1. School of Higher Education in Agriculture of Mateur, University of Carthage, Tunisia
2. International Center for Agricultural Research in the Dry Areas, Tunis, Tunisia
3. Department of Animal and Rangeland Sciences, Oregon State University, Corvallis, Oregon, United States
4. International Center for Agricultural Research in the Dry Areas, Amman, Jordan
5. International Center for Agricultural Research in the Dry Areas, Dubai, United Arab Emirates