Badger cull may not be long-term solution to TB
THE krebs trial may not be perfect, but it is a major opportunity to address the contribution of badgers to TB in cattle.
For over 20 years MAFF has used badger control to resolve the problems of TB in cattle with little success. In fact this solution was naive and short-term, says head of the Central Science Laboratorys wildlife diseases unit Chris Cheeseman.
He told visitors at a Farming and Wildlife Advisory Group farm walk, at Geoff Phipps, Home Farm, Caversfield, Bicester, Oxon, that consequently the TB problem has deteriorated in the last 10 years.
"MAFF promoted the idea that removing the maintenance host of bovine TB, the badger, was a good idea and because of this farmers linked TB in cattle to badgers.
"But there is still a TB problem in cattle and there is lateral spread amongst cattle themselves. One criticism of MAFF is that they pin-pointed the problem as being in badgers, while the cattle TB problem has not been resolved."
Culling badgers may not be the answer, says Dr Cheeseman. Badgers are social animals with their own social hierarchy. Removing badgers, therefore, causes disturbance in the population and can exacerbate their movement and spread the disease.
While TB remains endemic in badgers, adopting a policy of proactive control – wiping out the badgers in an area – is only a short-term solution. "In five to 10 years they will re-colonise old sets and the problem will return to previous levels. So would it be cost-effective?"
There is also the possibility that culling infected badgers might remove those which that have become resistant to bovine TB.
"This is a big unknown, but there is evidence to suggest resistance among some badgers and it would be counter-productive to remove these animals from the breeding population," he says.
A vaccine offers the only real chance of controlling TB in cattle and badgers, but it is no panacea. Its probably 10-15 years away and raises other questions, he warns.
For example a vaccine for badgers would be difficult to administer. "It would have to be given orally. This is a big problem as they would need baiting, and vaccine may only reach 50% of the badger population."
A cattle vaccine programme also raises problems concerning cattle exports. It may not be acceptable to our EU partners. Furthermore, cattle which are vaccinated would probably be positive to the TB test which adds further complications, adds Dr Cheeseman.