It's TB testing season

Author: Rob Powell BVetMed MRCVS

Unfortunately it is the time of year when lots of cattle are being housed and we are very busy TB testing. I recently attended a meeting on Bovine TB so have reported back some of the findings, along with some answers to some common questions that I get asked when on farm.


How much TB is around?

·         High risk area - the definition of a high risk area is that ‘TB is endemic in cattle and wildlife’. The average new breakdown rate in this zone is 10%. These areas will be in an annual testing zone for all animals over 6 weeks old with Pre-movement testing.

·         Edge area - the definition of the edge area is an area in which ‘TB is spreading or there is a short-medium risk of TB spreading’. The average new breakdown rate in this zone is 2%. These areas will also be in an annual testing zone with Pre-movement testing. This accounts for Hampshire, Berkshire as well as other places such as Cheshire and Derbyshire.

·         Low risk area - the definition of a low risk area is an area in which there is ‘a low risk of TB spreading’ these areas will be in 48 month testing zones with no Pre-movement testing. Only adult breeding females and breeding males will be tested.


What will happen if Bovine TB is found on my farm?

New Edge Area Measures:

·         The reactor animal will be DNA tagged by the vet and removed from the farm by the ministry and compensation will be paid. Upon slaughter this animal will be inspected for lesions and culture will be undertaken to try and grow Bovine TB.

·         All herds that Bovine TB is found on in the edge area will then either have their TB status suspended or will have their TB status removed if lesions are found or Bovine TB is cultured from the carcase. This will affect the next stage of the test.

·         If the Official TB status is suspended you will need two consecutive negative 60 day tests that pass on severe interpretation followed by a 6 month check test before returning to annual testing.

·         If the Official TB status is withdrawn you will need a Gamma interferon blood test rather than the normal skin test. This will be followed by a 60 day skin test and a 6 month check test before returning to annual.


How can I minimise the risk to my farm?

The main recommendations from the meeting were:

·         If possible aim for a closed herd. If this is not possible develop a ‘buying-in’ procedure (i.e. check the TB status of herd and ensure evidence of a Pre-movement test.

·         In a perfect world all purchased stock would be isolated for 2 months and the animals would be tested again in a Post-movement test. There is a cost to this in terms of extra labour and paying for a second test, however the skin test will not pick up animals that are in the very early stages of Bovine TB. Animals also have 60 days to be moved after a Pre-movement test so could pick up infection before being moved onto the next farm. This may not be practical or cost effective for a proportion of our clients but a TB breakdown is not cheap either.

·         Secure stock buildings against access by badgers, especially feed stores (concentrates, straights, maize or whole crop). Also feeding areas, stock accommodation and grass silage fences. If solid barriers are not possible use electric fencing (3 strands set at 10, 15, 20 and 30cm from the ground)

·         Bovine TB can survive in manure so ideally store manure for 6 months and try not graze for 2 months after spreading. Do not source manure from other farms.

·         Avoid grazing near badger setts or latrines and ensure cattle don’t have access to woodland. Reduce wildlife access to supplementary feed such as concentrate and mineral blocks.


3rd December 2013

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