Bovine TB not passed on through direct contact with badgers, research shows

Contact comes through contaminated pasture and dung, with significant implications for farming practices 

Damian Carrington

Friday 5 August 201607.05 BSTLast modified on Friday 5 August 201613.23 BST

Badgers and cattle never came into close contact during a new field study examining how tuberculosis (TB) is transmitted between the animals.

Most TB in cattle is contracted from other cattle but some infections come from badgers. The new research indicates that the disease is not passed on by direct contact, but through contaminated pasture and dung, with potentially significant implications for farm practices such as slurry spreading.

It also suggests why TB in cattle is so hard to control even when cattle and badgers are culled, as the bacteria can survive in fields for months. Eradicating TB will require addressing this risk, the new research implies.

TB is a serious problem for farmers, with 36,000 infected cattle slaughtered in Britain in 2015 at a cost to the taxpayer of about £100m. One key element of the government’s control programme, England’s controversial badger cull, is set to expand.

But the UK’s foremost experts say this “flies in the face of scientific evidence” and that the cull is a “monstrous” waste of time and money. The new research has not changed their conclusion.

The new study, carried out on 20 farms in Cornwall, aimed to shed light on how TB is transmitted between badgers and cattle, a route estimated to be directly responsible for about 6% of herd infections. “We know badgers can give TB to cattle but we have never known how,” said Prof Rosie Woodroffe, at the Zoological Society of London, who led the new research. “It is really difficult to track the movement of what is invisible - the pathogen.”

The breakthrough came thanks to new technology: a GPS collar small enough to be worn by badgers. The researchers tracked more than 400 cattle when they were in the territories of 100 badgers, with the total number of tracked days coming to more than 8,000.

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