As there is no known cure for Johne’s disease effective biosecurity is the key to avoiding its introduction. The new AHI guidelines detail where these risks come from and how to control them.

Notably, several of the risks focus on farm machinery and dung. As tractors are busy across all farms harvesting silage and spreading slurry, particular attention should be paid to these risks.

1. Introduced animals

Even animals that appear healthy may carry the disease without displaying any symptoms. To control this risk, the number of herds from which animals are introduced should be minimised and ideally they should only be from low-risk ones.

2. Biological materials

Colostrum is the main risk here. As calving has passed on many farms it is not of immediate concern. However, all colostrum used should be handled hygienically and come from Johne’s-free cows.

3. Slurry

As the bacteria responsible for Johne’s disease can be passed through dung, slurry is of major concern. Imported slurry can increase the risks of disease entering a herd and its application to pastures where young stock are grazing should be avoided.

4. Farm workers

Workers that have visited a number of farms can carry infected material back. Cleaning areas should be provided on farms to wash both hands and footwear.

5. Vehicles

Infective material carried on the tyres of machinery and tractors poses a similar risk as farm workers. Especially where machinery has been involved in slurry spreading elsewhere, tyres should be cleaned before entering the farm.

6. Farm visitors

As summer holidays are taken by many, visitors to farms may become more common. Similar to farm workers if they have visited other farms they may be carrying infective material.

7. Returning animals

Animals can be exposed to risks off-farm when they leave for shows and marts or contract-rearing units. All off-farm areas should have good biosecurity practices and all equipment used for transport should be cleaned on return.

8. Equipment

During this busy period on many farms it may be necessary to borrow equipment from neighbours and friends. While this should be avoided where possible, should it occur all equipment must be well-maintained and thoroughly cleaned before and after use.

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