ABSTRACT The experiment was conducted to evaluate the effect of Tree Lucerne dried leaves and to determine the optimum level of substituting for concentrate mixtures(CM)on feed intake, nutrient digestibility, body weight change, carcass characteristics and economic benefits of using Washera sheep fed on desho grass hay as a basal diet. Twenty-five intact male Washera sheep with an initial body weight of 16±4.01kg (mean±SD) were used for growth and digestibility trial. Sheep were vaccinated against sheep pox, Anthrax, and ovine pasteurellosis and injected with multi-vitamins before the starting of the experiment.The experiment was conducted using a randomized complete block design having five blocks with five treatments.The treatments were included: T1=0% TLDL+100% CM; T2=25% TLDL+75% CM; T3 = 50% TLDL+50% CM; T4=75% TLDL+25% CM; T5=100% TLDL+0% CM. The supplement feed was provided twice a day at 10:00 AM and 2:00 AM after the provision of basal diet.The basal feed was provided ad libitum at 20% refusal rate with freely available clean water in a separate trough throughout the experimental period. Experimental sheep were quarantined for 15 days adaptation with 7 days digestibility and 90 days growth trials followed by evaluation of carcass characteristics at the end of the experiment.The results of the experiment indicated that basal DM, TDM, OM, CP and ME intake were significantly different (P<0.01), but with no significant difference (P > 0.05) observed in fibers intake. The digestibility of DM, OM and CP were significantly reduced (P < 0.001) when increasing the substitution level of TLDL with the non significance difference of NDF and ADF digestibility.Body weight change, average daily gain, and feed conversion efficiency were significant difference (P<0.01) and higher in T1 than other treatments while lower T5 sheep xvii fed solely Tree Lucerne dried leaves. Ribeye area was significantly different (P<0.001)among treatment and non significance in SW, EBW,and HCW respectively. The Economic analysis also showed that supplementation TLDL was economically feasible with the net return of the treatments were 890 (T1), 862.7 (T2) and 853 (T3), 781 (T4) and 740 (T5) ETB. Hence, it was concluded that Tree Lucerne leave fodder could be used as alternative feed sources by replacing concentrate mixture up to 75% (T4) to improve feed intake,digestibility and growth performance of Washera sheep.Therefore it recommended that supplementationTree Lucerne dried leaves at optimum 75% was economically feasible and further investigation should be done by supplanting Tree Lucerne dried leaves for the low nutrient content of the basal diet. Keywords: Body weight gain, Digestibility, Feed Intake, Tree Lucerne leaves, Washera sheep.