1. Department of Fur-bearing Animal Breeding and Game Management, Faculty of Animal Bioengineering, University of Warmia and Mazury in Olsztyn, Oczapowskiego 5, 10-718 Olsztyn, Poland
2. Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, 10-748 Olsztyn, Poland
3. University of Science and Technology, Faculty of Agriculture and Biotechnology, 85-225 Bydgoszcz, Poland