Epidemiological Survey Of Round And Coronavirus In Some Large-scale Dairy Farms In Southern Xinjiang

Bovine Rotavirus(BRV)and Bovine Coronavirus(BCoV)are one of the most important pathogens in cattle digestive tract diseases.The clinical symptoms of yak diarrhea caused by these two viruses are very similar and difficult to distinguish.Most of the sick cows showed mental depression,dehydrated diarrhea,and the stool became yellowish white or grayish white,which seriously affected the growth and development of the calf and caused certain economic losses to the cattle breeding industry.Therefore,mastering the infection status of BRV and BCoV in this region has certain guiding significance for its prevention and treatment.In this experiment,ELISA antigen detection and molecular epidemiological investigation were carried out on BRV and BCoV of some large-scale dairy farms in southern Xinjiang..The results were as follows:1.On the basis of clinical diagnosis and histopathological examination,the diarrhea calf was detected by a quantitative PCR method in a large-scale dairy farm in southern Xinjiang.The results showed that there was BRV infection in the dairy farm of this scale.2.In 2018,Rota-Corona antigen ELISA was performed on 325 fecal samples from 12 large-scale dairy farms in southern Xinjiang.The antigen positive rate of BRV was 15.69%,the antigen positive rate of BCoV was 9.54%,and there were mixed infections.The positive rate of mixed infection antigen was6.77%;3.In 2018,from the 11 dairy farms with BRV infection detected by ELISA,one sample with the highest OD value was selected for RT-PCR typing,and 10 samples obtained the target band of 1062 bp.The target band of 715 bp size,the nucleotide homology alignment is determined to be G10 type BRV;4.In 2018,BCoV-positive samples were identified by Rota-Corona antigen ELISA for virus isolation and RT-PCR.CPE was isolated from virus isolation and culture.Based on this,RT-PCR was used to obtaina target band of 730 bp.Nucleotide homology alignments and genetic phylogenetic tree construction were confirmed to be BCoV and their isolates were obtained.In this study,clinical diagnosis,pathological observation,antigen ELISA,molecular epidemic virus investigation,virus isolation and culture methods were used to study the diarrhea and yak of some large-scale dairy farms in southern Xinjiang,and the infection of BRV and BCoV in south ern Xinjiang was mastered.The situation has obtained its epidemiological data,which provides a r eference for the comprehensive prevention and control of BRV and BCoV.