The Mycoplasma bovis bacterium is involved in bovine respiratory disease complex (BRD) and plays a role in chronic pneumonia and polyarthritis syndrome (CPPS). This disease is responsible for 25-40% of feedlot calf mortality and has surpassed shipping fever as the leading cause of death loss in high-risk fall-placed feedlot calves in Canada.
There are several theories to explain why CPPS has increased in prevalence. Undifferentiated bovine respiratory disease is now managed differently than in the past. Animals are often returned to their home pen immediately after being treated rather than staying in the sick pen for a few days. This means that their temperature is often not taken again to determine whether they have responded to treatment. Secondly, the preventative use of long-acting antimicrobials has helped to reduced sickness early in the feeding period. These products may eliminate other lung pathogens such as Mannheimia haemolytica and Pasteurella multocida and create an opportunity for M. bovis to take over and cause CPPS. The BVD virus may also play a role; it suppresses the immune system of cattle, so the risk of CPPS may also be higher when persistently BVD infected calves are present.
ObjectivesThis research project examined the effects of two different management practices on the occurrence of CPPS: 1) the prophylactic use of antimicrobials in newly arrived feedlot calves to prevent illness and 2) the therapeutic use of antimicrobials to treat sick calves.
Read the full report from the Beef Cattle Research Council, a division of the Canadian Cattlemen's Association, here.