1. Department of Pig Breeding and Production Technology, University of Life Sciences in Lublin, Akademicka 13, 20-950 Lublin, Poland1
2. Department of Pig Breeding and Production, Poznań University of Life Sciences, Wołyńska 33, 60-637 Poznań, Poland2
3. Department of Animal Cytogenetics and Molecular Genetics, National Research Institute of Animal Production, 32-083 Balice n. Kraków, Poland3
4. Department of Animal Hygiene and Environment, University of Life Sciences in Lublin, Akademicka 13, 20-950 Lublin, Poland4
5. Department of Breeding and Conservation of Genetic Resources of Cattle, University of Life Sciences in Lublin, Akademicka 13, 20-950 Lublin, Poland5