1. Vertebrates Morphology Department, Siedlce University of Natural Sciences and Humanities, Konarskiego 2, 08-110 Siedlce, Poland
2. Department of Breeding Methods and Poultry and Small Ruminant Breeding, University of Natural Sciences and Humanities, Prusa 14, 08-110 Siedlce, Poland
3. Department of Morphological Science, Faculty of Veterinary Medicine, Warsaw University of Life Sciences, Nowoursynowska 166, 02-776 Warszawa, Poland
4. Institute of Genetics and Animal Breeding, Polish Academy of Sciences, 05-552 Jastrzębiec, Poland
5. Department of Conservative Dentistry, Pomeranian Medical University, 71-466 Szczecin, Poland
6. Eurohouse, Dog Kennel Lane, Walsall WS1 2 BU, England, United Kingdom