 0. 05) lower than that of other groups. The results of this study there was no significant difference on growth performance and body composition of C. auratus gibelio when soybean oil,peanut oil and fish oil were used solely. It also suggested that fish oil,soybean oil and lard could be mixed together as a better oil source for C. auratus gibelio,which not only reduced feed costs but also enhanced fish growth.