The School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Aberdeen AB25 2ZD, UK. Department of Veterinary Surgery, Institute of Veterinary Medicine, Nicolaus Copernicus University in Torun, 87-100 Torun, Poland. Department of Histology and Embryology, Poznan University of Medical Sciences, 60-781 Poznan, Poland. Department of Anatomy, Poznan University of Medical Sciences, 60-781 Poznan, Poland. Division of Infertility and Reproductive Endocrinology, Department of Gynecology, Obstetrics and Gynecological Oncology, Poznan University of Medical Sciences, 60-535 Poznan, Poland. Division of Perinatology and Women's Diseases, Poznan University of Medical Sciences, 60-535 Poznan, Poland. Prestage Department of Poultry Science, North Carolina State University, Raleigh, NC 27607, USA. Physiology Graduate Program, North Carolina State University, Raleigh, NC 27695, USA. Department of Obstetrics and Gynecology, Faculty of Medicine, Masaryk University and University Hospital Brno, 602 00 Brno, Czech Republic. Department of Veterinary Sciences, Czech University of Life Sciences in Prague, 165 00 Prague, Czech Republic. Department of Diagnostics and Clinical Sciences, Institute of Veterinary Medicine, Nicolaus Copernicus University in Torun, 87-100 Torun, Poland. Department of Toxicology, Poznan University of Medical Sciences, 60-631 Poznan, Poland. Department of Basic and Preclinical Sciences, Institute of Veterinary Medicine, Nicolaus Copernicus University in Torun, 87-100 Torun, Poland.