1. Veterinary Centre , Nicolaus Copernicus University in Torun , Torun , Poland
2. Department of Anatomy , Poznan University of Medical Science , Poznan , Poland
3. Department of Obstetrics and Gynecology , University Hospital and Masaryk University , Brno , Czech Republic
4. Department of Histology and Embryology , Poznan University of Medical Science , Poznan , Poland