Effects Of Calcium Fatty Acids Replacing Fish Oil And Soybean Oil On Litopenaeus Vannamei

In order to study the feasibility of substituting saturated fatty acid calcium and unsaturated fatty acid calcium for soybean oil and fish oil in shrimp feed,saturated fatty acid calcium and unsaturated fatty acid calcium were used to replace soybean oil and unsaturated fatty acid calcium in shrimp feed.The application of fatty acid calcium in Litopenaeus vannamei feed was studied.Experiment 1:The experiment was conducted to study the effects of saturated fatty acid calcium and unsaturated fatty acid calcium on growth performance,body composition,immunity and metabolism of Penaeus vannamei.Three groups of Penaeus vannamei with initial body weight of（0.3±0.02）g were selected.The control group,calcium unsaturated fatty acid group and calcium saturated fatty acid group were recorded as D₁,D₂ and D₃,respectively.Each group had three replicates,40 shrimps per replicate,and the experimental period was 56 days.The results showed that the survival rate,weight gain rate,specific growth rate,liver-body ratio,crude protein and crude ash content of muscle of Penaeus vannamei had no significant effect（P>0.05）;the total antioxidant capacity of liver and pancreas,as well as the activities of amylase,trypsin,alanine aminotransferase,glutamic oxaloacetic aminotransferase,alkaline phosphatase and acid in shrimp.Sex phosphatase activity was not significantly affected（P>0.05）,but the activities of glutathione peroxidase in liver and pancreas of shrimp in D₃ and D₂ groups were significantly lower than those in D₁ group（P<0.05）,and the activities of glutathione peroxidase,glutathione S transferase and lysozyme in hemolymph of shrimp in D₃ and D₂groups were not significantly different（P>0.05）.Malondialdehyde content in D₁ group was significantly higher than that in D₁ group（P<0.05）,and there was no significant difference between D₂ group and D₁ group（P>0.05）;Malate dehydrogenase activity in D₃ group was significantly lower than that in D₁ group,glucose concentration in D₃ group was significantly higher than that in D₁ group（P<0.05）,and there was no significant difference between D₂ group and D₁ group（P>0.05）.It can be concluded that it is feasible to substitute calcium fatty acid for soybean oil in shrimp feed,and the substitution effect of calcium unsaturated fatty acid is better than that of calcium saturated fatty acid.Experiment 2:The aim of this experiment was to study the effects of unsaturated fatty acid calcium on growth performance,body composition,immunity and metabolism of Penaeus vannamei.Four groups of Penaeus vannamei with initial body weight of（0.3±0.02）g were selected.The control group,unsaturated fatty acid calcium replacing soybean oil group,unsaturated fatty acid calcium replacing fish oil group,unsaturated fatty acid calcium replacing soybean oil and fish oil group were recorded as V₁,V₂,V₃ and V₄,respectively.Each group had three replicates,each with three replicates.Repeat 40 shrimp.The trial period is 56d.The results showed that the survival rate,weight gain rate,specific growth rate,liver-body ratio,crude protein in muscle and crude ash content in muscle of Penaeus vannamei had no significant effect（P>0.05）;the activities of glutamic oxaloacetic aminotransferase,glutamic-pyruvic aminotransferase and malondialdehyde content in liver and pancreas of each group decreased first and then increased（P<0.05）.acid phosphatase activity,alkaline phosphatase activity and total antioxidant capacity increased first and then decreased（P<0.05）,while glutathione peroxidase activity decreased gradually（P<0.05）,but there was no significant effect on amylase and trypsin activity（P>0.05）;glutathione peroxidation in blood lymph of each group.The activities of malate dehydrogenase in the hemolymph of the V₁ and V₂ groups were significantly higher than those of the V₃ and V₄groups（P<0.05）,while the activities of alkaline phosphatase and the contents of glucose,total cholesterol and malondialdehyde in the hemolymph of the V₁ and V₂ groups were significantly lower than those of the V₃ and V₄ groups（P<0.05）.