Effects Of Dietary Choline-Chloride, Betaine Ahd Lysophospholipids On The Growth Performance,Fat Metabolism And Stress Resistance Of Crucian Carp,Carassais Auratus Gibelio

A feeding experiment was carried out to evaluate the growth performance, fat metabolism and blood indices of diets containing different additives by crucian carp, Carassius auratus gibelio (mean initial weight of7.46±0.2g), for67days.450healthy fish were randomly divided into five groups in the experiment, group1was control group fed basic feed, whereas group2,3,4and5were fed the basic feed added with0.05%lysophospholipids,0.1%lysophospholipids,0.1%betaine and0.15%choline-chloride, respectively. After being cultivated for67days under normal temperature,10fish were heat-stressed for2hours each tank, selected blood samples from six fish randomly before and after stress; and the same time,10fish were immersed in water containing1mg·L-1of trichlorfon keeping96h in the water temperature25℃, selected blood samples from six fish randomly before and after stress.At the end of the experiment, growth performance, fat metabolism and blood biochemical parameters were observed to estimate the function of these three additives.The results showed that weight growth ratio (WGR) of carps in group4(added with0.1%betaine)and5(added with0.15%choline-chloride) tended to be higher than that of fish in group1(control) and this difference was significant (P<0.05), and a lower feed conversion ratio (FCR) was found in group3(added with0.1%lysophospholipids),4(added with0.1%betaine) and5(added with0.15%choline-chloride) too (P<0.05). The apparent digestibility coefficients (ADC) of nutrients and crude protein content in body composition were significantly higher in experimental groups than those in control group (P<0.05). However, the liver fat, muscle fat content in experimental groups were lower than the control group, of which the test group of liver body ratio, liver fat content was significantly lower than the control group (P<0.05). The triglyceride level in group4(added with0.1%betaine) and5(added with0.15%choline-chloride) were lower than those in control group while the triglyceride level in group2(added with0.05%lysophospholipids) and3(added with0.1%lysophospholipids) were higher than those in control group (P>0.05). Reduced plasma cholesterol levels were found in experimental groups while the increased free fatty acid content were observed in experimental groups (P<0.05). The experimental groups significantly increased superoxide dismutase (SOD) of the volume (P<0.05), reduced malondialdehyde (MDA) and alkaline phosphatase (AKP) of the volume (P<0.05), while aspartate aminotransferase (GOT), alanine aminotransferase (GPT), glucose (Glu) have no significant effect (F>0.05).After heat stress, comparing with the normal temperature groups, the activity of serum SOD was decreased and the activity of MDA was increased in each group.In the betaine group the activity of serum SOD,TchE,GPT were increased significantly(P<0.05), while in the lysophospholipids group the activity of serum SOD,GOT were increased significantly (P<0.05).Comparing with the control group under high temperature, the activities of SOD,TchE were increased significantly(P<0.05), the activity of MDA and AKP were decreased, under normal temperature, the activity of serum SOD was increased significantly (P<0.05)and the activity of MDA and AKP were reduced in each group, the activities of other enzymes in groups were not changed obviously (P>0.05). After trichlorfon stress, the activity of serum SOD was decreased and the activity of MDA was increased in each group.In the betaine and lysophospholipids groups the activity of serum SOD,GOT were increased significantly(P<0.05), while the activity of MDA was increased(P<0.05). before the trichlorfon stress,the activity of serum SOD was increased significantly (P<0.05)and the activity of MDA was reduced in each group, the activities of other enzymes in groups were not changed obviously (P>0.05).In conclusion, it could improve growth performance, reduce the fat content in liver and enhance antioxidation function obviously by adding0.1%lysophospholipids, betaine and0.21%choline-chloride in basic diet of crucian carp, Carassius auratus gibelio in our study.