Crop-livestock systems are of vital importance to the livelihoods and food security of smallholder farmers throughout the developing countries of the world. Projected consumption trends indicate that demand for meat and milk will more than double in the developing countries over the next 20 years. These trends present a demand-led opportunity for very large number of smallholders to improve their livelihoods through market-oriented production based on judicious management of natural resources. If these market-driven opportunities are to be fully exploited by smallholder crop-livestock farmers, publicly funded research and development institutions need to come up with new ideas and partnership arrangements that will enable them to become more effective and better positioned to serve the interests of poor farmers.

In West Africa, crop-livestock systems have evolved along different pathways due to differential impacts of demographic and climatic changes, animal disease incidence, economic opportunities, policies and technologies. As the systems evolve, new opportunities and problems emerge. In the semi-arid zone, mounting population pressure and periodic droughts have led to an increasing competition for natural resources which threatens the mutually beneficial linkages between crop and livestock systems. In the sub-humid and humid zones, rapid urbanisation has increased the demand for food of animal origin with a concomitant need for research-based solutions to increase productivity while preventing natural resource degradation. All over the region, inappropriate policies have constrained farmers' access to input and output markets. Poor access to markets and inefficient marketing institutions prevent farmers from taking advantage of new economic opportunities, inhibit uptake of improved technologies and serve to lock farmers into a semi-subsistence mode of production and existence.

There is thus a need to take stock of lessons learned from past research and development activities aimed at promoting crop-livestock systems, to consider issues most likely to affect future intensification of crop-livestock systems, and to identify and develop strategies for future research and development activities on sustainable crop-livestock farming systems in West Africa.