Effects Of Dietary Surfactin Supplementation On Growth Performance,Lipid Metabolism And Liver Health Status Of Juvenile Grouper(Epinephelus Coioides)

Two trials were conducted to investigate the effects of dietary surfactin supplementation on growth performance,lipid metabolism and liver health status of juvenile grouper(Epinephelus coioides).Trial ?.Effects of dietary surfactin supplementation on growth performance,lipid metabolism and liver health status of juvenile grouperThree hundred and sixty juvenile groupers with initial average weight of(46.67±0.07)g were randomly divided into six groups with four replicates in each group and 15 fish in each replicate.The fish were fed diets supplemented with 0(control group),25,50,100,150 and 200 mg/kg surfactin for 56 days,respectively.Compared with control group,the significant improvement of growth performance was only found in 100 mg/kg surfactin supplementation group(P<0.05),the activities of protease and lipase in intestine were significantly increased(P<0.05),and the serum parameters were significantly modified(P<0.05).Blood lipid levels,crude lipid contents of whole-body and liver and fatty acid synthetase level were significantly decreased(P<0.05),while the activities of hepatic lipase and lipoprotein lipase were significantly increased(P<0.05).The antioxidant ability and free radicals scavenging capacity in liver were significantly improved(P<0.05).The above parameters of digestive enzymes in intestine,serum biochemistry,lipid metabolism and antioxidant ability in liver were partly modified in the other surfactin supplementation groups(P<0.05).The results of present trial indicated that dietary 100 mg/kg surfactin supplementation could have the best beneficial effects on growth performance,lipid metabolism and liver health status of juvenile grouper.Trial ?.Effects of dietary surfactin supplementation on growth performance,lipid metabolism and liver health status of juvenile grouper fed diets with different lipid levelsFour hundred and eighty juvenile groupers with initial average weight of(23.36±0.06)g were randomly divided into six groups with four replicates in each group and 20 fish in each replicate.Six diets with three lipid levels(6%,10% and 14%)and two surfactin supplementation levels(0 mg/kg and 100 mg/kg)were formulated to feed six groups of juvenile grouper,respectively.The trial lasted for 56 days.As for the juvenile grouper fed diets with low or medium lipid levels,the dietary 100 mg/kg surfactin supplementation could improve the growth performance and intestinal lipase activity,modify the serum biochemical parameters,decrease blood lipid levels,crude lipid contents of whole-body and liver and fatty acid synthetase level,increase the activities of hepatic lipase and lipoprotein lipase(P<0.05).The decreasing activities of transaminase in serum and improvement of antioxidant ability and free radicals scavenging capacity in liver were also found by surfactin supplementation(P<0.05).As for the juvenile grouper fed diets with high lipid levels,the dietary 100 mg/kg surfactin supplementation could decrease blood lipid levels and serum transaminase activities and improve the glutathione peroxidase activity in liver(P<0.05).There were no significant differences between grouper fed high lipid level diet without surfactin supplementation and grouper fed low or medium lipid levels diets with surfactin supplementation(P>0.05).The results of present trial indicated that the beneficial effects of dietary 100 mg/kg surfactin supplementation on growth performance,lipid metabolism and liver health status of juvenile grouper fed diets with low or medium lipid levels were greater than those of juvenile grouper fed diet with high lipid level.