The maternity pen can be a place of risk for Johne’s Disease
Exposure to Johne’s disease can occur in the maternity pen. Management of the maternity pen is critical in reducing the risk of disease transmission to newborn calves.
The birth of a calf is a time of joy, but danger lurks that can turn it into heartache. Calves are born with limited protection from disease because their immune system is not yet developed and maternal antibodies do not cross the placenta. Therefore, exposure in the maternity pen to disease pathogens can put the calf’s health at risk.
We know that young calves are the most vulnerable animals to infection with the bacteria that causes Johne’s Disease (JD), Mycobacterium avium paratuberculosis (MAP). Once infected, it is unlikely that the animal will ever clear the bacteria, but rather the bacteria will slowly replicate, eventually leading to clinically recognizable disease.
That is why protection of the calf from exposure to MAP is so important. Herd prevalence of JD can only be reduced long-term if new infections are reduced.
The results of two MSU research projects that were part of the Michigan Johne’s Disease Control Program (MJDCP) are especially important in understanding how the disease is maintained and transmitted in dairy herds infected with JD.
Dr. Roxanne Pillars did a study of the presence of MAP in environmental samples taken from seven JD infected farms that participated in the MJDCP. As a part of the study, samples were taken from the floors, feed and waterers of maternity pens over time.
In the study, 17% of the samples taken from maternity pen floors tested positive for MAP. This is alarming because calves are born onto these floors and therefore, at the point when the calf is most vulnerable, the risk of exposure to MAP is high.
Another study by Dr. Mike Bolton gives us even more cause for concern. He swabbed the skin of seven cows in the maternity pen or the close-up dry cow pen on a 140-cow herd with a JD prevalence of less than 5%. Swabs were taken and cultured from the hock, brisket, and udder. Fecal and blood samples also were collected to determine whether these cows were infected with JD.
Six cows tested negative for JD based on both the blood and fecal samples. One cow was positive on both tests. We would expect from those results that the risk of JD transmission to newborn calves would be present only from the infected cow.
However, the skin swabs revealed a much greater degree of risk. From five of the six test-negative cows, MAP was cultured from their skin. Therefore, a calf that suckles, and in the process may suck on other accessible parts, may be exposed to MAP from the majority of cows in a herd with even low disease prevalence.
Results from MJDCP further strengthen our recommendations to remove calves from the maternity pen soon after birth and not allow them to suckle for colostrum. Individual calving pens present the least amount of risk and pens should be cleaned between each calving.
Cows sometimes calve before they are moved to the calving pen. This usually means that they calve into a higher risk environment. Reducing the frequency of this is part of good maternity management.
Get calves off to a safe start in life. Provide them a welcoming environment and handling that keeps the joy in this wondrous occasion. Reduce the opportunities for exposure to MAP.
Visit the Michigan Johne’s Disease Control Project for more information.