[目的]调查奶牛嗜血支原体感染和垂直传播情况,为奶牛嗜血支原体病防控提供参考依据。[方法]2021年3月—2022年7月在河北省廊坊市香河县共采集9 家奶牛养殖场2 562 头奶牛血样。其中,采用直接血液涂片法、悬滴压片法、姬姆萨染色法、瑞氏染色法和PCR法对781 头奶牛进行病原体诊断,采用悬滴压片法和PCR法分别对不同年龄阶段的810 头奶牛和不同季节的971 头奶牛进行嗜血支原体检测,选取30 头病原体阳性妊娠奶牛和新生犊牛以检测垂直传播感染情况。[结果]直接血液涂片法、悬滴压片法、姬姆萨染色法、瑞氏染色法和PCR法检测781 头奶牛嗜血支原体的感染阳性率分别为75.54%、49.81%、55.57%、54.03%和46.61%,直接血液涂片法与其他方法检测的阳性率差异显著,悬滴压片法检测的阳性率最接近于PCR。泌乳牛嗜血支原体感染阳性率和发病率均显著高于犊牛和青年牛,不同年龄阶段PCR检测奶牛感染嗜血支原体阳性率和发病率依次为：泌乳牛>犊牛>青年牛。夏季奶牛嗜血支原体阳性率最高,PCR检测阳性率60.85%,与其他季节差异显著,夏季发病率最高为10.21%,但季节之间差异不显著。[结论]临床诊断可采用悬滴压片法和PCR法。该病感染率高而发病率低,与年龄、季节密切相关,且该病原体可通过垂直传播给犊牛。

[Objective]To investigate the infection and vertical transmission of Mycoplasma wenyonii in dairy cows,and to provide reference for the prevention and control of Mycoplasma wenyonii in dairy cows.[Method]From March 2021 to July 2022,blood samples of 2 562 dairy cows from 9 dairy farms in Xianghe County were collected,among which 781 dairy cows were diagnosed with pathogens by direct blood smear,droplet pressing method,Giemsa stain,Wright's stain and PCR.Mycoplasma wenyonii was detected in 810 cows at different ages and 971 cows in different seasons by droplet pressing method and PCR,respectively.30 pregnant cows and newborn calves with positive pathogen were selected to detect vertical transmission infection.[Result]The positive rates of Mycoplasma wenyonii infection in 781 dairy cows were 75.54%,49.81%,55.57%,54.03% and 46.61% by direct blood smear,droplet pressing method,Giemsa stain,Wright's stain and PCR,respectively.The positive rate of direct blood smear was significantly different from that of other methods.The positive rate of blood suspension by droplet pressing method was the closest to that of PCR.The positive rate and incidence of Mycoplasma wenyonii infection in lactating cattle were significantly higher than those in calves and young cattle.The positive rate and incidence of PCR detection of Mycoplasma wenyonii infection in cows at different age stages were as follows：lactating cattle>calves>young cattle.The positive rate of Mycoplasma wenyonii was the highest in summer cows,and the negative rate of PCR detection was 60.85%,which was significantly different from other seasons.The incidence was the highest in summer（10.21%）,but there was no significant difference between seasons.[Conclusion]The clinical diagnosis can be made by droplet pressing method and PCR.The infection rate is high but the incidence is low,which is closely related to age and season,and the pathogen can be transmitted to calves through vertical transmission.