DAFM has recently completed two large studies on the occurrence of Mycoplasma bovis infection in the Irish cattle population.
A seroprevalence survey for Mycoplasma bovis was carried out by DAFM Laboratories in conjunction with Animal Health Ireland during 2018. In this survey, a single bulk milk tank sample was collected from each of 1327 dairy herds and tested for antibodies to M. bovis. This survey found that 595 of the 1,327 samples that were tested (i.e. 45% of the herds that were sampled) yielded a positive result. Detection of antibodies in a bulk milk sample indicates evidence of previous exposure of at least one of the cows that is contributing to the bulk milk tank. Further analysis of results from this study is being planned to identify factors associated with those herds that had a positive bulk milk result.
Mycoplasma bovis is a common cause of respiratory disease in cattle. A second recent study undertaken by DAFM Laboratories was focused on the causative agents of respiratory disease in weaned cattle in Ireland. In this study M. bovis was detected in 16% of cattle that were submitted for post mortem examination and diagnosed with respiratory disease at one of DAFM's Regional Veterinary Laboratories. A previous DAFM study in 2001 identified M. bovis in 18% of pneumonic cattle lungs, suggesting that its contribution to bovine respiratory disease has changed little over the last 15 years.
While these studies did not differentiate between cattle in feedlot systems and those that were more extensively reared at grass, they do provide baseline information on the prevalence of this infection in the national cattle herd and its contribution to bovine respiratory disease in Ireland.
Animal health Ireland provides advice on its website for the prevention and control of endemic or "production" disease in cattle such as those caused by M. bovis infection.