Positive action on Johne’s, the silent disease
It is always pleasing to be able to write about something positive which is happening in the dairy industry.
The subject in question is Johne’s disease, and it is encouraging to learn how the dairy industry has joined forces to tackle it.
Johne's disease, also known as Paratuberculosis, is a chronic, contagious bacterial disease of the intestinal tract that primarily affects sheep, cattle (especially dairy cattle) and goats as well as other ruminant species. It is caused by Mycobacterium avium subspecies paratuberculosis. It is important to add that the disease cannot naturally be transmitted to humans, although the organism that causes it has been found on occasions in patients with Crohn's disease.
It is characterised by a slow progressive wasting of the animal and increasingly severe diarrhoea. Farmers who have experienced the disease will not need reminding that it is very costly. Infected dairy cows are twice as likely to have a cell count above 200,000 cells/ml, twice as likely to have milk yields 25 per cent below the herd average and likely to be culled early.
The losses continue until the disease is brought under control which sometimes can take years. As farmers and vets know, one real hurdle in control is that infected animals can test negative for the disease, often for several years. Hence it is sometimes called “the silent disease”.
Johne’s infections are almost always introduced to a herd by purchasing infected replacement breeding stock – although there are other risks of introducing the disease including importing slurry from other farms and swapping colostrum between herds. Animals are usually infected as calves with approximately 80 per cent of infections occurring within the first month of life. Ingesting faeces from contaminated bedding, udders, teats or buckets is a main route of infection.
Recognising the welfare and economic consequences of Johne’s, an industry-wide action group was established a couple of years ago which developed a strategy to tackle Johne’s. Known as the National Johne’s Management Plan, phase one had relatively modest ambitions; farmers assessed the risks of disease entering the herd and worked with their vets to develop a control strategy.
Earlier this year, the industry came together to discuss phase two of the initiative, building on the foundations created by the first phase of the plan. The key component of phase two is a system of independent veterinary certification of control activities on-farm. Milk purchaser-members of the NJMP will require their supplying farmers to obtain a signed declaration by a BCVA Johne’s certified vet annually, which states that the farmer has an appropriate and robust Johne’s management plan in place. The scheme will last for three years.
This very positive initiative is jointly funded by DairyCo and milk purchasers, and will surely help manage and reduce the incidence of Johne’s, the silent disease, in dairy herds.
John Sumner is secretary of Shropshire Chamber of Agriculture.
