David Hedges ventures into the debate over bovine tuberculosis epidemic in west WalesJuly 26th, 2011
Bovine tuberculosis (bTB) has reached epidemic proportions in the cattle industry, and is costing millions of pounds. Badgers are known to carry and transmit the disease. Despite being one of Britain’s favourite mammals they are also seen by many in rural Wales as a pest and the cause of much of the bTB problem in cattle.
In the Spring 2010 edition of Agenda I wrote a piece entitled To Cull or Not to Cull which looked at the controversy around the Welsh Government’s proposal for culling badgers in parts of west Wales. Whilst the Badger Trust’s legal challenge was rejected by the High Court, it was overturned by the Court of Appeal in July last year. This last decision rested on the poor definition of the cull area in the legislation, rather than on any other argument.
Culling has been seen as part of a wider set of measures to tackle bTB in cattle. These include routine testing and surveillance, pre-movement testing, movement restrictions, the removal and slaughter of infected cattle, the promotion of better biosecurity, and advice and support to farmers. The extent of the disease, the social and economic costs of its treatment and the uncertainty it creates for farmers whose livelihoods revolve around their ability to rear cattle has pressured governments to consider urgent action. The latest figures for Wales are no less worrying – £12 million paid out in compensation last year and over 10 per cent of all farms under movement restrictions.
It is interesting that Labour’s defeat in Westminster in 2010 and its success in forming a Government in Cardiff Bay following this year’s elections has marked significant shifts in policy in both countries. Here Labour has announced a review of the science before any cull. In England a number of vaccination trials have been replaced by proposed culls (likely next year).
The policy change in both countries has been accompanied by references to the need to ground the overall approach to tackling bTB in ‘the science’. In England’s case Caroline Spelman, the UK Government’s Minister for Environment, Food and Rural Affairs, has indicated a likely licensing system which would allow culling under certain conditions, which she says is based on scientific research.
Earlier this month John Griffiths, Minister for Environment and Sustainable Development in the Welsh Government, announced that he had commissioned a “review of the scientific evidence base” regarding the eradication of bovine TB in Wales. He also made clear that there would be no cull of badgers in what’s called the Intensive Action Area while the review is being carried out. Professor Christopher Gaskell, Principal of the Royal Agricultural College, has been asked to chair the panel of experts tasked with reviewing the scientific evidence base. He is expected to report in the autumn.
Professor Gaskell was one of a number of scientists who took part in a meeting in April this year at the Department for the Environment, Food and Rural Affairs with its Chief Scientific Adviser and Chief Veterinary Officer. One of its conclusions was that the
“…current trend for generally increasing bTB incidence in cattle clearly indicates that the current set of control measures is insufficient to bring about eradication of bTB in cattle. Existing control measures will not be fully efficient without effective measures to address transmission between badgers and cattle”.
The meeting also concluded that “if culling was undertaken, it should be in addition to, not instead of, existing bTB control measures in cattle, which should be maintained and strengthened”. These were clear views that culling is seen as having a positive effect on controlling bTB in cattle.
That meeting was also attended by Professor Lord John Krebs, Chairman of the House of Lords Science and Technology Select Committee and author of a 1997 report which concluded that badgers were a ‘reservoir’ of bTB and could transmit the disease to cattle. The report led to the ten year Randomised Badger Culling Trials in England. The results of the trials showed that widespread, highly coordinated culls, requiring the destruction of many thousands of badgers, resulted in a reduction in new infections in local cattle herds of about 16 per cent. Evidence also showed that there was an increased risk of bTB infection associated with land bordering on cull areas. This was attributed to ‘perturbation’, in which culling disrupts the social structure of badgers and the surviving individuals on the periphery of the cull area come into contact with cattle and badgers, spreading bTB.
Earlier this month Lord Krebs said:
“You cull intensively for at least four years, you will have a net benefit of reducing TB in cattle of 12 to 16 per cent. So you leave 85 per cent 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 an interview on BBC Radio 4’s Today programme he said “Killing badgers is the wrong solution”. He believes that a better option would be to try to develop a vaccine in the long term, and in the short term to use better biosecurity measures to prevent cattle from coming into contact with badgers and other sources of the disease, and to prevent them passing it to each other.
The successful development of vaccines for cattle and badgers appears many years away. The UK Government says it’s investing in the development of vaccines and will allow licenses for culling and also for culling and vaccinating as part of it’s latest plans. But effective oral bacterial vaccines which both prevent disease and transmission amongst badgers are only now being used in experiments on laboratory mice. The last UK Labour government had planned five pilot vaccination projects, but the new coalition government reduced this to one.
The National Trust’s Killerton estate in Devon was among the sites axed. However, at a cost of £80,000 per year, the National Trust is picking up the project, making use of the fact that some of the preliminary research (such as mapping out badger setts) has already been done. Eighteen tenant farmers are involved in the vaccination programme which started in May and lasts until 2015 . It covers an area of 20 square kilometres in the heart of cattle rearing country and one of the real hotspots for bTB in Devon. The vaccine is given to the badgers by trained and licensed experts. The badgers are caught in live traps, without being harmed, injected with the vaccine and then marked so that they are not given the vaccine twice during a trapping operation. It’s an expensive operation to vaccinate in this way (around ten times more expensive than controlled shooting according to DEFRA), which is why the development of an oral vaccine is so important. But the effect of vaccination needs to be tested and evaluated.
So what’s likely to happen over the next year? In England we’re likely to see applications for licenses to cull badgers and further campaigning and challenge by opponents, some of which may see action in the courts. One particularly controversial idea is that the licences will allow badgers to be shot in the field, rather than be trapped first. In Wales, despite Lord Krebs’ conclusion, its hard to see Professor Gaskell and his panel of experts recommending control measures for the disease which exclude culling. The pressures from farmers for culling to start and the growing costs of compensation are bound to weigh on the mind of the Minister. Maybe there’ll be something more positive on the vaccination front – or maybe some combination of culling and vaccination in parts of the country where the problem is worst. But what of the debate?
The geneticist Professor Steve Jones has recently reviewed the impartiality and accuracy of the BBC’s coverage of science. In his report he makes reference to policy emerging directly from science and cites the plan to cull badgers in Wales and not in England turning on disagreements about the epidemiology of bovine tuberculosis. But he goes on to say that broadcast coverage has concentrated on the views of farmers or of animal activists rather than on the technical aspects of transmission of the disease.
Bovine tuberculosis continues to be the subject of considerable debate. This is also true of the huge body of scientific research related to the disease. The BBC or any other broadcaster is unlikely to want to get too technical in its coverage – it doesn’t make good TV or radio. So we’ll continue to hear from proponents and critics on what the science tells us about culling, whether culling is an effective policy for controlling disease, and whether its ethically and morally right or wrong.