Scientific and technical assistance on the provisional results of the study on genetic resistance to Classical scrapie in goats in Cyprus

This EFSA Scientific Report reviews and discusses the provisional results of a study (EURL/Cypriot study) on genetic resistance to Classical scrapie in goats in Cyprus. It is concluded that the provisional results obtained in the study further support the lower susceptibility to Classical scrapie in goats carrying the D146 and S146 alleles compared to wild type (N146N) goats. The results from intracerebral challenge are not compatible with a level of resistance as high as the one observed in sheep carrying the ARR allele or in goats carrying the K222 allele. Final results from the oral challenge will be crucial in determining the level of resistance associated with the D146 and S146 alleles. Furthermore, it is concluded that the provisional results obtained in the study are compatible with the possibility to use the D146 and S146 alleles to build a genetic strategy to control and eradicate Classical scrapie in goats in Cyprus. However, the success of such a strategy will be determined by the level of resistance associated with the D146 and S146 alleles against infection with all the different TSE agents proved to be circulating in Cyprus, which at this stage of the EURL/Cypriot study remains to be definitively assessed. In addition, as compared to the results of the model developed in the study, it is concluded that the efficiency of the implementation in the field of a breeding strategy selecting for the D146 and S146 alleles may be lower due to potential practical constraints related to the management of genetic diversity, to the selection for production and health traits and to the need of moving animals for breeding purposes in Cyprus. Recommendations on aspects that may be considered when completing the study are formulated.