Take steps to keep your herd free from Johne's
Published 12/07/2011 | 05:00
Johne's Disease is a slow, debilitating disease that we are seeing more frequently in herds nowadays. In years gone by, the incidence of the disease was so low as to call it rare in this country. There were only two herds in this practice area that were known to have the disease.
More recently, we've seen more and more cases and now it's a disease we must all check for as part of the health status of our herds.
Johne's Disease spreads from dam to off-spring, particularly around calving time. The most obvious transfer of the disease occurs via the colostrum or first milk. The bacterium is present in the colostrum of the infected cow and when the calf suckles its dam, the bacterium enters the stomach of the calf.
In the first few hours after birth, the calf's intestinal wall can allow much larger proteins than normal to cross directly into the bloodstream. The bacterium is thus carried directly across into the calf's blood and the animal becomes infected for life. Therefore, the obvious way to break the cycle of disease is to avoid the consumption of infected colostrum.
To do this we must first blood or faecal test the cows and identify the carriers. Those cows then must have their colostrums discarded and their calves fed un-infected colostrums from a known disease-free cow. That sounds easy on paper but there are many complications with the steps just mentioned. We may discuss them another time.
For today's report, suffice to say that all well managed suckler farms would be well wise to set plans in motion to eradicate the disease from their herd. Discuss the hows and whys with your vet and take solace in the knowledge that Animal Health Ireland is putting a big effort into helping farmers to identify and control this disease.
The disease itself, as mentioned earlier, is a slow-growing disease that can take up to four years or more to show clinical signs. The most obvious signs include a profuse diarrhoea and chronic wasting away of adult cattle. Treatment is impossibly expensive and simply not an option.