The current experiment was performed using twenty (20) Borana bucks with 17.12 kg initial live body weight at on-station of Yabello Research Center. The aim of this experiment was to conduct the live weight change, nutrient and dry matter intake within economic viability of Borana bucks feed Lablab purpureus, Cowpea (Vigna unguiculata) and their mixture fed a basal diet of natural grass hay. Experiment consist seventeen (70) days feeding trial excluding two weeks of adaptation period to treatment diet. Experimental animals grouped into four blocks of five animals in each block to their respective treatment diet according to their body weight. Treatments diet arranged as T1 (400gm Cowpea+ ad-lib Natural grass hay), T2 (300gm Lablab + ad-lib Natural grass hay), T3 (267gm Cow pea+100gm lablab + ad-lib Natural grass hay) and T4 (100gm Cow pea+225gm lablab + ad-lib Natural grass hay). All Experimental bucks had free access to hay. Daily feed intake was measured and live body weight changes of experimental bucks were taken ten by ten days interval. The basal diet intakes of experimental bucks were higher in T2, T4 T3 and T1 accordingly. Experimental bucks had significantly affected by treatments and nutrient composition. Therefore, experimental bucks under T2 had higher (69.6g/d) than T4 (64g/d), T3 (53.22g/day) and T1 (51.79 g/day) respectively. Besides to this T1 (0.09) and T3 (0.08) shows lowest feed conversion efficiency and highest feed conversion ratio as compared to the other treatments. Treatment T2 (0.09) and T4 (0.08) shows highest feed conversion efficiency and lowest feed conversion ratio as compared to the other treatments According to the current finding total dry matter intake based up on percent body weight (%BW) and dry matter intake based on metabolic body weight (g/kgW 0.75 ) indicate significance difference in the treatments groups.. T1 has highest total variable cost in the current study followed by experimental animals in T4, T2 and T3 respectively. Bucks under T2 with T4 had indicates more profitable marginal rate of return more than T1 and T3. So, providing additional feed through preserving/growing forage during rainy season especially at lowland area is crucial. Therefore, the current study indicate that supplementation of forage legumes during dry season is biologically acceptable and economically tangible especially an area where feed shortage is critically scarce.