| dc.description.abstract | Mycoplasma bovis is a significant pathogen in cattle worldwide, responsible for diseases such as mastitis, pneumonia and arthritis. It is known to be present in many parts of the world and can have a serious economic impact on the dairy industry. It is likely that M. bovis is also playing a role in Alberta, Canada; however, little is known about how many dairy herds in this region have been exposed to the bacterium. This study aimed to estimate the herd-level prevalence of M. bovis infections in Alberta’s dairy herds using antibody detection in bulk tank milk (BTM) samples and to evaluate the association of herd characteristics, geographic region, milking system, herd size, and colony status with infection prevalence.
A BTM sample was collected from every one of the 460 dairy farms across Alberta to test for antibodies against M. bovis. The testing was done using an indirect ELISA (ID.vet). Two cut-off values were applied: the manufacturer recommended S/P% cut-off of ≥30% and one with ≥50% S/P% which has a higher specificity. The true prevalence was estimated using the test characteristics, and the data on the farms, such as region, herd size, milking system, and colony status. These results were used to investigate whether certain types of farms were more likely to be infected.
At the ≥50% cut-off, the estimated prevalence was 57.4%, which suggests that M. bovis is endemic in Alberta dairy herds. In the southern region and among farms of medium or large size, a higher percentage of the farms tested positive for M. bovis. No significant association was found with milking system or Hutterite colony status.
The ELISA test performed in this study was a good indicator for the prevalence om M. bovis in dairy herds in Alberta. This test can also be useful for surveillance of M. bovis in dairy herds. The high prevalence found in this study suggests that M. bovis is endemic in Alberta. Future studies, using PCR or clinical data, are needed to get a better understanding of how the infection spreads and how it can be controlled. | |
