72 (1) 20-26
Scrapie in sheep is the prototype of the transmissible spongiform encephalopathies (TSEs), of which BSE in cattle is the best known. Contrary to BSE in cattle, for which no genetic association with resistance has been found, sheep with a hereditary resistance to scrapie and BSE after experimental infection are known. Consequently, the selection of scrapie-resistant (ARR/ARR) sheep is currently one of the most important, if not the most important objective of the sheep breeding associations. The feasibility of obtaining a scrapie-resistant breed and the period in which it can be realised, mainly depend on the initial frequency of the ARR-allele of that specific breed. In this study, the PRNP-genotype and allele frequencies were sampled for the most important sheep breeds in Belgium. The genotyping of 854 animals revealed that 17.80 % of the tested animals are of the ARR/ARR-genotype and only 5 animals (0.59%) were of the most scrapie-sensitive genotype VRQ/VRQ. The frequency of the ARR-allele is 41.51%.