The leading regional farming newspaper "South West Farmer" carries a report on the National Scrapie Plan in its June edition that makes it sound like a good idea without any drawbacks. So the tireless (thank heaven) Alan Beat writes another letter
To: Stephen Ivall
Subject: Letters - scrapie
Your report on the National Scrapie Plan in the June issue (page 5) informs us that "the process is very simple", and that "fears that other valuable, even essential traits will be lost . . .appear to be groundless". However, scientific evidence does not support these claims.
Here are some relevant extracts from a report issued recently by Rare Breeds International:
# selection for the ARR "scrapie-resistant' allele in sheep could lead to the extinction of some native breeds of special genetic importance
# Rare Breeds International recognises 31 native breeds of sheep of special genetic importance in UK, and at least 9 of these would be at serious risk because of their low frequency of the ARR allele.
# Breeds particularly at risk include the genetically-distinct Northern Short-Tailed group of breeds, the high-performance Marsh breeds, and the environmentally-important Mountain breeds.
# In several breeds the commercial superiority of non-ARR genotypes has been noted."
It is significant that the government has just adopted sweeping new powers, without parliamentary debate, using Satutory Instrument 843 to drive forward the compulsory acceleration of the National Scrapie Plan, in response to fears that BSE may be present in the national flock but masked by scrapie. This perceived risk is entirely hypothetical and no scientific evidence has yet been found to support it.
It is uncertain whether the genotypes of sheep that display scrapie resistance are actually resistant, or instead have a longer incubation period before the disease manifests itself, with the result that commercial sheep are slaughtered before clinical signs appear. In this latter scenario, such genotypes may mask any possible BSE in sheep more effectively, so that to selectively cull the UK sheep flock in their favour will have the effect of increasing risk to human health – the very opposite of the political intention. Professor Ferguson-Smith of Cambridge University has pointed out that scrapie and 'genetic resistance to scrapie', has nothing to do with resistance to BSE in sheep. On the contrary, there is some laboratory evidence that animals with a scrapie-susceptible genotype may actually be more resistant to BSE infection.
The inescapable conclusion is that, at present, there is insufficient scientific knowledge to safely proceed with any move to eliminate scrapie-resistant genotypes from the national flock.