[Desertification and animal health in the Sahel].

This article reviews the causes of desertification proposed by various authors. For a long time, overgrazing of pastures in the Sahel was considered responsible for rapid degradation of the soil. Consequently, the owners of livestock have been accused of enlarging their flocks, and animal husbandry services of involuntary complicity, since their action has reduced the occurrence of epizootics which used to decimate the flocks. The underlying causes of overstocking of pastures and of desertification are in fact multiple and intertwined: population pressure, drought, changes in land ownership systems, social changes. For this reason, the problems of animal production cannot be treated in isolation, and strategies devised by numerous organisations for combating desertification are taking into account the different causes of a situation which can be described, without exaggeration, as a catastrophe. So far there has been no consensus on a given strategy, and results seem to be disappointing, perhaps because the resources have been inadequate, and the schemes have not been supported by the populations involved. Moreover, projects conceived on a global and theoretical basis may not cater for the diversity of actual situations. In contrast, animal health actions, by their concrete nature, directly involve nomadic and sedentary owners of animals and motivate the populations. They remain an indispensable factor in the development of livestock husbandry and its necessary integration with agriculture where both activities can coexist. They are also a preliminary step to intensification in pastoral zones, which makes better management of forage resources possible.