| At present,with the development of freshwater fish breeding,control from disease offreshwater fish becomes a top priority problem.The use of antibiotics greatly solve the diseasesin aquaculture.However,with the wide application of antibiotics,resistance and adaptability ofbacteria are also enhanced.And the side effects of antibiotics and large residual defect areobvious.Chinese herbal medicine has been widely used in aquaculture for its small resistanceand small toxicity.Studies have shown that Chinese medicine gallnut has antibacterial,anti-inflammatory,convergence and antiviral function,its antibacterial function has been appliedin aquaculture.The object of this research was aristichthys nobilis;0.50%,1.00%,2.00%extraction ofgallnut by alcohol and0.50%,1.00%,2.00%extraction of gallnut by water were added on thebasis of aristichthys nobilis diet.15d、30d、45d to collect samples of the intestinal contents andintestinal samples detected the digestion index for studing the effects from different extractionmethods and different concentration of gallnut on aristichthys nobilis digestivefunction.Experimental results showed that Trypsin content and Lipase content of gallnutexperimental group were lower than the control group after feeding15d,as the extension offeeding time besides C2.00%group in the experimental group,the rest of the groups content ofthe two kinds of enzyme increased,Trypsin content between groups were not significant(P>0.05),C2.00%group was always lower than the control group,the test contents of LipaseC2.00%was lower than other groups (P<0.05); Amylas content experimental group and controlgroup were not significant (P>0.05),but each experimental groups was always higher than thecontrol group.The trend of intestinal villus height and the value of the V/C were consistent withactivity of Trypsin.The value of V/C of foregut and hindgut were greater than the control groupexcept C2.00%,and between groups were not significant difference (P>0.05).But values of lowconcentration groups were higher than the control group,the values of C2.00%wasminimum,the intestinal villus height was significantly lower than the control group、S0.50%group、S1.00%group、C0.50%group after30d (P<0.05).The samples of the blood immune indexes of aristichthys nobilis were collected in15d,30d,45d.Results showed that the experimental groups have promoted content of AKP、SOD、LSZ,and high concentration groups were better than low concentration,water extractiongroups were better than alcohol extraction compared with control group;GLB content of experimental groups were higher than the control group,high concentration groups were betterthan low concentration groups,water extraction groups were superior to the alcohol extractiongroup;ALB content of C2.00%group from experimental groups in45d was minimum,othergroups were not significant difference than the control group (P>0.05);Overall level of ALB ofexperimental groups were not significant difference than control group (P>0.05).After45days Aeromonas hydrophila as indicator bacteria finished the toxicity test, andobservated the deaths of aristichthys nobilis.Results showed that Chinese gall groups reducedthe heavy mortality of septicemia caused by the Aeromonas hydrophila,the survival rates ofS2.00%group and C1.00%group were significantly higher than control group(P<0.01);Immunity indicators in the early infection and late infection suggested that immuneindex of blood、spleen、liver、pancreas、skin mucous of the experimental groups were higher thanthe control group,and the experimental groups greatly improved the immune function andcontroled the mortality rate of aristichthys nobilis,the effects of concentration of1.00%ofextraction by alcohol and concentration of2.00%extraction by water were better. |
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