1. Department of Animal and Poultry Science University of Saskatchewan, Saskatoon, SK, Canada S7N 5A8
2. Alimetrics Ltd., Koskelontie 19B, FIN-02920, Espoo, Finland
3. Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, PO Box 5003, N-1432, Aas, Norway
4. Poultry Cooperative Research Centre, PO Box U242, University of New England, Armidale, NSW 2351, Australia