1. Institute of Animal Science, 10400 Prague, Czech Republic
2. Czech-Moravian Breeders Association, 25209 Hradistko, Czech Republic
3. Institute of Nutrition and Genomics, Slovak University of Agriculture, 94901 Nitra, Slovakia
4. Department of Morphology, Physiology and Animal Genetics, Mendel University, Zemedelska 1, 61300 Brno, Czech Republic