Johne’s disease is caused by the bacterium Mycobacterium avium subspecies paratuberculosis (MAP) which affects cattle and other ruminants.
Johnes causes loss of body condition, diarrhoea and death; there is currently no cure for the disease.
Because there is no cure for the disease, the best defence against Johnes is to remove infected animals and maintain high levels of bio-security on farms.
Prevention is better than cure
Farmers work hard to maintain high levels of animal health and welfare on farms. Controlling Johne’s disease on your farm will only improve these levels.
MAPs spread is slow and hard to detect; once the bacteria is on your farm its eradication is difficult and often a long, drawn out process.
Like most animal health measures, prevention is better than cure. This starts by preventing MAP bacteria from entering your herd and interrupting its spread if it already has.
The only way this can be done is by regularly testing your herd for MAP bacteria, the most common ways of doing this are through blood testing or milk recording.
Johne’s disease will cost you
According to Animal Health Ireland (AHI) an infected herd without obvious signs of the disease is estimated to cost €33/cow/year.
For a 100-cow herd this amounts to €3,300 or 1.9% of total milk revenue, due to several factors.
These factors include: reduced production, early culling and reduced value of culled animals. Like with most diseases, it will also lead to increased veterinary costs, which will also increase over time as infection rates increase.
Herd status
According to AHI, most herds are not currently infected with MAP and staying that way is important, to avoid animal and financial loss.
If your herd does have an issue with a Johnes infection, it is important that on-farm management practices to prevent its spread are implemented.
This is done to reduce the spread of infection within the herd and minimise the impact of the disease within the herd.
Other benefits of testing for Johne’s disease
The control introduced to prevent the spread of Johne’s disease within a herd will also help to reduce the spread of other diseases in the herd.
This is particularly in relation to disease in calves such as scours and pneumonia.