1. Institute of Animal Physiology, Physiological Chemistry and Animal Nutrition; Schönleutnerstrasse 8; 85764 Oberschleissheim Germany
2. Clinic for Ruminants; Sonnenstrasse 16 85764 Oberschleissheim Germany
3. Institute of Epidemiology; Friedrich-Löffler Institute; Federal Research Institute for Animal Health; Seestrasse 55 16868 Wusterhausen Germany
4. Institute of Epidemiology; GSF; Ingolstädter Landstrasse 1 85764 Neuherberg Germany