Association between PrP genotypes and performance traits in a Welsh Mountain flock

The profile of scrapie has risen in recent years, with increasing public awareness that it is a disease that resembles BSE (bovine spongiform encephalopathy) in cattle and CJD (Creutzfeldt Jakob disease) in man. Eradication of scrapie is part of an EU control programme, to protect against the theoretical risk that BSE is present in sheep and goat populations, masked as scrapie. Major government intervention to bring scrapie under control has been a combination of selecting more resistant stock and closer surveillance of sheep and goat populations. Following recommendations of the Spongiform Encephalopathy Advisory Committee (SEAC), the UK National Scrapie Plan (NSP) was launched in July 2001 with the aim of increasing genetic resistance to scrapie. The genotypes that confer resistance/susceptibility to scrapie are categorised into five groups (Dawson et al ., 1998; Warner, 2003) (Group I5highest resistance, Group V5lowest resistance), and not only reflect potential resistance/susceptibility but also the potential for breeding animals to transfer alleles for resistance/susceptibility to their offspring.