1. Institute of Animal Nutrition and Storage of Plant Products of the Martin‐Luther‐Universität Halle‐Wittenberg. Emil‐Abderhalden‐Str. 25b, D‐06108 Halle
2. Research Institute for Biology of Farm Animals, Wilhelm‐Stahl‐Allee 2, D‐18196 Dummerstorf
3. Research Institute of Agriculture and Fishery of Mecklenburg‐Vorpommern, Dorfplatz 1, D‐18276 Gülzow