1. Department of Pig Breeding, National Research Institute of Animal Production , 32-083 Balice n. Kraków , Poland
2. Department of Animal Molecular Biology, National Research Institute of Animal Production , 32-083 Balice n. Kraków , Poland
3. Department of Immunogenetics, Institute of Genetics and Animal Breeding , Jastrzębiec, Postępu 36A, 05-552 Magdalenka , Poland
4. Department of Pig Breeding and Biotechnology , University of Life Sciences in Lublin , Akademicka 13, 20-950 Lublin , Poland