Table 1.
Sheep genotypes: prevalence, susceptibility and incubation period.
| genotype | prevalence of genotypea (%) | susceptibility to intracerebral BSE challenge | mean incubation period after BSE intracerebral challengeb (years) | ||
|---|---|---|---|---|---|
| national scrapie plan screening | abattoir screening | number positive/number challengedb | relative | ||
| ARR/ARR | 26.3 | 19.5 | 3/19 | 0.1 | 3.0 |
| ARR/Axx | 40.8 | 41.9 | 3/24 | 0.14 | 5.6 |
| Axx/Axx | 25.5 | 26.5 | 19/21 | 1 | 1.4 |
| ARR/VRQ | 3.4 | 5.5 | 1/11 | 0.14 | 5.1 |
| Axx/VRQ | 3.7 | 6.2 | 3/11 | 0.30 | 2.6 |
| VRQ/VRQ | 0.2 | 0.4 | 4/10 | 0.44 | 2.7 |
b
Jeffrey et al. (2001), Houston et al. (2003) and Bellworthy et al. (2005b). The allele labelled Axx represents alleles ARQ, AHQ and ARH.