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  BBC 14 Dec 05
Policy may have spread cattle TB
By Richard Black

EurekAlert 15 Dec 05
Badger culling to control TB in cattle has mixed effects

PlanetArk 15 Dec 05
Badger Cull Questioned as UK Tackles Cattle Disease
Story by Nigel Hunt

LONDON - Britain's farm ministry is due to announce on Thursday whether badger culling will have a role in tackling the spread of bovine tuberculosis in cattle, the day after two new studies raised questions about its effectiveness.

A group of scientists published a report in Nature magazine indicating culling would be most effective if undertaken over very large areas but, at such a scale, it would need to be determined whether the benefits outweighed the economic and environmental costs.

A second study in the Journal of Applied Ecology found culling increased badger movement in surrounding areas, boosting contact with cattle and other badgers and resulting in an increase in TB infection outside culling zones.

"These results help to explain why badger culling appears to have failed to control cattle TB in the past, and should be taken into account in determining what role, if any, badger culling should play," the second study said.

Badgers are a wildlife host for bovine TB and have been implicated in the spread of the disease. The UK government has backed badger culls on a trial basis for several years to determine their effectiveness in fighting the disease.

Wildlife group the Badger Trust said the studies showed that culling of badgers was not a viable option. "You would have to have culling from coast to coast and the end doesn't justify it," said Trevor Lawson, spokesman for the group said, noting the UK government had indicated most outbreaks were spread by the movement of cattle, not badgers.

A total of 20,423 cattle were slaughtered during the first eight months of this year following positive herd tests for bovine TB, up nearly 37 percent from 14,940 in the January to August period last year, according to data issued by Britain's farm ministry.

UK animal welfare minister Ben Bradshaw is expected to back pre-movement testing of cattle as part of the government's strategy for tackling the disease, industry sources said.

The outbreak spread rapidly as cattle farms restocked after the foot-and-mouth disease outbreak in 2001. There were 8,353 cattle slaughtered following positive tests in 2000.

The National Farmers Union, which backs some culling of badgers in infected areas, has said farmers would be willing to accept compulsory pre-movement testing of cattle "only if action to deal with the disease in badgers is taken simultaneously."

EurekAlert 15 Dec 05
Badger culling to control TB in cattle has mixed effects

According to a letter published in Nature, widespread culling of badgers caused a 19 per cent reduction in the incidence of cattle TB in the areas culled, but also led to a 29 per cent increase of TB in surrounding areas.

The researchers suggest the increase is caused by the remaining badgers roaming more widely. The team had previously found that localised 'reactive' culling increased TB incidence in cattle by 27 per cent.

Ecological data suggests that increased badger movement caused both increases in TB incidence.

Where badger population densities were reduced by culling, their usual territorial organisation broke down and the remaining badgers travelled longer distances potentially encountering more cattle.

Professor Christl Donnelly, from Imperial College London and first author, said: "The fact that widespread culling has both simultaneous negative and positive effects could have important implications for policies to control TB in cattle. Although we believe very large culling areas would act to reduce TB, it is not clear whether this would prove economically and environmentally sustainable."

Bovine tuberculosis can have serious consequences for cattle herds, and if found to be infected, cattle are compulsorily slaughtered. Although the infection can be spread from cattle to humans, the risk is extremely low due to routine testing of cattle for infection and pasteurisation of milk and milk products.

BBC 14 Dec 05
Policy may have spread cattle TB
By Richard Black Environment Correspondent, BBC News website

British government policies during the last 20 years may have contributed to the spread of TB in cattle.

Policy has been to cull badgers in areas near a TB outbreak; but new research says this spreads the disease because remaining badgers roam further. It suggests that to be effective, culls must be widespread and thorough.

The government is due to announce a new policy on Thursday, with farmers groups urging systematic culls and animal welfare groups arguing against. The government is giving no clue about its intentions, but opposition MPs believe an extension of culling will be involved.

Inevitable conclusion

"My impression is that the government has been moving almost ineluctably to the inevitable conclusion that regrettably we must bear down on both cattle and wildlife," said Geoffrey Cox, Conservative MP for Torridge and West Devon. "We do need an announcement now," he told the BBC News website, "we simply can't delay any longer."

Bovine TB has been spreading inexorably across Britain in recent decades, with incidence rising at about 18% per year. The annual cost is estimated at £60 million, which the National Farmers Union (NFU) says could rise to £145 million within five years.

Liberal Democrat Rural Affairs spokesperson Colin Breed MP also called for a decisive resolution, which he said should incorporate three elements: an immediate and focused programme of badger control in hot spot areas the introduction of pre- and post- movement testing of cattle immediate and increased Government support for the development of a vaccine

"If this situation is not tackled in an urgent and positive way," he said, "we will inevitably see a continuing spread of the disease and continuing misery in the farming industry."

Blame game

Historically, many farmers have blamed badgers for spreading the bovine TB bacterium, and in 1986 the government introduced a strategy of culling badgers around infected farms.

A decade later, a committee chaired by Professor John Krebs began a policy review which concluded that a proper scientific assessment was needed. Hence the establishment of the "Randomised Badger Culling Trial", also known by its acronym RBCT or "the Krebs trial". It has already shown that the established approach of "reactive culling" near outbreak farms increased the incidence of bovine TB by 25%; whereas "proactive culling", aiming to kill all badgers in the area, brought the rate down by 19%.

One of the new scientific papers, in the journal Nature, looked at farms just outside the proactively culled areas. "What we demonstrate is a 19% reduction inside culled areas, but an increase of 29% in surrounding areas," said Professor Christl Donnelly from Imperial College London.

"From that we demonstrate that a single policy could simultaneously benefit some herds and be worse for others," she told the BBC News website.

The other scientific paper, from the Journal of Applied Ecology, attempted to find a reason why culling has these apparently contradictory effects.

According to study leader Rosie Woodroffe from the University of California at Davis, the key is that badgers expand their ranges when adjacent setts are culled. "Everywhere where there is an impact on badger density there is also an impact on ranging," she told the BBC News website, "with animals travelling much more widely - not only in culled area but in adjoining areas.

"In reactively culled areas and around the borders of proactively culled areas you end up with not many fewer badgers, but with them travelling much further. "I believe this can account for the findings in the Krebs trial." Professors Woodroffe and Donnelly are both members of the Independent Scientific Group on Cattle TB, the government's advisory panel.

Policy issue

Britain and Ireland are the two countries hardest hit by bovine TB.

Habitat is undoubtedly a major reason; but Rosie Woodroffe believes the reactive culling policy may be another.

"It could have contributed to the spread of bovine TB," she said. "The strategy was never formally tested so we can't know; but it's certainly plausible it would have made things worse."

Now farming minister Ben Bradshaw is poised to announce a change of policy which is almost certain, whatever choices he makes, to bring opprobrium from one side or other of a highly charged debate.

"Badgers are not the main source of TB in cattle," said Colin Booty, senior scientific officer of the RSPCA, which is resolutely opposed to culling. "The trial results show that killing large numbers of badgers - most of which are disease-free - may even make the disease situation in cattle worse. Such a policy would clearly not be sustainable."

In the opposite corner is the National Farmers Union, whose vice-president Meurig Raymond told the BBC News website: "A proactive cull can have a big impact. "It would have to be done thoroughly, with well-defined boundaries."

Mr Raymond did acknowledge that farmers will have to accept stricter regimens of TB testing and restrictions on cattle movements if the disease is going to be controlled or eradicated.

Research published in May showed cattle movements to be the single biggest factor in TB spread.

Well done

The message from the two new scientific papers - which were both funded by Defra - is that if culling is to be effective, it has to be done over large areas and done thoroughly. During the Krebs trial, some landowners refused to allow Defra staff access for catching and killing badgers.

A policy of enforcing access might be too draconian for government to contemplate. Catching badgers with snares rather than cages is considered more effective, but also less humane. The cost of a culling programme is a further issue.

Christl Donnelly views the choice before the government as extremely difficult. "They have to decide on either very widespread culls over really expansive areas - but still some farmers would be upset to find themselves on the edge - or decide not to cull on the basis that on reasonable scales it's not going to be effective," she said.

"If I were in Ben Bradshaw's shoes, I honestly don't know; there is nothing I could choose that would make everyone happy."
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