Controversial badger cull one step closer

By Ruth Hendry - 19 Jul 2011 21:37:0 GMT
Controversial badger cull one step closer

UK Environment Secretary Caroline Spelman announced today that the government is "strongly minded to back" a cull of badgers in an attempt to halt the spread of bovine tuberculosis (TB). A devastating disease, bovine TB destroys farmers' livelihoods and cost the UK £90 million last year, when nearly 25,000 cattle were slaughtered.

The government intends for pilot culls to go ahead next year in two areas, most likely in the southwest of the UK where bovine TB is particularly prevalent. These pilot culls will be reviewed by an independent panel to determine whether culling is effective; if over 70 percent of badgers in an area of 150 square kilometres can be culled in a six-week period. If the pilots are successful, culls will continue across the UK.

However, is this policy really "science-led", as the government claim? A recent study, based on the analysis of data from the 10-year Randomised Badger Culling Trial (RBCT) set up by DEFRA, has shown that localised badger culling can more than double the risk of TB spreading from badgers to cattle. Badgers remaining after a localised, "reactive" cull can travel a large distance from the cull area, potentially leading to increased contact with cattle.

This is known as the "perturbation effect" and could explain why previous localised culls were ineffective at reducing the spread of TB in cattle. However, culls over a widespread area, involving the death of many thousands of badgers, can reduce infections in cattle by up to 16 percent. Despite this Lord Krebs, lead author of the RBCT, told The Guardian that a vaccine is a better option. He stated "You cull intensively for at least four years, you will have a net benefit of reducing TB in cattle of 12 percent to 16 percent. So you have 85 percent of the problem still there, having gone to a huge amount of trouble to kill a huge number of badgers. It doesn't seem to be an effective way of controlling the disease."

In the RBCT, badgers were trapped in cages and shot. However, the government, with the support of famers, propose using marksmen to "free-shoot" badgers as they emerge from their setts at night, which is much cheaper. This method has not been trialled and its efficacy is in doubt. Sadly for scientists concerned with gathering evidence, the government does not plan to monitor the perturbation effect of free-shooting. Mary Creagh, shadow environment secretary, told the BBC that the decision to allow culls "is driven by political expediency rather than sound science."

So what are the alternatives to a cull? The major alternative would be vaccination of cattle. Whilst an oral vaccine is not currently available, the previous government had promised to that one would be available to farmers by 2015, which could be much cheaper for farmers than a cull. Now, the current government has cancelled 80 percent of the vaccine trials.

Rosie Woodroffe, one of the authors of the RBCT, spoke to The Guardian "The culling plan is a very expensive distraction from really dealing with the problem...instead these enormous sums could be invested in increased biosecurity on farms and vaccine development." With strong opinions on either side, a legal challenge to any badger culls announced by the government appears almost certain.

Top Image Credit: © Mark Bond