Herd-level prevalence of Mycoplasma bovis antibodies in bulk tank milk samples in Austrian dairy herds and risk factors associated with herd seropositive status

Mycoplasma bovis is an emerging pathogen worldwide and is associated with various disease manifestations in cattle of all ages. Several potential herd-level risk factors associated with M. bovis positive herd status have been identified in recent years. However, only a few reports of M. bovis in Austrian cattle herds are available, and no nationwide prevalence data are available. The objectives of this study were to determine the apparent prevalence of M. bovis antibodies in bulk tank milk (BTM) samples from Austrian dairy farms and to identify potential risk factors associated with M. bovis antibody-positive herds. In total, 674 BTM samples were collected nationwide and analysed using the ID-Screen^®Mycoplasma bovis Indirect (IDvet, Grabels, France) ELISA. In addition, farm-specific data and management practices were collected through an accompanying questionnaire to identify potential risk factors for M. bovis antibody positivity status. An apparent herd prevalence of 5.2% was observed among Austrian dairy farms. The apparent prevalence across federal states ranged from 0% to 14.8%. Logistic regression analysis revealed a significant association between herd replacement policy (open vs. closed) and herd-level M. bovis antibody status (p = 0.005), with a closed herd replacement policy associated with a protective effect.