FORAGE YIELD AND QUALITY PROFILE OF 3 ANNUAL LEGUMES IN THE TROPICAL HIGHLANDS OF ETHIOPIA

Ethiopia has the greatest concentration of Trifolium species in sub-Sa haran Africa. These species have the potential to improve natural or s own pastures in the tropical highlands of Africa. The objective of thi s study was to evaluate the yield and quality of three annual forage l egumes at different growth stages, all grown at an altitude of 2390 m above sea level in the tropics. Two indigenous clovers, quartin clover (Trifolium quartinianum A. Rich.) and rueppell clover (Trifolium ruep pellianum Fres.), and one introduced legume, woolypad vetch (Vicia vil losa subsp. dasycarpa Roth), were sown in a black clay Vertisol for tw o years. Quartin clover and woolypod vetch atained maximum dry matter (DM) yields of 5.53 and 6.37 Mg ha(-1), respectively, at the pod stage , while the maximum for rueppell clover was 4.72 Mg ha(-1) at flowerin g. For all species, maximum accumulation of in vitro digestible DM (IV DDM) correspond with DM accumulation, while maximum accumulation of cr ude protein (CP) occurred at the flowering stage. At most harvest stag es, the clovers had greater IVDDM but less CP concentrations than wool ypod vetch. Woolypod vetch had a greater concentration of acid-deterge nt fibre (ADF) and neutral-detergent fibre (NDF) than the clovers thro ugh flowering. At later stages, however, woolypod vetch had less or th e same fibre content as the clovers. In all species, ADF and NDF incre ased while CP and IVDDM concentrations decreased with maturity in tota l herbage and stem fractions. In leaf fractions these parameters chang ed very little with maturity.