1. Institute of Biotechnology, Faculty of Biotechnology and Food Science Slovak University of Agriculture in Nitra Tr. A. Hlinku 2 Nitra 949 76 Slovak Republic
2. NPPC, Research Institute for Animal Production in Nitra Hlohovecka 2 Lužianky 951 41 Slovak Republic
3. Department of Animal Morphology, Physiology and Genetics, Faculty of AgriSciences Mendel University in Brno Zemědělská 1/1665 Brno 613 00 Czech Republic