Thirty Ossimi growing male lambs (5 months of age) with an average of live body weight (LBW) 20.85 i2.26 kg were divided according to their LBW into two similar groups. Group 1 fed control diet: concentrate feed mixture (CFM) plus bean straw (BS) at 3.0 and 1% of their LBW, respectively. Group 2 fed CFM and whole maize silage at 2 % of their LBW (test group). The digestion coefficients of all nutrients and feeding value of maize silage ration were higher significantly (P<0.01) than those of control ration. Digestibility coefficients of ration containing maize silage were higher significantly (p (0.01) in OM ,OM, CP,CF and NFE than control ration, while the differences in both CP and NFE were not significant between diets. The feeding value (TDN and DCP) of tested ration were higher significantly (W005) and (p < 0.01) than control ration. Daily gain, feed and economical efficiency were higher with maize silage group than control. Dressing percentage, prime cuts, weight constituents of longismus dorsi and chemical composition of slaughtered lambs fed maize silage were better than those fed control ration. It could be concluded that. it can partialy replace maize silage by 33% instead of concentrate feed mixture in growing lamb diets to improve their digestibility coefficients, nutritive value, daily gain, feed and economic efficiency and their carcass characteristic