TB is not spread from badgers to cattle through direct contact – Study

Badgers prefer land more than 50m from cattle and TB is more than likely spread between the two species in a shared environment, a new study has found.

Researchers at the Zoological Society of London have found, through the use of GPS collars on both badgers and cattle, that there is very infrequent direct contact between badgers and cattle.

The spread of TB from badgers to cattle is likely caused by cattle coming into contact with infected faeces or through feeding troughs.

By using the GPS collars and proximity-sensing contact-collars to explore opportunities for transmission of Mycobacterium bovis [causal agent of bovine tuberculosis]between cattle and badgers, the researchers found that cattle pasture was badgers’ most preferred habitat.

To give an unbroken picture of badger and cattle movements both indoors and outdoors, researchers used a combination of:

  • GPS collars (to monitor animal movement).
  • ‘Proximity’ collars (to detect when a collared badger is within a 2m radius of a collared cow and the location of the contact).
  • CCTV surveillance (to monitor indoor spaces).

The combination of all three methods in parallel allowed the researchers to identify when and where there is direct contact between badgers and cattle.

Nevertheless, although collared cattle spent 2914 collar-nights in the home ranges of contact-collared badgers, and 5380 collar-nights in the home ranges of GPS-collared badgers, researchers detected no direct contacts between the two species.

The research, which was published in the journal Ecology Letters, was based on dairy and beef farms in four areas across Cornwall, which range in badger density.

Professor Rosie Woodroffe of the Zoological Society of London, who led the study, said that advice to farmers will now need to be re-assessed.

Speaking to BBC News she said that there are loads and loads of things that farmers are being advised to do and there is no certainty that any of them will actually work and because of this, hardly any farmers implement any of these sorts of measures.

The researchers are now trying to identify how the disease is transmitted – with the most likely possibility is that it is through badger faeces and urine which may leave the TB infection in grazing pasture for many months.