The new scientific Comment paper by Paul Torgerson and colleagues was published on 11 June in Royal Society Open Science (RSOS) (here), and is a comment on two 2024 re-evaluations of the Randomised Badger Culling Trial 1998-2005 (RBCT) statistics (here and here). These re-evaluations were, themselves, a rebuttal of the comprehensive re-evaluation by Professor Torgerson’s group earlier in 2024 (here) which was prompted by the heavily peer-reviewed published evidence in 2022 (see here) that industry-led post-2013 badger culling was having no effect on bTB cattle herd breakdowns. The latest RSOS Comment paper (and its notable peer-reviewer findings) is well timed to accompany the Government’s new general intention to end badger culling by the end of this parliament (2029).
The current bovine tuberculosis (bTB) epidemic flared up in 2001 due to mismanagement of cattle distribution. Officially TB Free-Withdrawn cases (OTF-W) peaked in beef and dairy herds in 2015, starting to fall after annual testing from 2010 and the gradual tightening of TB controls in cattle. But Officially TB Free-Suspended cases (OTF-S), that are also indicators of new infection, have slowly risen. BTB remains embedded in herds in many counties, and is a costly and destructive force across much of England and Wales, and throughout Ireland.
This area of epidemiology has been a hugely controversial subject, largely due to RBCT findings in 2006 that suggested the European Badger Meles meles (a legally protected mammal) plays a highly significant role in bTB spread in cattle. Subsequent Governments have culled approaching 250,000 largely healthy badgers in England since 2013. The policy has been justified using the RBCT’s ‘perturbation effect’ hypothesis, where one specific analytical approach was used to claim that this hypothesis could explain beneficial and negative effects of mass badger culling. It was hugely uncertain and speculative, but treated as ‘established science’ and ‘irrefutable fact’ by those seeking to see badgers culled for all kinds of reasons.
The 2024 Torgerson re-evaluation, looked at the way in which the differences in the number of cattle herds in ten paired comparison areas of countryside in the RBCT trial were adjusted for, together with the varied duration of experimental study periods. Further, model selection used in the original analysis was examined. The task of assessing the suitability of models from among the most likely candidates was undertaken, bearing in mind that the pre-experiment plan for data analysis was loose and open to interpretation – see Supplementary Material 1 of the Torgerson paper. In this part of the analysis it is the selection of the most appropriate model that is the most critical for verifiable results. More plausible models than that used in the original 2006 analysis (here) were readily apparent. The new study was able to demonstrate how these more plausible models show no effect of badger culling upon herd BTB breakdown rate.
Further, the team looked at how newer pathogenic evidence and interpretation, including better understanding of categories of TB-test reactor cattle, now more accurately informs decisions on what represents a new herd infection and herd risk status. The paper described the reality that using ‘all BTB breakdown’ data is by far the safest conclusion for policy application. And when ‘all data’ is used, there is no effect of culling over all models. APHA and Natural England still claim that they believe this is wrong, which enables them to carry on licensing badger culling.
So whilst the original conclusion of the RBCT study reported that culling of badgers can make ‘no meaningful contribution’ to the control of bovine TB in cattle herds remains correct, the true reasons for this being the case are surprisingly different to those given in 2006. It is not, as originally suggested, because of positive effects (in cull zones) and negative effects (in neighbouring zones), but because there are no measurable effects to be found. The ‘perturbation effect hypothesis’ is a major casualty of the new analysis – if it exists, the RBCT found no evidence of it.
Whilst direct or indirect transmission between wildlife and cattle cannot be ruled out on rare occasions, it is not present at the significant scale reported by the RBCT model choice and data selection. Wildlife infection should no longer be blamed for the inadequacies that are all but entirely due to poor disease management by Defra and APHA who dictate every move of the livestock industry.
All this is positive news for livestock, badgers and disease control. The 2020 policy direction to abandon lethal badger interventions is justified, with a renewed focus on cattle measures that are known to be effective. The ‘hidden reservoir’ of BTB is now sufficiently well understood for ‘new generation’ TB tests to deliver far better detection rates. If there was greater scope for their use (currently restricted), these would give a real opportunity to vets and farmers to work towards the bTB elimination rates last seen in the 1960s. The logical conclusion from these newly published findings is that since badger culling has no measurable disease control value, badger vaccination is very unlikely to either. Any badger vaccination field trials would be an expensive distraction, when it is proven cattle testing and movement measures that need to be implemented at scale to tackle the epidemic effectively.
A new article in Vet Times reports on the Torgerson et al (2025) paper published in Royal Society Open Science last month, that has prompted calls to stop all badger culling immediately. The badger culling policy has, it says, relied on a ‘basic statistical oversight’.
The article picks up on comments by the new paper’s reviewer, Biomathematics and Statistics Scotland director Mark Brewer, who argued that “in such a contentious area as this, it is naive to imagine that a single analysis by a particular group of scientists should be seen as sufficient”.
In a noticeable first and potential change of direction, the article quotes Chief Veterinary Officer Christine Middlemiss as saying that Defra is “really looking to protect our key species through vaccination and progress that with badgers, as a key wildlife species, but cattle as well.”
The peer-reviewer of the new scientific paper, Torgerson et al 2025, published on June 11th is the Director of Biomathematics and Statistics Scotland (BIOSS). The paper is concerned with analysis of the Ranomised Badger Culling Trial (RBCT). Below, you can see the text of the review together with the authors responses, as addressed to the editor. Also highlighted (bold italics) are a few points that seem particularly important & difficult to disagree with, even if you don’t understand statistics. It should be noted that the two reviewers of the Mills et al. (2024) papers that Torgerson et al. is rebutting, declined to submit a review of the new Torgerson paper. In other words, they praised the two Mills et al papers, recommended them for acceptance, but declined the opportunity to defend their decision by explaining their thinking on Torgerson et al (2024 & 2025). They remain anonymous, which is interesting from an integrity perspective.
Torgerson: The reviewer has made a number of comments. We have addressed these where necessary and made some amendments to the text. We would also like to thank the reviewer for these helpful comments which we hope have improved our manuscript.
Reviewer: Comment. Overall it seems there is strong disagreement over competing data analyses on what is already a highly contentious issue, which has significant implications in terms of ecology and agriculture. I have been asked to comment on one small part of the ongoing discussion, which I will do – however, my overall, strongest recommendation is that, given the importance of the underlying issue (both scientifically and politically) that a proper investigation be conducted to establish an agreed position involving all parties. A continuing to-and-fro among different sets of authors – each, I am sure, well-meaning in their own ways – serves little purpose, and there are better, more efficient and effective ways of resolving disagreements than in the pages of an academic journal.
Torgerson: The underlying issue (mass culling of largely healthy badgers across much of England and in Ireland) is the result of the original analysis by Donnelly et al, first published in Nature in 2006 and papers derived from that, and subsequent analyses. Although the merit of the analysis has been questioned, only by having alternative data analyses published in peer reviewed journals is it possible for the UK Governments to consider amending the policy. Nevertheless, we have contacted Donnelly et al previously in an attempt to meet and to find common ground, but our attempts were rebuffed. In order to give the reader a clear idea of the applied implications of both our re-evaluation and the peer review comments, we have added some text to the conclusions: “Accordingly a very substantial number of publications that rest extensively or completely on RBCT statistical analyses may require major qualification or retraction. The justification for lethal control of badgers to-date appears to have been based upon basic statistical oversight.” Also there is a reproducibility crisis in science. Therefore it is important for these issues to be published as we believe they provide an exemplar of a major driver to the reproducibility crisis and misdirection of disease epidemic management.
Badger Crowd Comment: A scientific seminar and evening presentation on the work of Paul Torgerson and his team (then a pre-print) was organised in Oxford in November 2024 in order to allow debate with the RBCT scientists. All declined the invitation. DEFRA and APHA sent no representatives. Natural England sent one staff member but gave no feedback. Badger Crowd very much welcomes the reviewers suggestion to hold a “proper investigation…to establish an agreed position involving all parties.”
Reviewer: Comment 1) Section 2.1. I agree with the authors of the current contribution here that use of an offset here is likely a requirement, and that the comments from the Mills et al. (4) are naïve at best – it isn’t helpful to think of an offset as equivalent to setting a regression coefficient to 1.0, as of course the issue is that this is a log-linear scale and the point is that (under the Poisson) we assume proportional rates. I agree that it does not seem to make sense that the herd breakdowns vary only very slightly (the parameter value of 0.04) with the number of herds, although I would caution here only that it is possible some other variable/term in the model might be related to the number of herds, hence suppressing the parameter value (when including number of herds as a regression term rather than as an offset) owing to collinearity.
Torgerson: This is quite possible, and the collinearity is likely to be between the co variates of “triplet” and “baseline herds at risk”. Hence the motivation to explore the results of models where triplet was removed (which always resulted in a considerable reduction in AICc). Although it is not clear if the reviewer required a response to this statement, we have inserted the following text into the manuscript “The removal of “triplet” may remove any hidden effects possibly due to collinearity with number of herds, as well as substantially reducing the number of covariates and hence largely eliminate the issue of over fitting.”
Reviewer: Comment 2) I have personally written (Brewer et al, 2016 – https://doi.org/10.1111/2041-210X.12541 ) about the dangers of relying on the theoretical distinctions between AIC/AICc and BIC, so it should be no surprise that I share the current authors’ suspicions on the preference expressed in Mills et al. (4) for BIC. Also, why are the AICc values for Models 1 and 3 so much higher than the null model in Table 1? Is this just a feature of the small-sample correction? Otherwise I would not expect this at all (if I’m understand what the null model is, correctly); in the absence of other explanations here, given the high number of parameters in models 1 and 3 I would suspect poor model fitting with inflated variances due to collinearity. So, I agree with the current authors here, on the basis of the evidence in front of me (Sections 2.2+2.3, Table 1, supplementary material).
Torgerson: This issue is well taken. This was part of our arguments. Although perhaps not completely clear. We have edited the relevant text which now reads “Brewer et al (16) have written about the dangers or relying on theoretical distinctions between AIC/AICc and BIC. Nevertheless, Mills et al. (4,5) state “…a wide array of statistical techniques and study periods allows us to make robust conclusions regarding the effects of proactive badger culling which are informed by consistent scientific evidence from trial data, irrespective of which approach to statistical inference is taken.” This is demonstrably untrue. The analysis of “confirmed breakdowns” (OTFW) show that results are highly dependent on the approach to statistical inference and information criteria used. However, absence of any cull effect on the incidence of bTB, when total breakdowns are considered, is robust, irrespective of statistical method.”
Reviewer: Comment 3) The discussion on Bayesian models claims that the authors of Mills et al. (4) made coding errors. I do feel that then Mills et al. should be able to examine and (if relevant) correct these errors, and formally issue a correction in the pages of the journal. Otherwise, I don’t feel I have sufficient information to comment further here.
Torgerson: Here the reader needs to refer to both the coding on GitHub, which is where Mills et al have made their statistical code available and the code we have given in the supplementary material. We give an example here. In Mills et al, they claimed an offset was used with the following R code: rs1aB←stan_glm.nb(Incidence~Treatment+log(hdyrsrisk),+log(Hist3yr), offset = log(hdyrsrisk), prior_intercept=normal(0,10), prior=normal(0,10), data = rbctconf, refresh=0) Here you will note (in red) that log(hdyrsrisk) appears twice in the code, both as an explanatory variable and an offset. The effect of this is to shift the parameters of log(hrdyrsrisk) by a value of 1, whilst other parameter values remain unchanged, thus effectively having no offset. The correct code if a parameter value is to be fixed as an offset is: rs1aB<-stan_glm.nb(Incidence~Treatment+log(Hist3yr), offset = log(hdyrsrisk), prior_intercept=normal(0,10), prior=normal(0,10), data = rbctconf, refresh=0) or alternatively: rs1aB<-stan_glm.nb(Incidence~Treatment+offset(log(hdyrsrisk))+log(Hist3yr), prior_intercept=normal(0,10), prior=normal(0,10), data = rbctconf, refresh=0) We refer the reader to our supplementary material where it is fully explained together with the other errors in the code of Mills et al.
Reviewer: I agree with the current authors’ concerns on the statistical audit. I would go so far as to say that, given the important of the topic of this discussion, any audit should be carried out openly and transparently.
Torgerson: We have added short text at the end of section 4 “ It is important that trials include an audit that is open and transparent.”
Reviewer: Comment 5) Section 5 on the neighboring area study – again, from what I can see here, I would broadly agree with the concerns of the current authors.
Torgerson: No response required
Reviewer: Comment. 6) To clarify; I have no issue with the modelling of counts, as the use of a Poisson-form log-linear model is, in effect, modelling rates. To be more precise, I would suggest that the problem is not that Mills et al. (4) modelled counts, but that they did not properly scale those counts by use of an appropriate offset – and again, I am saying this on the basis of the evidence of the current work (only).
Torgerson: Here the reviewer appears to be agreeing with our approach by using the offset. But for clarity so readers can see the derivation of the offset (in the Poisson log-linear model) in our previous manuscript where there derivation is explained. Thus we have inserted the text “The mathematical derivation of the offset is explained in our previous manuscript on this issue (3).”
Reviewer: Comment. 7) Finally, I would like to address the quotation from Donnelly (16): “the suggestion of requiring independent replication of specific statistical analyses as a general check before publication seems not merely unnecessary but a misuse of relatively scarce expertise”. The point to me here is not that work should be “replicated” as such, but that work should be verifiable. The authors of Mills et al. (4) have apparently made their work – at least that related to the 2024 journal papers – available openly, and this is the key; openness and transparency are vital. I would even go as far to say that, 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.
Torgerson: Yes we agree, which is one of the issues with the original RBCT proactive cull statistical findings published in 2006, which was led by Donnelly: it was a single analysis by a particular group of scientists, and the Mills et al papers are also led by Donnelly et al. We think this is obvious and it should be verifiable. Nevertheless we have modified the text surrounding the quotation of Donnelly (16). It now reads: The position of Donnelly (17) that “the suggestion of requiring independent replication of specific statistical analyses as a general check before publication seems not merely unnecessary but a misuse of relatively scarce expertise”, needs revisiting. This case underlines the need not only for rigorous checks of statistical analysis but also validation of the statistical models and assumptions used within submitted manuscripts to verify them.
Badger Crowd Comment: For the last 6 months, Sir Charles Godfray and his ‘expert’ panel have been reviewing badger cull and bovine TB science published since 2018. Godfray was involved in the RBCT audit, the 2013 restatement of badger cull science and the 2018 science review. In other words, the single analysis (Donnelly 2006) that has supported the badger cull policy is being reviewed by (largely) the same ‘particular’ group of scientists who have been associated with the work for nearly 20 years. Donnelly herself has been ‘recused’, but has been replaced by another Oxford statistician from the same department. There is no outside scrutiny, and there is a case that there has been no “proper investigation ….to establish an agreed position involving all parties” as recommended by the peer reviewer. A proper investigation would be free from conflict of interest. Defra have refused to address this issue over the last six months.
In case you missed the point of all this, the new Torgerson paper shows how for multiple reasons that there is no evidence that culling badger delivers a disease benefit of bovine TB control in cattle herds. The current ‘closed shop’ of science at DEFRA has fallen flat in the past and should not be allowed to continue. They are selecting the scientists and science that they want to suit a civil service agenda and they don’t want to admit that they have been wrong for very many years. It is a flagrant example of policy driven science. And everybody is losing out because of it: the public (because of the enormous costs of policy), the farmers (because it is a policy that can never achieve its aims) and the badgers – because they are being inhumanely killed in huge numbers.
This intolerable situation cannot be allowed to continue. Badger culling must stop now, and an independent investigation or inquiry must be set up.
A prominent ecologist says an independent assessment of the latest study on badger culling is a “bombshell” takedown of the government’s evidence used to justify the policy. Tom Langton, a badger expert, said the conclusions by a top statistics professor should prompt the government to end the programme of shooting badgers to try to eradicate bovine tuberculosis (bTB).
Professor Mark Brewer, director of Biomathematics and Statistics Scotland, who reviewed the paper, praised the openness of earlier papers but wrote: “I would even go as far to say that, 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.”
A study by Mr Langton and colleagues published by the Royal Society criticised scientists who believed badger culling was successful in reducing bTB, claiming they had made coding errors.
In the new study, Prof Paul Torgerson wrote: “The justification for lethal control of badgers to-date appears to have been based upon basic statistical oversight.”
Last week, The Independent revealed that government body Natural England had this year re-authorised supplementary licences to continue badger culls across England – against advice from their own scientific chief. The new culls will lead to an estimated 5,000 badgers being shot dead. The government has already begun establishing teams to increase badger vaccination and launched a badger population survey. It announced on Wednesday that badger TB vaccinations rose by 24 per cent across England last year, to what it said was a record high, with 4,110 badgers being vaccinated.
But controversially, ministers have also reconvened a panel of experts led by Prof Sir Charles Godfray, who has long backed culling and assessed the randomised badger culling trial (RBCT), concluding that culling reduced the spread in bovine TB.
Prof Torgerson wrote: “A very substantial number of publications that rest extensively or completely on RBCT statistical analyses may require major qualification or retraction.” And Mr Langton called for the earlier papers, on which successive governments have relied for evidence to continue culls, to be retracted.
He said: “The independent reviewer’s views should help take a wrecking ball to a large volume of accepted badger-culling science. “This shows how misjudgement can create bad government policy, if statistics are not checked properly and brings to life the many claims that the public have been cheated over badger culling for over a decade.”
Badger lobbyists argue that more scrupulous hygiene on farms reduces TB. The Wild Justice organisation, jointly led by naturalist Chris Packham, together with the Badger Trust, have won permission for a full judicial review of badger culling. The RBCT, which ran from 1998 to 2005, suggested a reduction in TB infections in cull zones, but its findings were disputed because of the “perturbation” effect, where badgers from targeted families moved further away from their natural areas, potentially carrying disease risk with them. It’s estimated 250 papers have been published using the results of the RBCT.
Epidemiologist Prof Christl Donnelly, professor of Applied Statistics at Oxford University, told The Independent that in the light of recent correspondence they would make some minor tweaks to some of their models.
“Crucially, the position does not change: repeated widespread badger culling can reduce risks of bovine TB to cattle inside culled areas, while increasing risks to cattle on nearby unculled land,” she said.
A spokesperson for the Department for Environment, Food and Rural Affairs said: “TB has devastated British farmers and wildlife for far too long.“We are rolling out a comprehensive TB eradication package that will allow us to end the badger cull and stop the spread of this horrific disease.
“This includes launching the first ever national wildlife surveillance programme to better understand the disease and work to increase badger vaccination at pace.”
Government badger cull policy 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 RBCT claimed badger culling can reduce bovine TB in cattle; very many subsequent studies are heavily derived from it.
Disease benefits that have in recent years been ascribed to badger culling by civil servants and politicians are in reality, far more likely due to implementation of additional cattle measures that were put in place before or at the same time as culling. But Government scientists continue to infer that badger culling has caused a reduction in disease, simply because this is what was “predicted” by the results of the RBCT. its classic confirmation bias.
Below is a chronology of some key RBCT publications.
Inexplicably, the Natural England rationale for licensing the supplementary badger culls in 2025 year did not take the Torgerson et al 2024 preprint into consideration. This is despite considering un-peer reviewed reports this year, and preprints (notably Mills et al 2024) last year.
So although the peer reviewer (Prof M. Brewer, Director of Biomathematics and Statistics Scotland) of Torgerson et al (2025) favours this new evaluation, which concludes that “The justification for lethal control of badgers to date appears to have been based upon basic statistical oversight.”, it was not considered in the cull licensing for 2025. The peer review comments for the new Torgerson et al. Comment paper are available from the online link, and are well worth reading in full.
The justification for badger culling has been shown to be wrong in so many ways. Badger culling must stop immediately, on the basis of scientific evidence.
In response to the new scientific paper published in Royal Society Open Science today, Natalie Bennett has re-iterated the Green Party’s call to bring an end to badger culling. She is quoted as saying:
“The Green Party has long said that the badger cull is cruel, ineffective in controlling TB in cattle, and unscientific, and here is a demonstration of particularly the last.”
“Policy should not be made, or continued, on the basis that ‘we must do something’, even if that something is known either to not work or be actively harmful. Yet that is the position the government is now in.”
“The science is clear that tackling biosecurity and testing in cattle is the only solution to this issue that is causing heartbreak and loss to so many farmers.”
“I repeat our calls for an immediate end to the killing of badgers in this terribly nature-depleted nation.”
The London based Royal Society have published analyses that show how key aspects of methodology of the Randomised Badger Culling Trial (RBCT) published in Nature in 2006 were misdescribed and used implausible analytics. Original statistical appraisal that RBCT authors had claimed was too robust to require checking, was actually fallible, once clearly explained and tested.
The published Comment paper, addresses two scientific papers, also published in Royal Society Open Science in August 2024 by postdoctoral student Cathal Mills, supervised by Head of Department of Applied Statistics at Oxford University Professor Christl Donnelly, and Professor Rosie Woodroffe of the Institute of Zoology, (Mills et al I & II 2024). This work sought to defend the original analysis of the Randomised Badger Culling Trials (RBCT), (Donnelly et al 2006), which had been challenged by a full research paper published in Nature Scientific Reports in July 2024 (Torgerson et al 2024). A peer reviewer characterized one pivotal choice made in the two Mills et al. papers that tried to uphold the 2006 findings, as ‘naïve at best’.
Professor Paul Torgerson, Head of Epidemiology at the Zurich University Vet School, has led a team to undertake a detailed reanalysis of the original RBCT analysis. Papers derived from RBCT work have been used since 2013 by the Coalition, Conservative and now Labour Governments to justify badger culling. Labour however have called it ineffective, but without detailed explanation and have issued a new cull licence. Subsequent academic papers have relied heavily on the ‘ground zero’ Donnelly et al. 2006 publication to continue to claim that culling produces a disease benefit in cattle.
In Torgerson et al. (2024), and now also in the newly published and reaffirming Torgerson et al. (2025) “Comment” on the Mills et al (2024) papers, the most statistically and biologically plausible analytical options showed no evidence to support an effect of badger culling on bTB herd incidence. This is consistent with the 2022 analysis (Langton et al 2022) of part of the subsequent industry led badger culls in England (2013-2019), that was unable to detect any disease control benefit.
The “Comment“ also infers that the so-called “perturbation effect hypothesis” no longer holds convincing statistical support. This hypothesis first suggested in the 1970s was of badgers becoming frightened and disturbed (due to the catching and killing of them) consequently dispersing. Then directly or indirectly, badgers were alleged, to be responsible for multiplying the transmission of bTB to somehow cause half of TB cattle herd breakdowns. This mechanism was used to try to explain the claimed effect from the RBCT analysis.
The entrenched understanding of the role of badgers in bTB transmission to cattle over the last 20 years or so is further undermined and finally departs from any empirical support, sending a shockwave through beliefs that have become ingrained in farming, veterinary and Government thinking, where a high level of denial has already been in evidence since uncertainties were raised in 2019.
The implications of the new analyses are enormous, undoing extensive perceptions within multiple stakeholders that badger interventions are fundamental to any policy to control bTB in cattle. Whilst it clear that bTB introduced to wildlife from cattle is shared between wild mammals such as badgers, deer, rats and even domestic cats, exchange between wildlife and cattle has not been shown with sufficient precision in genetic studies to provide confidence. Infected wildlife may result simply from them being ‘spillover’ hosts, where infection dies out once disease is tackled in cattle. New cattle infections continue to occur due to poor testing sensitivity failing to identify disease, the incorrect designation of herds as ‘TB-Free’ when still infected, and continuous trading of infected calves and yearlings. The ongoing bTB crisis has cost the UK and Ireland an estimated £2 Billion in public payouts and lost productivity over the last 20 years alone, including over £1 Billion in England and Wales since 2013.
In 2024 the DEFRA Minister Daniel Zeichner invited Professor Sir Charles Godfray at Oxford University, to reconvene his 2018 review panel to consider the latest relevant scientific publications. Godfray, was involved in the statistical audit of the original RBCT analysis and in a 2013 report that appraised RBCT badger culling science, and a review in 2018 that recommended badger culling should continue. He has consistently endorsed RBCT statistics and badger culling.
The new paper and reviewer comments are available to read here.
Quotes from authors
Paul Torgerson, Professor of Veterinary Epidemiology at the Vetsuisse Faculty of the University of Zürich who has led the independent group said:
“The significance of our findings extends to several dozen papers written since 2006 that use the 2006 findings to build a theoretical case that badger interventions are a necessary part of bovine TB control in cattle, when they are not. Much work is now needed to highlight this issue by corrections, retractions and other measures to ensure students and practitioners are no longer misled. Bovine TB control must focus on inadequate TB testing and movement control of cattle where the problems are now well known.”
Tom Langton a nature conservation consultant within the independent group who has studied bovine TB control, has coordinated technical and legal scrutiny over badger culling since 2016. He said:
“The Government challenge to prevent further £1 billion spend over the next decade on more inadequate disease control will require fresh thinking and approaches. The Labour Government has rightly labelled badger culling as ‘ineffective’ and must surely now immediately cancel all badger culling licences while an inquiry is launched, as should Government in the Republic of Ireland, where thousands of mostly healthy badgers are also culled each year with no demonstrable reward. The failures of the TB testing system are now so well established it is unfathomable why prompt government action was not taken last year.”
In August 2024, Defra announced plans for a ‘refreshed’ bovine TB control badger strategy (here). On 30th January 2025, Defra issued Terms of Reference (here) for their ‘comprehensive new bovine TB review’, a look at ‘new’ science, which will inform their ‘refreshed’ strategy. This included details of the scientific panel which will be reviewing ‘new’ evidence that has become available since the last review was published in 2018. We have blogged briefly about this here. A new strategy would be the first since that presented in 2014, by Owen Paterson when he was Secretary of State (here). At that time, Patterson said:
“If we do not get on top of the disease we will see a continued increase in the number of herds affected, further geographical spread and a taxpayer bill over the next decade exceeding £1 billion.”
This is exactly what has happened, and what Steve Reed the new Secretary of State could be about to repeat. The outline for the preparation of a new strategy is brief:
First Bovine TB strategy in a decade to end badger cull and drive down TB rates to protect farmers livelihoods
New holistic approach will ramp up cattle control measures, wildlife monitoring and badger vaccinations
Proposals to be co-designed alongside farmers, vets, scientists, and conservationists to beat TB that devastates livestock farmers and wildlife
While Badger Crowd welcomes talk of an ‘end to the badger cull’, the new strategy proposals indicate that this is not guaranteed before the end of the current parliament (2029). This is completely unacceptable. The strategy proposes five more years of badger culling, all without sound scientific basis, and if implemented would result in the total number of culled badgers heading beyond 250,000, with no measurable disease benefit at all.
Holistic measures to ramp up cattle control measures are welcome, along with wildlife monitoring, but proposals for mass badger vaccination to be employed against bovine TB in cattle are based on unscientific beliefs, uncertainty and guesswork, using methods trialed and rejected in Wales. They are a further betrayal of what was promised and what is urgently needed. They are a scientifically unjustified continuation of the badger blame game, and as misguided as culling in terms of cattle TB control.
The scientific evidence just does not support the continued focus on badgers as a 50% source of bovine TB in cattle, despite the last Government’s claims and ill-informed media reports. There are no ‘benefits to bank’. Yes, general on-farm hygiene improvements are sensible to prevent disease generally, but the real core need is to change the SICCT gold standard regulations, giving more control to farmers and vets to use a wider range of tests. Re-education of the sector on the science of bovine TB and wildlife, over which they have been misled for many years, is urgently needed.
Who could oppose the statement that “The full strategy will be co-designed with farmers, vets, scientists and conservationists”? But this has been said before, and implemented with secret committees and closed-door briefings, usually with those who are beholden to Defra for grants and favour. It is a breeding ground for vested interests and cover-ups.
Engagement with scientists involved in important peer-reviewed science that questions badger culling (here, here and here) has been prohibited by Defra for at least five years, despite frequent requests for meetings or at least dialogue. Will there be continued resistance to accept the published science that challenges the views of those civil servants at Defra who have been pushing expensive and unethical policy for so long based on decades-old equivocal evidence? There is an uncomfortable history of bad decision making by those who now need to move along, to allow genuine progress.
What does the immediate future of badger culling look like?
Intensive & supplementary culling
The Labour manifesto in 2024 called badger culling ineffective. Sadly, since Labour’s election to power, Steve Reed (SoS for Environment, Food and Rural Affairs (EFRA)), Sue Hayman (Parliamentary Under-Secretary of State for EFRA), and Daniel Zeichner (Minister of State for Food Security and Rural Affairs) have all confirmed that the existing badger cull licences will be ‘honoured’ as they would have been under the previous Conservative administration. But where is the honour in doing the wrong thing? Culling will continue until January 2026. Leaked figures suggest that 10,769 mostly uninfected badger adults and cubs were killed in the 2024 supplementary, intensive and targeted culls to January 2025. How can a policy described by Labour as ineffective be implemented legally? There is no honour in retaining contracts that waste resources and distract from what really needs doing.
Targeted culling
On 14th March 2024, under the previous Conservative administration, Defra launched a five-week consultation on the next steps to ‘evolve’ what they call ‘badger control policy’. If implemented, this would have involved ‘targeted’ culling of badgers, seemingly at the discretion of the Chief Veterinary Officer. A general election and subsequent Labour victory meant that it was lawyers acting for Defra’s Secretary of State Steve Reed (and not the Conservatives Steve Barclay) that responded to a Judicial Review Application [AC-2024-LON-002292] against the ‘future of badger culling’ Consultation, as reported here. The ‘targeted’ badger culling proposals based upon Low Risk Area ‘hotspot’ (or epidemiological culling) were scrapped, although the new Labour government was unclear about its reasons. Effectively this decision provided the legal relief that the legal case sought (i.e. no targeted culling was implemented) and so it did not proceed to a hearing. As previously mentioned, the Secretary of State Daniel Zeichner has now instigated a fresh review of future bovine TB policy.
Low-Risk Area Culling
On the 22nd August 2024, a new consultation on licensing of a new badger cull in the Low Risk Area appeared online. So Labour did not just re-authorise existing licences, they are started new licences in new areas, this one in Cumbria in the Eden valley north and east of Penrith. This had a 100% cull objective, repeating the failed epi-cull of the immediately adjoining area, the subject of a report in 2023 (see here). This cull that was demonstrably the most ineffective cull of all, because badger killing began when cattle testing had cleared all herds in the area, beyond those chronically infected. Labour have revised their public presentation to say that all culling will finish by the end of this Parliament – by 2029.
Test, Vaccinate, Remove (TVR)?
The direction of travel of a recent trickle of papers published by government scientists suggests that the new Godfray review will switch from recommending badger vaccination experiments to TVR experiments, possibly while cranking up ‘hotspot’ culling (which is targeted culling with a different name) to keep the ‘old science’ going. Will there be, as in 2013, a ghastly pilot of the new policy that would provide DEFRA with what they need to keep the NFU and others happy with continued culling?
How did we get here?
The intensive badger culls have been in progress since the policy began in 2013, bringing the official total killed to May 2025, to around 240,000. Culled badgers have been predominantly healthy, killed on the premise of a hypothetical disease perturbation effect and supposed average 16% annual reduction in TB infections in cattle from culling, a concept designed by mostly Oxford academics that is now widely recognised as unsafe science, using unrealistic (and unexplained) extrapolation.
The February 2024 paper by Defra staff (Birch et al.) was being used to justify further culling in the March 2024 consultation, and falsely claimed that the culling programme thus far had been successful. With the Minister Steve Barclay stating “..bovine TB breakdowns in cattle are down by on average 56% after four years of culling..”. By sleight of presentation, he immediately muddles cause and effect. Authors of Birch twice acknowledge (on careful reading) that while they may speculate, the overall result cannot be attributed to badger culling: all disease measures implemented, including extensive testing, were analysed together with no control. There was no comparison of culled and unculled areas. It is far more likely to be cattle measures causing reduction in disease than badger culling, because decline began well before culling was rolled out. And in response to the introduction of annual SICCT testing in 2010 and short interval testing of infected herds. Birch et al also incorrectly under-reported the use of additional Gamma testing, which is a likely significant cause of disease decline. In truth, Birch cannot attribute benefit and provides no insight at all. Other cattle-based measures were also introduced alongside culling. So it’s been more a case of ‘Fake 56% News’ confirmation bias.
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.”
Badger culls have previously been justified using the guess-based ‘Risk Pathways’ approach of the Animal Plant and Health Agency (APHA) that purported to explain how disease arrives in a herd. Its ‘tick-based’ veterinary questionnaires implicated badgers as the default primary source of disease when adequate epidemiological information and investigation was lacking. Following publication of the report ‘A bovine TB policy conundrum in 2023‘ in April 2023, and with the speculative nature of their approach well exposed, APHA are now planning to use Whole Genome Sequencing (WGS) and a sample of dead badgers to try to justify culling on a local basis. These two methods of pinning blame on badgers fall desperately short however, as they do not prove an exact route or rate of transmission from badger to cow. Such a route may not even exist, or may be occasional or exceptional, occurring as a result of the constant infection of the countryside by infected cows. Badgers will just be getting bTB from cows, as with strain 17z in Cumbria, and rarely if ever giving it back. The proposed system for justifying badger-blame is still unscientific and unethical veterinary practice.
Why are APHA not checking back five or even ten years on moved stock to discover the improperly declared TB-Free source of new breakdowns? It would show them the true source of infection.
Refuting peer-reviewed science showing industry-led culling has shown no disease benefit
In their March consultation, Defra are at pains to continue to refute a study in the journal Veterinary Record (18 March 2022) by Tom Langton and veterinarians Mark Jones and Iain McGill. They do this on the basis of an un-peer reviewed letter published at the same time, which used incorrect data and made incorrect assertions about the methodology used, that was later corrected with some confused and unsubstantiated remarks. So where, 2 years later, is their measured alternative? Nowhere, because they can’t produce anything, even holding all the extensive data on individual farms in secret, as they do and always have. There are many ways they could test the data, so why don’t they? Or have they tested it but don’t like the results? There was no peer-reviewed rebuttal to Langton et al. under the old Conservative leadership with Defra refusing to meet and discuss. We have blogged about this sorry tale here and here and here.
Langton et al. 2022, was done in the most logical and clear-cut way using all the data. It shows what happens as unculled areas become culled, from 2013 onwards. The paper has two main findings. The first is really good news for farmers, cows and badgers. Data suggests that the cattle-based measures implemented from 2010, and particularly the introduction of the annual tuberculin skin (SICCT) test are 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, all well before badger culling was rolled out in 2016.
The second finding came from looking at the amount of cattle bTB in large areas in the High Risk Area that had undergone a badger cull, and comparing it with the amount of disease in large areas in the High Risk Areas that had not had culling. It included a six year period 2013-2019, so before and after culling was rolled out. Multiple statistical models checked the data on herd breakdowns over time and failed to find any association between badger culling and either the incidence or prevalence of bovine TB in cattle herds. The models that most accurately fitted the data were those that did not include badger culling as a parameter, suggesting that factors other than culling (cattle testing) were more likely to be the cause of the reduction in disease in cattle. Badger culling efforts appear to be to no effect. A summary of this research is available to read on our 18 March 2022 blog here. You can read an open access copy of the full paper here. A three minute video illustrating the work is available to view here.
Badger culling outcomes were always uncertain
With no analysis able to show a disease benefit from industry-led badger culling, the analysis from the original Randomised Badger Culling Trial (RBCT) remains pivotal to any decision to cull badgers. Published in Nature Scientific Reports in July 2024, Torgerson et al (2024) challenges the certainty of this original analysis. Read more about this here.
Commenting on this work, Professor David MacDonald writes “They found that the conclusions of the 2006 analysis are sensitive to the method of analysis used. Indeed, the analytical approach that Torgerson’s team judge to be the most obvious for the purpose, provides no statistical evidence for a culling effect, whereas a model comparison method aimed at selecting a model with the best out-of-sample predictive power indicates that the best model does not include the treatment effect of killing badgers. According to those statistics, killing badgers during the RBCT made no difference to the herd breakdowns, whether measured by either OFT-W or by OFT-W + OFTS.” In other words, badger culling in the RBCT showed no measurable disease benefit using the most appropriate analyses. On this basis, all badger culling must stop immediately.
New response from original RBCT authors
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 author) published two new papers in the Royal Society Open Science (here and here).
Rather than pushing for Test, Vaccinate & Remove (TVR) as seems to be the DEFRA & APHA current direction of travel (together with continued intensive, supplementary and low-risk culling), it is time to stop and implement the cattle-based measures that would finally get the disease under control.
Dick Sibley has shown why cattle measures are failing (see here). A BBC documentary screened on BBC2 at 9.00pm 23rd August (and now available on BBC iplayer) does an excellent job of illustrating the problems of inaccurate cattle testing, and provides solutions – without culling badgers. Called ‘Brian May – the Badgers, the Farmers and Me’, it is a must see, and make the realities of the problem and current negligent approaches more visible.
It is time to stop living in the past and putting faith in unsubstantiated beliefs that controlling badgers can play a significant role in the control of the bovine TB epidemic.
Natural England have confirmed that the nine (9) supplementary badger cull licences issued in 2024 have been authorized for their second and final year 2025, with culling running from 01 June to 31 January 2026.
This is despite Director of Science Dr Peter Brotherton’s concluding advice, that “Based on the evidence, I can find no justification for authorising further supplementary badger culls in 2024 for the purpose of preventing the spread of disease and recommend against doing so.”
He has, as in 2024, been overruled for reasons that will not be made clear for a few weeks, no doubt because if it is a re-run of 2024, the authorizations will also be added to the current legal challenge that our 2024 freedom of information response instigated. DEFRA are making it quite clear to enquirers that they are not involved in the decision making, which is a stretch, and details should come out in the legal papers when the case finally comes to court. Unless expedited however, few badgers could be saved due to the lengthy judicial process.
A further 11 areas may be authorized for the final year of four-year culling and the low risk area cull in Cumbria may enter its second year.
Back in the day, and well before their ‘not-so-sensible after all’ 2001 merger with the Department of Environment, Transport and the Regions (DETR), the Ministry of Agriculture, Fisheries and Food, (MAFF), were influential in deciding what government should do about badgers.
Badgers had being shown to be carriers of bTB, and capable of infecting cows, at least when locked in a small shed together with them for months. In their contribution to the 1980 Government review, (and tucked away in a long appendix), MAFF made significant claims that went wildly against the established veterinary thinking of previous decades. Previous established understandings had led to the effective elimination of the disease across most of Britain, no less.
In the video linked below, ecological consultant Tom Langton shows how bad epidemiology altered the course of bTB control, sending scientists, civil servants, politicians, farmers and vets floundering in the wrong scientific direction for over four decades.
npj Climate Action is an open-access, online journal published by Nature Portfolio. It focuses on research and action related to mitigating the hazardous effects of global climate change. It aims to bridge the gap between scientific research and practical climate action, informing policies at both local and global levels.
A paper entitled “The activism responsibility of climate scientists and the value of science-based activism” (Anguelovski et al (2025)) has recently been published in npj Climate Action. The arguments for the participation of scientists as so-called activists in the development and evolution of government policy are eloquently expressed and hard to disagree with. And these arguments transfer from climate science to many other areas of important environmental science, not least badger culling.
Quoting from this new paper, it is surely sensible that “scientists have the right and responsibility to engage in activism” because “their expertise and ethical responsibility position them well to change policy”. This has not been the case thus far with the science of badger culling, where independent peer-reviewed science has been dismissed by government scientists; the term ‘anti-cull activists’ has been used to try to slur individual scientists (and the peer-reviewers of their publications) and undermine the veracity of work that does not concur with the established Government policy view (see the un-peer reviewed letter in Vet Record, DEFRA press release & CVO blog). No peer-reviewed science has been published since to justify the criticisms made in these pieces. Gideon Henderson has since left his post as Chief Scientific Advisor for DEFRA without commenting further on the matter or substantiating his intervention. Chief Veterinary Officer Christine Middlemiss remains in post.
How refreshing to read the recommendation the “..broader societal role scientists can play should be recognized and respected”. This has certainly not been the case with Government funded badger cull science, where there has been no inclusion of published scientists whose conclusions upset decades of Government funded work. Not only has there been inadequate dialogue, but the only route to release of critical data and policy rationale has been through Freedom of Information requests or grueling legal engagement.
Badger Crowd is also happy to endorse the “call for the support of activists who engage with researchers in pursuit of evidence-based action.” As the paper’s abstract concludes, “Mutually supportive relations between science and civic groups will make science more horizontal, inclusive, and thus legitimate and impactful in the eyes of policymakers and society at large.”
Anguelovski et al (2025) includes a useful reminder of some important historical examples of scientific activists; “Think of Darwin’s debates with religious authorities, Snow’s work on cholera, or Rachel Carson’s Silent Spring. Entire branches of science (medicine, conservation biology) are defined by their activist agenda”.
So, we will look forward to future involvement of allbovine TBactivist scientists in the debate about the efficacy of badger culling and the direction of bovine TB policy. They have an important contribution to make. And it should have happened many years ago.
If you, as a member of the public, activist or scientist, support challenging the flawed science behind the badger cull and want to see a parliamentary debate on the issue, please sign the petition linked below calling to “End the Badger cull and adopt other approaches to bovine TB control”:
If you google “Is the Badger Cull Working?”, you get the following Artificial Intelligence (AI) overview:
“The badger cull, designed to reduce bovine TB in cattle, has faced significant debate and controversy, with evidence suggesting it has not been demonstrably effective in reducing disease rates.”
AI cannot always be relied on for accuracy or its ability to summarize complex science. But you can’t argue with this one sentence.
Natural England should ‘Stop the Culls’. Instead, this is what they will almost certainly do; they will announce that around 15,000 badgers were shot in 2024, and this will be deemed a ‘success’ due to their view of ‘anticipated’ benefit’ – as opposed to ‘measured benefit’. Then they will sign off licences to kill off another 7,000 across 16 counties of England.
They have no ability to say whether what they have done has had any effect on bTB in cattle and they resist scrutiny of uncertainties around this. They have undertaken no serious efforts to monitor ecological impacts of removing badgers. It has to be asked whether such actions are lawful? But the courts say the Government is in charge and can use its chosen ‘experts’ for advice. What chance do badgers have against such blinkered, cruel thinking and an uncaring administration?
How the badger culls will drag on in 2025………….
Note: Area 44 Avon was not approved to continue in 2024.
If you support challenging the flawed science behind the badger cull and a parliamentary debate on the issue, please sign the Protect The Wild petition linked below calling to “End the Badger cull and adopt other approaches to bovine TB control”:
A prominent ecologist says an independent assessment of the latest study on badger culling is a “bombshell” takedown of the government’s evidence used to justify the policy. Tom Langton, a badger expert, said the conclusions by a top statistics professor should prompt the government to end the programme of shooting badgers to try to eradicate bovine tuberculosis (bTB). 
Writing in a preamble to Badger Trust’s report ‘Tackling Bovine TB Together’, key badger ecologist and original 
Badger culls have previously been justified using the guess-based ‘Risk Pathways’ approach of the Animal Plant and Health Agency (APHA) that purported to explain how disease arrives in a herd. Its ‘tick-based’ veterinary questionnaires implicated badgers as the default primary source of disease when adequate epidemiological information and investigation was lacking. Following publication of the report ‘
Langton et al. 2022, was done in the most logical and clear-cut way using all the data. It shows what happens as unculled areas become culled, from 2013 onwards. The paper has two main findings. The first is really good news for farmers, cows and badgers. Data suggests that the cattle-based measures implemented from 2010, and particularly the introduction of the annual tuberculin skin (SICCT) test are 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, all well before badger culling was rolled out in 2016.
Commenting on this work, 
Back in the day, and well before their ‘not-so-sensible after all’ 2001 merger with the Department of Environment, Transport and the Regions (DETR), the Ministry of Agriculture, Fisheries and Food, (MAFF), were influential in deciding what government should do about badgers.
A paper entitled “The activism responsibility of climate scientists and the value of science-based activism” (
