1. 1 Department of Fur-bearing Animal Breeding and Game Management, Faculty of Animal Bioengineering , University of Warmia and Mazury , Oczapowskiego 5 , Olsztyn , Poland
2. 2 Department of Small Livestock Breeding , National Research Institute of Animal Production , Balice n. Kraków , Poland
3. 3 Department of Biological Functions of Food , Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences , Tuwima 10, 10–748 Olsztyn , Poland
4. 4 Department of Veterinary Prevention and Feed Hygiene, Faculty of Veterinary Medicine , University of Warmia and Mazury , Oczapowskiego 13, 10-719 Olsztyn , Poland