Prevalence of Mycoplasma bovis udder infection in dairy cattle: Preliminary field investigation in southeast France

Abstract

AIMS: To update epidemiological data on Mycoplasma bovis infection in dairy herds from six departments in the southeast of France, in order to obtain a first estimate of the prevalence of M. bovis infection through bacteriological investigations on bulk tank milk, and estimate the prevalence of M. bovis in clinical mastitis in this population of cattle. METHODS: To estimate a prevalence of M. bovis of 2%, with 95% confidence, a sample of >270 herds was required. Bulk tank milk samples were collected from herds between January and February 2005 and milk samples from cows with clinical mastitis were collected between January 2007 and March 2008. Bulk tank milk and composite mastitic samples were analysed for M. bovis using culture and/or PCR. RESULTS: Mycoplasma bovis was not detected by either technique in any of the 345 bulk tank milk samples. The prevalence of M. bovis infection in this population of dairy herds was <1%, with 95% confidence. Mycoplasma bovis was not isolated from any of the 166 composite samples obtained from 828 samples of mastitic milk. The prevalence of M. bovis in clinical mastitis was <0.44%, with 95% confidence. CONCLUSIONS: These preliminary results suggest that the prevalence of udder infections with M. bovis is very low in dairy herds in the southeast of France. These two studies provide preliminary data, that can be used to derive working hypotheses for future statistically representative investigations at the national level.