Volume 5: Animal Health, 1989-96
4a. Implementation, enforcement and monitoring of the animal SBO ban
Realisation of the importance of the animal SBO ban
Growing concern about BABs
Study of the effect of rendering on BSE infectivity
Recognition that as little as 1 gram of infective material was capable of transmitting BSE to cattle

4.292 Mr Simmons's finding that 'a small but significant' proportion of SBO was finding its way into animal feed provoked a flurry of activity within MAFF. Measures for more effective monitoring of the animal SBO ban that had been proposed and rejected previously now came under renewed consideration. The remainder of 1994 saw MAFF devoting increased attention to the enforcement of the animal SBO ban. Whilst Mr Simmons's report was timely in this respect, it was not the sole reason for this change of attitude. As the year progressed, the importance of the animal SBO ban and its integrity came sharply into focus as a result of a number of other developments. These developments, described below, form the background to the action taken by MAFF in relation to the animal SBO ban from this time. They are discussed in greater detail in Chapter 2.

Growing concern about BABs

4.293 The first case of BSE in an animal born after the introduction of the ruminant feed ban (BAB) on 18 July 1988 was not confirmed until March 1991. This BAB case was investigated by MAFF largely to discover whether it provided evidence that the disease might have been passed from dam to calf (maternal transmission). It was quickly followed by further cases and it was concluded that the most likely explanation for the majority of BABs was that they had been fed contaminated feed. By September 1992, within 18 months of the first identified BAB in March 1991, the number of confirmed BABs had risen to 220. ¹ A year later, in September 1993, the total had reached 4,010. By August 1994, the first cases born after the introduction of the animal SBO ban were confirmed, ² and by September 1994 the total number of BABs had reached 12,860. ³

4.294 Reports in February 1993 indicated that 73 animals born in 1990 were suspected of having BSE, some of which were likely to have been born after the introduction of the animal SBO ban. It was noted that, while the majority of cases were likely to have been fed cattle feed containing ruminant protein manufactured before the introduction of the RFB in July 1988, it was also possible that they had consumed feed intended for other species which could until September 1990 legally have contained SBO. ⁴

This appears to be the first time that consideration was given to the possibility that SBO incorporated in feed for non-ruminant animals was also a potential source of infection for cattle.

4.295 By early 1994 concern was expressed about the number of BABs and their possible effect on the management of the disease and predictions for its eradication. On 2 February 1994 Mr Ray Bradley, the CVL BSE research coordinator, minuted Mr K Taylor regarding the policing of BSE controls. Mr Bradley wrote:

I, amongst others, have stressed the importance of ensuring that these controls are being effectively policed with particular respect to ruminant feed (RF) ban and the SBO ban. It has always been important to do this but any deficits will be more plainly revealed for all to see in the next few years and there could be serious financial implications re compensation and disposal, not to mention drains on veterinary resources. ⁵

4.296 With particular reference to the SBO controls, Mr Bradley continued:

Hearsay reports have suggested that SBO and other offals are not as well separated as they might be . . .

. . .

I believe we are both of the opinion that whilst the [ruminant feed] ban was effective, though not completely so, after 18 July 1988 any infected [ruminant feed] getting through would be stopped by the SBO ban two and a bit years later. If the SBO ban itself is being abused then there is a weakness in this argument . . . It is therefore absolutely essential that effective audits are carried out and policing is continuous and sound and is seen to be so by the publication of results where this is appropriate . . . ⁶

4.297 He concluded by saying:

I believe we have to quickly and effectively reassess and if necessary, improve the policing of the controls both via MAFF and the local authorities. Any trickle of infected [ruminant feed] into the cattle feed chain could result in an unfortunate plateau of confirmed BSE cases in a couple of years which will be hard to deal with and may even prevent export of live breeding cattle, or reintroducing a ban if we are successful at having it lifted this year. ⁷

4.298 On 29 May 1994 Mr Bradley raised these concerns directly with Mr Meldrum. He reported:

There is hearsay evidence that the SBO ban is being abused, particularly by skulls (with brains inside) entering rendering plants with non-SBO offals . . . Even if abuse is happening it would not be of tremendous animal health importance unless MBM derived from the SBO was diverted into cattle feed since non-ruminants so far have not succumbed to [BSE] naturally or experimentally. This does not mean it is 'alright' since it is contrary to SEAC advice and the law.

It seems imperative that the RFB is completely enforced by the power of law. If we do not ensure it is watertight we will pay for it with continuing BSE confirmations in 4-5 years time and it may jeopardise live cattle exports if we successfully get these re-instated. Testing feed is one way this could be done and there seems to have been an inordinate delay in getting this established. ⁸

4.299 Mr Bradley's concerns were shared by Mr Meldrum. He explained in a statement to the Inquiry that from late 1993 onwards:

It was about this time that I was becoming increasingly uncomfortable about the number of BABs that were being confirmed and the possibility that BSE infectivity was present in meat and bone meal intended for feeding to pigs and poultry and was finding its way into cattle rations. ⁹

4.300 For a more detailed consideration of the monitoring and enforcement of the ruminant feed ban see Chapter 2 of this volume.

Study of the effect of rendering on BSE infectivity

4.301 Another development during this time which was to influence the action taken by MAFF on the monitoring and enforcement of the animal SBO ban was the results of a rendering study. The study to determine the effectiveness of various rendering processes on the inactivation of the BSE agent was established in November 1990 with joint funding by the UK Government, the European Commission and the European Renderers Association. On 21 March 1994 Mr Meldrum briefed Mr Soames on the preliminary results of these experiments. The submission was also copied to Mrs Shephard and Mr Packer among others:

The first phase of the project studied BSE. The bioassays have not yet reached an end point, so it cannot yet be concluded that any system provides effective inactivation. It is, however, already clear that the three systems which collectively provide most of the British rendering capacity do not provide effective inactivation - in fact it appears that only two plants are satisfactory and this would represent less than 20% of total red meat rendering capacity. At least one of the three systems appears to have had no detectable effect on the amount of infective agent present. This is particularly worrying because these three plants process a significant volume of product and are only used in the UK and USA.

The results support the hypothesis that BSE was caused by the presence of the agent in animal protein which was fed to cattle and underline the wisdom of the measures which have been implemented since July 1988 to prevent ruminant derived protein being fed to ruminant animals. ¹⁰

It continued:

. . . we should recall that meat and bone meal produced in the United Kingdom would not contain material derived from the specified bovine offals which are, in effect, destroyed.

. . . we should ensure that that these results are released in an orderly manner so that those involved are aware that there are no implications for human or indeed animal health and that no precipitate action is necessary. ¹¹

4.302 Mr Meldrum met with UKRA to inform them of the rendering experiment on 7 April 1994. It was recorded that:

The CVO indicated that MAFF were now aware that the ban on the use of SBO was not being fully implemented and wanted to discuss the implications with the industry particularly as it is now obvious that at least some of the rendering systems are incapable of deactivating the BSE agent. ¹²

4.303 In a statement to the Inquiry, Mr Fleetwood, who at that time was a Senior Veterinary Officer in the Animal Health (Zoonoses) Division and who had management control within MAFF of the rendering study, said:

In March 1994, results began to come on-stream from the first (BSE) phase of the rendering experiment. These results provided the first direct experimental evidence that infectivity may survive some forms of rendering. In my role as study sponsor, I communicated these interim results to MAFF staff (the CVO and Mr Eddy) and to the European Commission.

These results came as no surprise. They corroborated epidemiological evidence which suggested BSE had been present in MBM, having survived the rendering process. The particular concern, shared by all those involved including the industry, was that there was now definite evidence that BSE infectivity would survive certain processes, but no evidence of what processes would eliminate it.

However, to put this into context, it is important to note that eliminating BSE infectivity through the rendering process was a second line of defence - the first being the various legislative measures to cut off recycling of infection. ¹³

Recognition that as little as 1 gram of infective material was capable of transmitting BSE to cattle

4.304 In addition to the above concerns, during 1994 MAFF received the interim results of an experiment which indicated that the amount of infective material capable of transmitting BSE when administered orally to cattle was less than many had imagined. The experiment, known as the 'attack rate experiment', was started at the CVL in January 1992. It sought to investigate how many cattle in a group would be infected by oral inoculation with different doses of infected material. Information on how incubation period might be related to dose was studied. ¹⁴ The experiment also aimed to look at whether attack rate and incubation period differed for single and multiple exposures. Groups of calves received oral doses of BSE-infected cattle brain homogenate (1 g, 10 g, 100 g or 3 x 100 g on successive days), and were monitored clinically to the point at which they succumbed to the disease. ¹⁵

4.305 It is not clear precisely when the implications of the interim results of this experiment were first conveyed by CVL to MAFF officials. Meetings were held between representative of MAFF, CVL and UKASTA in August and September 1994 at which the interim results of the attack rate experiments were discussed. These are described below at paragraphs 4.370-4.373. The implications of these results are discussed in vol. 2: Science.