| Bovine viral diarrhea virus(BVDV)causes acute infectious diseases of cattle called bovine viral diarrhea [1],and chronic persistent infection is called mucosal disease.It is characterized by fever,mucosal erosion,ulceration,necrosis,diarrhea,cough,leukopenia,abortion of pregnant cows,malformation of the fetus,and stillbirth.Bovine viral diarrhea virus has now spread all over the world,hindering the development of animal husbandry.BVDV has been detected in many provinces and cities in China,causing different degrees of economic losses to our livestock enterprises.Now to understand the prevalence of BVDV in Hebei and Tianjin,this paper tested 132 milk samples by BTM ELISA in 7 dairy farms.The results showed that BVDV infection occurred in D or E,BVDV infection in the near future;B,C,F G has been in contact with BVDV in four games,and the AG field is still dominated by R4,which is dominated by negative fields.From 2016 to 2017,4105 serum samples(including 4 suspicious samples)were detected by ELISA antibody and antigen on 7 dairy farms.The results showed that the positive rate of BVDV antibody in 2016 was between 9.97% and 23.30%,and the average antibody was average.The positive rate was 13.96%,the antigen positive rate was between 0.65% and 3.83%,and the average positive rate of antigen was 1.97%.In 2017,the positive rate of BVDV antibody was between 7.87% and 18.50%,and the average positive rate of antibody was 11.64%.The positive rate was between 0.31% and 3.13%,and the average positive rate of antigen was 1.59%.It is basically consistent with the BTM BVDV antibody test results.The results of BVDV antibody detection in bovine serum samples from different seasons showed that the positive rate in winter and spring was higher than that in summer and autumn,and the positive rate of BVDV antibody in 2017 was lower than that in 2016;the detection results of BVDV antibody in bovine serum samples of different cattle ages It can be seen that the positive rate of BVDV antibody in adult cattle is higher than that in other cattle ages,and the positive rate of BVDV antibody in yak is the lowest;from the breeding mode,the positive rate of cattle field is from high to low,followed by self-propagation + introduction,self-production + In vivo introduction,self-propagation and self-cultivation;BVDV antibody positive rate of bovine serum samples in different culture modes from high to low is grazing + house feeding,house feeding,grazing;2016-2017 BVDV antibody in bovine serum samples from different cattle farms The positive rate of antibody was between 9.53% and 20.97%,and the average positive rate was 12.79%.The positive rate of BVDV antibody in A,B and F was the lowest,9.53%,9.61%,8.80%,D.The positive rate of BVDV antibody in E and E was the highest,which were 20.97% and 17.67% respectively.The detection results of BVDV antibody in bovine serum samples from different regions showed that the positive rate of BVDV antibody in Baoding area was the highest,and the others from high to low were Tangshan City.Nan County,Tian Jizhou District,Yutian County,Tangshan City,Baodi District,Tianjin Beichen District,north to south spread;after by RT-PCR test results showed that four suspected diagnosis of BVDV antigen in serum samples were positive.The positive rate of antigens in A and B fields is the lowest,and the highest in D field.Because BVDV is mostly concealed infection,in order to avoid pollution to cattle and bovine serum,antigen detection is performed on each PI cattle,especially D field,and the purification is eliminated in time. |
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