Environmental survival of Mycoplasma bovis on a white veal farm

Mycoplasma bovis is an emerging cause of bovine respiratory disease (BRD), particularly in intensive feedlots where disease is mainly spread by aerosol route over close distances. The present study aimed to investigate the occurrence of mycoplasmas in the environment of barns housing white veal calves presenting BRD. The majority of calves seroconverted to M bovis three weeks after arrival; there was little evidence of respiratory virus activity, but Mannheimia haemolytica and Pasteurella multocida were isolated from clinically affected calves. M bovis was detected in nasal swabs of sick animals and also on cages and mangers. The isolates were mostly of the same molecular type, suggesting the possibility of infection from the environment. Environmental resistance conferred by biofilm formation might play a significant role in the continuous circulation of M bovis within the white veal herd, indicating the need for all-in, all-out replacement systems and effective disinfection.