1. Food and Agriculture Organization of the United Nations (FAO); Animal Production and Health Division; 00153 Rome Italy
2. UMR SADAPT; INRA; AgroParisTech; Université Paris-Saclay; 75005 Paris France
3. Department of Energy and Technology; Swedish University of Agricultural Sciences; 75007 Uppsala Sweden
4. Lethbridge Research Centre; Agriculture and Agri-Food Canada; Lethbridge AB T1J 4B1 Canada
5. Department of Agricultural; Food & Nutritional Science; University of Alberta; Edmonton AB T6G 2P5 Canada
6. Ralph E. Martin Department of Chemical Engineering; University of Arkansas; Fayetteville AR 72701 USA
7. Animal Production System group; Wageningen University; PO Box 338 6700AH Wageningen The Netherlands
8. Environment Research Centre; Teagasc; Johnstown Castle Y35 TC97 Wexford Ireland