1 Center for Development Research (ZEF), University of Bonn, Bonn, Germany.
2 Agricultural Economics and Rural Development, University of Göttingen, Göttingen, Germany.
3 International Livestock Research Institute, Addis Ababa, Ethiopia.
4 The Jeanne Marchig International Centre for Animal Welfare Education, The University of Edinburgh Royal Dick School of Veterinary Studies, Roslin, UK.