In Burundi, the traditional grazing lands are rapidly declining as a result of accelerated reforestation programmes aimed at erosion control. However, these reforestation projects, if properly managed, could represent valuable feed resources for sheep production. This article describes results obtained in field trials combining sheep production and reforestation projects with trees of various ages and species, carried out from 1981 to 1990 in three different geographical areas. It proposes a sustainable policy for the best use of the different forest resources: trees, understorey vegetation and animals.