1. Department of Animal Nutrition and Animal Health, Faculty of Organic Agricultural Sciences, University of Kassel, D-37213 Witzenhausen, Germany
2. Food and Veterinary Office, District of Waldeck – Frankenberg, D-35066 Frankenberg, Germany
3. Landesbetrieb Hessisches Landeslabor, Department of Veterinary Medicine, D-35392 Gießen, Germany
4. Department of Internal Medicine and Animal Infectious Diseases, Faculty of Veterinary Medicine, Cairo University, Egypt