The government expects to decide its policy on badgers at about the time this issue of People & Science appears. It will do this on the basis of its recent consultation as well as ‘the available scientific and economic evidence, and the results of the spending review’. In the consultation, it proposed allowing badger culling – at the farmers' expense – in a number of TB hotspots. Below, the Badger Trust and the National Farmers Union set out the policy they want to see.
Concentrate on cattle, says Michael Hughes
Badger culling, whatever form it takes, is a crude, non-selective, ineffective, uneconomic, misdirected blunderbuss of a tool.
Its localised use in the random badger culling trials materially increased TB in cattle, and, applied more widely, its disease-reduction impact (frequently overstated by the pro-cull lobby) has been shown to be relatively short term.
Even in TB hotspots, around eight out of 10 badgers are disease free, so culling takes out many more healthy badgers than it does infected ones. Worse, when culling stops, the level of infection in the remaining badgers is higher than before.
So the way forward has to be through a combination of badger vaccination and rigorous, sustained cattle management. This must include improved testing. The current skin test is only 80 per cent effective at best. As a result, many infected cattle escape detection.
To understand why badger culling won’t work, you have to understand badger behaviour.
Badgers are social animals. They live underground in close, family groups and share the same strongly-defended foraging territories. Culling doesn’t simply reduce their numbers. It causes stress, destroys their social structure, and changes the behaviour of surviving badgers. They range much more widely; the prevalence of infection rises; and they may come into contact with more cattle, increasing the risk of disease spread. The effect is known as perturbation.
The Independent Scientific Group (ISG) on Cattle TB carried out the Random Badger Culling Trial (RBCT ). It amply demonstrated that perturbation has significant adverse consequences on the incidence of badger TB (bTB).
Proposed culls inadequate
Crucially, both proposed culls in England and Wales have been widely condemned as inevitably leading to greater perturbation. Neither embodies a control mechanism which will allow culling to be objectively analysed, and both ignore the ISG’s key conclusion that badger culling can make no meaningful contribution to the reduction of bTB.
Among other obvious shortcomings, the proposals include no requirement for culls to be conducted simultaneously and sustained for years. Both are essential criteria, says the ISG. In addition, as government admits, culling will cost farmers more than it will save.
The importance of cattle-to-cattle infection can’t be overstressed. The ISG demonstrated that buying cattle on the basis of a clear test from herds previously infected is dangerous, and can and does reintroduce disease back into a herd. Oddly, pro-cull organisations accept that, post foot and mouth, cattle sold from southwest hotspots to previously clean areas in the north were directly responsible for the introduction of bTB. But they appear unwilling to accept that the frequency of cattle trading within hotspot areas means transmission from cattle to cattle, herd to herd, is effectively continual.
Yes, of course, farmers must buy and sell. But if they also want to beat TB they have to stop importing and exporting disease.
The accredited herd scheme enforced very successfully in the late 60s and early 70s provides the template: double fencing to separate cattle from neighbouring cattle, increased biosecurity and a rigid rule that clean farms buy in cattle only from other accredited farms, and not from farms with lower disease status.
Badgers may be part of the TB problem, but they are not the root cause. To minimise their role, the aim must be to avoid perturbation. That rules out culling, and ought to usher in vaccination as a support mechanism for much more rigorous cattle-based controls. A pilot study completed early in 2010 indicated that vaccination reduces transmission within the badger population, which in turn could ultimately cut badger-to-cattle transmission.
Unlike culling, vaccination poses no perturbation risk and is publicly acceptable. In conjunction, ultimately, with a cattle vaccine, it must be the way forward.
We must cull badgers, says John Royle
The incidence of TB in cattle in England and Wales has been rising and spreading north and east for 25 years despite the introduction of a range of strict cattle control measures. These include annual herd and pre-movement testing in endemic areas, regular testing every three to four years in non-endemic areas, the slaughter of test-positive animals (over 25,000 in 2009) and strict herd restrictions preventing movements into and out of the herd.
It is clear to all those involved with and who understand livestock farming that cattle controls alone cannot and will not eradicate this disease. In those parts where there is no reservoir of TB within wildlife, namely the north and east of England and Scotland, the cattle testing and slaughter regime works well and herd incidence of TB is low. Unfortunately, across large parts of England and Wales badgers are directly involved in the cycle and transmission of TB and, more importantly, act as a reservoir effectively harbouring the disease.
Proactive culling effective
It is for this reason the NFU welcomes the coalition government’s commitment, as part of a wider package of measures, to develop affordable options for a carefully managed and science-led policy of badger control in areas with high and persistent levels of bovine TB.
Evidence from the Randomised Badger Culling Trial (RBCT ) has clearly and unequivocally shown that proactive culling, if carried out on a sufficient scale and in a coordinated manner, sustained over a period of time, will significantly reduce the incidence of bovine TB in cattle in high incidence areas.
Many argue that culling will only make the situation worse. However this is contrary to the follow-up evidence from the RBCT which stated that culling was associated with a 28.3 per cent reduction in herd incidence inside culling areas. On-going monitoring shows the positive effect of culling on herd breakdowns is maintained for at least five years after culling. It also shows that any negative effect on confirmed herd breakdowns in the surrounding 2km ring disappeared quickly.
We strongly believe that an industry-delivered control policy would be both humane and cost effective. Through the effective use of appropriate boundaries and buffers, opportunities for movement and interaction between badger social groups would also be significantly reduced.
Vaccination evidence lacking
While there is definitive evidence demonstrating a positive effect resulting from proactive badger culling, the same cannot be said for vaccination. Unfortunately there is no evidence to support the theory that vaccinating badgers will lead to a reduction in the disease in cattle. Using even the best estimates it would take many years for vaccination to have any meaningful impact, particularly in the endemic areas where the TB incidence in cattle is high and many of the badgers are already infected.
This lack of evidence to date, when combined with the high costs and practicalities of deployment, leave the role of vaccination in considerable doubt. Until this evidence has been gathered it is difficult to conceive how government or industry can advocate, let alone proceed with, the large-scale deployment of badger vaccination.
Break the cycle
The NFU believes eradication is only achievable, given the current scale of the problem, if action is taken now to break the cycle of disease. Using a combination of cattle measures, raising the awareness of on-farm biosecurity, implementing a coordinated badger control programme in endemic areas is a must. In the longer term, once the disease in cattle and badgers is more under control, we do see vaccination of badgers, preferably orally rather than by injection, playing a key role in achieving and maintaining disease free status.
For now, doing nothing is not an option.