Replacement of Noug Seed (Guizotia abissynica) Cake with Different Levels of Cowpea (Vigna unguiculata) Sewinet Variety Hay in the Ration of Growing Gumuz Lambs Fed Natural Pasture Hay as a Basal Diet Esubalew Shitaneh, 1, 2*, Bimrew Asmare2 and Aemiro Kehaliew3 1Ethiopian Institute of Agricultural Research, Pawe Agriculture Research Center P.O. Box 25, Pawe, Ethiopia 2Bahir Dar University, College of Agriculture and Environmental Sciences P.O.Box 5501, Bahir Dar, Ethiopia 3Ethiopian Institute of Agricultural Research, Holeta Agriculture Research Center P.O. Box 31, Holeta, Ethiopia The objective of this experiment was to evaluate the effect of replacement of noug seed (NSC) (Guizotia abissynica) cake with different levels of Sewinet (S) (Vigna unguiculata) hay on feed intake, digestibility, bodyweight change, carcass characteristics and to assess the economic feasibility of feeding regime of Gumuz growing lambs. The study was conducted at Pawe Agricultural Research Center by using 25 yearling intact male Gumuz lambs with an initial body weight of 18.26 ± 0.63 kg (Mean±SD).The lambs were assigned into five blocks based on their initial weight in a randomized complete block design (RCBD) and the feeding trial was conducted for 90 days followed by 7 days of digestibility trial. The treatments were ad libitum feeding of molasses treated natural grass hay supplemented with 272.3g NSC (T1), 200.73g NSC+105.55g SH (T2),134.3g NSC+211.86g SH (T3), 66.31g NSC+313.79gg SH (T4) and 417.98g SH (T5) on DM basis. The supplements were prepared to meet the daily crude protein (CP) and energy requirement of growing local lambs. The CP contents of NPH, SH and NSC were 4.99, 18.31 and 36.5%, respectively. The total DM intakes of lambs were significantly (P<0.05) increased with the level of increasing SH supplementation. On the other hand, the CP intake decreased with increasing levels of SH supplementation. Digestibility of DM, OM, NDF and ADF were improved by a higher level of SH supplementation of lambs but, CP digestibility was not affected by supplementation of SH.