Sample set used in the current study.

These represent 625 animals and 22 breeds drawn from an original set of 1810 samples collected. Qualifications for inclusion are: being genotyped for marker INRA111, having passed their first SICCT test, being recorded in the VeBus database and having at least four other samples from the same breed. The Table lists, for each of these breeds, the abbreviated code, the full breed name and the numbers of non-reactors (NR) and reactors (R), partitioned by whether they derived from the original (O-) Driscoll et al. study [14] (n = 141) or are new (N-) samples (n = 385).