| Porcine reproductive and respiratory syndrome?PRRS?is an acute and highly contacting infectious disease,called blue-ear disease,is caused by porcine reproductive and respiratory syndrome virus?PRRSV?.PRRS is the key control animal disease in China,because of obstaclingto breeding sows,piglets serious respiratory symptoms,high mortality,immunosuppression and mixed infection.Immunization is the major measure to against PRRS.The efficiency of PRRS vaccine is concerned with confections in pigs and genetic traits of the epidemic strain.Recently,the new strategies,nutrition facts and Chinese Medicine Polysaccharide adjuvantshave have been developed for enhancing the efficacy of PRRS vaccine has arouse attention of animal nutrition experts and veterinarians.It is a trend that adding natural nutrition facts and Chinese Medicine Polysaccharide to animal feed instead of antibiotics and chemicals.Evaluate the immune regulative effects of chinese medicine polysaccharide and conjugated linoleic acid calcium in piglet is the research purpose.Based on PRRS epidemiological surveys in different breeding mode,viral isolation and identify,genome sequence analysis,apply APS,IRPS and CaCLA in piglet.To evaluate the effects of immunomodulators and CaCLA on growth performance,fatmetabolism in piglets,through detecting antibody,cell factors,T-cell proliferate.This research main contents and results are as follows:1.Based on the established PRRSV,CSFV and SIV RT-PCR detection method,finally established the detection method of PRRSV,CSFV and SIV multiple RT-PCR reaction.Chosen the scale pig farms,free-range farmers and slaughterhouses randomly,collected a total samples of 1629 from 76 locations,detected the etiology of PRRSV by multiple RT-PCR.The results showed that positive rate of PRRSV in scale pig farms is5.32%;the positive rate of PRRSV in free-range farmers is 7.76%;the positive rate of PRRSV in Slaughterhouse is 2.81%;the positive rate of PRRSV+CSFV mixed infection in scale pig farms is 0.59%;the positive rate of PRRSV+CSFV mixed infection in Free-range farmers is1.22%;the positive rate of PRRSV+CSFV mixed infection in Slaughterhouse is 0.65%;the positive rate of SIV+CSFV mixed infection and PRRSV+CSFV+SIV mixed infection positive rate is 0.2.Based on the cytopathic effect?CPE?,RT-PCR reaction,gene sequencing,electron microscope and virulence test?TCID50?,isolated a strain of PRRSV from Xinjiang province.Results showed that the PRRSV strain can produced typical CPE in Marc-145 cells;the results gene sequencing proved that the strain is PRRSV;the typical PRRSV virus particles can be observed by electron microscopy;the TCID50 is 10-5/ml.We named the PRRSV strains XJu-1.The full-length genome of XJu-1 was 14987bp,including the poly?A?tail,belong to North American PRRSV isolates.XJu-1 was a novel strain with unique 150-amino acid deletion in NSP2.The XJu-1 strain is genomic variation.3.35 weaned piglets?Landrace×white?were randomly divided into seven groups,APS+IRPS high/low dose group,APS high/low dose group,IRPS high/low dose group,64-day trial period.Evaluate the polysaccharides compound group effects immune antibody.Results showed the antibody of active treatment groups are higher than control group on the day 7after immunization.The antibody of APS,IRPS reach to the peak on the day 34,44respectively.The antibody of APS+IRPS compound group reach to the peak on the day 34after immunity.The antibody of all active treatment group has the parabolaa trend,the antibody level of APS+IRPS compound group is highest and last longer than other groups.4.To detect the APS+IRPS compound group affects spleen lymphocytes proliferation and lymphocyte release IL-2,IL-6 and IFN-?by MTS assay.Add APS+IRPS compound,APS,IRPS?200ug/ml,100ug/ml,50ug/ml?to pig spleen lymphocytes,control groups I without Chinese Medicine Polysaccharide and ConA,control group II without Chinese Medicine Polysaccharide.Results showed the single dose group and compound group both can effectively stimulate lymphocyte proliferation,promoted pig spleen lymphocytes secreted IL-2,IL-6 and IFN-?also,the compound group works best,and has positively correlated with drug concentration.5.Two hundred and forty weaned pigs(?Duroc×Landrace×Yorkshire?,25 days of age,around 5.77kg,were randomly allotted to four diets supplemented with graded levels of conjugated linoleic acid calcium?CaCLA?at 0,0.5%,1%,1.5%to assess the effect of CaCLA on growth performance,immune responses and blood lipids concentrations of pigs.The results showed that the immunization antibody level of PRRS vaccine were no significant?P>0.05?between the experimental group and control.The concentration of IFN-?and IL-1 in experiment group were decline than control,and the difference were significant,but there is no relationship to the amount of CaCLA.1.5%CaCLA group and control was significant difference on the amount of IL-6 in serum.The amount of TNF-?in experiment had the tendency of decline than control,but there is no significant difference.The concentration of CD4+and CD8+in experiment group were no significant difference?P>0.05?;The effect of the average daily gain,the average daily feed intake and feed/gain were no significant?P>0.05?,the concentration of cholesterol,high-density lipoprotein and low-density lipoprotein in serum were no significant?P>0.05?between the experimental group and control. |
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