BSE controls final report, 20 December 2000, section 10, The controls: Specified Risk Material
47.Controls on specified risk material (SRM) are designed to prevent the parts of slaughtered animals most likely to contain the BSE agent from entering the food and animal feed chain. They were first introduced for cattle in 1989 and for sheep and goats in 1996. They have been regularly reviewed and strengthened since then on the basis of developing scientific evidence. A list of the tissues classified as SRM is at Annex G. A relaxation in respect of intestine and thymus of cattle of six months old or under and heads of sheep and goats (but not skull, brain or eyes of sheep which have at least one permanent incisor erupted through the gum or are aged over 12 months) was introduced in October 2000 when the EU Commission Decision37 on EU-wide SRM controls (adopted in June 2000) was implemented. SEAC’s view has been that: "On balance, however, the Committee felt that the benefit of introducing controls on SRM across the European Union, outweighed the slight increase in risk that may arise from any consequential change to the UK’s existing controls"38. Benefits will also derive from the controls on imports from third countries explained in paragraph 79. The list of tissues classified as SRM is being extended again from 1 January 2001 as shown in Annex G.
Cattle
48.Although the original cattle SRM controls were selected according to the prevailing knowledge39 of the pathogenesis of natural sheep scrapie, they have in fact proved to cover virtually all those tissues (predominantly in the central nervous system) in cattle in which BSE infectivity has subsequently been found experimentally (bearing in mind the comments made in paragraph 36 in relation to Annex H). As long as there are any cases of BSE, it would be unwise to allow the tissues most likely to contain infectivity (see paragraphs 35 and 36 and Annex H) to enter the human and animal food chains. Indeed the new EU rules require countries such as Finland and Greece with no known cases of BSE to implement SRM controls.
Sheep and goats
49.Controls for sheep and goats were introduced on a precautionary basis as a potential risk reduction rather than risk elimination measure, since BSE has never been found in the UK national flock. Results of research available so far (relating to experimentally transmitted BSE) indicate that the external signs of BSE in sheep are very similar to those of scrapie and that the BSE agent is more widely distributed in the bodies of genetically susceptible sheep than in the bodies of BSE-affected cattle (paragraph 25). It would be virtually impossible to remove all the affected tissues without destroying the saleable carcase. If, therefore, BSE is shown to be in the national flock, only sheep which could be clearly demonstrated to be free of BSE could be allowed to remain in the food chain. SRM-type controls would not be adequate. Contingency planning for such a finding is underway (see paragraph 27) and we fully support such work.
50.The tissues of sheep likely to carry most BSE infectivity would be those of the central nervous system. These are already covered by the SRM controls. The tissues next in the ‘infectivity hierarchy’ are lymphoid tissues, with muscle meat carrying the least risk. The intestines are rich in lymphoid tissues. Sheep intestines are used for sausage casings. In the UK about 10% of sausages consumed are estimated to be in natural sheep casings40. It has been said that the process employed in the production of sausage casings ensures that lymphoid tissue and, with it, any risk of infectivity is removed. However, we recommend that further research is undertaken to assess the validity of this assertion and to indicate any risks involved in this use of sheep intestines. We further recommend that the ingredient listing in the labelling of sausages should specify the species of animal from which any natural casing is derived.
51.For the longer term, we advocate strongly (with the caveats mentioned in paragraph 27) the introduction of other measures to eliminate scrapie (and, with it, any possible BSE) from the flock as a precautionary measure. It has been shown that certain sheep are genetically resistant to scrapie and a selective breeding programme using genetically resistant rams has been proposed. We fully support this proposal and urge its speedy introduction, given the long period of time required to become fully effective (see paragraph 27 above).
52.The SRM controls on sheep and cattle are enforced in licensed slaughterhouses and cutting plants by the Meat Hygiene Service whose enforcement is audited by the State Veterinary Service. In Northern Ireland the controls are enforced by the Veterinary Service of the Department of Agriculture and Rural Development. The results of the audit, which are published each month41, show extremely high compliance rates (99.4% for the year ended September 2000). Details of the audit failures are also given.
53. The industry has calculated (1998)42 the annual cost to the beef sector (covering loss of value plus disposal costs) of the SRM controls to be £14.68 million. Equivalent costs to the sheep sector were £3.27 million. In addition the Government spends approximately £23 million each year to enforce the controls.
54.We make no proposals for immediate changes in the SRM controls. For cattle, any future changes will depend on:
(i)whether or not there has been any relaxation of the OTM rule; and
(ii)achievement of low BSE status for the UK (ie incidence lower than that described in paragraph 20 above) under international rules, leading to a more restricted range43 of SRM controls being justified.
For sheep, future changes will be affected by:
(iii)evidence of BSE in the national sheep flock, in which case the current controls would be inadequate and additional measures would have to be considered; and
(iv)TSE resistance being successfully bred into sheep under the national programme, which could enable selectively applied controls to be introduced.
For both cattle and sheep, further changes could be made in the event of:
(v)the development and introduction on a commercial scale of diagnostic tests of proven reliability to indicate absence of TSE infection in animals or carcases where no clinical symptoms have appeared (see paragraphs 45 and 90). This could enable SRM controls to be targeted more closely.
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37 - Commission Decision 2000/418/EC, OJ L158 p76
38 - SEAC News Release 2/00, 8 June 2000
39 - This has subsequently been shown to be inadequate since infectivity in sheep has now been identified as being much more widely distributed in the body than originally thought.
40 - Information provided to the Secretariat by the Natural Sausage Casings Association.
41 - The BSE Enforcement Bulletin is available from Jill Wilson, FSA, Room 517, Ergon House, PO Box 31037, London SW1P 3WG, telephone 020 7238 6498, fax 020 7238 6487 or email jill.wilson@sfoodstandards.gsi.gov.uk
42 - A study of the competitive position of the red meat industry in Great Britain in relation to the collection, processing and disposal of animal by-products both in Great Britain and other EU Member States (Meat and Livestock Commission, June 1998).
43 - The list of tissues classified as SRM for lower BSE status countries under current EU legislation relates to cattle over 12 (rather than 6) months old and does not include the whole head (as opposed to the skull including the brains and eyes), the thymus, the spleen or the intestines (apart from the ileum).