1. Department of Pig Breeding , National Research Institute of Animal Production , Krakowska 1 , Balice , Poland
2. Department of Animal Nutrition and Feed Science , National Research Institute of Animal Production , Krakowska 1, 32-083 Balice , Poland
3. Department of Animal Molecular Biology , National Research Institute of Animal Production , Krakowska 1 , Balice , Poland
4. Department of Animal Breeding and Product Quality Assessment , Poznań University of Life Sciences , Złotniki, Słoneczna 1 , Suchy Las , Poland