| In this experiment,1500 paramisgurnus dabryanus of 15-20 g were selected and divided into 5 groups.Each group was divided into 3 repetitive test groups.According to the concentration of Lycium barbarum polysaccharide,they were divided into control group(0.00%),LBP1 group(0.50%),LBP2 group(1.00%),LBP3 group(2.00%)and LBP4 group(4.00%).The research focused on the effects of Lycium barbarum polysaccharide on digestive function,non-specific immunity and anti-Aeromonas hydrophila of paramisgurnus dabryanus by changing the concentration of Lycium barbarum polysaccharide in diet so as to obtain the optimum concentration of Lycium barbarum polysaccharide and hence to provide theoretical basis for loach breeding.1.Lycium barbarum polysaccharides on digestive function of paramisgurnus dabryanusIntestinal tissue samples from 14 d,28d,and 42 d paramisgurnus dabryanus were collected,and intestinal sections were prepared to measure the height of the villus and the depth of the crypt.At the same time,the hepatic and pancreas were separated to determine Amyla(iodine-starch colorimetric method)and Trypsin(arginine ethyl ester method),Lipase(triglyceride method)digestive enzyme activity.The results showed that Lipase activity in the test group significantly increased(P<0.05)compared with that of the control group,significantly inhibited Trypsin activity(P<0.05),but had no significant effect on Amyla activity(P>0.05);The height and crypt depth results showed that the LBP3 group and the LBP4 group were significantly increased in the experimental group compared with the control group(P<0.05).2.Effects of Polysaccharides from wolfberry on non specific immunity of paramisgurnus dabryanusAfter fasting for 24 hours,blood samples were collected from tail vein at the 14 th,28th,and 42 th day.Some of the blood samples were collected for AKP(diphenyldisodium phosphate method),LSZ(turbidimetric method),CAT(ammonium molybdate colorimetric method)and SOD(nitrite formation method).Moreover,plasma was collected by heparin anticoagulant tube to determine TP(Coomassie brilliant blue method),ALB(bromocresol green colorimetric method),and GLB(TP-ALB).The results showed that the activity of AKP,LSZ and SOD of paramisgurnus dabryanus was promoted by adding LBP of different concentration in the experimental group,and the activity of LBP in the high concentration group was stronger than that in the low concentration group.The activity of LSZ in the experimental group was significantly higher than that in the control group at 42d(P < 0.05),but LBP had little effect on the activity of CAT.Compared with the control group,the contents of TP and ALB in the experimental group showed an upward trend with the increase of days.At 42 d,the contents of TP and ALB in the high concentration group were significantly higher than those in the control group and the low concentration group(P < 0.05);at 42 d,the contents of LBP4 group were the highest,but the effect of LBP3 group was the best.3.Effects of Lycium barbarum polysaccharides on the resistance of paramisgurnus dabryanus to Aeromonas hydrophilaAfter 42 days of feeding,Aeromonas hydrophila was used as the indicator bacteria to carry out the challenge test,the mortality,survival rate,blood cell count were observed,and the immune indexes in blood and liver and pancreas were detected at the later stage of infection.The results of virus attack test showed that the survival rate of the experimental group was higher than that of the control group,and the survival rate of LBP3 group was significantly higher than that of the control group(P < 0.05);the immune indexes of blood,liver and pancreas of the experimental group were higher than those of the control group at the later stage of infection,which greatly improved the immune function and reduced the fatality rate of paramisgurnus dabryanus. |
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