1. Animal Breeding Department, Institute of Animal Science, Warsaw University of Life Sciences, Ciszewskiego 8, 02-786 Warsaw, Poland
2. Apiculture Division, Institute of Animal Science, Warsaw University of Life Sciences, Nowoursynowska 166, 02-787 Warsaw, Poland
3. Institute of Genetics and Animal Biotechnology, Polish Academy of Science, Jastrzębiec, Postępu 36A, 05-552 Magdalenka, Poland