Abstract:
In order to understand the infection of bovine respiratory disease complex(BRDC) in beef cattle in Guizhou, the experiment used PCR method to analyze the lung samples of 169 cases with BRDC submitted for inspection in 2018—2019 for the detection of Mycoplasma bovis,Trueperella pyogenes,Pasteurella multocida,and Mannheimia haemolytica,and the difference of the positive rates between different years, seasons was analyzed, as well as pathogen infection. The results showed that Mycoplasma bovis,Trueperella pyogenes,Pasteurella multocida,and Mannheimia haemolytica were all detected in the disease materials submitted for inspection in Guizhou from 2018 to 2019,and the average positive rates were 24.9%(42/169),20.1%(34/169),15.4%(26/169) and 7.7%(13/169),respectively. Compared to 2018, except for a slight decrease in the positive rate of Mycoplasma bovis,the positive rates of the other three pathogens were all on the rise in 2019.The disease occurred throughout the year, and more frequently in summer and autumn.The majority of infected cattle were single infection, with a positive rate of 26.6%(45/169);mixed infections also existed, and even quadruple infections, and mixed infections of Mycoplasma bovis and Trueperella pyogenes were common. The results suggested that BRDC of beef cattle in Guizhou cansed by these 4 pathogens, which Mycoplasma bovis and Trueperella pyogenes infection were dominant.