The Effect Of The Diet With Different Lipid On The Growth,Body Lipid Content And FAS Of The Chinese Mitten Crab, Eriocheir Sinensis

Many trials were carried out to evaluate the effect of different oils and different dietary fish oil levels on the growth, lipid contents FAS activity and FAS gene expression . Four diets with different dietary lipid and four diets with different fish oil levels were formulated and fed three a day to Chinese mitten crab Eriocheir sinensis cultivated in 80cm X 50cm X 45cm plastic tanks,which in the different life stage. Each diet was triplicates. Trial lasted for 28 days. Sampling took out at the end of every week. Meanwhile body weight was measured. FAS activities were analyzed with 751-GW UV spectrophotometer. Body lipids were measured. The main results are shown as follows:1. The effect of different oil and different fish oil levels for different life stage on the growth is significant. In Juvenile stage, significant difference observed in the weight gain rate of Chinese mitten crab with different oils diet. The weight gain ratio was significantly higher in lard and bean oil group than in fat free and 6% fish oil group (P<0.05) .In the trail with different dietary fish oil levels, 4% fish oil group showed higher weight gain than the rest (P<0.05) .In the trail with different oils for mature crab,the same phenomenon was observed as in the Juvenile stage. Significant difference was observed in growth between the group feeding 4% fish oil group and the rest among the four groups with different fish oil levels (P<0.05 ) .2. The effect of different oil and different fish oil levels for different life stage on the TL/HWW (Total lipid/ Hepatopancreas wet weight) and TL/MWW (Total lipid/ Muscle wet weight) in hepatopancreas and muscle is significant. In the hepatopancreas of Eriocheir sinensis Juvenile ,No significant difference observed in the TL/HWW of Chinese mitten crab with different oils diet excepting fat free group and lard group; In the trail with different fish oil, TL/HWW was significantly lower in 6% fish oil group and 8% fish oil group than 2% fish oil group and 4% fish oil group (P<0.05) .In the muscle, Significant difference observed in the TL/MWW of Chinese mitten crab fed different oil, TL/MWW was significantly higher in lard group than fat free group soybean oil group and in fat free and 6% fish oil group (PO.05) ;The results of trial with different fish oil level in the muscle were the same as in the hepatopancreas.In the stage of mature Eriocheir sinensis, Significant difference observed in theTL/HWW of Chinese mitten crab with different oils diet, TL/HWW was significantlylower in 6% fish oil group than in lard group fat free group and bean oil group(P<0.05) ;The result of trial with different fish oil level in the hepatopancreas was thesame as in the Eriocheir sinensis juvenile.In the muscle, TL/MWW with different oil dietwas similar to Eriocheir sinensis juvenile, TL/MWW was significantly higher in lard group than fat free group and 6% fish oil group (P<0.05) .No significant different observed in the TL/MWW of mature Eriocheir sinensis with different fish oil levels (P>0.05).3. No significant different observed in the NL/TL (Netual lipid/Total lipid) of Eriocheir sinensis juvenile and mature with different oil diet and fish oil level(P>0.05).4. The effect of different oil and different fish oil level for different life stage on the FAS activity in hepatopancreas and muscle is significant (P<0.05) . In the Eriocheir sinensis juvenile hepatopancreas, FAS activity was significantly higher in lard group than fat free group and 6% fish oil group (P<0.05), FAS activity was significantly lower in 6% fish oil group than the other groups (P<0.05) . In the trail with different oils for juvenile Eriocheir sinensis, No significant difference observed in the FAS activities between 2% fish oil group and 4% fish oil group (P>0.05),but its FAS activities was significantly higher than 6% fish oil group and 8% fish oil group.The results in muscle with different oil and different fish oil was the same as hepatopancreas.The results in the mature Eriocheir sinensis were the same as juvenile Eriocheir sinensis.5. The effect of different oil and different fish oil levels for mature Eriocheir sinensis on the FAS gene expression is significant. In the trail with differnet oil diet,the ranking of the abundance of FAS mRNA in mature Eriocheir sinensis hepatopancreas from higher to lower was lard group,bean oil group,fat free group and 6% fish oil group at fourteen and twenty-eighth day. In the trail with differnet fish oil level,the ranking was 2% fish oil group, 4% fish oil group,6% fish oil group and 8% fish oil group.