Blood Testing

There are a range of testing options available to dairy farmers to verify the Johne’s status of individual farms.

Initial Screening

Samples should be taken from a selection of animals using the following criteria for selection:

  • Between 3 – 7 years old
  • Cows affected by lameness
  • Generally depressed animals
  • Repeat high SCC or mastitic cows
  • Cows demonstrating a drop in milk yield

Alternatively cows should be tested before culling. This will provide an indication of whether Johne’s disease is a problem in the herd.


Repeated screening following the criteria above can be used to monitor herd status. Your vet can advise you which animals should be selected and the frequency of the screening required.

Individual Cow Testing

Whole herd screening involves testing all animals over two years of age. The frequency of this testing should be determined in discussion with your vet. The results of this testing should be used to inform management decisions as part of an ongoing control programme. Your vet will be able to advise on available programmes.

The NMR Group offers a number of different Johne’s surveillance programmes for dairy farmers. To view the options available, please visit the NMR website.