1. Department of Genetics and Animal Breeding, Poznan University of Life Sciences, 60-637 Poznan, Poland
2. Department of Animal Nutrition and Feed Management, Poznan University of Life Sciences, 60-637 Poznan, Poland
3. Department of Animal Science and Center for Integrated Animal Genomics, Iowa State University, IA 50011-3150, USA
4. Hy-Line International, Dallas Center, IA 50063, USA