1. Clinic for Animal Reproduction, Faculty of Veterinary Medicine, Freie Universität Berlin, Königsweg 65, 14163 Berlin, Germany
2. Center for Protection of Experimental Animals, German Federal Institute for Risk Assessment (BfR), Alt Marienfelde 17-21, 12277 Berlin, Germany
3. Federal Office of Consumer Protection and Food Safety (BVL), Gerichtstraße 49, 13347 Berlin, Germany
4. Clinic for Ruminants, Faculty of Veterinary Medicine, Justus-Liebig-Universität Giessen, Frankfurter Str. 104, 35392 Giessen, Germany