1. 1 Institute of Animal Breeding , Wrocław University of Environmental and Life Sciences , Chełmońskiego 38c, 50-375 Wrocław , Poland
2. 2 Department of Genetics , Wrocław University of Environmental and Life Sciences , Kożuchowska 7, 51-631 Wrocław , Poland
3. 3 Department of Animal Molecular Biology , National Research Institute of Animal Production , 32-083 Balice n. Kraków , Poland
4. 4 Department of Epizootiology and Clinic of Bird and Exotic Animals , Wrocław University of Environmental and Life Sciences , Norwida 31, 50-375 Wrocław , Poland