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About The Badger Crowd

The Badger Crowd is a support and fundraising coalition including Badger Groups and Trusts around the UK. Ecologist Tom Langton has fronted recent challenges with support from ‘The Badger Crowd’. The legal team is Richard Turney and Ben Fullbrook from Landmark Chambers, London & solicitor Lisa Foster and paralegal Hannah Norman of Richard Buxton Environmental and Public Law, Cambridge. Dominic Woodfield of the ecological consultancy Bioscan UK is working extensively on aspects of the case is a national authority on ecological impact assessment and has provided expert witness evidence on ecological assessment including impacts on SSSI’s. Many other scientists, researchers and legal commentators assist in the background. The Badger Crowd believes that legal challenges are an important fight, not just for the badger but also for the future of our countryside and the farming industry. The badger cull policy is failing farmers, tax payers and our precious wildlife and will make the bTB epidemic worse.

Defra’s badger vaccination hopes: the mask slips

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How did we get here?
Guardian headline from 2020


Back in 2020, Defra were not pleased. Boris Johnson had forcibly overruled Defra Minister George Eustice to impose a gradual move from badger culling to badger vaccination (BV). Defra were not happy about this because their 2018 ‘Godfray’ review had stated, (in this case correctly), that badger vaccination had unknown efficacy in terms of reducing cattle TB. Industry had ‘no appetite’ for BV. Funds and training for experimentation with it at scale were ruled out, making implementation impossible.

Meanwhile, the National Farmers Union (NFU) and pro-cull lobbyists who heavily influence Defra, were happy to see tens of thousands of largely healthy badgers shot each autumn, and were in no mood to swap their guns for vaccine.

But there were no grounds for optimism that the bovine TB (bTB) policy was fully effective and sufficient. While bTB levels, as recorded by Defra’s increasingly wobbly headline measure ‘herd incidence rate’ 0TF-W (confirmed) were coming down with better testing, OTF-S (so-called ‘unconfirmed’) cases were slowly rising. Failure of the tuberculin skin test (SICCT) to sufficiently detect infected cows was becoming more and more obvious to anyone looking responsibly at the problem.

Low Risk Area (LRA) culling slips into the mix

In 2023, the Defra plan seemed to be to keep BV as a small ‘also ran’ badger intervention in a few locations, like it’s small Sussex ‘VESBA’ pilot study (see here). With the 2024 general election in view, Defra tried to side-step the BV plan to enable something called ‘targeted’ culling. This exploited a loophole that had been slipped into the 2020 policy. It allowed for the culling of badgers where APHA claimed assessment indicated ‘need’ (see here). This new culling sideline was built on the hopelessly speculative Low Risk Area (LRA) culling policy which blamed badgers for the spread of TB once it had been introduced via cattle to remoter areas. Clusters of new infections were termed ‘hotspots’. The new policy involved culling up to 100% of badgers in large core areas. It is not possible to demonstrate any disease benefit from such approaches, but this did not stop APHA and Natural England claiming that it was a success, on expectation alone. This was actually a policy with no scientific way to measure success, as a detailed technical review (that Defra and Natural England simply decided to ignore) pointed out (see here).

Chief Veterinary Officer ‘targeted culling’ plans rejected

To permit ‘targeted culling’, Defra and Natural England had to dump their ‘uncertainty’ standards, as again there was no certainty or even likelihood of efficacy. They rejected any dialogue over the issue. Instead a public consultation attempted to give the Chief Veterinary Officer sweeping powers to establish badger culling at will, and without referral.

The ‘cull at will’ endgame of the badger control policy ran into problems in May 2024 when Rishi Sunak called the general election early, and Labour exposed the badger culls as ‘ineffective’ in their manifesto. Unfortunately, Labour’s full grasp of the science and mechanics of the bovine TB and badgers issue was still hampered by two decades of entrenched thinking by Defra’s civil servants, including in and out of house vets and academics. These individuals must have been fearful of how two and a half decades of research, now looking tatty under close independent scrutiny (see here), had created a complex and flawed demonisation of badgers, and had heavily polarised stakeholders. The frittering of so many £ Billions without coherent results, plus stakeholder misery, might have to be accounted for one day too.

The July 2024 election brought both a hiatus and a degree of common sense to the situation, with targeted culling proposals scrapped, allowing Defra to kick the confused impasse into the long grass for a while. For appearances, Natural England dredged up yet more Heath-Robinson and selective scientific opinion to justify pulling out of culling a few years early. But they were quickly slapped down by Defra who prioritised giving farmer ‘certainty’ over science – intensive and supplementary culling continued. They also gave in to industry pressure to start a new LRA cull in Cumbria (see here) based on yet more  speculative guesswork. The unimpressive results of LRA culling were ignored. With hindsight (and some Ministerial insight, see Spectator article), it seems that a shady pre-election deal by Steve Reed with the NFU in 2023 was another reason for the continuation of the intensive and supplementary culls. Although unknown to NFU, it is likely that giving farmers their last couple of years of culling may have been a ‘softener’ to the ‘surprise’ announcement of on farm inheritance tax in October 2024.

2025 Policy review update adds to the confusion

New Minister Daniel Zeichner, unaware of the uncertainty and shifting science around the issue, reappointed the same bTB science panel chosen by Michael Gove to deliver the Conservative Defra agenda. Thus Prof Godfray was reappointed as panel chair, and Defra picked up the reigns again. The Godfray panel needed to massage their 2018 ‘don’t know’ view on BV efficacy into a new policy direction; they obliged in their 2025 review update, contradicting the clear lack of credible supporting evidence. After the election in 2024, and before the re-appointments, Defra had visibly signalled a BV policy direction, taking it as read that it could work. It took time and legal pressure for Defra to admit that the APHA’s ‘Birch’ paper could not link badger culling  2013-2020 to bTB OTF-W decline, reversing Defra’s embarrassing media spin. But Defra persisted with their vague 2020 assumption that BV could reduce disease in cattle, and this is the direction they were pointing.

On 30th August 2024, new Minister Daniel Zeichner promised a ‘strategy refresh’ – although large parts of the 2018 review were either already significantly obsolete or outdated. There would be a year of consultation with key ‘stakeholders’. It all sounded very fair.

But the dozens of people who were cherry picked to ‘co-design’ the refreshed strategy were very close to Defra and under their influence & control, or from industry. Across 2025, Defra paid external agencies to question these favoured representatives in stage-managed workshops, to help rubber stamp its vision of the future. The NGO wildlife sector were struggling to form a collective voice and to be heard. By the autumn they began to complain more visibly about being excluded from the consultation process. Only the Westminster Hall Debate in October 2024 created and promoted by Protect the Wild gave hope that an end to the madness of badger culling was both possible, and in fact was the pre-election promise to be honoured.

Keeping culling alive

Yet despite all this, Defra, were still unhappy. They were trying to keep the door to all badger interventions well and truly open. They placated the NFU with promises that it would be alright in the end, with agri-eyes beginning to shift towards Reform Party politics, and they maintained their scientific position on need for intervention.

The Godfray panel review update had predictably been encouraged to keep the need for all badger interventions alive, as both a face-saving exercise and Defra/NFU wish-list option. They also floated the vastly expensive Test Vaccinate Remove (TVR) option. TVR has uncertain outcomes and no proof of principle, but it kept  badger culling ‘on the table’ for pro-cullers. This is despite a recent report on a large scale study in Northern Ireland that could demonstrate no evidence of any clear bTB cattle benefit. The obliging Godfray panel provided Defra with the pathway to give the NFU what they might wish for; a TVR pilot in 2026 or 2027, testing the resolve of Labours political position.  

Meanwhile, Defra had organised a return to crudely estimating badger density in the winter of 2025, based on sett activity. Under FoI they claimed not to be estimating badger numbers. This gave them the appearance of being busy, taking the focus away from spending too much time on a stagnating policy, as disease control began to flatline. They also decided to push out on badger vaccination with a £1.4 Mn project in Cornwall. This involved paying the NFU to see if Cornish farmers might accept BV if told it might help reduce bTB in cattle, along the lines of the inconclusive VESBA Sussex badger vaccination project, where intensive use of gamma tests had shown some value.

In reply to a parliamentary question by Baroness Bennett on 30th July 2025, junior Minister Sue Hayman denied that the Cornish vaccination project would be assessed in terms of cattle disease efficacy, conflicting with what local farmers had been told and were saying to the press. It seemed a strange statement that may yet prove to be untrue. It seems that data generated by the project is likely to be added to APHA’s national BV research project (see below).

As 2025 ended, a freedom of information response revealed what Defra’s plan was all along. Defra had announced the allocation of around £20 Mn over 4-6 years to BV. This is not a huge amount given the mountain of work required (see here), with the cost per vaccinated badger estimated at nearly £800 once staffing, logistics and operational costs are taken into account.

A secret study uncovered

But what were Defra really up to? The clue was that APHA had started to use any and all recent data from BV to look for change in nearby TB herd breakdowns and compare it against places without BV.  Defra promoted media coverage of a ‘record increase’ in BV which meant very little as the numbers were still relatively tiny. There was no sign of any attempt to replace culling with BV. Why?

What Defra were pursuing was an in-house plan to try to justify the concept of BV. They were aware that their scientific basis for BV was as weak or weaker than it was for culling, and that government needed better evidence. A legal challenge on this issue was possible, either from NFU or the voluntary sector. Some of the APHA staff with past publications who were invested in claiming a need for badger interventions, cobbled together a narrative article about it. They were trying to argue a case for BV that the Godfray panel update could champion (see here).

This arrived just in time to be quoted by the ‘Godfray panel’, who also commissioned a further article using simulated data to try to suggest that badger culling after 2013 might not have been ineffective. This also supported a case that BV vaccination might not be wholly useless (see here). All looking a bit desperate.

Defra’s main plan now is to expand its farm-based badger vaccination analysis. They are going to compare farms/farm clusters in places where badger vaccination has been done since around 2020 (in Cumbria, Cheshire, Sussex, Cornwall and elsewhere) with those where no badger vaccination has been done. The aim is to try to create some science to show BV efficacy. The problem? Such an analysis will be confounded by its inability to control for important variables such as cattle movements and frequency and type of testing. It is all but impossible to undertake meaningful analysis in such circumstances; see APHAs previous efforts on badger culling here, here and here.

Defra have disclosed in recent weeks:

The analytical approach being developed by APHA involves quantifying exposure to badger vaccination at a herd level, rather than by looking at large contiguous areas, which was the approach taken for the Badger Control Policy.

Quantifying badger vaccination exposure at a herd level means that cattle herds potentially affected by disparate small scale badger vaccination programmes can then be combined in a single analysis.

The aim of the analysis is then to compare these cattle herds to those where vaccination did not take place, potentially controlling for the numerous other factors which may influence bTB risk.

This approach is challenging, but it is hoped that this can develop a statistical framework to estimate the effect of badger vaccination in the future. In addition to the approach detailed above, there may also be further analytical approaches that can be applied to larger contiguous badger areas which may become more common as the vaccination policy progresses.

Can APHA bTB science ever be trusted again?

Defra have again kept data secret, preventing external scrutiny. They may not have enough data from badger vaccination to-date, so might want to add information they will be collecting over  the next few years. Defra should know that at the herd level, analysis of proactive badger culling data from the RBCT showed no disease benefit. They are withholding any post-2013 herd level analysis from intensive badger culling, probably because it shows no effect.

One potential problem is that the data available is large enough to produce a range of results, according to how it is selected and handled. This is why it should be done openly according to a pre-planned analytical protocol, and not exclusively by those with interest in outputs that support previous beliefs and perceptions. This, as international experts are pointing out, is where everything has gone wrong in the past (see review history for Torgerson et al 2025, explained here).

Zoologists and statisticians who have produced work supporting badger interventions in the past, that have now been shown to be equivocal, should not be the only individuals involved in such work. So far Defra have suggested that decisions on such appointments may not be entirely in their hands, which is suspicious. Further information is being sought on these important points of principle.

Defra’s tendency to throw ‘all the tools in the box’ together at bovine TB, rather than the right tools, means that it is not possible to tell which intervention has had effect and which has not. There is a bigger problem in terms of learning and adapting, when the combination of tools is not working well enough. This is no way to proceed and those in charge badly need to overhaul to an ineffective system.

More unscientific publications?

As indicated above, industry may have made the study of BV a condition of them not opposing it. Keeping BV on a small localised scale could be a government strategy to simply wait for a future government to allow a return to intensive badger culling. After all, the Godfray panel claimed that culling was ‘likely’ to have had an effect, despite the lack of credible scientific evidence. Defra don’t seem to want this advertised because it undermines their old beliefs in the role of badgers in bTB, that are still being used to sustain culling in the Low Risk Area. Having trained farmers and veterinarians for decades to believe that badgers have driven the spread of disease, they have no appetite for admitting they were wrong and re-training them out of a bad habit.

Pretences and deceptions – will they continue?

Pretending that BV can have an effect on cattle TB without evidence is untenable. Having a review panel express their opinion in a way that contradicts that lack of evidence has been unhelpful. Are we really going to see a new chapter of misleading science coming out of Defra?

There are some bad signs. The strategy refresh consultation over last year ignored key scientific stakeholders and refused to consider advice outside its 2018 review update. This is despite that review containing multiple errors and misleading statements, only one of which has been corrected to-date.

Corrected model outputs from Silverman model


Is there no one in government with the moral compass to do the right thing and start again? Has the strategy been refreshed or is it simply being pushed further into the mire?

2025 News round-up

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January

On 30th January 2025, Defra issued Terms of Reference for a ‘comprehensive new bovine TB review’, as part of a refreshed bTB eradication strategy, first announced in August 2024 (see here). A panel for the new review, was to be chaired, as previously, by Professor Sir Charles Godfray. It was his work (with others) and his advice that was used to help establish and maintain badger culling from 2013. Godfray, rooted at Oxford University, has long been associated with those designing and undertaking aspects of the controversial Randomised Badger Culling Trial (1998 – 2005). Indeed, he chaired its so-called ‘independent’ statistical audit (Godfray et al 2004).

Following discovery of serious statistical irregularities in the key 2006 RBCT proactive badger culling publication in more recent years, lead author Christl Donnelly, Professor of Applied Statistics at Oxford University, recused herself from the panel. But surprisingly, she was replaced by a recently arrived colleague Professor Sir Bernard Silverman FRS, Emeritus Professor of Statistics, also at Oxford University.

Other panel members, of what later in the year became known as the Strategy review ‘refresh’ or ‘update’, were the same as in the 2018 review: Professor Glyn Hewinson CBE of Aberystwyth University, Professor Michael Winter OBE University of Exeter and Professor James Wood OBE of University of Cambridge. So once again, it was largely the same set of academics as appointed in 2017, looking at the science in which they personally have a historical interest and potentially, future stake. With the new findings to be read alongside the earlier review, despite much of the 2018 material being superfluous or out of date.

Defra refused to adequately address multiple protests against the panel  appointments for  ‘conflict of interest’, simply saying those concerned were ‘esteemed’ and ‘distinguished’; that was enough for Defra. They later said the checking system relied on members own self-referral.

February

On February 15th, Prof Ian Boyd,  past Defra Chief Scientific Advisor (as Badger culling was developed) and  major influence in the culling of over 250,000 mostly healthy badgers), was the guest of Sir Charles Godfray in Oxford, for Boyd’s book promotion (Science and Politics). Bovine TB and badgers was the most mentioned topic, but the wider issue was of politics distorting the scientific process in general. Boyd’s main thrust appeared to be to point a finger at politicians (‘charlatans’ he calls them in the book) and also at the Royal Society. 

Boyd suggested that there is continuing pressure to produce results to fit a political agenda, mistakes are commonplace, they continue to be made, and the way to prevent the same thing from happening in the future is far from clear. He wished he had known more about Bovine TB before taking on his role. You can read more about who said what here.

March-May

Spring 2025 saw new scientific papers on badger vaccination, the Test / Vaccinate / Remove (TVR) approach and even badger contraception. This flurry of papers from government scientists seemed to be looking to satisfy the politicians stated aim to switch from badger culling to non-lethal methods. But with TVR lurking in the background as a potential closet return to culling.  

Robertson et al (2025) claimed that “Modelling studies evaluating different strategies for controlling TB in badgers predict that badger vaccination will reduce TB prevalence in badger populations and lead to corresponding reductions in cattle herd disease incidence.” But without direct evidence and yet again stretching and trying to normalize APHA’s efforts to cause-argue policy from equivocal science, dubious assumptions and partisan models. Along exactly the same lines (and almost as if to provide Boyd fresh evidence for his government science take-down), Smith & Budgey (2025) reported that a “combined approach of vaccination and selective culling (TVR) based on test results may give a more robust method of disease management than just vaccination on its own.”

The preprint by Palphramand et al (2025) (to be published in Science Direct Jan 2026) suggests that “co-administration of BCG vaccine and and GonaCon (a contraceptive) enhances the protective effect of the booster vaccination.” This is research work carried out on a small captive population of badgers caught from the wild.

June

Supplementary badger culling was authorized for a further year on June 1st. Natural England‘s scientific rationale for licensing did not take into account the Torgerson et al (2024) preprint which highlighted serious statistical issues with the Mills et al (I & II) (2024) upon which they relied. In doing so, it continued with its policy of ignoring key stakeholders and relevant evidence and simply obeying Defra’s mandate to carry on culling thousands more badgers, despite mounting evidence against it’s efficacy.

On 11th June, The Royal Society published Torgerson et al (2025), undermining the RBCT conclusions of a disease benefit from proactive badger culling. This effectively removed any credible scientific rationale for it. Defra did not respond to the new publication. You can read more about this paper & its significance as a watershed moment for British biological sciences here.

On June 12th, a day later, the BBC reported that “Farmers to get support vaccinating badgers”, confirming that badgers would continue to take substantial blame for bovine TB in cattle. Clearly, Steve Reed, Daniel Zeichner, and the Defra Ministers continue to be misled by their personnel who are unable to admit (due perhaps to responsibility for financial waste and pride / position), that badger culling has been both unnecessary and worthless.

July


On 30th July, Baroness Bennett of Manor Castle Green received a reply to her written Parliamentary Question:

“To ask His Majesty’s Government what assessment they have made of the paper by Torgerson and others published in the Royal Society Open Journal on 11 June claiming that other studies of badger culls contain methodological weaknesses; and what plans they have, if any, to ensure that the Cornwall Badger Vaccination Pilot has a peer-reviewed protocol before any work can continue.”

Junior Minister Sue Hayman replied for the government saying “Unlike previous badger culling studies, the Cornwall Badger Project is focused on testing different methods of delivering badger vaccination, rather than evaluating the impact on bovine TB in cattle.”

So all the Cornish badger vaccination project can hope to show is whether Cornish farmers are prepared to engage.

August

In late July/early August it was widely reported that Jeremy Clarkson’s Diddly Squat Farm in Oxfordshire (subject of TV show ‘Clarkson’s Farm’) had gone down with bTB reactors, having bought cattle from sources with relatively recent breakdowns.


Whilst The Daily Telegraph foolishly speculated that “the presenter was unable to stop transmission of the bacteria from badger to cow”, epidemiologist James Wood on Farming Today said “The challenge is with this [testing] system, the controls are imperfect, so that when we clear a farm with TB we know that a proportion that maybe as high as 25 or 50%, a proportion will have one or two animals that are still likely to be infected.” Clarkson expressed doubt about testing and a need for information and then went silent as several of his stock were destroyed. No doubt Defra were nervous of the high profile of the story, and aware of how its flawed bTB testing system could be more widely exposed. See our blog on the story here.

September

In September, the delayed (due in June) Godfray review update was published (see here). Key points:

  1. It confirms (page 75) in a massive ‘wake-up’ finding, that Torgerson et al (2024 & 2025) papers do show that the key 2006 RBCT proactive badger culling paper by Donnelly and others in Nature journal got the modelling hopelessly wrong. This has massive implications for a wide number of papers and official  reports that have used that paper’s calculations to build further models and create policy and financial estimates.
  2. Remarkably, it went to the lengths of producing its own new (binomial) model, claiming a culling benefit, but with lower statistical significance (it has gone from P < 0.005 to P < 0.05). However, there were mistakes and multiple issues with this model that were outlined in a new preprint by Prof Paul Torgerson (here), also posted September 2025. There has been no subsequent response from Defra. The authors have made some rudimentary remarks about agreeing to differ and the differences being subtle, which they certainly are not.
  3. The manner in which the new model was checked before publication is subject to close scrutiny due to suspected irregularities.
  4. The “bTB perturbation effect hypothesis” (used to justify culling healthy badgers) became un-evidenced, as it is statistically unsupported by Godfray’s model (as well as Torgerson’s models), undoing the RBCT conclusions even more comprehensively (see here) and triggering calls for retraction of key papers (see here).
  5. It failed to deliberate on the ‘confirmed’ versus ‘unconfirmed’ continuum in the identification of reactors, that was clarified in 2018, but not by the 2018 review. This obfuscates on what is a central issue, both in bTB testing and badger culling science. The panel just feebly recommended further research. This is despite Natural England formally asking the Godfray panel to focus on it.
  6. It inexcusably repeated errors in Birch et al (2024), notably the under-declaration of interferon gamma use (see here and here) which was introduced at the same time as badger culling and makes it impossible to separate the effects of badger culling from cattle measures. It also mistakenly claims it evaluated “before-after differences in treated units with those in untreated units” which is a very worrying mis-reading of the methods. Birch was a time series study, with no comparison of separate culled and unculled areas.
  7. It uses an unpublished report that the panel asked specially to be made available (Robertson et al (2025) to claim that Langton et al (2022) may not have detected a disease benefit had there been one. The unconvincing efforts in this preprint have been addressed here (Langton 2025).

October

On 13th October, there was a much awaited Westminster Hall debate (view here) on ending badger culling, precipitated by a 100,000 parliamentary petition coordinated by the successful lobbyists and wild animal protection advocates Protect the Wild. Although the two-hour session was a massive improvement on previous dreadful badger cull debates (reflecting the cull of dinosaur politicians lost in the 2024 general election), it remained (perhaps not surprisingly) ‘behind the curve’ on recently published science.  Happily, the majority of voices spoke earnestly about a wish to stop badger culling and address TB testing failures and to manage the disease effectively. Minister Angela Eagle reaffirmed Labours commitment to ending the badger cull by the end of this Parliament, with the possibility of all culls ending in 2026 following a review of the last cull area (no. 73) in Cumbria in the New Year. However, it is likely that Defra will do everything in its power to prevent this, via introducing TVR pilots.

Also in October 2025, Prof. Torgerson published a letter in Veterinary Record (see here) reporting his request for a  retraction of the Donnelly et al (2006) paper by Nature journal.

November & December

Meanwhile in Northern Ireland, a Parliamentary question by Miss Michelle McIlveen (from the DUP) tabled on November 18th made it clear that a €6.4m investment for a cross-border pilot regional cooperation programme on tackling bovine TB had been secured, with use of TVR as an experiment. This was leaked by the Ulster Farmers Union who wanted intensive badger culling and exposed DAERA’s attempt to instigate lethal interventions, despite previous undertakings not to do so without consultation.

On 2nd December Andrew Muir (Minister of DAERA of Northern Ireland), responding to a further Parliamentary Question about this funding replied that “Wildlife Intervention is a key part of that plan, which is why we will consult on wildlife intervention options in the spring of next year.”

So it looks like badger interventions are part of the bTB control plans in Northern Ireland, going forwards with a clumsy attempt to use TVR as a route towards wider culling. This is the approach already shown to be unnecessary by correct use of RBCT data, the post 2013 industry culling in England and long term badger culling and vaccination in the Republic of Ireland.

A letter published 13th December in Vet Record (here) raised questions concerning the continuation of badger blame following criticisms of the recent Godfray review. A response from the Godfray review panel was published alongside, repeating their view that “reasonable people can disagree about the best way to analyse complex data“. They remain, however, like Defra, unwilling to enter into a discussion on any of the analyses.

The Badger Trust / Wild Justice Judicial Review hearing against Natural England (on an incorrect reason for granting 2024 Supplementary badger cull licences) listed to start on 16th December was postponed due to “a court administrative error”. The case will now be relisted “sometime in 2026”.

And there has been much more going on, bubbling along beneath the surface that is work in progress, and that we will report on when we are able. We had hoped for better in 2025, with the science supporting badger culling now completely undone. But it looks as if it will take a little longer before the fundamental importance of the new publications is understood and accepted.

Thanks go to….

As in previous years, Badger Crowd would like to thank the hundreds of people who have worked together to support this years work to expose and halt the cruel and needless killing of badgers as a part of ineffective livestock disease control. As the mass culling of in the region of 6,000 badgers in 2025/6 is completed at the end of January 2026, there is still no formal recognition from Defra that this has been one of their biggest wildlife blunders.

It is thanks to all of you that we have collectively been able to protest, campaign, lobby, publish and report, and we can only hope that next year finally sees some truth and honesty from those who would seek to cover up the sins of the past. Particular thanks are due to all at Protect The Wild for their relentless public awareness work, especially the successful government petition and Westminster debate, backed by the general public. Also to Betty Badger (aka Mary Barton) and friends who maintained the Thursday vigil outside Defra offices, protesting the injustice (see article in the Spectator). Thanks also to the regular forums of the national ‘Voices for Badgers‘ network, the tireless Oxford Badger Group and so many others who have campaigned, donated and supported. And not to forget those who put endless hours in to protect badgers and their setts from multiple threats in their own areas. A massive shout out too to all those in the field, unblocking illegally infilled badger setts and those opposing snares. New legislation could be on the way – we certainly hope so. Thanks to all for your strength and determination.

It was the combined care and effort of all those taking a stand, no matter how large or small, that is helping bring mass badger culling to an end in England. We must now continue our opposition to culling in Ireland. We must ensure that accurate science now guides policy away from unnecessary, unverifiable and cruel protected species interventions. Badger culling must not be allowed to continue or ever happen again. There is much work still to be done, but the continued determination and energy of so many can prevail.

Badger Vaccination:

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There’s no evidence that it can work….

There are many government reports and a growing number of academic papers investigating the potential use of badger vaccination to attempt control over bovine TB infections in cattle. They mostly start from an outdated government premise that badgers are somehow a maintenance host, responsible for half or more of herd breakdowns. Scientifically there is acceptance of the lack of evidence for efficacy of badger vaccination as a method to reduce bovine TB incidents in cattle herds. There is just an assumption that if they were involved, reducing levels in badgers might aid bTB control.

Badger vaccination can be expected to reduce bTB in badgers, but………

Published analysis has for decades shown that, as expected, vaccinating badgers can reduce the prevalence of bTB in them (Aznar et al 2018, Benton et al 2020, Robertson et al 2025, Smith et al 2022). But without reliable information on how this relates to cattle bTB breakdowns, the huge cost of a highly intrusive wildlife intervention may be just another pointless waste and distraction to addressing the very well established and overdue shortfall in cattle testing and movement control – the problem that perpetuates the epidemic.

The government field trial ‘Vaccinating East Sussex Badgers’ (VESBA) scheme in Sussex study is coordinated by a commercial veterinary group. It has organised a badger vaccination project within a  250 km2  area, (see in APHA’s Year End Descriptive Epidemiology Report of Bovine TB in the Edge Area of England 2024, East Sussex). Latest reporting suggests that badger vaccination may reduce the prevalence of bTB in cattle, feeding the government narrative. But its a guess.

The messaging outputs from such studies, as with those from badger culling, are often not scientifically rigorous. They tend to originate from anecdotal comments by those involved expressing belief that some good is being done. In this case, because breakdowns reduced from 15 to 1 during a period from 2018. But this is the same period that the study area was subject to heavy Gamma interferon testing. The effects of vaccination are not separable from the enhanced cattle measures used in Sussex  – principally Gamma testing – that are being implemented simultaneously. This was the approach used by APHA to claim benefits from badger culling since 2013 in the ‘High Risk’, ‘Edge’ and ‘Low Risk’ areas, brought out like an old party trick to try to claim success, where none could be quantitatively shown.

Is the ‘placebo’ effect of telling farmers and vets that vaccination is (or is likely to) benefit cattle, the key to getting them to accept enhanced testing with its greater loss of stock to premature slaughter? This appears the philosophy behind badger vaccination (and culling previously). Even if such an approach is ethical, it cannot work due to the number of infections often left in the herd, even after gamma testing.

If badger culling has had no measurable impact on btb in cattle, neither will badger vaccination?

For badger vaccination to effect cattle herd breakdowns, badgers would need to be transmitting bTB to cattle in pastures at a relatively high frequency, and this has never been demonstrated. Nor has any plausible, evidenced transmission route been shown – the key element of basic epidemiology. Badger culling has also not been shown to have a measurable effect on rate of bTB herd breakdown. (See summary of the science here).

More recently, reference has been made to Whole Genome Sequencing (WGS) papers to make claims of transmission rates between and within cattle and badgers.

Study of the APHA epidemiology  reports for each county illustrates how WGS use for tracing in breakdown investigations cannot show  badger to cattle transmission. For investigations, WGS is only applied to identify clades. This is just a slight improvement on looking at spoligotypes. In practice, WGS for disease control leaves large uncertainty as to the source of tb in cattle, attributing badger as the default. If WGS was applied at finer resolution, and sufficient isolates were available, the data could clearly and unequivocally trace the source of disease back to the index case, at the individual level and in real time. But that isn’t being done.

The current disease report system does not take into account the incorrect assumptions made in APHA’s interpretation of WGS information. Every week, this leads to herds reinfecting themselves from ‘sleeper’ infections. With ‘badger blame’ used as a default cause by employing unscientific deductions. Published work explains different interpretations (Sandhu et al 2025).

Published journal  studies can only try to crudely estimate the frequency with which transmission occurs, nor the exact route or rate. Their capacity to show the route of transmission of pathogen between hosts is still in its relative infancy and requires intensive studies over many years. They are constrained by accuracy in controlling and sampling multi-host situations in varied commercial settings over relatively long periods of space and time. Study outcomes are dependent on choices made within complex models that are often not clearly identified or published, are speculative, and should be considered with utmost caution. Most papers since 2014 do flag this heavily but observers may try to quote them selectively. The results reported by WGS studies are not consistent, with differing conclusions.

Some of the WGS studies refer to and are parameterised with results from the still uncorrected  RBCT analyses in their modelling, which subsequent to successful challenge, should now be seen as scientifically unsupported. Many use the RBCT’s supposed benefit of badger culling as inference in introductions, discussions and conclusions and are now out of date.

The unpopularity of vaccination with …… well almost everybody

Since the 2020 Next Steps policy revision, Defra have begun slowly  to promote badger vaccination, investing in pilot schemes like VESBA and academic studies like “Investigations on attitudes towards bovine TB control: badger vaccination”, by Henry Grub of Imperial College, which strangely still remains undisclosed, with Defra claiming that they don’t have a copy.  Despite this, most stakeholders are opposed to, or at best, lukewarm about it. Farmers, who have been misled over the efficacy of badger culling and other interventions have very mixed views. A lot of work and expense would be involved if they were to adopt badger vaccination, with benefits unclear.

The British Veterinary Association and British Cattle Veterinary Association do not yet seem to have taken on board the new science surrounding ‘ineffective’ badger culling, and apparently have not revised their positions on interventions. Nature conservation organisations vary in their response to badger vaccination. Some Wildlife Trusts seem to support it in an off-hand way on the basis that it is a move away from culling and could help cattle, while some do not. The RSPCA supported it 5 years ago, but no longer seem to and the Badger Trust moved against it in 2024.

The putative benefits of badger culling (and by implication other badger interventions) have been undermined by new analyses over the last few years. It is a complex issue for everybody to access, (see here.) Smaller organisations especially, struggle to get a clear view on the science if they don’t have access to specialist scientific advisors. Whatever the views of the various stakeholders, badger vaccination leaves significant blame for disease transmission with badgers. That view is now scientifically unjustified.

The financial cost of badger vaccination

Badger vaccination is not a cheap option. The £1.4m badger vaccination trial underway in Cornwall is tiny relative to the landscape scale badger vaccination that it was suggested would be needed to vaccinate badgers in areas coming out of culling in the HRA. And the Junior Minister has confirmed it will not show if it can have an effect on cattle TB rates.

Defra have agreed a contract of £1.8 Mn for the supply of badger BCG vaccine for the next 5 years, and at least £18 Mn for its use over 4-6 years. They have ordered £200,000 of Badger BCG for 2026 from the manufacturer AJ Vaccines in Denmark (Defra FOI). With estimates for the cost of one badger BCG dose at around £33, the aim seems to be to vaccinate around 6,000 badgers. This will increase the number of badgers vaccinated above and beyond that vaccinated in small schemes in, for example nature reserves, which has been by about 25%: from around 3,000 to 4,000 badgers. The result amounts to ‘vaccination lite’ – a tokenistic approach that reflects the scientific lack of confidence in it having any value, (see Farmer Weekly).

The vaccine cost is of course only part of the spend; labour, traps and other associated costs can bump up the price to several hundred pounds per badger. One abandoned Welsh government program in 2015 estimated its costs at over £800 per badger and the maths suggests the new vaccination costs will be similar.

The practical challenges of vaccinating large number of badgers over a large area

The logistics of a vaccination project over a large area looks daunting. Vaccinators need to be trained. Sett locations and access for cage placement and pre-baiting need to be well understood. Permissions for access need to be managed. This will incur further cost. It remains to be seen whether this is feasible within an already sceptical industry, and with volunteers luke-warm at best, about getting dragged-in.

Ethical consideration of interfering in a population of wild animals

Then there is the question of the ethics of interfering with a wild animal population without good reason. Badgers, while susceptible to bovine TB, are relatively resilient to it and may carry several strains around. Their life expectancy is sufficiently short that they are unlikely to die from infection. Despite wild claims, including those in published literature, they have not been shown to be a ‘self-sustaining’ or a maintenance reservoir for bTB infection. It is likely to fade down and out once cattle are clear – in a similar way to that seen in possums in New Zealand. Without re-infection from cattle, it is likely that the disease would die down naturally. Benefits to the badger population from vaccination are unknown, but could be improved health and improve fecundity.

Just not necessary…….

Recent re-analyses (here and here) of badger culling trials have shown that there is no proof of any benefit to cattle from badger culling, and measurable benefit from badger vaccination is unlikely too.  From the evidence, it is not justifiable to embark on a hugely expensive and intrusive badger vaccination programme, the benefits of which are dubious, and  according to past approaches, unquantifiable. It is just more squandering of public funds when the failings of the current cattle testing system remain poorly addressed, yet are so plain to see.

References

Aznar I, Frankena K, More SJ, O’Keeffe J, McGrath G, De Jong MC. Quantification of Mycobacterium bovis transmission in a badger vaccine field trial. Preventive veterinary medicine. 2018 Jan 1;149:29-37.

Benton CH, Phoenix J, Smith FA, Robertson A, McDonald RA, Wilson G, Delahay RJ. Badger vaccination in England: Progress, operational effectiveness and participant motivations. People and Nature. 2020 Sep;2(3):761-75.

Langton, Tom, 2021. Where is the March 2020 ‘Next Steps’ policy trying to take us?, YouTube video of Voices for Badgers

Langton, Tom, 2025. Cattle tuberculosis; badgers finally in the clear. British Wildlife Newsletter online 28.11.25.

Robertson A, Chambers MA, Smith GC, Delahay RJ, Mcdonald RA, Brotherton PN. Can badger vaccination contribute to bovine TB control? A narrative review of the evidence. Preventive Veterinary Medicine. 2025 May 1;238:106464.

Sandhu P, Nunez-Garcia J, Berg S, Wheeler J, Dale J, Upton P, Gibbens J, Hewinson RG, Downs SH, Ellis RJ, Palkopoulou E. Enhanced analysis of the genomic diversity of Mycobacterium bovis in Great Britain to aid control of bovine tuberculosis. Front Microbiol. 2025 Mar 25;16:1515906. doi: 10.3389/fmicb.2025.1515906. PMID: 40201440; PMCID: PMC11975571.

Smith GC, Barber A, Breslin P, Birch C, Chambers M, Dave D, Hogarth P, Gormley E, Lesellier S, Balseiro A, Budgey R. Simulating partial vaccine protection: BCG in badgers. Preventive Veterinary Medicine. 2022 Jul 1;204:105635.

‘Perturbation Effect Hypothesis’ for badgers and Bovine TB is now unevidenced

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The ‘perturbation effect hypothesis’ is the reported ‘negative’ effect of reactive and proactive badger culling, described in the Donnelly et al (2006) paper “Positive and negative effects of widespread badger culling on bovine tuberculosis in cattle” and also many other publications since 2003. The 2006 paper was one of the key published papers reporting on the findings of the Randomised Badger Culling Trial experiment (RBCT) 1998-2005.

RBCT reporting (Bourne et al 2007) theorized that culling could increase cattle TB incidence in culled and neighbouring (surrounding) areas by disrupting badgers’ territorial organization, resulting in their increased dispersal and theorised spread of disease within badgers and on to cattle. It was the ‘perturbation effect hypothesis’ that grabbed attention and  initially delayed the consideration of badger culling, because of the claim that it was why badger culling might make bovine TB cattle herd breakdowns increase.

The RBCT had three sets of trial areas; these were pro-active culling (badger density reduced by average 70%, reactive culling (100% culling around breakdown farms only), and no-cull control areas.

The ‘reactive’ arm of the RBCT culling trial was cancelled early because the experimenters suggested that bovine TB had increased. In reality, and mistakenly, insufficient data had been generated to propose any such result. A review by UK Chief Scientific Adviser Prof David King, suggested later (2007) that mass proactive badger culling could plausibly reduce bTB cattle breakdowns if done over a large enough area (to hard boundaries) and avoiding any perturbation effects if they existed at all (King 2007). This itself was stated without competent statistical checks; it was the perturbation effect hypothesis that drove mass culling of mostly healthy badgers over large areas as opposed to localized culling.

And so that is what has been undertaken since 2013. Instead of using reactive culling at and around known breakdown farms, ‘Intensive Culling’ was, over a period of years, rolled out over much of the High Risk Area and then the Edge Area. Often regardless of the local land use or the disease risk, if the ‘cull zone’ land was in the High Risk Area, the target was to kill 70% of the badger population, although the size of the population was often poorly understood and ‘guesstimated’. The result has been that over the last 13 years, more than 250,000 largely completely healthy badgers have been culled to unknown densities, using mainly a method opposed as causing unnecessary suffering by the British Veterinary Association.

Recent re-evaluation of the RBCT data and modelling has shown that there is an “Absence of effects of widespread badger culling on tuberculosis in cattle”, (Torgerson et al 2024, Torgerson 2025). There are no positive and no negative effects, because that is the true conclusion from normal and credible statistical appraisal and data selection from the RBCT experiment.

While badgers, like deer and other mammals both domestic and wild can be infected with bovine TB, the extent to which they may be responsible for a small proportion of cattle herd infections, especially in intensive livestock systems is unknown. If it occurs, there is no reliable data available that wildlife transmission to cattle can establish, maintain or  perpetuate – this falsehood has been normalised by a few authors keen to bolster wrong claims. Indeed the strongest available evidence lacks indication that wildlife controls, such as culling badgers, has an effect on reducing the incidence of tuberculosis in cattle. Failures of the bTB cattle testing system, on the other hand, allowing infection to hide and to be spread via cattle sales is widely understood and accepted.

The binomial analysis of the RBCT proactive cull data in the September 2025 Godfray panel policy review update, claims that there is still a benefit from badger culling, but at a much lower level of significance (P <0.05).  However, this model leaves out the data for the all-important variable ‘time at risk’, which was also the downfall of the 2006 Poisson analysis of RBCT data. It provides no support for any effect of badger culling on cattle herd bTB breakdowns when undertaken correctly (see here). But by presenting the model as preferable to that in Donnelly 2006, it effectively removes the analysis that suggested a negative effect – the ‘perturbation effect hypothesis’ is therefore unsupported.

Thirteen years of the ineffective culling of quarter of a million badgers has been scientifically unjustified and why it was ineffective is now plain to see. There are no evidenced effects of badger culling, either positive or negative. Badger interventions of any kind are simply not be justified on the core policy science.

The upcoming Bovine TB control strategy refresh needs to reflect what has happened to the understanding of scientific developments in recent years and months.  It is time to remove perceptions and obstacles based upon incorrect analysis and incorrect derivative studies, and to get on with the necessary enhanced cattle testing measures that are known to work but held back by unnecessary red tape. Before more money and resources are wasted, before animal welfare harm perpetuates, and before more rural lives are ruined. At the moment, policy is unsubstantiated, supported by unconvincing advice, based on biased conflicted opinions and uncertain evidence.

Bringing the science of badger culling up to date

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The original Randomised Badger Culling Trial (RBCT) analysis

The Government’s English badger cull policy since 2011 has rested all but entirely on the RBCT analyses, the first of which was Donnelly et al (2006). It is the science that DEFRA has used to create intensive, supplementary and Low Risk Area (LRA) policy and in court to defend their decisions to ‘experiment’ with badger culling. The claim from this work was that badger culling along similar lines can reduce bovine TB cattle herd breakdowns by around 16% per year; dozens of subsequent studies used in policy and to inform economic and operational models  on which the badger cull policy hangs, were heavily derived from and dependent on the RBCT and most of these remain in place in 2025.

A challenge to the RBCT analysis

First preprinted in December 2022, a comprehensive re-evaluation of the RBCT was published in July 2024 in Nature Scientific Reports (Torgerson et al 2024). The new study re-examined data from the RBCT proactive culling experiment, using the most epidemiologically appropriate range of statistical models, in accordance with the experiments design. It concluded that most standard analytical options show no evidence to support an effect of badger culling on bovine TB in cattle. The statistical model selected for use in the original study in 2006 was one of the few models that did show an effect from badger culling. However, various criteria suggest that the original model was not an optimal model compared to other analytical options then available; the most likely explanation for the claimed culling benefit was that the chosen model ‘overfitted’ the data and used a non-standard method to control for disease exposure. This gave the model a poor predictive value, i.e. it was not useful in predicting the results of badger culling. The more appropriate models in the Torgerson study strongly suggest that badger culling did not bring about the disease reduction reported. Further, inclusion of ‘all reactors’ to the tuberculin test showed no effect of culling irrespective of the model used.

Shortly after, on 21st August  2024, and as a response to Torgerson et al 2024, two of the authors of the original analysis of the RBCT from 2006 (together with a third student author) published two new papers in the Royal Society Open Science journal (Mills et al 2024a&b) using large amounts of the Torgerson preprinted models and doubling down on their original conclusions saying they were ‘robust’. On 16th September 2024, a ‘Comment’ response to the new Mills et al. 2024 papers was submitted to the RSOS: “Randomised Badger Culling Trial—no effects of widespread badger culling on tuberculosis in cattle: comment on Mills, Woodroffe and Donnelly (2024a, 2024b), (Torgerson et al 2025). After a delay of eight months, this was accepted (with minor modifications) on April 23rd 2025 and published on 11 June. This new publication further exposed the flaws of the original RBCT analyses and the more recent attempt to defend it (Donnelly et al 2006 and Mills et al 2024a&b). The findings were endorsed by a senior biostatistician who described key aspects of analytical choices in Mills et al. and the 2006 paper as “naive at best” (Brewer 2025). A letter in Vet Record from October (Torgerson 2025) states that “A request has been sent to retract the 2006 RBCT proactive culling paper, as the results have been shown to be untenable. In my view papers published since 2006 that are reliant on the veracity of the RBCT analysis and results also need to be corrected or retracted.“

The latest Godfray review update of the science of bovine TB (Godfray et al 2025) published in September 2025 agreed that the Torgerson et al. 2024 analysis is the more ’natural’ way to analyse the RBCT data, but beyond its brief to review scientific material published since 2018, decided to undertake its own analysis. This used a binomial rather than Poisson approach to conclude a badger culling benefit from the RBCT data, but at a much lower level of significance than previously presented – it was transformed from ‘weak’ not ‘strong’. Thus agreeing with Torgerson and destroying evidence for the perturbation effect hypothesis.

However, the Godfray/Silverman RBCT model in the review update has additional flaws, and it is not based on the complete data set; it did not include the important ‘time at risk’ variable.  As a result, its binomial model follows a similar pathway as the 2006 analysis. When time at risk is included with the appropriate adjustments, the results suggest no effect of culling. In reality the Godfray/Silverman work pulls down the Donnelly 2006 analysis and then itself, completely undermining the RBCT and a vast volume of subsequent science and policy based upon it. A preprint outlining the various problems with the new model was posted in October 2025 (Torgerson 2025).

Godfray’s review update concluded that the RBCT now provides “limited (if any) insights into the design and likely value of including culling in a control programme”, despite the basis and inference it provides for a large number of later studies, including whole genome sequencing (WGS), which it now looks to for “valuable new information about the risk of infection from badgers”. The huge importance of the loss of Donnelly et al (2006) and its associated papers as plausible science is not mentioned.

APHA analysis of the industry-led badger culls

Brunton et al (2017) and Downs et al (2019) analysed data from the first two, and then up to four years of culling respectively, but for only 2 and 3 cull areas respectively. Large benefits from culling were claimed, but neither had sufficient data to draw robust conclusions and both were heavily caveated. Both repeated the statistical flaws of the Donnelly et al. 2006 analysis and Donnelly was a co-author. These papers too are now invalidated by the recent appraisals.

In March 2022, a new study (Langton et al 2022) in Veterinary Record journal, looked at data from the first six years of badger culling. Firstly, it looked at herd breakdown incidence and prevalence of cattle bTB in areas that had undergone a badger cull and compared them with the data from areas that had not had culling. This was done over a seven-year period 2013-2019, so before and after culling was rolled out in 2016; hence it was a study of the first three years of culling. Multiple statistical models checked the data on herd breakdowns over time and failed to find any association between badger culling and either the rate of incidence or prevalence of bovine TB in cattle herds.

Secondly, the 2022 paper looked at the trends over time of disease rates for the same period. Data suggests that the cattle-based testing and movement control measures, including annual tuberculin testing from 2010, were most likely responsible for the slowing, levelling, peaking and decrease in bovine TB in cattle in the High Risk Area (HRA) of England during the study period, in most areas well before badger culling was rolled out.

Despite being rigorously peer-reviewed (by 4 peer-reviewers, including Vet Records in-house statistician), the paper and its authors were attacked by Defra in the media and on their blog, and its findings were not accepted. The Chief Veterinary Officer and Defra’s Chief Scientific Advisor published a rebuttal letter alongside Langton et al, claiming their data showed that badger culling was working. Six weeks later Defra admitted that their data was wrong and published a new graph of data. They maintained, however, that this did not change their overall conclusions about the new paper, and did not respond to the rebuttal arguments that the authors put forward in the 2nd April 2022 issue of the journal Veterinary Record. Criticisms by government suggested that greater declines had happened in culled areas, but the confidence intervals were too large to show any clear effect. No analysis was offered by Defra to back up the claim who attacked the papers authors, the peer reviewers and the journal. Subsequent ‘Freedom of Information’ requests released emails showing that Defra had sought to block the paper after it had been accepted.

No further comment was made from Defra until (at the Request of Godfray/Silverman) the posting of a preprint, Robertson (2025), that used the disputed analyses (from Donnelly 2006 & Birch 2024 see below) to generate data simulations, to claim that Langton et al may not have detected a disease benefit if one had existed. This used a lower estimated change of 2.8% reported in the first years of culling by RBCT model outputs, rather than the substantial claimed benefits in the more recent APHA papers. The arguments put forward by Robertson are addressed in a brief preprint by Langton (2025) demonstrating that a normal approach to checking data variation shows the Robertson claims are highly likely to be spurious.

The February 2024 paper by Defra staff (Birch et al.) was used to justify further culling proposals in the March 2024 Defra ‘targeted culling’ consultation, and implied, using convoluted wording and without any evidence, that the culling programme thus far had been successful. This was repeated heavily by the Minister and trade press, creating a mass mis-information process that was countered by the incoming Labour government that called culling ‘ineffective’. Authors of Birch twice acknowledge (on careful reading) that while they may speculate, the overall changes in disease levels cannot be attributed to badger culling: all disease measures implemented, including new additional and extensive testing, were analysed together with no control. Claims of badger cull benefit from this analysis are further undermined by its under-declaration of the use of Gamma interferon testing; Birch claims this wasn’t being carried out during the first two years of culling, but government data suggests otherwise (see here and here). There was no comparison of culled and unculled areas, despite the Godfray review update suggesting that there was. Birch cannot attribute recorded benefit to badger culling and provides no insight at all.

Writing in a preamble to Badger Trust’s report ‘Tackling Bovine TB Together’, key badger ecologist and original RBCT scientist Professor David Macdonald writes that the authors of Birch “… do not claim to have measured the consequences of badger culling, and indeed they have not”, and, “there is still no clearcut answer regarding the impact of this approach to badger culling on controlling bTB in cattle or, more broadly, whether it’s worth it.”

A flawed method to identify the source of infection

Badger culls have previously been justified using the guess-based ‘Risk Pathways’ approach of the Animal Plant and Health Agency (APHA). This system sees farm vets invited to speculate on the likely origin of infection. If they are unable to link it to a previous cattle infection (they only look back four years), they often tick the box that blames an environmental source, by default badgers. No evidence is required. However, a study in TB-Free Switzerland of a single-source new outbreak found suggested persistence of bovine TB in a dairy herd for nearly fifteen years without detection (Ghielmetti et al 2017). Further, it is now accepted that the standard SICCT test, at standard interpretation, has an average herd sensitivity of around 50%, thus missing up to half of infected herds and several infected animals per herd; hence disease is remaining undetected in around 20% of herds. The lack of scientific evidence supporting the APHA approach in the Low Risk Areas to identifying the source of disease is discussed in the independent report Griffiths et al (2023).

A new way to blame badgers – Whole Genome Sequencing (WGS)

The Godfray review update (2025) strongly endorses the use of WGS, saying; “…recently introduced  techniques, especially WGS, have provided valuable new information about the risk of infection  from badgers, consistent with, but significantly extending, the original inference from the RBCT that badgers do present some risk to cattle”.

However, this is a broad and unqualified statement . While WGS studies (there are  around nineteen of them) generally report some evidence that a particular strain has been found, time-dated, in a sampled badger and a sampled cow, they do not accurately report the frequency with which transmission occurred, nor the exact route, which may even be via another organism. WGS’s capacity to deliver conclusive findings in the exact route of transfer of pathogens between hosts is still in its infancy and constrained by accuracy in controlling and sampling multi-host situations in varied commercial settings over relatively long periods of space and time. Outcomes are dependent on choices made within complex models that are often not published, are speculative and should be considered with utmost caution. The results reported by WGS studies are not consistent; conclusions reported differ widely. The Godfray review update listed some of the findings but did not do any critical evaluation of them; this remains absent. There is a risk that the Godfray review may repeat the same failings as the Godfray restatement of RBCT findings in 2013, published by the Royal Society,  by not checking the veracity of publications.

Some of the WGS studies have used results from the original RBCT analyses in their modelling, which subsequent to successful challenge, should now be seen as scientifically unsupported. Many use the RBCT’s inference of the supposed benefit of badger culling as inference of a likely transmission route from badger to cow and likewise are now unsound.

Are ‘unconfirmed’ reactors infected with bovine TB?

The Godfray review in 2025 was charged with ruling on the matter of whether cattle which react to a lesser extent to the SICCT test, but where they pass subsequent tests should be categorised as infected. This distinction is of great significance because when ‘all’ data (confirmed and unconfirmed) are included in the RBCT analyses, no badger culling benefit is found (in Donnelly et al 2006 or Torgerson et al 2024). Also, because until recently, stock known to be infected (Officially Btb-Free Suspended (OTF-S)) could be kept in the herd and traded in England.

Importantly, APHA epidemiological monitoring of bTB incidence currently focusses on confirmed reactor data (Officially BTB-Free Withdrawn (OTFW)) to report on the progress of disease control. Inclusion of unconfirmed animals in the data (prevalence) indicates that the disease remains largely unchanged after 12 years of Badger Control Policy (BCP) (Langton and Torgerson 2025). An explainer for the jargon around this issue is available here.

The Godfray update did not determine this issue however, saying only; “Detailed research is needed to allow these questions to be addressed systematically in ways that achieve a  consensus among the various stakeholders.

Policy implications for badger culling are considered here.

BTB control contradictions at the APHA

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In late November 2025 APHA published online their annual report on bTB for last year: “Bovine tuberculosis in England in 2024 Epidemiological analysis of the 2024 surveillance data and historical trends in cattle.” It is a disappointing read.

In 2023, APHA said:

“A new Disease Report Form (DRF), for recording cattle TB incident investigations, is under development. This aims to enhance data capture and review the methodology around how we assess source attribution to improve understanding of TB transmission pathways and the evidence base for biosecurity advice.”

But in their latest report, APHA are once again using the tired, outdated and discredited veterinary ‘risk pathways’ approach (see chapter 2 of this 2023 report.). It has still not been properly revised, and is being used again to speculate about the source of new infections. As a result, APHA continue to point ‘by default’ to badgers. They do this by ignoring the thousands of undisclosed infections from breakdown herds incorrectly declared bTB-Free each year due to the flawed testing regime that they have imposed on farmers for decades. These herds get rid of higher risk animals to other farms and at auction for years after they have been suspended following the identification of reactors. The APHA are very well aware of this.

This undetected disease in the herd continues to be overlooked for reasons that remain unclear. Perhaps one reason for the apparent intransigence to this overwhelming problem is that disruption to the industry supply-lines are limited, but the result is that the epidemic continues across England.

Let us remind ourselves that this ‘risk pathways’ system is based on a tick-based form that is completed by farm vets, who when invited to speculate on the likely origin of infection, and seem unable to link it to a previous cattle infection, possibly due to lack of information – just tick the box that blames badgers. No evidence required and the farmer is reassured it’s not their purchasing that has led to a breakdown. But……………..

Cattle testing is missing us to half of infected animals

  • It is now accepted that the standard SICCT test, at standard interpretation, has a low average sensitivity of around 50%, thus missing up to half of infected animals. Some would say lower.
Standard SICCT test, at standard interpretation, has a low average sensitivity of around 50%
Standard SICCT test, at standard interpretation, has a low average sensitivity of around 50%
  • Government’s external vet of choice, Cambridge University’s James Wood claimed on BBC Radio 4’s Farming Today earlier this year that: “The challenge is with this [testing] system, the controls are imperfect, so that when we clear a farm with TB we know that a proportion that maybe as high as 25 or 50%, a proportion will have one or two animals that are still likely to be infected.“
  • A study in Switzerland found suggested persistence of bovine TB in a dairy herd for nearly fifteen years without detection.
  • New studies have been testing bulk milk tanks on farms for bTB  antibodies using Enferplex testing (1,2) essentially doing a whole-farm bTB test in one go, indicating  that up to 40% of dairy herds have bTB infection.

Let’s blame badgers anyway

These shocking facts make a nonsense of the new APHA report and the ridiculous levels of badger transmission suggested. It is just so confused and contradictory. It states that  over half of new TB incidents occurring in 2024 in England, and nearly 60% of those in the HRA, were disclosed in herds that had experienced a TB incident in the preceding 3 years (recurrent herd incidents). These are herds that will be selling out infected surplus stock on a routine basis. Therefore, recurrent infection of cattle herds remains an important driver of the epidemic in these risk areas (Table1.1).

But at the same time it claims that the main risk pathway identified across all HRA counties during veterinary investigations was via potential exposure to infected badgers, which supposedly accounted for a weighted contribution of between 37.1% (Devon) and 67.2% (Shropshire).  So over half of new incidents are in herds that previously had TB (and this doesn’t account for disease from brought-in stock), but at the same time up to around one to two thirds are blamed on badgers. And it actually contends with pure guesswork, that “Recurrent herd incidents can occur due to a number of factors which includes residual infection, exposure to infected wildlife, poor biosecurity and high risk trading practices, amongst others” when it knows a large majority is infection breaking out again from within herds where it has been present all along.

This is veterinary nonsense and it just has to be queried who is in charge. Why do the APHA want to keep reporting such speculative claims? The most obvious reason is that bTB is totally beyond the current control system. Surely they cannot believe that it is anything other than the daily sale of inadequately tested stock that maintains the disease. Stock that in Wales, it is now unlawful to sell. Whatever happened to risk-based trading? Why does APHA hide the reality that newly OTF breakdown herd stock are massively risky?

And there is no acknowledgement of recently published science that shows that culling badgers during the Randomised Badger Culling Trials,(see here and here) and during the industry led culls (here) since 2013 cannot be shown to have resulted in any disease benefit. The central evidence for badgers being a significant source of infection is now absent. So why this continuing fixation with trying to blame badgers? Is the problem just too big for anyone to take responsibility? Why did they throw the most experienced cattle vet off the BTB partnership for exposing why the current testing system has failed in dairy herds?  

APHA are an organization that appear frozen in their capacity to change, despite the growing evidence of systems failure. This is a report for 2024 and there is nothing to suggest this year will be any different. APHA surround themselves with those who want to blame and kill or interfere with badgers, often it might seem just to hide their past oversights. When their badger policy since 2013 is an epidemiological mistake of epic proportions, heaping prolonged misery and suffering on cows, farmers and badgers at public expense and with no end in sight.

Additional References

(1) Hayton, A. (2025) Can Bulk Milk Revolutionise TB testing? A study to examine the contribution of bulk milk testing to bovine tuberculosis(bTB) surveillance and control in Great Britain. British cattle Veterinary Association Congress, Edinburgh 9-11 Oct. 2025.

(2) Hayton, A., Watson, E. and Banos, G. (2023), Bulk milk testing for bTB surveillance. Veterinary Record, 192: 85-85. https://doi.org/10.1002/vetr.2670

 

 

Low Risk Area (LRA) culling must be scrapped for good

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A Cumbria badger bloodbath

At the Westminster Hall Debate on the 13th October, Angela Eagle the Defra Minister of State confirmed that the badger cull would come to an end in February 2026 in all but one area. Cull Area no. 73, south of Carlisle, was initiated by Labour as a new cull zone last year (around what was called hotspot 29). It is large (183 sq km), and it can potentially run for up to five years (to 2029) with a 100% kill target, and some vaccination of any survivors. Voters have been incensed that despite Labours pledge to stop the culling that they described in their manifesto as ‘ineffective’, not only has it continued, but this new zone has been added..

So why oh why did Labour do this, when the two previous low risk area (LRA) culls have absolutely nothing at all to show in terms of bovine TB benefit for cattle herds? (See reports & addendum updates here). Pressure came from the local branch of the NFU who said  that they had been promised culling north of the initial cull area, Cumbria Area 32, that culled hundreds of badgers from 2018 (see more here). And APHA gave in, under Labour’s nose, with Natural England issuing licences to “maintain the confidence of the farming community”. Daniel Zeichner did nothing to stop it, before he was fired, after little more than a year in post.

And Natural England (NE) who issue the culling licenses, decided to ignore an independent expert report (left) showing why LRA culling is based on circumstantial information and assumptions; available data actually suggests that the cull will bring no disease benefit at all. This independent report was disregarded by both Natural England and the Godfray review, apparently because it showed an image of a process involved in badger culling, which illustrated the content of the report: a picture of a badger in a cage trap about to be shot (see below).

So the only detailed technical report by non-vested scientists was discounted because it showed a picture of the methodology being employed. This decision lacks impartiality, but it is consistent with the biased and selective use of science throughout the various government justifications provided for culling. Let’s not forget, Natural England were found in breach of their statutory duty in the High Court (2018) (see more here) for trying to hide the need to protect nature reserves from the potential effects of the mass removal of badgers. More recently, Natural England, most likely at Defra’s request, cynically tried to stop Wild Justice and Badger Trust taking a legal case against culling by asking the court to require them to pay more adverse costs if they lost. The court rightly told them they had no case and to go away. Such actions are a well known government tactic to cause delay, frustrate environmental justice and run up costs.

Basically, with Low Risk Area badger killing, cattle herds in LRA so-called ‘hotspots’ are blasted with extra cattle tests and movement controls to reduce TB, so the number of breakdowns starts to go down. Then, once bTB is going down, they move in to try to kill all the badgers and then to declare culling has worked, even though breakdown incidents continue at a similar rate.

It’s a travesty. Professor Charles Godfray’s review panel recently reported to Defra, calling it a ‘proof of principle’, when there is no proof of anything. Low Risk Area culling has been a failure:

  • Failure because APHA give farms within 3 km of breakdown farms a full 30 days to  move (get rid of) suspect stock before they are tested and/or restricted. Guaranteed to spread disease.
  • Failure because the core evidence behind badger culling policy 2013- 2025 is now redundant and riddled with statistical error.
  • Failure because data shows cattle gave strain 17z from Northern Ireland to Cumbria stock and then Cumbrian badgers, but there was never any evidence of badgers spreading it other than pure government speculation.
  • Failure because APHA tell Cumbrian vets to blame badgers if they are seen on a farm and not because cattle have been brought in from herds with a breakdown in the previous five years.
  • Failure because in Lincolnshire Area 54 there have only been a few breakdowns, yet over 500 badgers have been shot.
  • Failure because Natural England have kept making LRA cull areas bigger, so more and more badgers can be killed.
  • Failure because Godfray too ignored the evidence in front of him, to back up Low Risk Area culling for Defra.

Bovine TB control in Cumbria is failing

Last year saw a record number of TB breakdowns in the County of Cumbria with  a massive 39 breakdowns recorded for 2024

Area 32 – the first LRA cull in 2018 in Cumbria

Over 1000 badgers were killed between 2018 and 2021 in Area 32. During 2024 there was one B6-23 (strain 17z) breakdown (of NI origin) in northwest Cumbria. The B6-23 breakdown in 2022 just outside Area 32 has now been attributed by APHA to cattle movements. Cattle movements are being attributed where previously it was badgers getting the blame, but it is all ‘form-fiddling’. This saves face on making the Area 32 results look even more of a meaningless failure.

Area 73 – the new in 2024 cull area

It looks like the outdated and crumbling Animal and Plant Health Agency’s IT system (called SAM) is struggling. IbTB mapping is being updated less regularly and  has become a poorer online reference guide for disease control.  New breakdowns are being attributed to cattle movements here too, not badgers for some reason. A local shooting gang has been accused by local people of shooting cats as well as badgers and apparently wants to move to reactive culling. While behind the scenes, Labour is now apparently reported to be flagging to APHA to shut the whole thing down and not carry on for another two years as had been proposed under Daniel Zeichner’s short reign.

Area 54 – the Lincolnshire 2020-2024 cull area

Lincolnshire Area 54 Cull Area that began in 2020, and had hardly any TB breakdowns, has culled 523 badgers. Rather pathetically, they claim that the area is on track to be TB-Free in 2038 (whereas previously it had been predicted to be TB-Free by 2025); badger culling cannot be expected to contribute to this ambition in any shape or form.

2020         

139 shot

2021           

161 shot

2022              

80 shot

2023             

89 shot

2024             

54 shot

 

It is unclear if badger vaccination is being done in Lincolnshire Area 54, but in 2025 at least the shooting stopped. The end result? Many healthy badgers have been killed with nothing  to show for it. The area still has very few herds and breakdowns from the occasional unwise purchase of stock from the west.

It’s time for the wasteful, cruel and pointless Low Risk Area culls to stop for good and to acknowledge the flawed  science and evidence on which they were based.

Approaching 2,000 badgers have now been slaughtered in the Low Risk Area since 2018, due to reckless movement of high-disease risk stock, inadequate testing and negligent control rules. Labour has caried on against the public outcry. It must move to stop all badger culling in the Low Risk Area immediately and focus on the cattle measures that are known to work.

Government abandons RBCT as badger TB intervention evidence

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250,000 dead badger later……….and bovine TB is still rampant

A quick reminder of why the RBCT is so important

The Government’s English badger cull policy since 2013 has rested all but entirely on the RBCT analyses. It is the science that DEFRA has used to create policy and in court to defend their decisions to experiment with badger culling. The original RBCT conclusions claimed badger culling can reduce bovine TB cattle herd breakdowns; dozens of subsequent studies on which the policy hangs, are heavily derived from and dependent on it.

The ‘Godfray panel’ review of the science (published earlier 4th Sept. 2025) produce their own new re-analysis of the RBCT which claims to show a benefit from culling badgers, but at a much lower level of significance than previously presented – it is weak not strong. The panel then follows Defra’s shift from 2023, that the RBCT is no longer pivotal to the policy that badger interventions are necessary in the control of bovine TB. It claims that  it is ‘likely’ that other science shows that badgers are a sufficient disease risk to cattle to warrant intervention. More on this below.

Government scientists continue to infer that badger culling has caused a reduction in disease since 2013 when the badger cull policy was implemented, and in no small part  because this is what was “predicted” by the results of the RBCT. This is classic confirmation bias. So the correct interpretation of the results of the RBCT analysis remain hugely important to understanding the role of badger culling, or lack of it, in the control of bovine TB. Defra and now Godfray’s attempt to unlink it are strange, suspicious and somewhat unconvincing.

Below is a chronology of some key RBCT publications.

16th February 2006, “Positive and negative effects of widespread badger culling on tuberculosis in cattle” was published in Nature by Donnelly et al.

10th May 2019, “Badger Culling and Bovine TB in Cattle: A Re Evaluation of Proactive Culling Benefit in the Randomized Badger Culling Trial” was published in the Journal of Dairy and Veterinary Sciences by Tom Langton.

13th December 2022, First version of “Absence of effects of widespread badger culling on tuberculosis in cattle” was posted as a preprint on Research Square by Torgerson et al..

15th July 2024. “Absence of effects of widespread badger culling on tuberculosis in cattle” was published in Nature Scientific Reports by Torgerson et al.

21st August 2024. “An extensive re-evaluation of evidence and analyses of the Randomised Badger Culling Trial (RBCT) I: Within proactive culling areas”  and “An extensive re-evaluation of evidence and analyses of the Randomised Badger Culling Trial II: In neighbouring areas” were published in Royal Society Open Science by Mills et al..

16th September 2024. A ‘Comment’ response to the new Mills et al. 2024 papers was submitted to the Royal Society Open Science: “Randomised Badger Culling Trial lacks evidence for proactive badger culling effect on tuberculosis in cattle: comment on Mills et al. 2024, Parts I & II” by Torgerson et al.. This was pre-printed with bioRxiv on 20th September.

11th June 2025, ‘Comment’ response to the two new Mills et al. (2024) to the Royal Society Open Science was published: Randomised Badger Culling Trial—no effects of widespread badger culling on tuberculosis in cattle: comment on Mills, Woodroffe and Donnelly (2024a, 2024b),  by Paul Torgerson et al. (2025), was published by the Royal Society Open Science.

4th September 2025, Bovine TB strategy review update, Professor Sir Charles Godfray CBE FRS (Chair),Professor Glyn Hewinson CBE FLSW, Professor Sir Bernard Silverman FRS, Professor Michael Winter OBE, Professor James Wood OBE. This review contains  a new RBCT analysis by Bernard Silverman.

15th September 2025. “The Randomised Badger Culling Trial (1998-2005); proactive badger culling analyses were not weak, but invalid.” New pre-print by Professor Paul Torgerson. Version 2 posted 29th October 2025.

Natural England’s selective use of published and pre-printed work

Natural England’s rationale for licensing the supplementary badger culls in 2025 did not take the Torgerson et al 2024 preprint into consideration. This is despite considering un-peer reviewed reports, and preprints (notably Mills et al 2024) last year.

Their rationale for licensing the intensive culls in 2025 took into account a draft of the new Godfray review analysis, immediately favouring it over Torgerson et al 2024 and Torgerson et al 2025, (see more here). Notably they also took into account the new APHA (Robertson) pre-print which attempts to claim that Langton et al 2022 is ‘unlikely’ to have found an effect of culling, should one have existed.

Basic flaws and statistical problems with the new Godfray review

Complex statistics is difficult for the non-specialist to understand, and difficult to explain to other non-specialists. But it is important to convey the extent and gravity of the problems with this new Godfray/Silverman analysis. Here goes…….

  • Silverman has coded 4 binomial regression logit link models of the RBCT data.
  • He says that he has compared the results of the 4 models using AICc information criteria.
  • However, the output figures reported were for Bayesian Information Criteria (BIC), not AICc as they were labelled. This was corrected with an erratum on 16th September, with a claim that “the rest of the analysis and interpretation is unaffected”. This is not the case.
  • When the correct AICc figures are used, the values for models 3 & 4 (with & without badger culling) are all but the same – there is no real difference.
  • Further, as the Godfray group used a quasibinomial model for inference, it would be best practice to use QAICc selection criteria. Using this method, it is the model that does not include culling that has the best co-variate. I.e. culling has no effect.

In addition to the problems with the AICc/QUAICc model selection criteria, Silverman has not correctly adjusted for time at risk (exposure to disease) in his models. Time at risk varied from 2.72 to 6.73 years between areas studied, so this difference needs to be included in their models.  As Silverman has used binomial regression, to do this adjustment correctly, you need to have the complementary log-log function in the link (rather than the standard logit link that he used). When this is done, there is no effect of culling.

Silverman has also not dealt with the over-fitting issues of his models, something that was a feature of the Donnelly et al 2006 model. He has chosen to code the model to predict the time at risk, but the method for this creates a high number of variables relative to the number of data points, resulting in over-fitting of data, poor residuals and poor predictive power. In other words, he is using models that are not the most appropriate for the trial and data. Torgerson et al (2024 and 2025) show that the most appropriate models with the best model rating criteria show no effect of culling.

As Professor Mark Brewer pointed out in his review for the Royal Society of Torgerson et al 2025, ”work should be verifiable.” That is, if there really was a significant effect from badger culling in the data from the RBCT, it should be apparent in far more than one specially selected model and specially selected information criteria; it should be possible to verify it with a range of analyses.

As Professor Brewer also pointed out, “..in such a contentious area as this, it is naïve to imagine that a single analysis by a particular group of scientists should be seen as sufficient.” But that is essentially what has happened again; one group of scientists from Oxford University has been allowed to defend their legacy publications, and exclude scientific views that disagree with their own.

What science is left to support badger culling without the RBCT

Godfray refers to the 2024 Birch et al paper, incorrectly suggesting that it compared culled and unculled areas. In reality it was just a time series of data. The reduction in disease over the period of the cull cannot be attributed to badger culling. All disease measures implemented, including the introduction of extensive testing were analysed together with no control. There was no comparison of culled and unculled areas. In fact, the concurrent increase in SICCT testing and introduction of Gamma testing over the period of culling is greatly understated in Birch. See letter in Vet Record for more on this.

The Godfray report quotes two genomics papers to support the role of badgers in the transmission of bTB to cattle. There have been a number of genomic papers published in recent years on this issue, and they reach a range of conclusions. These papers are not definitive. They rely heavily on selective modelling, and many rely on the RBCT for data or inference. They are not evidence of significant disease risk from badgers, or that badger interventions would significantly reduce any disease risk.

Many other prominent scientific papers which have previously been used as evidence for badger culling have been invalidated by Torgerson et al 2024 and 2025 and now even by by the incorrect Godfray panel’s massive demotion of the statistical effect. Done properly the review should have gone back to its 2018 text and corrected it, to remove findings based on these now invalid studies.

The panel have relied on publications which have used flawed methods of analysis. It is important that these papers are now corrected, retracted or marked with expressions of concern in order that further work and funding is not mis-directed.

Most importantly of all, badger interventions designed at reducing TB in cattle must be stopped immediately. They remain wasteful, inhumane and indefensible.

Westminster Hall debate on ending Badger Culling, 13 October 2025

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The Westminster Hall debate of the Protect the Wild petition, held on 13th October, was a significant improvement on previous badger cull debates.  The majority of voices spoke earnestly about a wish to stop badger culling and address TB testing failures as soon as possible. There wasn’t a repeat of the nonsense we have previously seen;  “too many badgers” and “killing hedgehogs, bees and ground nesting birds”. And the Minister Angela Eagle concluded by committing to ending the badger cull by the end of this Parliament (2029), possibly hinting at terminating remaining licenses to bring all culling to a conclusion in 2026.

But the debate remained very much ‘behind the curve’. MP’s referenced scientific studies that have now been shown to have used implausible statistical methods (Brunton et al 2017 and Downs et al. 2019), or have implied inaccurate conclusions from government analyses (Birch et al. 2024). Several drew their facts from the latest “Bovine TB strategy review update” by the Godfray review panel, but as Badger Crowd has repeatedly pointed out, the scientists who worked on this document are largely the same scientists who have supported the now impugned previous work that claimed badger culling  could be effective. They are, quite naturally, strongly resistant to accepting that this view may be wrong; they are simply not independent, as claimed. MP’s are looking to the Godfray Review for inference, but they are not getting a balanced summary of recently corrected science.

The narrative being put out by some MP’s was that the scientific consensus remains that badgers give bTB to cattle at a rate that necessitates badger intervention. Others said it was all over exaggerated and the issue remains uncertain at best. With the results of the RBCT no longer able to support a benefit from badger culling, the implied transmission from badgers to cattle reverts to being an un-evidenced idea. DEFRA has been unable to show that the culls since 2013 have produced a disease benefit, although they claim that it is ‘likely’. This is presumably based on their own confirmation bias, based on out of date studies. They are hanging their hat on Whole Genome Sequencing (WGS) to keep blaming badgers, and Angela Eagle, reading the Defra script given to her, said that this could provide a definitive answer. However, with methods available at the moment, WGS is very much open to interpretation. It provides a range of outcomes that greatly vary and rely on a range of choices and decisions that are not always readily quantifiable and checkable. Often their inference is once again taken from the RBCT, that badgers are responsible for a significant amount of disease in cattle, but this is now unlikely or uncertain at best.

No MPs mentioned specifically the 2024 Torgerson et al reanalysis of the RBCT, or its subsequent defense from the original RBCT scientists (Torgerson et al 2025), which definitively show that the RBCT could show no disease benefit  from its results. The hastily put together RBCT analysis annexed at the end of the recent Godfray review claiming to show a smaller badger cull benefit at much lower level of significance has significant statistical problems, and is currently being investigated.

So while we are encouraged that the language and thrust of the WH debate is better than it has been previously, clearly the implications of recently published science have not yet filtered through to MP’s, and perhaps this will take a bit more time. The questionable briefing notes for the debate (generated from government documents)  are a clue as to why this is the case. The same civil servants who served the Conservative government with their strong ambitions to cull badgers are now serving a Labour government, who is aiming to stop culling badgers. But these are people who are invested in their previous views, with published scientific papers and reputations to protect. Do we have to wait for a wave of early retirements before we start to see the objective view of the science that the issue deserves?

Are both sides of the badger cull argument ‘mining the data’?

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It has been claimed that the disagreement about the Randomised Badger Culling Trials (RBCT), and what that central study tells us about whether badger culling can reduce bovine TB breakdowns in cattle, is a result of ‘data mining’ from both sides. That is, both sides are selecting the methods of analysis that give them the result they want. Is this a true representation of the current situation which sees different analyses giving opposite results? Or is the claim just a bit of a smokescreen?

Basically, there are two models that are used to claim that badger culling produces a disease control benefit to cattle;

1. Donnelly et al 2006 produced the only Poisson model (there are many others available) that says badger culling ‘worked’ with around a 20% benefit (P 0.005%).

2. In the recent Godfray review of evidence, Bernard Silverman downgraded the Donnelly model and produced the only binomial model (of 4) that indicates badger culling had an effect, with around a 17% benefit (P 0.05%). A similar effect but at a much weaker level.

However, the Donnelly model did not correctly adjust the data for the number of herds in each trial area, nor the ‘time at risk’. And the recent Silverman analysis did not correctly adjust for ‘time at risk’. So neither analysis correctly adjusts for exposure to disease during the experiment.

Professor Torgerson’s reanalysis of the RBCT data in 2024, published In Nature Scientific Reports, reviewed a wider range of analyses in accordance with veterinary principles, the most appropriate/best fitting of which (based on model rating criteria and parsimony) suggested the superior models showed no benefit from badger culling.

If there was a convincing effect from what is a relatively small amount of data it would be visible in most or all of the analyses undertaken. Two selected models that have not been properly adjusted for important variables compare poorly to stronger ones that don’t. Claiming a benefit from badger culling from the RBCT is not verifiable because the claimed effect is not consistent. The correctly specified models consistently show badger culling produces no visible effect on disease in cattle.

For those wishing to read more about the recent reanalyses of the RBCT, our post on the 11th June Royal Society Open Science paper shows how the original 2006 analysis and subsequent attempts to support it were flawed and even ‘naive’, and our post from September 17th outlines statistical issues with new analyses in the recent Godfray review.

So the answer is that there is no data mining going on, at least not by those seeking to independently check the data. Just a thorough review of the best statistical way to understand the simple data involved, using the kind of approaches that the original scientists implied that they would use.

Further evidence against the culling of healthy badgers

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A letter published last week in Vet Record (4/11 October) highlights further evidence against the culling of healthy badgers. The letter by Professor Paul Torgerson focuses on the recent scientific take-down of the supposed bovine TB ‘benefit’ from badger culling reported from the Randomised Badger Culling Trials (RBCT). He describes the subsequent attempt to rescue the purported positive effect of badger culling in the recently released “Bovine TB strategy review update” Godfray review. A new preprint (here) outlines the errors in the new statistical models produced. Professor Torgerson concludes that “Had the (original) analysis been done correctly in 2006 then it is almost certain there would have been no badger culling since 2013”.

Godfray Review 2025: Defra Revision? Correction? Or just further scientific howlers?

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On Friday 26th September, Defra changed the “Bovine TB strategy review update” but simply made things worse by adding another layer of confusion.

The correction of reported Information Criteria as now shown in the Godfray Review

An error was reported as “a revision to a line of code”. In the document itself, the change is referred to as a ‘cut and paste error.’ Red text in a box next to the correction (see above) suggests that ‘The rest of the analysis and interpretation is unaffected’.

The replacement red numbers, now show the  outputs from their 4 models described, but this time the difference between models 3 and 4 is insignificant. To put it in technical terms, a delta (difference) AICc of 0–2 suggests both models have similar support from the data.

However, far from the analysis and interpretation being unaffected as they suggest, the revision does have serious implications for the inferences drawn. The ‘update’ is actually a correction due to the wrong results being inserted into their models in Annex 4. The results reported as AICc (Akaike Information Criterion) were in fact the results from Baysian analysis (BIC) (which they did not report on).

However, BIC is not the correct IC for model selection, due to the small number of data points and large number of coefficients to estimate. The small sample size equivalent (was this really not tried?) would be appropriate (BICc), especially for logistic regression. Applying BICc favours a model which suggests that the incidence of herd breakdowns is independent of culling (i.e. culling produces no effect).

If AICc is used for model selection, a model suggesting a weak effect of culling is only slightly favoured, model 3: 173.58 vs model 4: 173.87. This difference is too small to draw any inference from; it is effectively a toss-up between the two models. The incorrectly reported IC results showed a bigger difference: model 3:151.58 vs model 4:159.38). It is this greater significant difference, which is what the peer-reviewers seem to have picked up on. Hence the big question, what were the peer reviewers sent? And given that one or both reviewer assumed the code was right, were they commenting on the wrong results?

Apparently Defra have been asked this all-important  question and an answer is pending. Maybe they don’t know and need to ask?  The answer could alter the Chapter 6 discussion hugely. A very large number of people are interested to find out who knew what and when.

The Information Criteria as originally presented in the Godfray review

One might pose the question “did the Godfray group try the small sample size BICc?” Given that they obviously tried BIC (as that is the output they incorrectly reported), the correct form of BIC would be the small sample size correction as there are only 20 data points. Interestingly, when BICc is applied, model 4 (without badger culling at 196.00) is favoured over model 3 (with badger culling at 200.96). I.e. badger culling has no effect.

However, notwithstanding all this incredible muddle,  it would have been more appropriate to select the most favourable model of a series of over-dispersed models, using the quasi version of AICc, which is QAICc, especially as the quasibinomial model was subsequently used for statistical inference.

When the QAICc is applied to their models, the results strongly favour a model which again suggests bTB incidence in cattle is independent of badger culling (i.e. culling produces no effect).

A pre-print outlining some of the problems with the new analysis is available here.

Reasonable people can disagree….

When dealing with the recent academic publications on the RBCT, (which have been reported on here), and which arrive at different conclusions, the Godfray review has stated at para 6.LXX:

“…reasonable people can disagree about the best way to analyse complex data such as these.”

That is an interesting response to the current differing views. A short article entitled “When Can Reasonable People Disagree?” is quite insightful on this. We borrow a couple of apposite quotes below:

“To say that “reasonable people can disagree” can encourage suspension of judgment in response to important matters of personal and social concern.”

“There is a related tendency to use the expression “reasonable people can disagree” to create an equivalence when it comes to conflicting beliefs that large groups of people hold. A common perception exists that if a large enough group of people believes something, it has met the litmus test for being a “reasonable’ belief and the people involved “reasonable people.” This is a familiar critical thinking error. The fact that a large group of people believes something does not provide us with a compelling reason for thinking it is true.”

“Respect for persons might require engaged listening. It might require careful consideration. It does not require treating weak evidence as if it is strong nor does it require treating unsound arguments as if they are sound. Far from being kind, we are actually doing one another an injustice when we engage one another as if all arguments are equally compelling.”

The point is, and it is a  point made by Prof mark Brewer earlier this year in his review of Torgerson et al 2025, it is more a question of can reasonable people agree?  And the answer to that appears to be not yet. But there  needs to be conversation. So far Defra has refused to have that conversation. Will that continue or does it have to wait until there is an inquiry into the crisis?

In any event, this muddle is so bad that the Godfray review will need to be rewritten. That is unavoidable now. The mistakes are too obvious, too profound and too important to remain as a part of the narrative.

While there is a ‘it doesn’t matter anyway’ type sentence to cover up any exposure, it is quite clear that it really does matter. The mistakes alter everything, including the economic forecast on badger culling benefit.  

Its time for Defra to change the way they do business.