The document presents case studies of animal production systems research in Africa, Asia and Latin America in order to assess the methodologies followed, the results, the constraints, and also to derive lessons for future activities. It discusses new development concerns and how they can be incorporated in the research agenda. It identifies constraints on animal production systems research and to propose suggestions to overcome them. It promotes the exchange of information across regions, as well as the more efficient use of resources for research, through horizontal collaboration among institutions in developing countries