BSE (Hansard, 17 July 1997)

§ Mr. Rooker

Professor Anderson, who heads the team at Oxford University, was a member of the epidemiology sub group of the Spongiform Encephalopathy Advisory Committee (SEAC) which advised Government on maternal transmission. That advice was made public through a MAFF press notice issued on 18 April 1997, copies of which are available in the Library of the House.

I understand that Professor Anderson's team are shortly to publish further papers. Professor Anderson has recently been reported as saying that the higher incidents of BSE in larger herds, as compared with smaller herds, could be due to one of two factors, either:

(i) greater use of concentrated cattle feed in larger herds; or
(ii) horizontal transmission from cow to cow as opposed to maternal transmission which is from a cow to its own calf.

Professor Anderson went on to say that he was not able, on the basis of the information available to him, to distinguish between these two hypotheses.

The variation in risk according to herd size is one of a number of observations first published by scientists from the Central Veterinary Laboratory, Weybridge in the Veterinary Record in 1992. I am putting a copy of that paper in the Library of the House. The view of my own advisers is that the more likely explanation for the higher incidents in the larger herds is more intensive use of animal feed in such herds as this ties in with certain other epidemiological observations, including the fact that a number of large herds which had a high incidence of BSE have, as a result of changing feed patterns, eradicated BSE within those herds which had been free for some years. This explanation argues in favour of the feed rather than the horizontal transmission hypothesis.

I must emphasise that Professor Anderson was talking about research findings not yet published and I will of course look to the independent advisory committee, SEAC, for further analysis of this work.