1. Division of Anatomy, Department of Human Morphology and Embryology, Wroclaw Medical University, 50-368 Wroclaw, Poland
2. Department of Veterinary Surgery, Institute of Veterinary Medicine, Nicolaus Copernicus University in Torun, 87-100 Torun, Poland
3. Department of Toxicology, Poznan University of Medical Sciences, 60-631 Poznan, Poland
4. Department of Basic and Preclinical Sciences, Institute of Veterinary Medicine, Nicolaus Copernicus University in Torun, 87-100 Torun, Poland
5. Department of Diagnostics and Clinical Sciences, Institute of Veterinary Medicine, Nicolaus Copernicus University in Torun, 87-100 Torun, Poland
6. Physiolgy Graduate Faculty, North Carolina State University, Raleigh, NC 27695, USA
7. Prestage Department of Poultry Sciences, North Carolina State University, Raleigh, NC 27695, USA
8. Department of Obstetrics and Gynecology, University Hospital and Masaryk University, 601 77 Brno, Czech Republic