When it comes to calving time, the risk of Johne’s Disease infecting calves is higher than at other times of the year.
Johne’s is an infectious bacterial disease of cattle and other ruminants which usually become infected in the early weeks of life.
Animals usually become infected during the early weeks of life following the consumption of milk or food contaminated with the bacteria, which are shed in the dung or milk of infected adult cattle, according to Animal Health Ireland (AHI).
The infection develops slowly and the signs of disease vary depending upon the stage of infection but AHI has said that signs begin with reduced productivity followed by weight loss, scour and ultimately emaciation and death.
AHI has said it is crucial to minimise the contact newborn calves are likely to have with adult dung that might contain the bacteria (known as MAP) that causes Johne’s disease.
It also advises to try and ensure calves avoid consuming colostrum or milk that might contain MAP.
The following are measures that should be considered around calving:
1. Cull all Johne’s Disease infected cattle that are showing signs of the disease, i.e. those wasting or chronically scouring.
2. Ensure no test positive or test inconclusive cows are permitted to calve in the same environment as test negative cows.
3. As far as possible calve these animals individually and clean the area thoroughly before any other cattle, particularly those less than six months of age, are permitted access.
4. Remove all calves as soon as possible from their dam (‘snatch calving’) to minimise calf contact with adult dung.
5. The offspring of infected cows have a higher risk of themselves being infected. Therefore treat them as high risk animals.
6.If kept for breeding, they should be calved down in a separate calving area from that used by test negative cows.
7. Ensure dry cows are clean as they enter the calving area i.e. teats and flanks are free from dung.
8. Minimise the number of animals calving at the same time in the same pen as this reduces the risk of newborn calves being exposed to multiple cows, their dung and their milk.
9. Ensure calving areas are regularly cleaned and as a minimum that additional bedding is added such that cows are calving onto a clean and dry surface.
AHI has said that achieving adequate control of Johne’s disease is challenging and requires long-term commitment over several years.
One of the best ways to prevent the introduction and spread of infection is to participate in a control programme such as the AHI Johne’s Disease Control Programme over several years.
Participation in such programmes for limited periods of time, or only partial adoption of control measures, will limit the extent to which the disease can be controlled or prevented, and the assurances that can be provided in relation to the herd’s Johne’s Disease status.
