Effects Of Dietary Supplementation With APS On PRRSV MLV Immunological Regulation Effect And Antiviral Function

Porcine reproductive and respiratory syndrome(PRRS)is an infectious disease with breathing difficulties,violet ears,and complications of other infectious diseases being the main features.The pathogen of PRRS is porcine reproductive and respiratory virus(PRRSV).This study used animal testing with a number of indicators of track detection,Primary discussion for APS resistance ability of PRRSV.The dissertation consists of three parts as follows.1.To explore the effect of feeding astragalus polysaccharides(APS)on the immunity against Porcine Reproductive and Respiratory Syndrome(PRRS),A total of 70 gilts were allotted to two groups and were inoculated with the experimental group and control groups.70 gilts were selected to be fed with either APS for 14 days at 200mg/kg in the experimental group or normal diet in the control group.Eight days into the feeding of APS,the gilts in both experimental and control groups were immunized with attenuated PRRS vaccine.At both 10 th and 25 th days after immunization,blood was collected for the detection of PRRS antibody(IgG)and cytokines(IL-2 and IFN-?)in order to investigate the impact of astragalus polysaccharides on PRRS vaccine,which provides a theoretical basis for the application of astragalus polysaccharide as a PRRS vaccine enhancer.The results showed that APS obvious inhibited(P<0.05)the immunity of PRRS vaccine when the PRRS antibody S/P values were between 0-1.0.When S/P values were above 1.0,however,no impact was observed(P>0.05).Feeding APS along with vaccination of attenuated PRRS vaccine promoted the elevation of IL-2 levels and extended the continuous increase of IFN-? levels,which helps improve PRRSV vaccine-mediated cellular immune response to enhance the effect of PRRSV's cellular immunity.2.The choice of the appropriate method about PRRSV This inquiry experiment with different dilution multiple PRRSV attenuated live vaccine for sample,The different dilution sample using RT-PCR?real-time RT-PCR and POCKIT nucleic acid analyzer for testing PRRSV.The results showed that: POCKIT nucleic acid analyzer has high sensitivity and cost-effective,the use of APS in anti-PRRSV test for pregnant sows PRRSV pathogen testing.3.Feeding astragalus polysaccharides for the pregnancy sow against PRRSV research This test is to natural infection of PRRSV pathogen positive pigs for experimental animals.The objective of this study was to find add APS on the pregnancy sow against PRRSV effects in the body.70 gilts were selected through pregnancy with 25 days after inseminate.The gilts to be fed with either APS for 60 days at 200mg/kg in the experimental group C or normal diet in the control group D.In feeding APS 30 and 60 days respectively launching antibodies,cytokines(IL-2 and IFN-?)and routine blood test.For detecting PRRSV from umbilical cord blood and statistics reproductive information at childbirth.The results showed that 25 days to 55 days of pregnancy,feeding APS can effectively slow down the level of platelets;Feeding APS can effectively improve the level of PRRSV antibodies in 60 days;by birth cord blood PRRSV test case,test group cord blood testing PRRSV poisoned rate was 0%(0/35),the control group D cord blood testing PRRSV poisoned rate was 17%(6/35),the feeding of astragalus polysaccharides can effectively reduce the rate of PRRSV poisoned in cord blood;Meanwhile the pregnancy sow in the middle of a pregnancy class Th1 cytokines(IL-2 and IFN-?)significantly increased,and IFN-? has maintained high level to the late pregnancy.