Detection and Analysis of Diarrhea Pathogens in Yak Calves in Qinghai-Tibetan Plateau Region
In order to investigate major diarrhea pathogens in yak calves in Qinghai-Tibetan plateau region,from June 2021 to August 2022,239 fecal samples were collected from diarrheic calves on 21 farms in Qinghai Province,Tibet Autonomous Region and Sichuan Province to be used for detecting 6 diarrhea pathogens including bovine rotavirus A(BRVA),bovine viral diarrhea virus of genotype 1(BVDV-1),bovine coronavirus(BCoV),infectious bovine rhinotracheitis virus(IBRV),enterotoxin-producing Escherichia coli(ETEC)and Salmonella by real time fluorescent PCR.The results showed that the individual positive rate of the samples was 64.44%,and the positive rate at farm level was from 42.86%to 90.48%;the individual positive rates of BRVA,BVDV-1,BCoV,IBRV,ETEC and Salmonella were 28.87%,26.78%,5.44%,28.45%,17.57%and 16.32%,respectively;for samples from Qinghai Province,the positive rates of BRVA(35.29%)and BVDV-1(30.88%)were higher,those of IBRV(93.75%)and ETEC(75.00%)from Tibet Autonomous Region were higher,and those of BRVA(24.46%),IBRV(22.30%)and BVDV-1(27.34%)from Sichuan Province were higher;the mixed infection rate was 62.99%,including double,triple and quadruple infection rates of 42.86%,15.58%and 4.55%,respectively,no quintuple infection or above was found,mixed infection with BRVA,BVDV-1,IBRV and other pathogens were predominant.In conclusion,the above 6 pathogens were widely prevalent in diarrheic calves in Qinghai-Tibetan plateau region,but different depending on different regions,with common mixed infection.Therefore,BRVA should be further detected and controlled,inactivated vaccines of BVDV-1 and IBRV should be applied and popularized in yaks.