1. Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, 06120 Halle (Saale), Germany
2. Institute of Animal Science, University of Hohenheim, 70599 Stuttgart, Germany
3. Institute of Animal Nutrition and Physiology, Kiel University, 24118 Kiel, Germany
4. Julius Kühn Institute, Federal Research Centre for Cultivated Plants, Institute for Crop and Soil Science, 38116 Braunschweig, Germany