CORRECTED TRANSCRIPT OF ORAL EVIDENCE To be published as HC 725-i

House of COMMONS

MINUTES OF EVIDENCE

TAKEN BEFORE

ENVIRONMENT, FOOD AND RURAL AFFAIRS COMMITTEE

 

 

Badgers and cattle TB: Final Report of the Independent Scientific Group

 

 

Monday 18 June 2007

PROFESSOR JOHN BOURNE, PROFESSOR CHRISTL DONNELLY, PROFESSOR JOHN McINERNEY and PROFESSOR ROSIE WOODROFFE

Evidence heard in Public Questions 1 - 107

 

 

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Oral Evidence

Taken before the Environment, Food and Rural Affairs Committee

on Monday 18 June 2007

Members present

Mr Michael Jack, in the Chair

Mr Geoffrey Cox

Mr David Drew

Mr James Gray

Mr Dan Rogerson

Sir Peter Soulsby

David Taylor

Mr Roger Williams

________________

Witnesses: Professor John Bourne, Chairman, Professor Christl Donnelly, Deputy Chairman, Professor John McInerney, Member, and Professor Rosie Woodroffe, Member, Independent Scientific Group on Cattle TB, gave evidence.

Q1 Chairman: Ladies and gentlemen, in the words of a famous and old radio programme, if everybody is sitting comfortably, then we will begin. There is a sense of déjà vu amongst quite a lot of us around this table that once again we are discussing territory with which we have become familiar over the last few years in dealing with policy matters connected with the control and eradication of bovine TB. Here we are once again with the final report of the Independent Scientific Group on cattle TB before us. Can I for the last time, perhaps with a tinge of sadness, welcome Professor John Bourne, the group's Chairman, supported today by Professor Christl Donnelly, the Deputy Chairman, Professor John McInerney, who is a member of the group, and also Professor Rosy Woodroffe. You have been before the Committee before, for which we are grateful. We have had a chance to look briefly at your final work of scholarship on this particular subject and we are very grateful to you, at relatively short notice and in fact on the very day when your findings became public, for coming to join us. Without doubt, you have given a real boost to Farming Today. Those of you who were up on Saturday morning would have heard Farming Today this week with the run-in to this, and indeed, this morning you could not have got away with it; Professor, you were on the radio at an early hour. So we were well armed with your views before we even got into the House of Commons. Nonetheless, we are genuinely grateful to you for coming and being before us today. One of the things that we are just trying to work out in terms of the modalities, Professor Bourne, is what Defra are actually now going to do with this information, because we understand that, in terms of your principal findings, they managed to get hold of them a little ahead of the public, which is perfectly understandable and no criticism is implied. When you presented your findings to Defra, did they give you any indication as to how long they were going to take to digest what you had put before them and try and give some indication to the concerns in the farming and wildlife areas as to what on earth they were going to do now?

Professor Bourne: These findings are not new; they are not new to Defra. If I take you back to September 2005, when we were asked by Mr Bradshaw to pull down early, prematurely, trial data to inform his Autumn Statement, we did that. We advised him that we did not wish to do that but we did, and we presented at that time evidence of a positive proactive culling effect and evidence of an edge negative effect. We did extrapolate that on the basis of models because it was suggested we did to what would happen if one culled over a larger area. We did state at that time that while theoretically that was possible, pragmatically it would be extremely difficult to achieve, but it would require far more analysis and data and a cost benefit consideration before it could even be considered as a policy option. We followed that in September 2005 with a statement in January 2006, of course, which related to the consultation document. You will recall there were three proposals for culling and we were surprised to see two of them highlighted which clearly the scientific evidence negated, and I was forced, as you know, to write to the Minister at that time and again express our guarded views about culling over large areas. We extended those discussions with Defra, and I have a record of discussions on 22 March 2006 with Defra, where we advised them very clearly that future policy should have a cattle-based focus and that culling would make matters worse. As we extended our analyses, I met with the Minister, Mr Bradshaw, on 24 April, repeating those comments at a discussion with him that localised culling was ineffective, proactive culling extended to 300 square kilometres was likely to make matters worse in the way the Government perceived it would be done. I met Mr Bradshaw again on 29 November 2006 and presented more detailed analyses, because by this time we were able to analyse the full 50 plus triplet years of the trial where we had hardened up on our data, closer confidence intervals, and made it clear to him that culling would make things worse and one should focus on a cattle control policy. I repeated that with Mr Miliband on 1 February. In the interim, of course, we had weekly discussions - probably more frequently than that - and certainly our monthly meeting with Defra officials, so they clearly knew where we were coming from. All the scientific publications that left the ISG went through Defra's hands. Copies were rested with Ministers long before they were in the press. Defra colleagues were asked to advise on those publications and their advice was always taken; it was extremely useful. Ministers received a copy of all those publications pre publication. So it is not only in the last few weeks that they have appreciated what the developments have been with our work but they did see fairly forward not a complete draft report on I think it was May 22 of this year. It has been an ongoing process of reiteration and communication during that period.

Q2 Chairman: In terms of this piece of work, is it, if you like, the ultimate review of all the information that you have? The message I am getting is that really not a lot has changed since we last discussed your findings. In other words, you have had a chance to look back over, as you were saying, all of the data now from the randomised trials. You have looked at that but then you had looked at them before. The conclusion that you have come to, which is effectively that large-scale culling really does not have a part to play, is entirely consistent with everything you have said, so it is almost as if you have peer-reviewed your own research and come back to the same conclusions as before. Is that a fair summary of where you are?

Professor Bourne: We constantly evaluate our research but we do so in discussion with Defra. As you know, it has been our policy to work to strict scientific practice and good guidelines - we can talk about that later - which involves publication of our work in peer-review journals, and we have purposely gone for high-quality journals. We have publications in those journals, international peer review. In addition to that, of course, we have had our work audited independently by auditors appointed not by us but by Defra. The final audit report from the statistical auditor came in today and I believe you have copies of that. I think he makes some very pertinent conclusions as far as the thoroughness of the work we have done and does indeed make recommendations for how science should be developed and translated into policy for the future.

Q3 Chairman: Do you know if Professor Godfrey, who has himself done work, I seem to recall, in 2003, when Defra established an independent scientific review, notwithstanding all that you have said in terms of putting this material into high-quality scientific journals, are you aware that Defra are planning to do that in terms of the latest publication?

Professor Bourne: I am not aware of that. It has been mooted but I am not really aware.

Q4 Chairman: From a scientific point of view, would you be distressed if such an exercise were required?

Professor Bourne: From a scientific point of view, given the rigidity of the audits we have gone through and the peer review, I would have thought it was unnecessary, but if Defra want to do it, good luck to them.

Q5 Chairman: That answers that question. You mentioned that Defra have had sight of this since 22 May and were aware before that of the work that you were doing. The name of your group is the Independent Scientific Group. Can you tell the Committee if at any time you came under any kind of pressure from either Defra or its Ministers and or both that might have been deemed to be a way of influencing the direction of travel of the work that you were undertaking?

Professor Bourne: No. If one goes back to the outset, of course, we had great trouble in getting much of the work in place but I think we fought our corner pretty well and retained our independence. It is very interesting. You mentioned the Godfrey Report, and one of the recommendations of the Godfrey Report was that we should use our independence, that we should report not to Ministers but to the Chief Scientific Adviser. He made other recommendations too which have subsequently been shown to be wrong. Fortunately, the Minister did not respond to those recommendations. I do not think in fact Defra ever responded to his report.

Q6 Chairman: Could you just say that again, Professor Bourne, because Mr Cox missed the point.

Professor Bourne: Professor Godfrey in his report suggested that we did lose our independence - I am not sure he even realised what he was doing - by suggesting that we reported not directly to Ministers but indirectly to Ministers through the Chief Scientific Adviser. I also said that Godfrey made other recommendations - he made two, in point of fact. One was that he suggested that 50 triplet years was inadequate for the power of the experiment and we might have to extend that by several more years, and that has been proven to be wrong. He also suggested that data should be released prematurely to Defra at that time but fortunately Ministers rejected that. I think you know how strongly we reacted to that suggestion. It would have completely undermined the trials.

Q7 Mr Williams: When you say that Professor Godfrey's conclusion that there were not enough triplet years has been proved to be wrong, is that because of the statistical analysis of the work that has been done or is that some independent review of his conclusions?

Professor Donnelly: At the time we did alternative calculations and we believed that we were on track to get the level of precision that we needed in 50 triplet years, but the real proof of the pudding is yes, once you have the data, calculating confidence intervals, and the fact that we have been able to estimate the impact of proactive culling plus or minus ten per cent.

Professor Woodroffe: Professor Godfrey and members of his group have gone out of their way to express their conviction that our results are correct.

Professor Bourne: We have had pleasant exchanges with Professor Godfrey.

Professor Woodroffe: One of them last time we were here. He was with us.

Q8 Chairman: Before we get into the detail of your work, a fact which just caught my eye re-reading some of the material behind what you have been doing, if we go back to 1986, there were at that time 638 cattle that were compulsorily slaughtered because they had TB. We come to 2004 and the figure had risen by that time to about 22,500. It just occurred to me, I suppose, because TB has become such an accepted part of life in certain parts of the country as to why the massive increase? Why from 1986, at a relatively low level incidence, has TB suddenly gone on the upward march? Can you refresh my memory as to why that occurred?

Professor Bourne: As a result of the work we have done, we believe there are two factors contributing to this. One is the contribution that badgers make - there is no dispute about the fact that badgers do contribute to the cattle disease - and the other is the contribution the cattle themselves make to the disease, which subsequent work has shown to be related to the limitations of the tuberculin test, the fact that so many infected, undetected animals remain in the national herd and these animals are simply being moved around.

Q9 Chairman: What I was getting at was that, at a relatively low level, there would there would not obviously be the same degree of public attention as there is now because what we have seen is suddenly from, being almost unnoticeable - 600 is not unnoticeable but very low levels of disease...

Professor Bourne: There is a doubling every four and half years.

Q10 Chairman: I was just intrigued to know why all of a sudden, 1986-87 double, did it start to multiply up over that period? What was the epidemiology of this sudden explosion of this particular disease, which I presume had been chugging along at a low level?

Professor Bourne: It had been increasing since the late Seventies.

Q11 Chairman: But what was driving that?

Professor Bourne: Those two aspects that I talked about, the contribution that badgers make and the contribution that cattle themselves make. We had no idea at that time what the badger contribution was and we cannot be absolutely precise about that now. Modelling suggests that it might be 30 per cent or no less but that modelling is imprecise and it does not take into account perturbation, but it does indicate that the cattle contribution is very, very large. We do know, of course, in parts of the country the contribution from cattle is almost solely responsible for the development of the disease and the long-distance geographical transmission of the disease.

Q12 Mr Williams: The tuberculin test very much in the same form as was being used at the time the Chairman is talking about was a tool that was used to almost eliminate TB from the national herd.

Professor Bourne: That is very true. They were very subtle changes, of course, in the way that test was used over the period from 1960 to 2006, certainly into the 1990s. It was developed as a herd test. The obvious way to use a herd test is, if you find an infected herd, to take it out. There are, unfortunately, no historical figures about the number of herds that were actually slaughtered in the 1960s, just the number of cattle, and I think if you go back and see how many cattle were slaughtered in the 1960s, it makes the 22,000 we have now pale into insignificance. It was up around the 40,000-50,000 mark per year. Herds then were very small, very much smaller. As the disease eradication programme progressed, cattle testing regimes in fact were eased, and they were further eased - I am not sure of the timing of this; it could have been the late Eighties or into the Nineties - moving from one-year to two-year to three-year to four-year testing. One does not know the direct answer to your question but I suspect the rigidity of cattle testing was relaxed. The movement control which we saw in the Sixties with the tested herds, the TB-free herds - you were not allowed to buy an animal from TB-infected herds and they had to be double-fenced. All those features were relaxed when the whole country became designated free of TB but, of course, the whole country was not free of TB; there were patches of infection which still remained in the West Country which were ascribed to badgers. Whether it is true to ascribe them to badgers or not I do not know.

Professor McInerney: In the last 20 years also there have been quite significant changes in the structure of the cattle economy and herd sizes are very much larger now so that you get infection within a large herd and it can amplify very much more within that herd. Secondly, the statistics show there is a great deal more cattle movement because of the wider trading activities of cattle farming.

Q13 David Taylor: Professor Bourne referred to the smaller number of larger herds and Professional McInerney just referred to the degree of transport. What was the aggregate size in the Sixties when you were talking about 50,000 cattle being slaughtered a year and what happens now as paling into insignificance? What was the size of the national herd then approximately, as opposed to where we are now? That is a factor as well, I would have thought.

Professor Bourne: I do not know. It surely was much greater then than now, many more million than that. The size of herds, I do not know. I can only talk from my experience when I was in practice in Cornwall, when the majority of herds were 19, 20, 25 cattle, sometimes less, and a herd of 60 animals was large.

Q14 David Taylor: The aggregate size of the national herd would also be a driver in terms of the statistics, would it not?

Professor Bourne: Yes, surely.

Q15 Chairman: Just to conclude this section, just to set us on our road, summarise for us, if you would, the current state of your final conclusions.

Professor Bourne: With respect to badger culling, our findings are that localised culling, in whatever form that may take, will not contribute to the control of cattle disease and is likely to make the situation worse. If one considers proactive culling over the area the size of the trial areas, 100 square kilometres, we have demonstrated that within the culled area there is a beneficial effect of 23 per cent and in the peripheral area outside of the culled area there are an increased number of breakdowns to the extent of a 25 per cent increase in breakdowns in that area. That occurs as a result of systematic culling carried out by a professional team over a five-year period where badger removal was about 70-73 per cent, which suggests a trapping efficiency of 80 per cent, which is consistent with the design criteria of the trial, and yet when one translates the numerical number of herds breaking down and those not breaking down, it results in a very small number of herds saved from breaking down over a five-year period, 14 herds over that period being saved from breaking down. That is the difference between those that have not broken down on the inside and the increased number breaking down on the outside. So it is a very modest return for five years culling, sustained, and when that culling is carried out, we have shown that it has to be across the whole patch simultaneously. You cannot do it piecemeal. That worsens the problem.

Q16 Chairman: Just to help me understand the statistics of what you have said, if after five years you have dropped 20 per cent, roll it forward; if you carried on doing it for another five years, what would the statistical drop be?

Professor Donnelly: What we have shown is that we have trends in both the benefit inside the proactive trial areas and also trends outside. So the detrimental effect gets less bad over time and the beneficial effect gets better over time, but we were not able, on the basis of this data, to extrapolate beyond the fourth annual cull. All ten areas received at least four culls, some as many as seven.

Q17 Chairman: Just stop there, because it is quite easy for a non-expert like me to get lost. If after five years you indicated there were two findings: minus 20 in the area which has been culled and plus 25 per cent increase in events occurring outside, across the border, what I wanted to get some feel for is, if you carried on culling in the next five years, and then another five years, what is the trend? Do you ever get to the Nirvana of the extinction of the disease after 20 or 30 years in the culled area and total ravaging outbreak everywhere else? That is what I am trying to get a picture of.

Professor Donnelly: We were able to estimate well after four culls, so the figures that John reported, the 23 per cent and 25 per cent, are averaged over the whole period of the trial. So the best picture that we are able to estimate at the end of this period is a 33 per cent benefit inside and an 11 per cent detrimental effect outside, and there is a general trend for both of the situations to improve.

Q18 Chairman: I am trying to get the idea. If you devote more time, is there a cumulative benefit?

Professor Woodroffe: Perhaps I can talk to that because, of course, the root of all of this is what is happening to the badgers. What is happening to the badgers is that after about three culls your number of badgers caught per cull plateaus, so you catch most on the first cull, you catch on average fewer on the second and by about the third cull, each time you go back and cull, you are culling a similar number from then on, but what keeps continuing to go up is the proportion of badgers that you catch close to the boundary. So what is happening is that, as you cull the badgers inside the area, more are coming in from the outside. The genetic evidence shows the same. So I think that unless you have some barrier to prevent badgers from re-colonising, probably what is going to happen is that, as fast as you cull the badgers, more come in. We also know that successive repeated culling increases mixing within the badger population, increases TB transmission within the badger population, and so you are going to continue to have a number of badgers present within the area and a higher proportion of those are going to be infected, and my suspicion, based purely on the ecology, is that you are not going to continue down to eradication; you are going to reach some sort of stable point where it does not get any better, unless you had some sort of physical barrier that prevented the badges from re-colonising and, unfortunately, given that badgers dig and climb, fencing them is extremely difficult. There are very few natural boundaries that would prevent that re-colonisation from occurring.

Q19 Chairman: What I was trying to get some feel for was, if you carried on doing it and at the same time adopted all the measures of bio-security cattle movement, whether in fact you would then crack it; in other words you would say in an area, "Right, we have bottomed this." The message I am getting from you is no.

Professor Woodroffe: Yes, from a badger ecology perspective, no. You cannot eradicate the TB in the badger by culling.

Q20 Mr Williams: Just to take the reasoning of the Chairman a little bit further, as I understand it, the average over the five years or four years was 23 per cent improvement and 25 per cent, but then the actual figures in the fourth or fifth year were 33 per cent less breakdowns and 11 per cent more. It seems to me you are going in the right direction. What we are trying to get to is, is it that the process has not been carried on over a long enough period of time to achieve the most beneficial results?

Professor Bourne: You are not only considering the time you do it, but that then takes you into the area over which you cull, because you are continually going to get the drain of badgers into the culled area, as Rosie indicated.

Q21 Mr Williams: The ecology of the badger has been explained but the actual numbers of herds breaking down, which is what we are about, in a way, seems to be improving and going in the right direction.

Professor Bourne: If you consider the number of cases actually saved, it is still very, very low.

Q22 Mr Williams: Even per year towards the end of the experiment?

Professor Bourne: Yes.

Q23 Mr Williams: Are those figures in your report?

Professor Woodroffe: After the first cull, if you do the benefit versus the detriment, the detrimental effect in the first year is so huge that in fact if you did proactive culling once, or even twice, your overall outcome is that you just make things worse.

Q24 Mr Williams: What we are saying is that yes, we understand at the beginning, when you remove a huge part of the population and you get lots of movement of badgers, you do not get very good results in terms of herd breakdown but as you are going on, it improves.

Professor McInerney: One of the difficulties that you groping for is: can we extend on from the five-year experience to another five years and another five years? One can, if one is speculative, but it would be a very dangerous thing to do to extend five years' experience into 20 years. The simple answer to your question, Chairman, is, if you can get 25 per cent of TB removed with five years' culling, can you get another 25 per cent so that in 20 years you have got rid of it? My understanding of the ecology is that no, it is not that simple, which is a pity because if it was that clear, one could at least sit down and say, "OK, can we contemplate a 20-year culling programme? Where might we be and might that be worthwhile?" I would tend to shudder at the cost of a 20-year culling programme given the cost of a five-year culling programme but I can see why one would like to feel that the ability to control the disease could be just rolled on from the five years' experience of this cull.

Q25 Chairman: I ask these questions because among those who will listen and reflect on what is being said, there are those who are entirely with you and those who remain deeply sceptical, and we just have to try and tease out whether in fact the idea of a cumulative policy has any merit.

Professor Bourne: There are other important caveats to this culling programme and those are that the culling is done sequentially on an annual basis by professional teams over a very, very long period. You may wish to comment further on the professionalism required, particularly in relation to land access and also the level of trapping efficiency that you might expect to get.

Professor Woodroffe: The level of effort that this took was in the region of 40 trap nights per square kilometre per year for five years, but the way that the trapping was done was not just that you sling out some traps and wait. Bear in mind that not every land holder provided consented to cull. In order to achieve the most effective culling success that we could, traps were deployed around areas of inaccessible land to try to achieve the best removal that we could, including areas that were inaccessible for trapping. That was successful and we were able to show that by culling around those, in patches of accessible land we were able to suck the badgers out, but that sort of process requires a great deal of experience in badger natural history and behaviour, recognising field signs and so on. It is something that professional staff are needed to do. The level of success that we achieved is various different measures showed that the density of badger field signs, various different measures of badger activity in proactive areas was about 70 per cent lower in the proactive areas towards the end of the trial relative to the areas that were not culled, and bearing in mind this substantial evidence of immigration of badgers into the area, that suggests we are catching more than 70 per cent of them each time, it is just that more keep immigrating. So our trapping efficiency is probably upwards of 80 per cent, I would estimate, on that basis. We have been criticised for having not removed enough of the badgers but a lot of those badgers that are there are ones that came in from outside and we have genetic evidence in support of that.

Professor McInerney: Even if you did go on for five years and five years and five years, at the end of it you would only have managed to eliminate the badger element of TB, and since we do not know exactly how much that would be or how that might change over time, it is very difficult to predict therefore what the TB occurrence would be at the end of a long and extended culling programme.

Q26 Mr Rogerson: We are saying that it is possible potentially to have an impact through quite a large-scale cull in an area but the problem is that it is re-populated. In an area such as, for example, a peninsular, might it be possible to look at what happens if you were looking at tougher measures of controlling it in the herd and also some form of cull in an area that is quite well geographically defined?

Professor Woodroffe: Yes, we can speak directly to that because one of our trial areas and was West Cornwall, the Penwith Peninsula, but we had a variety of different trial areas with different permeability of the boundaries to badgers. The extent to which badgers can immigrate into an area certainly influences the course of infection in the badger population over successive culls, so each time you cull the badgers across all the different trial areas, you see on average that the prevalence of infection in badgers goes up. So each time you cull, the prevalence is higher and higher and higher, to the extent that by the fourth cull the prevalence in the badgers has roughly doubled and that is to do with mixing of the badgers, breakdown of the social organisation, which causes disease to spread. What we see is that that effect is influenced by this boundary permeability, so in the badgers we see that places like West Penwith, the prevalence in the badgers actually did not rise; it remained roughly constant. So you are really successfully there forcing down the density of infected badgers. Unfortunately, when we looked for a similar effect on the impact of culling on the incidence of TB in cattle, we were not able to detect any effect.

Professor Donnelly: The difficulty, of course, is it was not set up to be able to distinguish within these groups of ten comparisons, so certainly we would expect on the basis of the mechanism that we believe is taking place that it is extrapolation on that basis rather than what we have been able to estimate from the data.

Q27 Mr Rogerson: So it is possible, and farmers in a place like Cornwall who would want to perhaps co-operate in some form of action of this nature, that if measures were taken to deal with it within the herd as well, the testing programme and so on, that some form of a generalised control...

Professor Woodroffe: I would make two comments on that. One is that if we stick with that specific example, which is an area I know well, being from there, that actually all of the areas where we worked in the course of the trial, Triplet F, the West Penrith proactive area, had the lowest land owner consent, far and away; half the area was accessible to us, so if that was the place that we considered the best, that would probably offset the benefits for an area like that. One point to which this is highly relevant is comparison with results from the Republic of Ireland, where there has been a great deal of discussion and speculation over the application of the Irish findings to ours. Of course, one of the key differences between our trial and the trial that was conducted in the Republic of Ireland was that, whereas we chose representative areas of high TB risk to cattle, in setting up the Irish study they chose the areas where they thought that culling was going to work best, and they deliberately chose the four places in Ireland where they could find places with these sort of geographical barriers to badger immigration, and where they could not find barriers like that, they had very substantial areas which they culled but from which they never reported the incidence of cattle TB. What I think that means is, I suspect it is probably the case that those sorts of geographical boundaries might well be expected to influence the impact of badger culling on cattle TB incidence and perhaps a comparison with Ireland might lend support to that. There are very few places in Britain that have those sorts of geographical barriers, so whilst it might be something that is locally potentially of some value, in terms of national TB control it is probably not that useful.

Professor Bourne: You mentioned Ireland. I think there are other issues there which are important in comparing the Irish situation with the one in this country. They certainly have a much lower badger population than we do. In tackling their badger culling they, of course, used snaring and have less welfare considerations than we were forced to give to the trapping that we carried out in the trial. Very importantly, they had 100 per cent farmer co-operation and we did not get that. Defra could not find out who owned 13 per cent of the land area in our trial area, in spite of the resource they have to try and resolve that issue. Thirteen per cent of the land over here just was untrappable in that sense. The other thing is that there is no badger group in Ireland. The social attitude to the badger over there is totally different to social attitudes here.

Q28 Chairman: We are going to come on to Ireland in a little while. Just on a point of methodology, you have made it very clear to us that peer review - in other words, you are not coming under flak from scientists that in some way your analysis and its conclusions were flawed, but you have just made the point that you had at least half a hand tied behind your back because you could not get 100 per cent land owner co-operation, and you made that point of contrast in relation to the Irish trials. I suppose it is an impossible question to answer but nonetheless, I might ask it: if you had had, were there examples within all of the trials that you did where you got 100 per cent land owner co-operation and, if so, were there any significant differences between the lower order where you did not get that co-operation and those areas where you got a higher percentage of co-operation?

Professor Donnelly: There certainly were no areas with 100 per cent coverage but what we did find was we divided up in further analyses - and this is part of the IJID paper that was just published. We actually looked at farms that were on accessible land versus farms that were on inaccessible land and we did not find a significant difference between them. In fact, the non-significant difference was in the opposite direction to what you would expect, so what we found was that those farms on accessible land actually did slightly worse than on inaccessible. There was nothing in the statistics to show that the benefits were different. The explanation for that is that actually, the vast majority of areas of inaccessible land were very small. So while we had direct access to about 70 per cent of the land area, traps were deliberately placed on the boundaries and about 70 per cent of the remaining land was within 200 metres of accessible land.

Professor Woodroffe: Which is well within the ordinary daily ranging behaviour of badgers. On successive culls we were clearly sucking more and more badgers out from those areas of inaccessible land, so we were pretty convinced that we were removing substantial numbers of badgers from those little pockets of inaccessible land, even though we could not place traps on that land.

Professor Donnelly: We showed that per square kilometre in the little strips just around the inaccessible land on subsequent culls we actually took out more badgers per square kilometre than on the remainder of the accessible land.

Professor Bourne: It did require tapping expertise to achieve that, of course.

Q29 Mr Cox: I am in danger here of getting into territory that we may explore later but, as I understand your report - help me if I am wrong, Professor Bourne -you have consistently said in this report that though as an instrument of general national policy you take the view that culling is not a cost-effective or sustainable policy, it may be - and I am looking here at number 8 of your general conclusions - that areas with boundaries impermeable to badgers could contribute to TB control on a local scale, although you make the point that, of course, such areas in England are relatively few.

Professor Bourne: There we were referring actually to the odd farm that does build badger-proof boundaries. I am aware that some of these farms do exist in the South West. We recognise that they are expensive and we recognise that although they might make a contribution to that farm, they make no contribution to the national impact.

Q30 Mr Cox: Can we also look at paragraph 5.16 at page 90 of your report, where you deal specifically with the impact of permeability of trial area boundaries. What you seem to conclude there is that your trial, scientifically speaking, can really shed very little light - indeed, you say "currently available data shed no direct light on whether a proactive culling policy would be more beneficial if conducted in more geographically isolated areas". It follows from that report, if one can take the black and white letters, that in areas which may be geographically isolated or maybe otherwise able to be impermeable to the immigration effect, that it is conceivable - and Ireland would seem to support that - that culling might be beneficial.

Professor Woodroffe: Yes. You are absolutely right to pick up the difference between page 90 and page 20 whatever it is, and that is an extrapolation. Within the areas that we actually studied we found no impact of boundary permeability on the effect on cattle, bearing in mind that most of the trial areas had areas that were considered to be 100 per cent permeable to badger immigration.

Q31 Mr Cox: But you had no evidence either way. That is the point.

Professor Woodroffe: We could not detect any effect, but we were able to detect an effect on the badgers themselves and we were able to show that you did not get this rise in the prevalence among the badgers in badger TB prevalence in these areas the badgers could not easily re-colonise, and it was on the basis of that that we extrapolated to suggest that perhaps therefore, if you were to expect culling to work anywhere, that would be where you would expect it, but we have not detected ourselves in the trial an effect of barrier permeability on TV incidence in cattle.

Q32 Mr Cox: Professor Woodroffe, forgive me, but the report says it sheds no light on whether a proactive culling policy would be more beneficial if conducted in more geographically isolated areas. The conclusion that that states is either way: it might be, it might not be.

Professor Woodroffe: It might be or it might not be. Exactly.

Q33 Mr Drew: Can we move on to policy? Professor Bourne, it would be interesting to know if you have had a discussion with Ministers since the report has been made available?

Professor Bourne: No.

Q34 Mr Drew: So have not met Ministers?

Professor Bourne: No. I last met Ministers on 1 February.

Q35 Mr Drew: Can we move on then to looking at how the Government may come to its policy evolution. When you were interviewed this morning on Farming Today, you were somewhat querulous about how Defra were going to handle the scientific data and then subsequently translate it into policy, given that you felt they did not have a good track record with their attempts to draw up their consultation document. Is there any discussion on how you might help them with that, given that you have not talked to Ministers, but presumably you have talk to officials about how they might be wanting to take policy forward?

Professor Bourne: We have not directly had these discussions, no. I certainly have had more discussions with the scientific expertise within Defra based at VOA and recognise the quality of that expertise, and I think the frustration they experience in not having adequate opportunity at extending science into practice. You mentioned the consultation exercise. That was just one indicator.

Q36 Mr Drew: It was a fairly important one.

Professor Bourne: Yes. There was an even more important one, and that relates to the discussions we had with Defra in 2001 on work to develop the gamma interferon test. It was apparent at that time that future policy would demand improved diagnostic tests. We discussed with Defra ways in which field data could be gathered to provide information to inform on a range of policy options, and they rejected our proposals and went ahead with a pilot trial on the grounds that they could not afford to do anything else, and you know the outcome of the pilot trial. It did provide some very informative data but it did not inform scientifically in the way one would have hoped. We have advised that there has to be a closer working relationship with scientists, particularly in Defra, to ensure that appropriate data is collected to inform on future policy options. Also, that data available from the testing of animals is regularly interrogated with a clear strategic view as to what that data might tell them and how that in turn can in be implemented into policy in a way that we have called adaptive management, which really means extending scientific findings into the policy of disease control. We have not seen signs that that has happened and we believe it is critically important that it should. Equally, we have stressed - and I think this is a very important recommendation of the report - the Defra should develop a very clear strategy. At the moment it would claim it does have a strategy, the strategy of reducing the incidence of disease in high-risk areas and preventing its geographical spread, but what are the details of that strategy? It has not really been thought out. I believe there should be a clear strategy of what they want to achieve, what is achievable, what resources are necessary to do that, and this should be driven by a focus group involving scientific informed individuals driving that, certainly with farmer input because they are important stakeholders, and in that way develop a strategy, sell that strategy to stakeholders and drive it forward in a way that one sets targets and knows where one is going. That would in turn require that the whole thing is costed. I am not aware that Defra have ever costed any policy and determined how the policy can be matched to cost. They have certainly bought the increasing cost of compensation payments but that is not the same as what we are proposing. These are the elements of our proposals which relate to data collection, rigorous and ongoing data analysis and interrogation, and how one uses that to feed into a strategy that has already been focused and you have a group driving it. I do not see the mechanisms within Defra at the moment to do that.

Q37 Mr Drew: What has been your response to ministerial statements, written and oral, that have come out since your report has been published?

Professor Bourne: I was aware of Mr Miliband's statement this morning. I am not aware of any others.

Q38 Mr Drew: What is your response to that? It is fairly anodyne.

Professor Bourne: It does not say anything. If I were a badger welfarist, I would see something there for me and if I were a farmer I would see something there for me but really it did not say anything.

Q39 Mr Drew: In the weeks leading up to the publication we have had everybody spinning against everybody else.

Professor Bourne: That has happened for the last ten years.

Q40 Mr Drew: We have had at least a week of inspired leaks in the press which said that Ministers were going to bite the bullet and were going for large-scale culls. We have now had all the stuff this weekend where effectively Ministers are now saying they do not need to bite the bullet because there is no need for large-scale culls. We have obviously had various organisations, like the Badger Trust, making its own threepenny-worth. This has not been helpful in trying to get a scientific rationale of your report. You make a comment about that in terms of some of the critics that you have had to deal with over the years. They all seem to have got their retaliation in first. Have any of them helped you at all in trying to make your case?

Professor Bourne: Not at all. Absolutely not. Absolutely and utterly not. I certainly made the case to Ministers, both to Mr Bradshaw and to Mr Miliband, and collectively, in the meetings we had in November last year and February this year that it would really be helpful if Defra embraced the science and stimulated discussions with the NFU in particular based on science to develop science-based policies. I have seen no sign of that. It may be happening in the background but I am not aware that it is happening and, if it is, it has certainly had no impact on the NFU response.

Chairman: Come back on Wednesday and you can see the other side of the coin.

Q41 Mr Gray: I am new to the Committee since you were here in 2006. I have just been reading the papers and forgive me if I have missed something. It seems to me there is a difference in tone between what you said particularly in your letter in 2006 and what you said in your report. If I could just quote a couple of bits that confused me rather, in your open letter of January 2006 you said, "Intensive culling over a large area and over an extended period of time could in principle reduce cattle breakdown rates", which I interpreted to mean that you thought that there could be a place for extensive culling over a long period.

Professor Bourne: Read on.

Q42 Mr Gray: In the second half you say there are logistical difficulties, yes, but let us leave aside...

Professor Bourne: Read on, read on.

Q43 Mr Gray: Perhaps you would like to answer the question in a moment and then you can tell me the bits that I have not actually...

Professor Bourne: The bits that you have missed out said it can only be considered as a policy option with a cost benefit analysis.

Q44 Mr Gray: Professor Bourne, perhaps you would let me ask the question before you seek to answer it.

Professor Bourne: You were quoting a letter and you were not properly quoting that letter.

Q45 Mr Gray: Perhaps I can ask the question. Perhaps that is a better way to do it, ask the question first and then let you answer it. My naïve interpretation of your letter then - and you can correct me in a moment - was that you said that under some circumstances, although there are logistical difficulties attached and there are costs attached, intensive culling, in your words, over a large area over an extended period of time could in principle reduce cattle breakdown rates. Am I wrong in thinking that means you think that under some circumstances extensive culling could break down cattle breakdown rates? Is that right or wrong?

Professor Bourne: Mathematical modelling in extrapolation from trial data suggests that if you cull over a large area, you would ultimately get positive gains with respect to the area culled relative to the area that you were not culling, where we know one had this perturbation effect.

Q46 Mr Gray: So the answer is yes.

Professor Bourne: I also stated very clearly in that letter that there would be extreme logistical difficulties in achieving this with respect to culling over a large area repeated regularly over a large period of time, and it could only be considered as a policy option if there was an adequate cost benefit analysis.

Q47 Mr Gray: What sort of logistical difficulties?

Professor Bourne: The logistical difficulties are the ones that we had to face in doing full surveys of these areas, getting a trapping force into the fields to do culling across the whole piece at the same time and continuing it for this very long period. There is a real logistical difficulty.

Mr Gray: Hang on a minute. The logistical difficulties of doing it ---

Q48 Chairman: Let Professor Bourne answer.

Professor Bourne: We also stated that if one required a cost benefit analysis and we have subsequently been able to do that because we have been able to identify the number of breakdowns that would be saved as a result of this sort of practice and the costs that would be incurred, but the fact the Government stated very clearly that they would not do this themselves, they would not be responsible for this, but farmers would in fact have to do this of their own bat, increases the logistical problems of doing this.

Q49 Mr Gray: Let us leave the logistical difficulties to one side because there is no logistical difficulty in the world that it is not possible to overcome. What I want to focus on is what you said in your January letter, which was that in principle an extensive cull over an extensive period might well be beneficial in terms of reducing TB. That is what you said in your letter. Was that wrong or has the science developed since then?

Professor Bourne: As an extrapolation, as a modelling exercise, that was correct but we are bound to write caveats to that, which I would have thought would have been a clear message to Ministers of the difficulty of doing that and the likelihood that the whole thing just would not be achievable. Subsequently, of course, we have been able to do a cost benefit analysis.

Q50 Mr Gray: We will come back to the cost benefit analysis and cost, of course, is a separate matter but the important principle which has not really come over in the coverage today is that in that letter you accepted the principle, leaving aside the difficulties, leaving aside the logistics, leaving aside the costs, and those of course are big difficulties, according to my naïve reading of it, that an extensive cull over a wide area might have some benefits for reducing TB, leaving aside the logistics, leaving aside the costs. If that is the case, can I ask you a second question about area - you hinted at it a moment ago but we did not actually develop it quite as much as we perhaps could have done. Given that the tests were over ten square kilometres, and quite good effects were seen inside the ten kilometres squares, although there were bad effects around the border, what would happen if that were very much wider? For example, in the old days it used to be that the cull was across the whole of the county. Imagine that all the badgers in the county of Wiltshire were exterminated, what effect do you think that would have? Do you not think that possibly your tests being in small areas - ten kilometres is a very small area in terms of the land mass of Great Britain - given that you accept the principle that it does actually work, and leaving aside the logistics and leaving aside the costs - we will come back to that in a moment - do you think the small area over which the test was done might have constrained the outcome?

Professor Bourne: If you look at page 105 of report, we express there the confidence limits that extrapolation suggests you might expect with trapping over a very large area. They are very wide confidence intervals. You ask if one culled out the whole of Wiltshire, what would the effect be on the whole of Wiltshire. The data from the trial would suggest that you would have a positive impact on cattle breakdown within the Wiltshire area, and it would be difficult to tell you what that was; one could extrapolate. One sees the very wide confidence intervals. But you would certainly have an unwanted effect in the neighbouring counties of Hampshire, Somerset, Dorset, what counties there are surrounding Wiltshire. Pragmatically, I think, attempting to cull badgers over such a large area would present extreme difficulties, difficulties which we have mentioned, with respect to how you would have to cull that area.

Professor Woodroffe: If I could just continue on the theme that Professor Bourne has started, this issue about logistics is not just a question of you would have to do it and it is always achievable. The problem is what happens if you do not achieve it. If you attempt to cull badgers across the whole of Wiltshire, if you fail to achieve that, if there are chunks that you cannot access, if you do not do it all simultaneously, if you do not do it as we did it in this case, where we had large numbers of people coming in simultaneously over large areas to cull badgers, anything that you do which reduces a simultaneous, very widespread effect risks making the situation worse. So where culling is localised, you get the perturbation effects, you increase TB risk to cattle.

Q51 Mr Cox: Subject to permeability of boundaries.

Professor Woodroffe: Wiltshire being really quite permeable.

Mr Cox: I understand that.

Q52 Mr Gray: There is a lot of rain there.

Professor Woodroffe: So, for example, we showed that, as I mentioned previously, every time you do a proactive cull across the whole area, the prevalence of infection in the badgers goes up on each cull. If you do not do that simultaneously but instead you do that cull as several sectors that you do successively, the increase is actually 1.7 times as much. So if you do not do a simultaneous cull, in make the situation not just a bit worse but quite a lot worse in the badgers. So simultaneous culling is very important, good land access is very important, targeted culling around inaccessible areas is very important, and everything that you do which, because of logistical constraints, because of lack of land owner compliance, because you are just trying to do something on a massive scale, takes you away from an absolutely simultaneous cull, performed very extensively simultaneously, is going to take you more towards piecemeal culling, which is going to entail a high risk of making the situation worse rather than better. There is a big difference between saying in principle that you could reduce TB risk to cattle by culling badgers over very extensive areas, although within the range of areas we have projected the differences, the net effect is pretty small. The overall effects are very modest but there is also an increasing chance that you make it worse, especially if you are going to do that as - one of the culling approaches that was formerly included in the consultation document was licensing farmers or farmers' representatives to do the culling. Without the resources of being a large government department, farmers trying to do it themselves or having contractors trying to do it themselves and so forth is going to take you more towards this piecemeal culling, which will have a massive risk of making things worse rather than better.

Q53 Mr Gray: I see the logistical difficulties but you get my point that if there were to be in principle benefit from it and given that this is costing the nation billions of pounds, it might well be we could devote huge resources to it if indeed it was going to be the final solution. Is there not some argument in favour of doing that? Is that something which you considered?

Professor Bourne: One could certainly do that, just as the Irish plan to remove badgers from 30 per cent of their land mass.

Professor Woodroffe: I am actually not sure that it is even achievable given the badger densities we have in TB infected areas of Britain, the lack of geographical boundaries. I think another difference between Britain and Ireland is that we have substantially higher baseline background badger density, so that immigration pressure is always going to be there. I am not convinced that you actually could eliminate badgers from Wiltshire, try as you might.

Professor Bourne: The feasibility of it is extremely difficult but also, of course, it would not be the end of the cattle TB problem. It would make cattle TB controls very much easier but there would still be a very large cattle TB problem that would have to be addressed through improved diagnosis.

Mr Gray: They have brought it to one strand.

Mr Cox: You would have to bear down on both sides of the disease.

Q54 David Taylor: My colleague Mr Gray has been trying to tease out whether there really were differences in time in the Committee's attitude between January 2006 and 18 months later, as we are now. I would like to see if there are differences within the Committee. I know it is not a seminar on semiology but nevertheless, can I point to Professor Bourne's letter to the Secretary of State where he refers to "badger culling can make no meaningful contribution to cattle TB control in Britain", which is drawn from paragraph 9 of the overview, where you mention a very similar point, "cannot meaningfully contribute towards future control", but yet, rather significantly, at paragraph 10.48 on page 172 we, the collective Committee, concluded that badger culling is unlikely to contribute positively. "Unlikely" and "cannot" are two distinctly different descriptions. I wonder what lies within the two different boundaries that they represent, Professor Bourne.

Professor Woodroffe: As the author of several of these sentences, I am very happy to speak to them. I will just add while Professor Bourne is looking it up that saying badger culling is unlikely to contribute positively in a scientific forum is pretty damning. That is about as strongly as you ever say anything in a scientific paper.

Q55 David Taylor: It is not the Chairman firming it up; it is just a scientifically alternative way of expressing the same set of circumstances?

Professor Bourne: No, I think there are two issues here. What we are saying is that badger culling, in the way it can be conducted in the UK, we believe, cannot possibly contribute to cattle TB control, and in using the word "meaningfully", what we mean there is that if it is the only inducement that would encourage farmers to co-operate fully and introduce effective cattle control, it could have an effect.

Q56 David Taylor: There is a difference to me between "cannot", which is a zero percentage probability and "unlikely", which is less than a 50 per cent possibility. There is a big void there, is there not?

Professor Woodroffe: There certainly is not any disagreement within the group about the conclusions.

Professor McInerney: It is important to get a little perspective on this. In 2006 when the letter was written, a certain amount of data came through and the analysis was leading to some conclusions. By the time we get our final report, there is a lot more data. The trends inside and outside the areas have become more firm. Whereas in 2006 the net effect on breakdowns was that the outside effects were neutralising the inside ones, as the trends have developed, we now find within 100 kilometres squared there is a net positive effect, but it is 1.4 breakdowns out of 50. This is where we do not think it is meaningful, if you believe it is worth throwing all this culling effort in order to prevent one and a bit breakdowns. We do not feel that is very meaningful in terms of policy. It is the raw numbers of what you achieve rather than technically whether it is zero or just a little bit above zero. In the end, our judgment is that this is not a very effective policy if all it achieves, after all this effort, is a minimal effect on breakdowns when there would seem to be opportunity to have a much bigger effect doing other things.

Q57 David Taylor: To me, as a statistician, an equivalent phrase to "cannot meaningfully" would be "is highly unlikely to contribute positively".

Professor Bourne: We are working within scientific competence limits.

Q58 David Taylor: 95 per cent?

Professor Bourne: Yes indeed. It is difficult to be utterly positive about everything.

Q59 David Taylor: "Cannot" is utterly confident to me.

Professor Bourne: We are confident that it will make no useful contribution.

Q60 Chairman: Can I make quite certain that my ears did not deceive me a moment ago when you said with your almost impish smile, "Left to its own devices, culling is not the silver bullet but if it induced some other activity as a quid pro quo it might have a role to play"? Is that what you were communicating to me?

Professor Bourne: It would be very unfortunate if that happened but that is exactly what I was communicating to you because farmers have made it clear they will not cooperate unless they can kill a few badgers. Farmer cooperation is absolutely essential to get this disease under control. It will be an appalling thing for us if farmers were given the opportunity of knocking off a few badgers just to get their cooperation.

Q61 David Taylor: Professor Woodroffe used the phrase "a thin strip round the 100 square kilometre area." What do you have in mind by "thin strip"? In the 100 kilometre area what might be the typical population of badgers and how thin is the strip in terms of dispersal, as it were?

Professor Woodroffe: You would have about 400 or 500 badgers within a 100 square kilometre area. Are we talking about how many in the peripheral area?

Q62 David Taylor: Yes. How big is that peripheral area?

Professor Bourne: In the 100 square kilometres, the radius is 5.64 and the periphery is two kilometres.

Professor Woodroffe: We detect effects of culling on badger population density and ranging behaviour as far as we looked, which was two kilometres outside the cull area. We have searched for evidence of impact on cattle and what we see is that most of the effects on cattle are within that two kilometres and they do not seem to go further than that. The genetic evidence suggests that on later culls badgers are coming regularly from four or five kilometres away.

Q63 Mr Gray: Why are we using kilometres rather than miles?

Professor Woodroffe: Because scientists work in SI units. We are in the European Union now.

Professor Bourne: The total area of two kilometres periphery is about 80 per cent of the inside core area.

David Taylor: I thought it was more like 45.

Q64 Mr Cox: I must pick you up on something you just said, Professor Bourne, which I have to say on reflection I would invite you to reconsider. You said, "Farmers have indicated that they will not cooperate unless they can kill a few badgers." That is as flippant a remark as I have heard given against a community of people who are very decent and law abiding, under enormous pressure, and I do believe that you should reconsider that astonishing remark.

Professor Bourne: Maybe so, but ----

Q65 Mr Cox: Do you reconsider it or not?

Professor Bourne: Yes, I do. Farmers have consistently stated they will not cooperate with government in developing improved cattle controls unless there is culling of badgers.

Q66 Mr Cox: I simply do not accept that as a version. At the moment on the evidence as it exists, the farming community as I understand their position believe that there is a role for culling. We will look at your new report and we will see what Defra does by way of the development of policy but I do not think it assists the debate and it certainly does not help the confidence of the farming community in the integrity of your conclusions to make remarks like that.

Professor Bourne: The farming community consistently believe, as you say, that culling has a part to play in reducing cattle TB in spite of the scientific evidence which shows that localised culling has no contribution to make except to make it worse.

Q67 Mr Cox: Let us take as a given that you believe in the conclusions that your group has reached. That does not mean, with respect, that there cannot be legitimate room for disagreement or indeed room for consideration that further research might yield different results. This is the question I really want to come to you about: that you have not in the way in which you have reached your conclusions had to take into account social factors which you overtly and explicitly do. A farmer looking at this will see the results in Ireland and see that dramatic effects can be achieved within the four areas and then be told by your group, because it is clear throughout your report that you do say this, that one of the essential distinctions between Ireland and England is that culling on the scale that Ireland are contemplating would not be socially acceptable. Indeed, you have said that today. If it were possible for a government, let us say, to take compulsory powers to achieve the type of culling mentioned by Professor Woodroffe, simultaneous, across a wide area to achieve elimination over a significant tract of territory, it looks does it not from the Irish results and from your own conclusions that there could be, on the incidence in cattle, some significant effect?

Professor Bourne: Yes. I responded to that in relation to the question asked by Mr Gray. Clearly it is possible to take badgers out over large areas if there is a will to do it. Professor Woodroffe suggested that even that would be impossible to do in this country.

Q68 Mr Cox: "In this country" meaning across the country as a whole.

Professor Bourne: We are talking about the county of Wiltshire. The other question is what level of impact would you expect on cattle TB. The four areas trial gives a range of figures. It is difficult to quantify exactly what the contribution of culling is because of the way the science was designed and conducted. Professor Donnelly has carried out an analysis which suggests the reduction in cattle TB incidence is possibly about 50 per cent. I was speaking with the individual running the Irish TB control programme a week ago, along with Professor Donnelly and Sir David Cox, and the question was asked, "What is happening in the trial areas with respect to cattle TB incidence?" He said, "Well, it is not very clear. It seems to have reduced and now it seems to be plateauing off." It is unclear what impact culling of badgers is having on Ireland. We will have to wait and see.

Q69 Mr Cox: The published science on it is clear.

Professor Woodroffe: Could I clarify that? You referred to the effects detected in Ireland as dramatic and it is true that some of the headline figures ----

Q70 Mr Cox: Significant.

Professor Woodroffe: ---- that are quoted in that scientific paper are dramatic. There are numbers like 95 per cent bandied around. That was for one of their areas in one of the years. I would like to add a note of caution and draw attention to some issues concerning the interpretation of results from Ireland. You will be aware from looking over our report that one of the effects we detected was that, as you move deeper into our trial areas, the effect of culling appears to improve. There is a trend suggesting that as you go deeper in you get more beneficial effects on cattle TB, which is consistent with finding this greater reduction of badger population density in those areas and smaller effects on badger prevalence and infection. All of that is consistent. In Ireland, where they were not able to identify an area that was completely bounded by geographical barriers to badgers, they had what they call buffer areas and these buffer areas were six kilometres wide.

Q71 Mr Cox: They took out at the same level as the removal areas.

Professor Woodroffe: They have never published the cattle incidence data from those areas.

Q72 Mr Cox: I understand it exists.

Professor Woodroffe: I am sure the data must exist but those data were never published.

Q73 Mr Cox: If it were inconsistent with their conclusions, it would be scientifically dishonest, would it not? What are you suggesting?

Professor Woodroffe: I am suggesting that we would love to see those data.

Q74 Mr Cox: These are reputable scientists. If the data was contradicted by information in their possession which they have not published, it would be scientifically dishonest. Are you seriously suggesting that the Irish scientists are capable of that type of deception?

Professor Woodroffe: No, I am not accusing anybody of deception. Their peer review paper does not include that information which would be informative to the debate.

Professor Bourne: What we are suggesting is the assessment we presented to ministers, when the Irish data was published in 2006. There is evidence for a substantial impact on cattle TB incidence as a result of culling in the four areas trial but it is not possible to be precise about the extent of that impact ----

Q75 Mr Cox: You are saying you do not have all the data.

Professor Bourne: ---- because of trial design and data accumulated and the way that data was analysed.

Q76 Mr Cox: The Irish trial was reviewed, was it not, by Professor Godfray against whom I appreciate you have already registered a number of criticisms? He presented a report of the four areas culling trial in which he and his panel expressed themselves to be entirely satisfied, not necessarily with the entire quantitative data, but with the conclusion that very significant results had been achieved.

Professor Bourne: Which is totally consistent with the report we presented to ministers and consistent with exactly what we are saying now.

Q77 Mr Cox: There we sit with the farming community looking across the Irish Sea and seeing that, with a will, with a different social attitude to quote the expression that your report uses, genuine, significant effects can be made with the instrument of culling. That is how they will see it, is it not?

Professor Bourne: Of course. Let me remind you: in the report we do make the point that elimination of badgers, culling short of elimination cannot make an impact. We accept that elimination of badgers would make an impact if it was achievable. Let me take you back to 1999 when we started this work. It was made very clear to us by ministers of the day - and they have not refuted it since - that elimination of badgers over large tracts of the countryside was not an option for future policy.

Q78 Mr Cox: Is it not the function of science ----?

Professor Bourne: It was on that basis that we designed the trial. We also had to take into account welfare considerations with respect to method of culling used and limitations on culling with respect to ensuring that cubs were not killed or died underground.

Q79 Mr Cox: You had a closed season.

Professor Bourne: Yes. Those were the clear, political limitations that we operated under. I have no reason to believe that those political limitations have been changed.

Q80 Mr Cox: You make an extremely fair point. That of course does not always come out in the publication of your results. Is it not the function of science to present a list of options to the government and allow the politicians to decide what is politically unacceptable? The danger about the interpretation of your report from those who are listening to this and reading it is that you have concluded, as a matter of science, that it can be of no effect. In fact, your conclusions are substantially affected by political and social limitations imposed on them.

Professor Bourne: We repeatedly say "culling as conducted in the trial." It is important we do say that. Those limitations were not imposed by ourselves. They were imposed by politicians.

Professor Woodroffe: I would like to acknowledge the work of the Defra Wildlife Unit who are the people that did this work.

Q81 Mr Cox: Most of them have been sacked of course.

Professor Woodroffe: Absolutely. They are the people who were confronting animal rights activists on a daily basis and in some cases were being physically threatened. Having been out with them and seen it at the sharp end, I have enormous respect for them. That is an important influence on what is possible and achievable in this country and that is different in Ireland. It is not just a question of politicians making a decision about how things are going to happen. There is a public response that has to be taken into account in planning the logistics.

Q82 Mr Cox: One thing is for certain: the public response might change if it turned out that bovine TB started in a significant way to affect human health.

Professor Bourne: Absolutely.

Q83 Mr Cox: I appreciate it appears from your report, to the educated reader, that you have been set these social and political parameters in which your conclusions are ultimately delivered.

Professor Bourne: We do extend that and we accept that elimination of badgers would have an impact in the way it can be achieved using techniques we have used in the trial. We are extending those techniques to other operations which would include the same welfare constraints.

Professor Woodroffe: We have also considered in the course of our report to what extent greater reductions in badger population densities would improve the effect on cattle TB incidence. Given the substantially higher badger population densities in British agricultural environments, given the lack of geographical barriers to immigration, achieving elimination would be extraordinarily difficult, even if you were using snares or gas.

Q84 Mr Cox: Your data on densities is not particularly good, is it? I read the part of your report that deals with it. You concluded 40 per cent of English conditions in Ireland?

Professor Woodroffe: We compared the sett densities in the British and the Irish areas prior to culling and we also compared the capture rates.

Q85 Mr Cox: The main sett densities were not too dissimilar, were they?

Professor Woodroffe: No, the main sett densities are not such a good indicator of badger numbers.

Q86 Mr Drew: I have some difficulty with the Irish trial because it has been so spun by both sides. It is difficult to know what the reality is. It is good to reread the scientific evidence. Unless I have this wrong, the one thing I understood from the Irish trial was that at the end they determined that a culling policy was unsustainable. Is that true or not?

Professor Bourne: Correct, but nonetheless they are extending culling to the point of elimination in 30 per cent of land mass.

Q87 Mr Drew: Even though it is an unsustainable policy?

Professor Bourne: Yes.

Q88 Mr Cox: It is unsustainable in the long term.

Professor Bourne: They are calling it a reactive policy. It is reactive in name but in effect it is to eliminate badgers over 30 per cent of land mass. Their argument is, "We are not contravening the Bern Convention because we are not touching badgers on 70 per cent of the land mass." I do not know what the Bern Convention will say about that. I have no idea.

Q89 Mr Cox: Can we be accurate because it is important that we are accurate. In fact, the government's official policy in Ireland is that an effective scheme to control tuberculosis in badgers with which cattle may come into contact is now recognised as a prerequisite for the eradication of tuberculosis from the Irish cattle population. That is the official statement from the Irish Government. It is true that the scientists like Griffin have said that it is not sustainable in the long term and they call for a vaccine.

Professor Bourne: The comments I make in my chairman's over view which relate to 30 per cent elimination I cleared and had written by the guy who is running the TB control programme in Ireland, because I was sensitive about that very point.

Q90 Mr Cox: You are absolutely right that they are saying 30 per cent, from my contact with them.

Professor Bourne: He said it was in the public domain and he directed me to the publication where that is absolutely stated. I doubly checked with him: "Are you absolutely sure I can say this? Will you be offended if I say this?" He said, "No, that is absolutely our strategy." At the end of the day I think you have to accept that it is the price society puts on the badger. Clearly in Ireland society has opted not to put a price on the badger. In this country there is a price on the badger and also on badger welfare.

Q91 Mr Cox: I beg your pardon: they put a price on it in terms of the suffering of the families and the slaughter of tens of thousands of cattle.

Professor Bourne: Whatever has driven that I do not know but the fact is that a price has been put on the badger in this country which related to the way we were able to carry out our scientific work. That is exactly what we report.

Q92 Chairman: The message I am getting is that everything you have said is drawn from and is consistent with the findings of the work that you were asked to do. You are not saying to us that the options to do whatever they want to do are not still available to ministers if they were so minded, having listened to what you have said and any other trial or intervention. If they want to come up with a strategy that involves every known possible contributory element to the ultimate elimination of bovine TB, it is up to ministers to choose. You are one part of the menu of information and opportunity You have delineated in clear terms what your findings are within the terms that you were asked to look at.

Professor Bourne: That is true, except that by extending our experience from the trial to large areas we are pretty clear about the necessity of culling over a very large area systematically and sequentially for a very, very long time, still maintaining an edge effect so there would be winners and losers. That could have an impact on cattle TB. At the other extreme, it is elimination of badgers across large tracts of the countryside to a point where you will find no badgers or no badgers with TB.

Q93 Chairman: Even if you followed your thesis of where you think that culling would work, your conclusion was that there are not going to be that many incidents of bovine TB that would be reduced. Is that right?

Professor Bourne: Exactly. That is the whole point of chapter nine.

Q94 Mr Gray: On the question of spin or PR, I know it is not your area of expertise but for example you were talking on the Today Programme this morning. You said that culling has "nothing to offer in terms of controlling cattle disease. Culling does not provide the answer." What you meant, in the light of the conversation we have just had, is that under the circumstances - namely, small areas; secondly, no extensive culling across the nation; thirdly, the eradication of the kind we have been talking about, no cubs and all these other things you describe - "under the constraints I was given by ministers, culling has no role to play. In fact, under other circumstances, outside what ministers have said, outside the political arena, it might." Do you not think it would have been better to have said that scientifically there may be a way in which culling would work but I am very sorry; society is not ----?

Professor Bourne: My introductory statement to Farming Today which was not recorded was that one cannot do justice to a 278 page report in a few minutes on Farming Today. After giving that interview to Farming Today, I e-mailed my colleagues and said, "I really threw caution to the wind today by giving Farming Today a 45 minute interview knowing that they would editorially select exactly what they wanted." I understand what you are saying but you have to appreciate we are in the hands of an editorial team. It was exactly the same with the Today guy.

Chairman: We will set up the Quoted Out of Context Organisation to offer comfort and sympathy to each other.

Q95 Mr Gray: We know all about that but do you not think that the overall impression, because of that process you describe of selectivity, coming out of Today and all the newspapers is that badger culling does not work but what you should have said is that badger culling does not work under the circumstances that were described to us?

Professor Woodroffe: Having been the person who took the lead on exploring every form of badger culling that we could come up with that has ever been suggested to us, you make many presentations and every time you give a talk somebody says to you, "Would it not work if you did it this way?" or "Could you not do that?" We have considered systematically every form of badger culling that we, colleagues or opponents could come up with. We have evaluated that in terms of not only of our findings from the randomised badger culling trial but also in the light of findings from Ireland, Thornbury and East Offerley.

Q96 Mr Cox: Hartland?

Professor Woodroffe: We are familiar with all of the evidence. Interpreting that in the framework of what we now understand on the basis of this nearly ten years of work about the deep, underlying mechanisms that run the dynamics of bovine TB within cattle and badgers and agricultural systems in Britain, we reached the conclusion that badger culling could not contribute meaningfully to TB control.

Q97 Mr Cox: Except in localised areas.

Professor Woodroffe: In geographically isolated areas, perhaps it might.

Q98 Mr Cox: You have said that.

Professor Bourne: That related to areas that have been badger proofed.

Q99 Mr Cox: We have looked at 5.16 where there may be impermeable barriers.

Professor Bourne: We also explain that it is difficult to identify.

Chairman: It is quite clear that we are still in the work in progress area. We have another session on Wednesday and we have to go and speak to the Minister. I think it is time we moved on to other measures, principally to vaccination.

Q100 Mr Drew: I am interested because it is my area that has a trial under way. As you will know, where we have run into arguments both with yourself and Defra is that we always call for plan B. We never specified what plan B was going to be. I am pretty sure I know what plan B is going to be. It is going to be vaccination. The problem is we are always ten years away and we are always debating: should it be cattle or badgers that are vaccinated. If I was to have more than a hunch - I have spent my life arguing this - we have to get that vaccine in place. Everybody, including the Irish, would agree that vaccination long term is the only sustainable policy. Why do we not try much harder to get a vaccine? My argument would be a vaccine to be used in badgers rather than cattle because of the problems with vaccination of cattle and TB free status and so on. Why do we not just go for that and move it forward more quickly? Forget the rest of this because to cull or not to cull is not any longer a question. Let us go for vaccination and try and persuade Defra to put some serious resources into this and hope that it does pay dividends. It did with human beings, after all.

Professor Bourne: It has not yet. Defra are doing exactly that. We carried out a review of vaccination, as you know, which we published in 2003 with the expectancy that that work would continue over a long time frame before it led to any extension into the field. We produced a full report with the expectancy that another group other than us would pick it up and take it forward way beyond the life of the ISG. That has happened. Defra have a group in place to extend this work. We have only briefly commented on vaccination in our report to emphasise the main findings of the document that we published in 2003 and to emphasise the problems of getting a badger vaccine into the field and particularly in collating data and evidence that the vaccine was achieving what we hoped it would achieve in respect to reducing cattle breakdowns. It is a very long haul. I think it is unfair to suggest that not enough scientific effort is being directed into this area. Internationally, there is a massive global programme. The scientists at VLA of a very high calibre are closely linked into that programme as indeed are the guys who are sitting on that Vaccine Committee at the moment. Success demands a number of things. With respect to developing a badger vaccine, it does require developing a way of getting this to badgers in the field. We know there are serious limitations for BCG but no one suggests it does not have a role. Measuring the contribution it makes is difficult. With respect to getting improved vaccines, you are waiting for scientific breakthroughs and you cannot predict those. Even when one has a cattle vaccine, there has to be a clear strategy for how you are going to use that in cattle. I am not persuaded that Defra have given this any thought at all. They have not given it any thought at all yet.

Q101 Mr Williams: The Chairman and I met with the president of the Royal College of Veterinary Surgeons the other day and we asked her about this and whether there was a technical problem in getting a breakthrough. The Chairman will correct me if I am wrong but the response was that the real problem is the cost between taking it from the laboratory to getting it to market and all the regulatory processes that have to take place then. We asked her, "What do you think the cost would be?" She said, "Perhaps £20 million." If you look at that in relation to what it is costing this country in terms of TB at the moment, it would seem to me that that would be a very little contribution to solving a big problem.

Professor Bourne: I am sure she is right about the market. It would be extremely limited because no other European country ----

Q102 Mr Williams: The process of taking it from ----

Professor Bourne: In fairness, you really should talk to the committee that is now in place driving the vaccine programme. I would certainly give that our total support, as we have. I would also highlight that again there is no quick fix here. It is going to be a long haul.

Q103 Chairman: One of the points that the president did make to us was that the requirements of the vaccine as defined by Defra in their judgment - I hope they do not mind us quoting around lunch table conversation, because the information may not have been given with the rigour that would have been the case had they been giving evidence to us - and the impression I gained was that what this vaccine was supposed to be doing, if you like, the performance criteria, had been set at such a high level that going back to using BCG, for example, would not score. In other words, it was not good enough to achieve the kinds of results that they would say were effective. The vets were saying, "It is better than anything and it has worked in human beings."

Professor Bourne: I do not think that is true. That is not the approach that Defra are taking. My understanding is that they are developing the possibility of a BCG vaccine to use in badgers. The situation in cattle is very different.

Q104 Chairman: It is currently costing Defra £90 million a year to deal with the consequences of this disease against a current background where all the ways to mitigate it do not seem to be having any serious effect. You might say, "If the government wanted in the long term to save themselves a shed load of cash, they would bung a great deal more money at it to try and crack it now."

Professor Bourne: I do not think that is the answer. You should speak to the group driving this programme. From my perspective, I am quite assured of the competence of the scientists and the group. Throwing more money at the problem is not going to provide the answer. They are effectively linked into an international network that is massively funded. You just have to wait for science to deliver. Defra meanwhile, from my knowledge, are pursuing the option of using a BCG vaccine in badgers and developing appropriate delivery systems. At the moment they are looking at aspects of safety control for purposes of registration. I do urge you to speak to the group that has now taken on responsibility for this work.

Professor Woodroffe: To add a note of caution on vaccination, it would be marvellous if you could vaccinate badgers effectively. In New Zealand, they have something called a possum puffer, used for remotely delivering the vaccine to possums. One issue you have to confront is that, if you are putting vaccine out in the environment for badgers to consume, there is a strong risk of cattle encountering it and therefore becoming sensitive to the test. It is not all roses.

Mr Williams: Professor Bourne this morning said that with improved testing there could be a reduction in TB incidence without badger culling. What is the scientific evidence for that? Is that an extrapolation or does that have real substance?

Chairman: Mr Rogerson wanted to add to that with a point about the gamma interferon testing.

Q105 Mr Rogerson: There is quite a lot in here about what could be done to speed things up to be far more accurate by a combination of testing.

Professor Bourne: It is based upon cattle pathogenesis findings which are documented in the report in one of the appendices, work that is being carried out primarily in laboratories of VLA in Weybridge, Stormont and IAH. It is also extrapolation, taking information from a simple model that Sir David Cox has developed and using that model to predict how the application of these techniques would influence the curve with respect to the reproduction rate of the disease. He determined a reproduction rate of 1.1. That relates to between herd transfer, not within herd amplification of the disease. That figure has also been arrived at by an independent approach, developed by the workers at the University of Warwick, which does suggest that an effort to improve diagnosis would tip the balance and bring the reproduction rate below one and bring a downward trend to the incidence of the cattle disease. He also postulates from the model that improving diagnostic sensitivity would have a speedier effect on reducing the incidence of disease. As one is talking about herd to herd transmission, animal movement controls as well as diagnosis are important components of that.

Professor Donnelly: In terms of the way the model works, essentially what you are looking at is trying to shorten the time between a herd becoming infected and it being cleared. Improving test sensitivity is one way of doing that so you are sure you are not missing anything. You can talk about it as a herd test but if there is only one animal in a herd that is infected it is the per animal accuracy that matters. Either improving the sensitivity - that is, the proportion of infected animals that are correctly detected - or testing more frequently, so shortening test intervals. Those two things, especially if they are combined together, reduce the time that a herd spends potentially infectious to other herds and in circulation. Obviously since that work was done pre-movement testing has been brought in and we have discussed the possibility of doing that with more sensitive tests and even the possibility of adding in post-movement testing, which would add another level of security. From that modelling work, it showed 1.1 as the figure that characterises the rate of increase of the disease. Estimating the reproduction number has been used in many other human and animal diseases but it allows you to say that one is the threshold of where you just have continuing disease at a level. If you could do things so that the model predicts it goes below one, that suggests not that you would get instant eradication but that you would start on a decline. Both faster testing and improved testing through greater sensitivity are predicted to do that.

Q106 Mr Cox: Perhaps somebody could deal with the question of the edge effect and the 25 per cent incidence outside the culling areas. There was a question by a number of epidemiologists that the findings of that 25 per cent did not seem to have sufficient of a time lag in order to produce the effects that were observed. I am sure that is easily dealt with by you because you will have heard it before and therefore you will have devised some thinking.

Professor Woodroffe: We know that to cause that effect badgers have to start ranging more widely, contacting one another more often and contacting cattle more often. That happens within the course of a few days in response to culling. What has to happen next is that cattle have to be tested. They have to become exposed and develop sensitivity to the test. That takes about three weeks. We have published the sequence of events and it has gone through peer review.

Q107 Mr Cox: You would argue that the period is relatively short?

Professor Woodroffe: Yes.

Professor Bourne: Our remit throughout our study has not been badger protection. It has been control of cattle TB. That has been our driving force throughout the work we have done. How can one best control cattle TB? Our whole report is directed to cattle TB control.

Chairman: Can I thank you very much indeed for your final appearance before us as the Independent Scientific Group? As individuals and experts it may not be your final appearance before the Committee. Thank you very much indeed, as always, for your contribution and your patience in dealing with our questions. We appreciate it very much.