1. Polish Academy of Sciences, Institute of Genetics and Animal Breeding, 05-552, Jastrzebiec, Poland
2. National Veterinary Research Institute, 24-100 Pulawy, Poland
3. Department of Cell Biology and Electron Microscopy, Institute of Biology, Jan Kochanowski University in Kielce, 25-406 Kielce, Poland
4. Medical Practice, 03-081 Warsaw, Poland
5. Faculty of Animal Sciences, Warsaw University of Life Sciences, 02-786 Warsaw, Pol