Cattle movements spread TB

Wednesday June 01, 2005 15:12

by Mother Earth

Farmlands all over Ireland are laced with badger snares. The Government Lab in Lucan, Dublin, is a Slaughter House for our indigenous wildlife. Will the Government put an end to the mass slaughter of Badgers now? Or is this something else that the Irish Farmers Association (IFA), the Meat Industry, and the Government will continue to cover up?

NEWS RELEASE: National Federation of Badger Groups

Cattle movements, not badgers, are the best predictors of bovine TB

A paper to be published in Nature on 26 May 2005 [1] has found that cattle movements "substantially and consistently outweigh all other variables" for predicting the presence of bovine tuberculosis (bTB) amongst cattle.

Dr Elaine King, Chief Executive of the National Federation of Badger Groups, said: "After 30 years of blaming badgers for spreading bTB, farmers and vets have to face up to the reality that farming itself is to blame for the massive escalation in the disease and its spread all over the country. Until DEFRA gets a grip on cattle movements, bTB will continue to cost tax payers a fortune in needless compensation payments every year.

"The movement of TB-infected livestock was allowed by MAFF in the wake of foot and mouth disease. The farming unions claimed credit for MAFF's catastrophic decision. As a result, bovine TB has spread to every veterinary division in England and to previously unaffected parts of Wales and Scotland.

"Badgers, deer and other wildlife may yet be shown to play a minor role, but the current scientific evidence confirms that DEFRA's new strategy to clamp down on the movement of cattle is going to be effective in controlling bovine TB, provided the measures are properly enforced. Farmers and a minority of vets should stop opposing those measures immediately."

The research, by Dr William Wint and colleagues at Oxford University's Environmental Research Group, looked at more than 60 possible predictors of TB and statistically narrowed the field to 20 predictors. Dr Wint has told the NFBG that:

"Cattle movement substantially and consistently outweighs all other variables in predictive power. The prediction is for the presence as opposed to spread or incidence - of bTB. The key parameter is cattle movement into a location from an area that has recently been infected. Movement is important at the national scale and for areas outside what might be termed the 'core' bTB areas.

"For the core areas, where bTB is widespread, movement remains a significant predictor in most but not all years and it is not as dominant in its influence as it is elsewhere. This is probably because movement levels don't vary enough at the local scale to be useful predictors. But we are confident that movement plays a role in the core areas."

Dr Wint says that further time and analysis would allow his team to "home in" on the different kinds of cattle movement involved in bTB spread. He speculates that the length of time an animal spends at a location may also be a predictive factor, but further research is needed.

The researchers successfully predicted the presence of bTB in previously unaffected areas and Dr Wint warns: "If current trends continue, there may be a risk that bTB will become established in North-east Wales, Cumbria and the Scottish Borders."

Dr Wint used existing data to test the strength of different predictors. Cattle movement consistently came out on top. Other less significant predictors of the presence of bovine TB were:

- the seasonality and timing of climatic variables (particularly relative humidity, rainfall and air temperature); and - vegetation (particularly the percentage of managed grassland).

Interestingly, human population density and an index of badger presence were also predictors, though neither was as consistently significant as cattle movement.

ENDS