1. Clinic of Farm Animals, Faculty of Veterinary Medicine, Aristotle University of Thessaloniki, Thessaloniki 54627, Greece.
2. Department of Obstetrics, Gynaecology and Reproduction, Faculty of Veterinary Medicine, University of Kafkas, Kars 36300, Turkey.
3. Department of Reproduction, Faculty of Veterinary Medicine and Zootechnics, University of Mexico, Mexico City 04510, Mexico.
4. Clinic for Cattle, University of Veterinary Medicine, Hanover 30173, Germany.