1. Institute for Animal Breeding and Genetics, University of Veterinary Medicine, 30559 Hannover, Germany
2. Clinic for Swine, Ludwig-Maximilians-Universität München, 80539 Munich, Germany
3. Clinic for Cattle, University of Veterinary Medicine, 30173 Hannover, Germany
4. Institute of Pathology, University of Veterinary Medicine, 30559 Hannover, Germany
5. Clinic for Horses, University of Veterinary Medicine, 30559 Hannover, Germany
6. Department of Immunobiology, University of Lausanne, 1066 Epalinges, Switzerland