Volume 11: Scientists after Southwood
4. The Spongiform Encephalopathy Advisory Committee (SEAC)
Deliberations and advice
2. Advice on breeding from the offspring of BSE-affected cattle

2. Advice on breeding from the offspring of BSE-affected cattle

MAFF's early advice to veterinary surgeons

4.150 On 30 April 1988, a short article appeared in the Veterinary Record. It included the following advice:

In the light of experiences with possibly similar diseases in other animals and in the present state of knowledge on BSE it is recommended that the progeny of affected cows should not be retained for breeding purposes. ¹

The Southwood Working Party considers maternal transmission

4.151 The Southwood Working Party's Report was published in February 1989. ² In its report, the Working Party qualified its estimations of future infections in cattle by saying:

No allowance has been made either for new infections arising from maternal transmission: insufficient time has elapsed to determine whether maternal transmission occurs in BSE and if so at what incidence. Given the age distribution of the BSE cases at the onset of clinical signs and therefore the number of offspring which will survive the minimum incubation period, the occurrence of maternal transmission, should it occur, is unlikely to be witnessed until 1990.

Though maternal transmission would increase the number of cases on its own it would probably be insufficient to sustain BSE in the national cattle population because it is likely that the number of offspring per case which will reach a susceptible age and produce their own offspring will be less than one. ³

4.152 The Report did not make any recommendation on breeding from the progeny of BSE-affected animals. ⁴

The BVA offers advice

4.153 On 25 January 1990, the British Veterinary Association (BVA) issued a press release giving the following advice:

[W]hile there is at present no evidence of vertical transmission (research is continuing) it would be prudent for farmers not to breed from calves from confirmed BSE parents and to be punctilious in keeping movement records. ⁵

4.154 On 6 February 1990, Mr Gummer, Minister of Agriculture, met Mr Andrews, ⁶ Mr Meldrum, Mrs Attridge, ⁷ Mr Cruickshank, ⁸ Mr Capstick ⁹ and other MAFF officials to discuss BSE. Mr Meldrum advised that there was a 'three to one chance in favour' of maternal transmission being proved. This prompted Mr Gummer to suggest that MAFF should not wait for proof, and 'should identify what measures we would wish to take once proof was established, and adopt them now'. Mr Meldrum said that there were a number of policy options to be explored. Mr Gummer therefore asked for a paper to be prepared setting out the options, with accompanying recommendations. ¹⁰

4.155 In a manuscript note dated 12 February 1990, Mr Meldrum informed Mr David Kyle, the Assistant CVO with responsibility for animal health and welfare, that he had asked Mr Kevin Taylor, Veterinary Head of Notifiable Disease Section, to provide a paper on 'maternal transmission and the various options'. Mr Meldrum suggested to Mr Kyle that 'we need to have a plan that we can implement if and when more results become available'. ¹¹

4.156 In a minute on the same day, Mr A J Lebrecht, private secretary to Mr Gummer, asked Mr Lowson, Head of Animal Health Division, to prepare the paper requested by Mr Gummer. He was asked to collaborate with Mr Meldrum and to present it by 16 February 1990. ¹²

Preparation of advice for Ministers

4.157 On 8 February 1990, Mr Meldrum provided Mr Taylor with 'some thoughts' for inclusion in the paper being prepared. ¹³ He set out policy options that he thought MAFF might consider:

1. Keep the present policy, which was to record the unique ear number of the progeny: Mr Meldrum noted that this was attracting criticism from the industry and practising veterinary surgeons, who believed that more should be done;
2. Advise owners not to breed from progeny: Mr Meldrum said this was the option supported by the BVA, and noted it was 'a wise course to follow in case maternal transmission does take place'. In addition, MAFF could use existing powers to require that such progeny were retained on the farm of origin and were not sold except for slaughter or fattening;
3. Slaughter the most recent calf born of an affected dam: Mr Meldrum noted that this would be a 'crude instrument of control', given that healthy animals would be slaughtered; and
4. Slaughter all progeny of affected cows: Mr Meldrum explained that scientists had suggested that if progeny of affected cows were to be slaughtered, then all progeny should be slaughtered because there was no evidence that maternal transmission was restricted to the most recent calf born. ¹⁴

4.158 Mr Meldrum noted that 'there are clear presentational difficulties in destroying some thousands of healthy cattle when we have no evidence that maternal transmission can occur and where there is no evidence that the cattle themselves have actually been exposed'. He concluded that:

I am clearly of the opinion that we should not require slaughter of progeny of cattle affected with BSE but it would be wise to consider whether option 2 should be pursued to limit the animal health damage that could occur in a herd should maternal transmission occur. ¹⁵

4.159 On 19 February 1990, Mr Lowson provided Mrs Attridge with a draft note on maternal transmission for Mr Gummer, which was accompanied by a more detailed paper prepared by the State Veterinary Service (the SVS Paper). ¹⁶

4.160 The SVS Paper set out possible control measures, listed in order of increasing severity:

1. improved identification of calves - this was recommended, irrespective of any other measures adopted (see vol. 5: Animal Health, 1989-96, ch. 5 on cattle tracking);
2. advise owners that progeny of BSE cases should not be retained for breeding;
3. control movement of progeny by marking or licensing to prevent breeding;
4. segregate the offspring of BSE cattle - it was noted that this would be impracticable, and would attract suspicion and undermine confidence in existing control measures;
5. slaughter the female progeny of BSE-affected cows; and
6. slaughter all progeny of BSE-affected cows, and all their progeny - it was noted that this step could not be justified, so would not be considered further. ¹⁷

4.161 The SVS Paper argued that the main source of infection - contaminated feed - had been eliminated, with the result that maternal transmission was the only possible means of future transmission. ¹⁸ However, it stated that 'maternal transmission alone is incapable of maintaining the epidemic'. ¹⁹ It did not therefore recommend slaughter or segregation of progeny. However, the Paper did recommend that owners be formally advised that the progeny of BSE-affected cases should not be used for breeding. If Ministers felt there was a need to go further, then it suggested controls on the movement of progeny by marking or licensing could also be implemented. ²⁰

4.162 Mr Lowson's draft submission briefly summarised the main points in the SVS Paper. He said:

The SVS Paper concludes that it would make sense to introduce now restrictions on the use of the offspring of BSE cattle for breeding. As indicated in the note, it is possible to envisage simply issuing advice to farmers rather than using compulsion, but Ministers would certainly be asked why, if there was a problem, they were not taking compulsory powers to deal with it. The only realistic option may therefore be to introduce a compulsory licensing and marking system to ensure that BSE progeny are not used for breeding . . . Such a step would go well beyond the advice of the Southwood Committee . . . and Ministers might feel it appropriate to seek the advice of [SEAC] on the point first. ²¹

4.163 The draft submission asked Ministers:

(i) to endorse the view that the slaughter or segregation of the offspring of cattle infected with BSE would not be appropriate;

(ii) to indicate whether they want to pursue the question of restrictions on the use of such offspring for breeding, and if so whether [SEAC] should be consulted first .

4.164 Dr Pickles, Principal Medical Officer DH, provided Mr Lawrence with her comments on Mr Lowson's draft submission on 20 February 1990. She qualified her remarks by noting that they represented 'a personal viewpoint since I have not had time to consult on a collective DH view'. In addition to pointing out a lack of cost-benefit analysis, Dr Pickles commented on obtaining expert advice:

It is in my view essential to consult outside experts, ie, [SEAC]. Firstly because there may be alternative interpretations of the scientific data, and the mechanism of transmission of scrapie from ewe to lamb is a case in point; secondly because there may be alternative ways of controlling infection which should perhaps be looked at, even if just to dismiss (eg caesarean section, at least for valuable calves or those for export, or restocking from overseas); and thirdly because it is useful for Ministers to be able to confirm that new actions are endorsed by outside expert opinion. ²²

Mr Lowson's final submission to Mr Gummer

4.165 Mr Lowson's final submission was forwarded to Mr Gummer on 22 February 1990. Both the submission and the SVS Paper attached had been amended in line with comments received from various MAFF officials. However, the final submission also contained some substantive changes. ²³

4.166 In particular, Mr Lowson observed that to adopt the SVS Paper's recommendation either to advise against breeding from progeny of BSE affected cows, or to implement legislative controls to prevent such breeding:

. . . would go well beyond the advice of the Southwood Committee . . . In the absence of any new risk to public health even if maternal transmission were shown to occur, there is no reason for the Government to abandon its stance of proceeding on the basis of the best scientific advice. ²⁴

4.167 Mr Lowson also noted that the introduction of further controls would 'risk that the public will perceive such controls as tantamount to an admission that there is a risk to public health from consumption of calves of infected animals'. ²⁵

4.168 Mr Lowson recommended that Ministers:

(i) . . . endorse the view that the slaughter or segregation of the offspring of cattle in which BSE is confirmed would not be appropriate;

(ii) . . . seek advice from [SEAC] on the question of restrictions on the use of such offspring for breeding;

(iii) note the arguments made on the possible impact of new measures. . . ²⁶

MAFF Ministers consider the advice

4.169 On 14 March 1990, Mr David Curry, one of the Parliamentary Secretaries at MAFF (the other was Mr Maclean) chaired a further meeting as requested by Mr Gummer, attended by Mr Maclean and MAFF officials. ²⁷ The note of the meeting records that Mr Curry summed up the discussion on breeding from calves produced by BSE animals as follows:

It was agreed that there would be considerable benefits obtainable through voluntary action. However, whether controls were voluntary or statutory, we could not expect complete coverage and some animals would slip through the net. If statutory action was taken, this would send signals which would re-inforce public concerns about the disease. There would also be a significant marketing effect on beef. At the same time, it was recognised from experience of management of public relations and the political climate, that there would be demands for statutory controls which would be difficult to resist. At this stage, it was for consideration whether we should pre-empt what would, inevitably, be seen as a weakness later, even though such a decision would not necessarily have a scientific basis. ²⁸

4.170 It was agreed that the advice of SEAC should be sought, 'in the knowledge that [SEAC] would judge the matter on objective scientific criteria, which might question the value of statutory controls'. It was also recognised that there would be other criteria to take into account, 'and that it was likely that some form of action would be taken on breeding, irrespective of [SEAC's] recommendations'. ²⁹

4.171 Mr Curry requested that the draft advisory note to farmers, which was being drafted at that time, should include a paragraph advising that there should be no breeding from the offspring of BSE-affected cows, 'in anticipation of action in this area'. ³⁰

4.172 Mr Lowson prepared the requested passage on breeding for inclusion in the advisory note, with a draft press release highlighting the advice. He submitted them to Mr Andrews on 19 March 1990. ³¹ The passage read:

Experiments are being carried out to determine whether BSE can be spread at calving. Results may not be available for several years. Spread at calving would make the eradication of BSE more difficult. Therefore, even though transmission at this time is not known to occur, Ministry advice is that calves born to cows which are or which become confirmed cases of BSE should not be used for breeding. ³²

4.173 Mr Gummer met senior MAFF officials ³³ on the next day to discuss the outcome of the meeting on 14 March 1990. It was confirmed that SEAC's advice would be sought on breeding from the offspring of BSE affected cows. It was further agreed that segregation of BSE offspring would be impractical, and that a slaughter policy should not be pursued in the absence of evidence that it was desirable. ³⁴

DH's consideration of the advice

4.174 On 2 April 1990, Dr Pickles expressed concern to Sir Donald Acheson, the Chief Medical Officer:

We had agreed with MAFF that any new initiatives would be subject to outside expert advice from [SEAC].

However, it now seems MAFF are preparing to offer new advice to farmers without that expert advice. Within the draft advisory note attached, it is recommended that 'even though transmission is not known to occur, Ministry advice is that calves born to cows which are or which become confirmed cases of BSE should not be used for breeding'. This advice is new.

This arose from the MAFF Ministers' view that should there be action that we might want to take were BSE shown to be passed on from cow to calf, we should take that action now. Advice from within MAFF was to have breeding records of all cows/calves and advise against or prohibit breeding from any cows who are themselves offspring of cows who later develop BSE. Although pressed to refer the whole matter to [SEAC], it seems MAFF propose to refer only the question of whether these offspring of cases should be slaughtered. ³⁵

4.175 Dr Pickles was concerned that with no substantial new evidence following the Southwood Report, taking action not recommended by that group might 'call into question the rest of the Southwood advice, including the remoteness of the risk to humans'. ³⁶

4.176 Dr Pickles set out her reservations with MAFF's proposed action:

there is no substantial new and relevant scientific evidence since Southwood reported a year ago. So taking action not recommended by that group might call into question the rest of the Southwood advice, including the remoteness of the risk to humans.

The public/press will be worried by the giving of this advice and the net response could well be that these identified offspring of BSE cases become not acceptable as beef cattle or for export either. There will be pressure to turn informal advice into statutory controls. Farmers will then lose money unless they ignore the advice or evade new controls, setting off more media worries. Yet the experts will have to admit it is impossible to identify all calves born to cows infected with BSE, since many of these will have been killed before showing symptoms. Hence more public worries about the ineffectiveness of the new 'controls'.

There is no substantial benefit and the whole exercise is unlikely to warrant the cost and hassle. Even if BSE is transmitted from cow to calf, the epidemic will almost certainly die out in a few years.

Why have an expert group if their advice is not asked for on a matter as major as this? Justification for any new action should be that advice was sought and then followed. There is only a month to wait before the first meeting of the experts. ³⁷

4.177 Annexed to Dr Pickles's minute was a document entitled 'Maternal Transmission', which set out DH's understanding of the reasoning behind MAFF's proposals. Under the heading 'Comments from DH on the proposals include', it was said that:

There may be pressure from the farming lobby for advice on breeding. So far, this issue has not been taken up more widely. Bringing attention to it with new measures has to be fully justified and that justification has yet to be produced. This looks like MAFF digging another big hole for themselves to fall in. ³⁸

4.178 Sir Donald agreed that:

. . . it would be foolish of MAFF to make such a decision of this sort which must be based on a view of risk of transmission from cows to calves without seeking advice. If they do not they will undermine [SEAC] from the start. ³⁹

4.179 On 4 April 1990, Mr Lowson informed Mr Lebrecht that he had sent a copy of the draft advisory note to DH on 19 March 1990, and that DH had now told MAFF that they objected to the reference to breeding from offspring of affected cattle. DH's concerns were:

to offer advice to farmers would go beyond what the Southwood Committee advised, which would call into question the rest of Southwood's recommendations;

to put out advice so soon before asking [SEAC] to advise on the topic would run counter to the objective of proceeding on the basis of scientific advice only; and

to put any kind of question mark against a new category of animal would heighten public concern about the safety of beef. ⁴⁰

4.180 Mr Lowson noted that these arguments 'were ventilated at Mr Curry's meeting, and it is the CVO's strong recommendation that advice about breeding should be offered'. He also said that the BVA's view was consistent with Mr Meldrum's, 'and we know that some at least of the [SEAC] members already support it'. However, Mr Lowson suggested that DH's concern 'certainly cannot be brushed aside'. ⁴¹ This left three possible courses of action:

One possibility would simply be to drop the reference to breeding from the leaflet, and to deal with any enquiries by saying that we were seeking further scientific advice on the topic, even though Southwood did not make any recommendations. Another would be to recommend that farmers should seek advice from their veterinary surgeons about breeding from the offspring of BSE cattle. The third possibility, which corresponds with the approach which Ministers have so far adopted, would be for them to seek to impress upon DOH colleagues the importance that they attach to this point . . . ⁴²

4.181 Mr Curry and Mr Maclean both responded that they agreed with Mr Meldrum, and that the reference to breeding should be retained in the advisory note. However, there was also concern that MAFF should not be seen to be pre-empting the deliberations of SEAC. ⁴³

4.182 Dr Metters, Deputy Chief Medical Officer, minuted Sir Donald Acheson on 10 April about MAFF's proposal to issue advice on breeding. He said that Dr Tyrrell's view was that the advice should be delayed until SEAC had considered the issue. Dr Metters had spoken with Mr Meldrum, and pointed out that issuing the advice before SEAC had considered the issue would undermine their credibility. Mr Meldrum had admitted that MAFF would be reluctant to issue the advice if DH had doubts, and following Dr Metters's affirmation that it did, conceded that he could agree to wait, though other officials might not. Dr Metters said that Mr Meldrum had indicated that if Sir Donald conveyed DH's views to Mr Andrews, then this would be enough to delay the issue of advice. ⁴⁴

4.183 Mr Maclean wrote to Mr Roger Freeman, DH Parliamentary Secretary, on the same day to explain MAFF's position. He noted that farmers' organisations and other representative groups had been pressing MAFF for official advice on breeding from offspring of BSE-affected cattle, and that he believed such advice should be offered. Mr Maclean suggested that 'if we were not do so, we would be accused of irresponsibility'. He continued:

The strong recommendation that I have received from the State Veterinary Service is that farmers should be advised not to use the female offspring suffering from BSE for breeding. In doing so it would be important to make it clear that this was a common-sense precaution to reduce the risk of the introduction of BSE to farms which had not already suffered it, with no implications for human health and on the basis of no new scientific evidence of maternal transmission. We would, as already discussed between officials, want to seek the advice of [SEAC] on the topic, but in the meantime I do not see how we could issue advice to farmers which did not contain any information on the one point on which they most want to be advised. ⁴⁵

4.184 After reading the letter, Dr Pickles minuted Dr Metters on 11 April 1990 and reiterated DH's arguments against the issue of advice. She suggested:

It seems that we and MAFF may have different views on the facts. The first sentence of the second paragraph [of] Mr Maclean's letter suggests animals suffering from BSE might be used for breeding - we understood all ill animals were slaughtered. His next sentence mentions introduction of BSE to farms as if herds that have not had clinical cases are free of infection - it was our understanding that all cattle in this country must be regarded as suspect for subclinical infection. Whilst we still believe BSE has no direct implications for human health, and any new measures will not change this, we are also concerned about public perceptions of risk and the anxiety caused by any ill-judged new moves. These are all good reasons for using the mechanisms we have set up to get the advice of independent experts. ⁴⁶

4.185 Dr Pickles attached a draft letter for Mr Freeman to send to Mr Maclean. It pointed out that Mr Maclean had previously agreed that 'important new measures were to be approved by both departments and also that these would be based on advice from [SEAC]'. In suggesting that the issue of the advice should be delayed until after SEAC had considered the matter, it continued:

I think it is important we stick to these agreements, particularly as my own officials appear to have a rather different interpretation of the facts available - a clear indication that we need independent expert advice. As you say, there is no relevant new scientific evidence on maternal transmission, so we must be careful in the presentation of new advice that goes beyond what was recommended by the Southwood group in case this calls into question the rest of their advice. ⁴⁷

4.186 The final version of Mr Freeman's letter, sent on 17 April 1990, said:

I think it is important we stick to these agreements, particularly as [SEAC] is to meet on 1 May. To issue this advice just before they meet will only undermine their credibility. As you say, there is no relevant new scientific evidence on maternal transmission, so we must also be careful to ensure that any new advice that goes beyond that recommended by the Southwood group is backed by independent experts.

I believe the right approach is for you to delay the issue of the advice to farmers, or to issue it with no comment about breeding, and present the problem to [SEAC]. Depending then on their views, we can reconsider what advice, should be offered. ⁴⁸

4.187 Following receipt of Mr Freeman's letter, the issue of the advisory note was delayed until SEAC had considered the issue, and Mr Maclean asked that the draft advisory note be forwarded to SEAC for its consideration. ⁴⁹

4.188 It appears that Mr Gummer had already resigned himself to this approach. On 11 April 1990, the Press Office forwarded the draft text of the advisory leaflet to Mr Gummer. A manuscript note on the covering minute records:

The Minister discussed this with the Secretary this morning; He has decided that the leaflet should be submitted to [SEAC] for comments before it is used. ⁵⁰

4.189 On breeding, the draft advisory leaflet read:

Experiments are being carried out to determine whether BSE can be transmitted from dam to calf. Results may not be available for several years, but the existence of such transmission would mean that the eradication of BSE would take longer and be more difficult. Therefore, even though transmission is not known to occur, Ministry advice is that calves born to cows which are or which become confirmed cases of BSE should not be used for breeding. ⁵¹

4.190 On 24 April 1990, in relation to a suspected BSE case born after the ruminant feed ban, Mr Bradley suggested to Mr Meldrum that at worst it indicated the possibility of maternal transmission existed. He continued:

However, there have been no reported cases yet in the offspring trial even though some animals are over two years old and some had exposure or possible exposure to MBM before July 1988. There is still time of course for these to develop BSE but the . . . case, even if confirmed, may be the unusual example rather than the norm. ⁵²

SEAC consideration

4.191 SEAC considered the breeding issue during its first meeting on 1 May 1990. The paper on this matter, which had been provided to SEAC by MAFF, asked:

Is it advisable, in advance of clear evidence about the natural transmissibility of BSE, to control the use of offspring of identified BSE cows for breeding - considering (a) animal health aspects and effect on the extent of the epidemic and (b) wider issues such as perception of the media, public and export trade. And is it reasonable to maintain the position that there is no scientific justification for the slaughter of the offspring of cattle suffering from BSE? ⁵³

4.192 The paper went on to ask, in the light of the above consideration, whether it would be appropriate to introduce controls on breeding and whether such controls should be in the form of a compulsory system involving marking the relevant animals, or by advice to farmers. The SVS Paper, which had been prepared for Ministers in February 1990, was also provided to SEAC. The Paper is described in detail at paragraph 159 above.

4.193 The minutes record that SEAC had several reservations about MAFF's proposal to issue advice:

The incidence of subclinical infection invalidated any action proposed. Any advice against breeding from BSE offspring might imply breeding from other cows was acceptable, and yet this was not necessarily the case since these animals could have silent infection. The evidence with natural scrapie suggested there was no association with birth order, so even young cows might be capable of passing infection on to offspring. With the proposed measures, there would be incentives to cheat, perhaps even leading to an increase in infection as farmers offload suspect animals, with difficulties in buying in replacement cows at appropriate ages. There could be disposal of certain useful genes if BSE-offspring were not used for breeding. It was possible infectious but resistant genotypes would be selected, leading to further problems. The effect on the public and the meat trade was thought important: if all these offspring could be properly identified then there would be difficulty in finding buyers for them, but if not properly identified there would be presentational difficulties and little chance such measures would have any effect. In view of the expected elimination of the disease eventually in any case (barring horizontal transmission), at best new measures might be able to accelerate this slightly. At worst, new measures could conceivably make the epidemic worse, although minimal effect was most likely. Introduction of new measures now would lead to suspicion of something unpleasant being concealed.

Proper modelling would be very valuable in formulating advice here and the committee reiterated how important it was that this was undertaken.

Whilst not persuaded that the BVA's advice should be endorsed, for all the above reasons, the committee supported obtaining more accurate breeding records and noted MAFF's intention of strengthening the legislation in this area. ⁵⁴

4.194 The day after SEAC's meeting, Dr Pickles informed Dr Metters that the committee 'were not persuaded on MAFF's proposed line . . . vindicating our stance that this action should await independent expert advice'. ⁵⁵

4.195 On 9 May 1990, Mr Lowson sent a letter to Dr Pickles to help finalise the minutes of SEAC's first meeting, and said, 'I will put fresh advice to our Ministers about advice regarding the use for breeding of the offspring of BSE cattle'. ⁵⁶

4.196 Mr Meldrum forwarded his comments on SEAC's first meeting to Mr Lowson on 14 May 1990. On the breeding issue, he said:

The Committee have been over influenced by the possibility that sub-clinical infection not only may occur but that such animals, as in scrapie, could transmit maternally. That is also pure conjecture, particularly as there are already indications that the agent of BSE is a single agent and that there may not be a genetic resistance to the agent in cattle. I would argue, strongly, that it is far better to offer advice for a percentage of the population where disease has been confirmed, even though this would not cover those where sub-clinical infection may exist, than to offer no advice at all and to extend the duration of the epidemic . . .

All in all the arguments deployed are not convincing to me . . . and, if this is the view of the Committee, then it will not be supported by me . . .

You will, I am sure, understand my position and that I must in such situations retain the right to offer my own advice to Ministers. All of this reinforces my earlier view that in such delicate situations it is imperative that I am in a position to present my case to [SEAC]. You will appreciate that there was no one present at that meeting from the SVS in support of the paper that you had circulated beforehand. ⁵⁷

4.197 The next day, Mrs Attridge sent Mr Gummer a draft submission prepared by Mr Lowson, in light of SEAC's advice. ⁵⁸ Mr Lowson's submission said that:

[SEAC's] arguments are convincing and the Minister is therefore recommended to agree to the release of the advisory leaflet . . . without the passage on the use of the offspring of BSE cattle for breeding. If challenged on this point, we can point to the strong scientific advice that we have received. ⁵⁹

4.198 Mr Gummer met NFU representatives on the same day to discuss BSE issues, including the proposed advice on breeding. The note of the meeting records that:

The Minister said that, given he was basing his position firmly on reliance on scientific advice, he could not possibly with credibility take a decision which contradicted that advice and might lead to a worsening of the situation. ⁶⁰

4.199 Although the NFU representatives expressed some doubt about the advice given by SEAC, they 'eventually accepted that the Minister could not stand against that advice, given its source'. ⁶¹

4.200 Mr Maclean met Mr Andrews, Mr Capstick, Mrs Attridge, Mr Meldrum and Mr Simon Dugdale, the Chief Information Officer, on 16 May 1990. It was noted that a statement was being prepared on SEAC's advice on breeding from the offspring of BSE-affected cows, which would be put to Dr Tyrrell for endorsement within the next day or two. Mr Maclean thought the advice 'should come out in full'. Although Mr Meldrum said the obvious advice for veterinarians to give to farmers was that they should not use offspring of affected cows for breeding, he acknowledged that 'in the context of general advice to farmers, [SEAC] was right to draw attention to the problems [it] had identified'. ⁶²

4.201 At SEAC's next meeting, on 17 May 1990, two draft letters were circulated for the Committee's consideration. ⁶³ The first was a draft letter to the CMO, which stated:

[T]here is no scientific evidence currently available to support official advice against the use for breeding of the offspring of cows suffering from BSE, even if infection can pass down from cow to calf, a possibility that cannot be excluded at present. Decisions about breeding should be left to individual farmers and their veterinary advisers.

Because the likely origin of the epidemic has been eliminated, the outbreak in cattle will be self-limiting unless infection can be spread freely between cattle - in which case restricting breeding would be pointless. So at best, restricting the use of the offspring of BSE cattle would accelerate the decline that was likely in any case. Because of the possibility that subclinically infected animals might infect their offspring, not all potentially infected calves might be identified, which would reduce any benefit. Other possible consequences might even be unhelpful, since it could lead to the increased dispersal of infected animals to other herds, and to the loss of valuable genetic material. We support MAFF's intention to impose more stringent requirement to secure better records of cattle, their offspring and their movements. In any case, vertical transmission, if this is found to occur, would make no difference to the remoteness of the hazard for humans.

This viewpoint may need to be revised in the light of new scientific information. ⁶⁴

4.202 The minutes of the meeting record that the draft letter was agreed by the Committee. The letter was sent later that day to the CMO.

4.203 During the meeting, the Committee discussed what they regarded to be the 'assumed facts on vertical transmission':

Scrapie spreads in sheep mainly from dam to offspring and also from adult to adult but the exact mechanism is unknown. But when scrapie infects mink it does not spread. To date we cannot say whether BSE will spread naturally among cattle or not but we note an experiment has been set up to determine whether transmission was possible from cow to calf.

We assume that affected and some exposed and unaffected cattle herds contain infected animals. Therefore in the worst case, calves may be infected whether or not there has been BSE disease in the herd and may subsequently themselves breed while still healthy. Even if infection from the dam is 100 per cent, and if at least some infected dams become sick and produce fewer calves, the epidemic will be self limiting. However, to the extent that infection can spread from adults to other cattle or be reintroduced into cattle by some other route, then the self-limiting effect will diminish. ⁶⁵

4.204 In the course of these discussions a second draft letter, addressed to the Veterinary Record, was distributed. The second draft letter attempted to set out the Committee's position on this matter in greater detail than that addressed to the CMO. The minutes of the meeting record that 'difficulty was found in expressing the genetic arguments, particularly the possibility that "resistant" (ie, long-incubation) genotypes might be selected'. ⁶⁶ The draft stated:

In forming this advice we have envisaged the worst possible scenario, namely that BSE can be transmitted from infected cows to all their calves . . . Even with this worst case scenario, barring the occurrence of horizontal transmission, the epidemic will not be self-sustaining and will die out, probably to very low levels within the next decade. The reason behind this is simple: since the feed ban will prevent new index cases, and only one in five calves from infected cattle is used for breeding, and because of premature loss through BSE each infected cow has on average less than five calves, the prevalence of infection will fall with every succeeding generation. If only a proportion of calves born to an infected mother is infected the drop in the overall infection rates would occur more rapidly.

At first sight, it may appear that the recent advice from the BVA, that the offspring of known cases should not be used for breeding must be helpful . . . However, only a proportion of infected cows - those that survive long enough to present with symptoms - can be identified. Animals used for breeding in place of the identified BSE offspring could well be themselves infected. Indeed, if the identified BSE offspring become marked in some way, there may be temptations to offload these from the herd early so they become precisely those animals brought in for breeding. Many farmers would not have records good enough to convince themselves, or the purchasers of their calves, that they could identify even those few animals which had mothers known to be infected.

There are other consideration, however. Some of the genes discarded in such a programme may have other positive attributes and so should not be disposed of lightly. Furthermore, much more work needs to be done about the potential role of genetic factors in the control of BSE and it would not be wise to take any action that might prejudice this.

[I]n view of the possibility that there could be deleterious consequences, we believe it is inappropriate to offer general advice . . .

In formulating our advice although we were conscious of the presentational aspects, and also the possible economic consequences of new actions, these did not influence the decision we reached which was based on the scientific evidence available at the time. We did conclude, however, that even were BSE vertically transmitted, this would not be relevant to human health. On current evidence, the risk to humans from BSE is remote. ⁶⁷

4.205 This second draft letter was not agreed at the meeting.

4.206 Later that day, Mr Gummer issued a press release, which quoted a statement he had made in the House of Commons that day. On breeding, he said:

There are some who have suggested there should be a ban on breeding from the offspring of BSE cattle. The Southwood Committee did not recommend that. But I was concerned to ensure that all up-to-date information was taken into account so I referred the question back to [SEAC]. They confirm fully what Southwood said. ⁶⁸

4.207 It appears that, following SEAC's second meeting, Dr Tyrrell considerably redrafted the 'second letter', which had been discussed at the previous meeting but had not been agreed. Mr Meldrum was provided with a copy of the revised draft, which was now a more detailed document entitled 'The Scientific Background to the Control of BSE in Cattle'. On 31 May 1990, Mr Meldrum wrote to Dr Pickles saying that he had 'severe reservations about this paper since it does contain a number of inaccuracies and misconceptions'. He thought the paper needed further redrafting, which he believed a member of SEAC was doing in any event. He concluded by saying that, 'it might be advantageous if I were to see a copy of the paper before submission to Ministers in view of the importance of this issue and the delicacy of its presentation'. Copies of Mr Meldrum's letter to Dr Pickles were sent to Mr Lowson, Mr Kevin Taylor, Dr Kimberlin and Mr Lawrence. ⁶⁹

4.208 SEAC next met on 13 June 1990. A further draft of the paper was discussed by the Committee together with an alternative draft by Dr Kimberlin. ⁷⁰ The paper was now entitled, 'Breeding from identified BSE offspring and the control of BSE in cattle'. The minutes of this aspect of the meeting are very brief. However, they record that following discussion, the secretariat was asked to provide a further draft. The key points to emerge were:

- the need for clarification of the reasoning behind the view that the epidemic would die out if transmission was from cow to calf only; and

- a recognition that the possibility of limited horizontal transmission of the disease was a more important problem than that of simple maternal transmission and hence precautions at calving including disposal of placentae [which was known to carry the infective agent in scrapie] could be important. ⁷¹

4.209 In respect of the first key point identified above, the draft paper explained the view that maternal transmission alone would not maintain the disease, in very similar terms to the paper which was presented to the previous meeting on 17 May 1990. That explanation is set out at paragraph 203, above. In the latest draft the explanation was as follows:

We believe, however, that even with free vertical transmission, barring the occurrence of other than very restricted lateral transmission, the number of cases will fall to a very low level within the next decade and the epidemic will not be self-sustaining and will die out. The reason behind this is as follows: since the ruminant protein ban will prevent new infections from feedstuffs and only about one in five of all calves of dairy cows is used for breeding, and because each cow has on average substantially fewer than five calves, the prevalence of infection will fall with each generation. If only a proportion of calves born to an infected mother is infected or only some infected mothers can pass on the infection, the drop in overall infection rates would occur even more rapidly . . . We emphasise that even were BSE vertically transmitted, this would not be of relevance to human health.

SEAC members provide evidence to the Select Committee

4.210 On 18 June 1990, Dr Tyrrell, Dr Will and Dr Kimberlin gave evidence to the House of Commons Select Committee on Agriculture. ⁷² Dr Tyrrell was asked:

On page 16, in the second paragraph, your report [the Tyrrell Report ⁷³] states that: 'If BSE becomes established as an endemic infection of cattle, selective breeding would become a major option for the control of BSE'. Yet in your later note you advise Ministers against a breeding ban. Could you explain why you now think that it is unlikely that BSE will become endemic in cattle?

He responded:

I think there are two ideas woven together in your question, if I may say so. One is our judgment on whether BSE will become endemic or not. The other is whether genetic methods of control might be sought by breeding. I think the answer about whether it will become endemic really turns on our belief that probably the Southwood Committee's general conclusion was right, that this is likely to be a dead-end host, and if it is a dead-end host, then the disease will die out as the infected animals finally die or become sick. ⁷⁴

4.211 Asked whether it would be desirable to ensure or hasten the eradication of the disease from cattle by avoiding breeding from the offspring of BSE-affected cows, he stated:

We have been having discussions actually on that very point because it is a very difficult one and we wish to give a clear answer and we are still arriving at [what] we think is the right way to present it. I think that is the most honest thing I can say to you. ⁷⁵

4.212 When asked why, if BSE was so like scrapie, BSE should not act like scrapie in respect of maternal transmission, Dr Kimberlin responded:

I think the short answer to your question is that BSE, whatever it turns into, did not start out by being scrapie. It started out as a TME [transmissible mink encephalopathy] story, an infection, if you like, that should not have been there but got in through the mink feed. One of the remarkable things about the TME mink disease story is that it is a dead-end infection, so that at the top of my list I would put, since BSE started like TME it is likely to continue that way, and it is only if circumstances change and it now becomes an endemic infection of cattle, in the manner that scrapie is of sheep, that we will be faced with a rather more difficult problem, potentially, of eradication. ⁷⁶

4.213 Dr Tyrrell then interjected to say:

. . . it is true that the agent is expected to behave like mink, be a dead-end disease, but I think we should say as honest scientists that we do not know, and that is why the Southwood Committee recommended - and we thoroughly endorse - a large-scale, I must admit expensive, experiment to try and determine whether, in fact, maternal transmission does occur, because this is a crucial fact to have. I should tell you then that at the moment our thinking, which is incomplete, is moving in the direction of saying that, as there is no real evidence that transmission does occur, there is really no need to stop people breeding from affected cattle or from earlier calves for instance. But it might turn out that it did, if transmission does occur, in that case it could be a wise precaution to make sure there is an adequate register of the breeding and of the fate of calves which come from animals which in the end prove to be infected, so that if we decided in perhaps a couple of years' time that this was a real risk and not just a hypothetical one, we might move as efficiently as possible towards doing something appropriate about those potentially infected animals. But at the moment there would be some losses which might be entirely unnecessary if one decided, 'we will take the worst action head on and we will kill off or prevent breeding from all the progeny', and that, I think, will be a decision finally for administrators, ministers, farmers and so on to take.

4.214 It was then suggested to Dr Tyrrell that SEAC was:

second-guessing to a great extent with regard to whether it is going to be a dead-end source or not and we know that it is not in sheep. Surely it would be better, to quote a Minister, to use belt and braces and ban the breeding at this particular stage, because if we find out you were wrong, Dr Tyrrell, then the problem is going to be much greater in two or three years' time.

Dr Tyrrell responded:

[T]he science is very difficult because we are proceeding on the basis of analogies and hypotheses about what might happen if breeding proceeded and there is no sure knowledge. I feel that, to be perfectly honest, in the area of managing the British beef herd we have to deal with much less well established science and scientific principals than we have when we are dealing with the safety of human beings, so it is a more difficult issue.

We have suggested that as a half way house we put forward the idea of adequate records so that if we are wrong any necessary, administrative action can be taken and we do not in two or three years time say, 'Oh, but we were wrong and we never thought of it before', and then did not do anything ahead of time to govern and prepare for a route of action that would be needed if we were wrong. That is the line.

SEAC's fourth meeting and finalisation of the paper on maternal transmission

4.215 SEAC further discussed the draft paper on maternal transmission at its fourth meeting 2 July 1990. At that meeting, Dr Tyrrell said:

The objective in this and other cases was to produce 'opinions' which set out clearly what was implied by scientific knowledge. It was for others to decide what policy decision should flow from this. These 'opinions' could be backed up by more detailed notes setting out their scientific basis. ⁷⁷

4.216 The minutes of the meeting further recorded that following 'detailed discussion', the secretariat was asked to produce a further draft, which after clearance by Dr Tyrrell would be shown to other members for agreement in a very short timescale.

4.217 The final paper, 'Control of BSE in Cattle', was agreed and published on 12 July 1990. The paper set out the basis for SEAC's advice to Government on breeding from offspring, as follows:

10. Slaughtering, or avoiding breeding from, the female offspring of affected cows may harm the productivity of the herd and would remove animals which could be valuable for improving the stock - eg, because of their potential milk yield or quality. There could also be a tendency for animals which were infected, but had not yet shown clinical disease, to be disposed of to other farms rather than to be retained for breeding, thereby dispersing infected animals to other herds. If, as we believe is possible, maternal transmission does not occur, such measures would obviously bring no benefit because the only animals that will develop clinical signs in the future are those which are already infected but have not yet succumbed to clinical disease.

11. If the disease were transmitted from dam to calf exclusively, or nearly exclusively, there would still be a tendency for the disease to die out, because cows which became clinically affected would have fewer calves than those which remained well, and infected animals would not produce enough calves for the epidemic to be maintained. Consequently preventing the progeny of cattle suffering from BSE from breeding would do no more than accelerate the self-limitation of BSE that would occur anyway.

12. If the mechanisms of transmission were like those of scrapie, the value of applying restrictions to the offspring of known BSE cattle would be severely limited because infection could be passed to their calves and even to their offspring's offspring before the dam showed signs of the disease. Some cows could pass the disease to their offspring without ever developing clinical signs of BSE.

13. The factors in paragraphs 10-12 above were the main considerations which led us to the conclusion that we could not advise the Government to take measures to limit the use of the offspring of cattle suffering from BSE for breeding. ⁷⁸

MAFF issues the Advisory Note to Farmers, June 1990

4.218 On 31 May 1990, Mr Maslin forwarded to Mr Maclean a revised draft advisory note for farmers. Mr Maslin suggested that to take into account SEAC's advice, the section on breeding be changed to:

Experiments are being carried out to determine whether BSE can be transmitted from dam to calf but results may not be available for several years. If you wish to obtain advice on breeding from the offspring of cows affected with BSE you should consult your veterinary surgeon. ⁷⁹

4.219 MAFF issued the Advisory Note to Farmers in June 1990. It set out general guidance on BSE symptoms, the slaughter and compensation scheme and health and safety. Mr Maslin's suggestion for the breeding section was also included. ⁸⁰

4.220 During oral evidence, Dr Francis Anthony of the BVA was asked what his understanding was for MAFF's withdrawal from its 1988 advice (see paragraph 4.150 above). He responded:

I wish we could have understood. We were extremely frustrated as an association because the advice not to breed from an animal which might be carrying a disease which we did not know was transmissible or not maternally, there is no other advice. ⁸¹

4.221 On 12 July 1990, MAFF issued a press release to coincide with the publication of SEAC's paper, 'Control of BSE in Cattle'. It quoted Mr Gummer's written answer to a Parliamentary Question:

I have today received [SEAC's] paper on the Control of BSE in Cattle. This paper discusses the scientific background to the opinion which the Committee offered on 17 May to the effect that there is no scientific evidence currently available to support official advice against the use for breeding of the offspring of cows suffering from BSE and that some possible consequences might even be unhelpful. ⁸²

The Agriculture Select Committee's report on BSE

4.222 In their report on BSE, published on 10 July 1990, the House of Commons Agriculture Select Committee (the Select Committee) commented on whether there should be a ban on breeding from the offspring of cows with BSE. SEAC's advice was considered, and the Select Committee said that it found SEAC's reasoning 'neither fully convincing nor fully clear'. It acknowledged that Dr Tyrrell had admitted that the advice was produced in haste, and that a second report was being prepared. The Select Committee continued:

The essence of Dr Tyrrell's advice is that decisions on whether or not to breed from the offspring of confirmed cases should be left to farmers on their veterinary surgeon's advice. His reasons for this are abstruse and depend less on pure science than a series of finely balanced judgements about whether particular constraints on breeding would be warranted by their likely effectiveness. Our own view is that this is an area where scientific advice needs to be considered in conjunction with other factors and where, beneath the agonising over technicalities, the issue may be a comparatively simple one. If it was known that BSE was maternally transmissible, no Government could countenance the offspring of BSE-affected cows breeding freely since that would signal an indifference to eradicating the disease. Since it is only speculated that the disease is maternally transmissible, what is at issue is whether one proceeds on the basis of speculation or awaits certain knowledge.

The judgement is a fine one but, in our view:

no legislative action is necessary unless maternal transmission is confirmed;

in the interests of public confidence, farmers should be discouraged from breeding from animals whose dams have been affected by BSE. ⁸³

4.223 The Select Committee suggested that one way of achieving this would be for MAFF to 'indicate that it would not pay compensation on animals which had been knowingly bred from a dam with BSE in its lineage'. ⁸⁴

The Government's response

4.224 On 24 July 1990, Mr Lowson sent a submission to Mr Gummer, which advised that the Select Committee's recommendations on breeding should be rejected. ⁸⁵ Mr Gummer acceded to this advice when he met with MAFF officials the next day. ⁸⁶

4.225 In November 1990, the Government presented its response to the Select Committee's report. On breeding from offspring of BSE cows, the Government stated:

The arguments are complex and it is important that [SEAC's] views should be read in full. But the Government finds them convincing and therefore does not accept the Select Committee's recommendation on this point.

It follows that the Government does not accept either the recommendation that farmers who breed from known BSE cases should not get compensation if the offspring succumb to BSE. Such action would act as a clear discouragement to reporting suspect disease, even though it is a legal requirement. Moreover, the Animal Health Act 1981 lays down that if the Minister requires the compulsory slaughter of an animal, the owner must be compensated. ⁸⁷

Subsequent advice on breeding, 1995-96

4.226 Towards the end of 1995, MAFF began work on revising the original 1990 Advisory Note to Farmers. A draft version was submitted for SEAC's consideration at its meeting on 23 November 1995. On maternal transmission the draft stated:

Experiments are being carried out to determine whether BSE can be transmitted from dam to calf. Although these will not be completed until 1997, it is already clear that this happens rarely, if at all. If you wish to obtain advice on breeding from the offspring of cows affected with BSE, you should consult your veterinary surgeon. ⁸⁸

4.227 However, by the time the final version was distributed in September 1996, maternal transmission studies had indicated that BSE could be maternally transmitted (see vol. 2: Science). Thus, the advice issued was:

Experiments have shown that BSE can be transmitted from a BSE-infected dam to her calf. This maternal transmission of BSE is most likely to occur when a calf is born within six months of its dam developing clinical BSE; around 1 per cent of cows which die of BSE will have produced a calf which will die of BSE as a result of maternal transmission. This will not prevent the eradication of BSE. MAFF advice is that you do not retain for breeding the most recent offspring of a BSE-affected dam. You may wish to obtain further advice on breeding from the offspring of cows affected with BSE from your veterinary surgeon. ⁸⁹

Discussion

4.228 When examining advice on breeding in vol. 5: Animal Health, 1989-96, we discussed the part that SEAC had played. We set out here the conclusions that we reached.

4.229 The possibility that there might be a genetic factor in susceptibility to BSE, or that BSE might otherwise be transmissible from cow to calf ('maternal transmission') led both the MAFF veterinarians and the British Veterinary Association (BVA) to conclude that it was preferable that the progeny of cattle with BSE should not be used for breeding lest they, having been infected with the disease, should pass it on to their own progeny.

4.230 On 30 April 1988, MAFF recommended, in the Veterinary Record, that the progeny of affected cows should not be retained for breeding purposes (see paragraph 4.150). This would have brought the advice to the attention of veterinarians, but not to most farmers. On 25 January 1990, the BVA issued a press notice giving the same guidance (see paragraph 4.153).

4.231 On Mr Gummer's initiative, the SVS prepared a paper setting out the options for action to address the possibility that BSE might be vertically transmissible. In essence, the choice was between simply advising farmers not to breed from the progeny of cattle affected by BSE or imposing regulations that would prevent them from doing so. The latter course raised tricky policy considerations. If statutory action was taken, this might reinforce public concern about the disease and have an adverse effect on the market. If no mandatory action was taken, the public might criticise MAFF for failure to take adequate precautions. In the event the decision was taken to refer the matter to SEAC (see paragraph 4.187).

4.232 We do not believe that it can have occurred to MAFF that there would be anything controversial about giving advice not to breed from offspring, pending the possibility of SEAC recommending more stringent measures. Dr Pickles's intervention, in a matter which was pre-eminently one of veterinary expertise, cannot have endeared her to the MAFF veterinarians.

4.233 The arguments raised by Dr Pickles against the issue by MAFF of advice against breeding from the offspring of dams affected by BSE were:

1. Southwood had not given such advice. For MAFF to do so might call in question the soundness of other parts of the Southwood Report, including its assessment that the risk to humans was remote.
2. Such advice would raise concerns on the part of the public and the media about the offspring of BSE victims. This might lead to their being made the subject of an export ban.
3. There would be pressure to replace such advice with statutory controls.
4. The result might be a loss of income to farmers.

4.234 Dr Pickles added that there would be little benefit from the advice as, even if maternal transmission occurred, BSE would almost certainly die out within a few years.

4.235 The question of the extent to which the proposed advice would be beneficial in expediting the eradication of BSE, should maternal transmission occur, was one that called for expert input from the veterinarians. The points raised by Dr Pickles were essentially political questions.

4.236 In those circumstances we question whether SEAC had much to contribute to the debate. MAFF's veterinarians were as well if not better placed to provide the expertise that was needed to inform the debate. It was for MAFF administrators and for Ministers to weigh veterinary considerations against the wider political implications of the proposed advice.

4.237 We can, however, see force in Dr Pickles' point that, having just set up SEAC, it might discredit the Committee to proceed to issue advice without consulting them. In these circumstances, we consider that Mr Gummer acted reasonably in deciding that guidance from SEAC should be sought before MAFF's advice to farmers was given.

4.238 The basis on which SEAC's advice was sought, however, was not satisfactory. They appear to have been expected to produce an opinion on a difficult matter at their first meeting. They were asked not merely to advise on the scientific justification for taking action in relation to breeding from the offspring of cattle suffering from BSE, but to have regard to 'wider issues such as perception of the media, public and the export trade'. We do not think that SEAC was the right body to reach a decision that involved evaluating those wider issues. Yet the minutes of SEAC's meeting indicate that much of their discussion was devoted to these issues.

4.239 It seems to us that after their meeting SEAC had some difficulty in formulating a scientific basis that justified their disapproval of the advice that MAFF had wished to give to farmers. Dr Tyrrell failed to produce a convincing explanation of this when he appeared before the Select Committee and SEAC's final paper did not persuade us that Mr Meldrum's position was unsound. But SEAC, dealing with this matter at their first meeting, was constrained to advise under pressure. For most members of SEAC policy on animal breeding was unfamiliar territory. Their advice is not a matter for criticism.

4.240 Mr Gummer felt that he could not take a decision which contradicted SEAC's advice as he was basing his position firmly on scientific advice. We, like the National Farmers' Union (NFU), appreciate the difficulty that Mr Gummer would have had in disregarding the first advice to be proffered by the new advisory Committee. Mr Meldrum commented in a minute to Mr Lowson:

. . . in such delicate situations it is imperative that I am in a position to present my case to the Tyrrell Committee. ⁹⁰

4.241 We sympathise with Mr Meldrum. On a matter such as this, it would have been preferable for SEAC to have had the benefit of hearing from him.

4.242 In summary, we consider that a preferable way to have made use of SEAC in relation to the breeding issue would have been:

1. To have targeted the advice sought on the scientific issues.
2. To have allowed SEAC more time to reach a considered advice.
3. To have invited SEAC to discuss the veterinary issues with Mr Meldrum or some other member of the SVS.

4.243 Although this episode provides a lesson for the future about the way in which the Government should make use of scientific advisory committees (we discuss this further in vol. 1: Findings and Conclusions,), we do not think that it calls for criticism of any of the individuals who were involved at the time.