1. Unit of Reproductive Medicine – Small Animal Clinic University of Veterinary Medicine Hannover Hannover Germany
2. Clinic for Cattle University of Veterinary Medicine Hannover Hannover Germany
3. Institute for Biometry, Epidemiology and Information University of Veterinary Medicine Hannover Hannover Germany
4. Clinic for Obstetrics, Gynaecology and Andrology of Large and Small Animals Faculty of Veterinary Medicine Justus‐Liebig‐University Giessen Giessen Germany