Epidemiological Investigation Of Bovine Infectious Rhinotracheitis In Shandong Province And Isolate,Identified A IBRV Strain

Infectious bovine rhinotracheitis is caused by infectious bovine rhinotracheitis virus,which belongs to Bovine berpesvirus-I.In addition to high fever,nasal fluid and dyspnea,it can also cause slow weight gain,decreased milk production,abortion,etc.,seriously endangering the development of cattle husbandry.To further understand the IBR infection in some cattle farms in shandong province,this study investigated the epidemiology of IBR in some cattle farms in shandong province,in the course of epidemiological investigation,a IBRV was isolated and carry out a preliminary study on it,the main contents are as follows:1.Epidemiological investigation of infectious rhinotracheitis in some cattle farms in shandong provinceEpidemiological investigation was carried out in 15 dairy farms in Jinan,Tai 'an,Dezhou,Dongying,Weifang and Linyi,a total of 1981 serum samples were obtained,489 samples of calf serum and 1492 samples of adult bovine serum,neutralizing antibodies in serum samples were determined by ELISA and serum neutralization method.The result showed that ELISA method was used to detect that 14/15 cattle farms were positive for IBRV gB antibody,and the field positive rate was 93.3%,indicating that cattle farms in shandong were generally infected with IBRV.Further analysis showed that the antibody positive rates of calves and adult cows in different regions and cattle farms were significantly different,and there was no significant correlation.Some samples with negative and positive by ELISA method were randomly selected for serum neutralization test,The results showed that the SN value of neutralizing antibody less than 5.66 can be used as the negative standard of IBRV antibody,the positive detection rate of trace serum neutralization method was slightly lower than ELISA method.2.Isolation and identification of IBRVIn the course of epidemiological investigation,a virus was isolated,and the samples were verified by PCR identification,sequence analysis,MDBK cell inoculation,plaque purification and animal regression.This tests were proved that the isolated virus strain was IBRV,which was named IBRV-TA strain.