Multipurpose fodder trees in Ethiopia : farmers'perception, constraints to adoption and effect of long-term supplementation on sheep performance

Many organizations in Ethiopia have promoted exotic multipurpose fodder tree species particularly Sesbania sesban for livestock feed and soil improvement. Despite the apparent benefits, the number of farmers planting these trees was low. Moreover, some farmers feeding Sesbania sesban reported reproduction problems in sheep. The latter was supported by a few short term reproduction studies conducted in Ethiopia. The present thesis was conducted to assess farmers’ perceptions about multipurpose fodder trees and about constraints to adoption, and to study effects of long-term feeding of Sesbania sesban on sheep performance. The farmers’ perception was studied by a field survey among 235 farm households from three district with different dominant farming systems (wheat, teff or coffee as the major crop) and the sheep performance studies were a series of experiments at the International Livestock Research Centre in Debre Zeit, Ethiopia. Farmers planted exotic multipurpose fodder trees for their feed value. The valuation for other purposes (soil and water conservation, use as fuel wood) depended on cropping system, vegetation cover and availability of alternative local fodder trees. Major constraints to adoption were agronomic problems, low multipurpose value, and land shortage. Farmers’ decision making criteria to adopt multipurpose fodder trees encompassed multiple objectives: farmers preferred local fodder trees to exotics for biomass production, multi-functionality, life span, and compatibility to the cropping system. In terms of feed value, ease of propagation, and growth potential local fodder trees were ranked lower than or comparable to exotics. A significant correlation was observed between farmers’ feed value score of a fodder tree species and the crude protein content assessed in the laboratory. The number of Sesbania sesban trees currently planted on-farm was about 30% of the recommended number for meat or milk production. Despite some farmers (11.8% of users) reported reproduction problems in sheep, the feed value of Sesbania sesban was appreciated across farming systems. However, the feed value was appreciated more in the wheat- and the teff-based farming systems than in the coffee-based farming system. From the results of the series of on-station experiments conducted for one whole reproductive cycle from post-weaning up to first lactation it was observed that supplementation of Sesbania sesban at 30% of the ration (0.98% of body weight) improved basal and total feed intake and digestibility, growth rate and the overall reproductive performance of sheep. No observable adverse effects of possible anti-nutritional factors in Sesbania sesban were found in this long term study. We conclude that the introduction of exotic multipurpose fodder trees need consideration of farmers multiple criteria, of local resources and knowledge and of the diversity of the farming systems. Introduction should be accompanied by practical training of farmers and of extension agents. The studies show that Sesbania sesban is a potential protein supplement that can be used to substitute commercial concentrates for smallholder farmers in the Ethiopian highlands.