1. Federal Research Station for Animal Production, Agroscope Liebefeld- Posieux; 1725 Posieux Switzerland
2. Swine Clinic
3. Department of Clinical Research
4. Division of Clinical Neurology; Department of Clinical Veterinary Medicine
5. Department of Veterinary Anatomy
6. Institute of Veterinary Anatomy; Vetsuisse Faculty; University of Zürich; 8057 Zürich Switzerland
7. Institute of Genetics; Vetsuisse Faculty; University of Berne; 3001 Berne Switzerland