As the problems of impact assessement are rather intractable, a fairly simple dual approach is proposed. First the major components of environmental impact of current agricultural production systems in Africa (i.e. impact of cropping, livestock keeping, fuelwood and timber extraction and burning) are summarised. Second, "danger zones" in which current and future environmental impacts will be most severe and on which ILCA has focused its problem solving-research is identified.

Inadequate feed supplies remain a major constraint to sustainable cattle production in general, and milk production in particular, in smallholder production systems throughout sub-Saharan Africa. In the emerging peri-urban dairy production systems in West and central Africa, for example, poor development of feed resources has invariably resulted in milk production being sustained at comparatively high feed costs, thus reducing the competitiveness of locally produced milk.