Institute of Computer Science, Warsaw University of Technology, Warsaw, Poland, ICS 00-665 Warsaw (MW, PG), Grid Computing Competence Center-GC3, University of Zurich, 8057 Zxc3xbcrich (SM, AM), Swiss Institute of Equine Medicine, Vetsuisse Faculty, University of Bern and ALP-Haras, 3001 Bern (AP), Institute of Genetics, Vetsuisse Faculty, University of Bern, Bern, 3001 Bern (AP) and Functional Genomics Center Zurich, CH-8057 Zurich, Switzerland.