1. Department of Nutrition, Genetics and Ethology Ghent University Merelbeke Belgium
2. Research and Development Trouw Nutrition Amersfoort The Netherlands
3. Department of Reproduction, Obstetrics and Herd Health Ghent University Merelbeke Belgium
4. ILVO (Flanders Research Institute for Agriculture, Fisheries and Food) Melle Belgium
5. Department of Animal Nutrition Wageningen University and Research Wageningen The Netherlands
6. North Carolina State University Raleigh NC USA