Sixteen multiparous lactating buffaloes in 2^nd and 5^th lactating season and weighing 500 to 600 kg were used after 8 weeks of calving in complete switch–back design with four groups. Buffaloes in the first group were fed the control ration (R1) containing  60 % concentrate feed mixture (CFM) + 20 % rice straw (RS) + 20 % berseem hay (BH) on DM basis, while in the other groups buffaloes were fed rations consisted on DM basis of 40 % CFM + 20 % RS + 40 % sugar beet tops silage (SBTS) and corn silage (CS) in different ratios, 2:1 (R2), 1:1 (R3) and 1:2 (R4) on DM basis, respectively. Results showed that the contents of CP and ash increased with increasing the proportion of SBTS, but OM, CF and NFE contents increased with increasing the proportion of  CS in the rations. Digestibility coefficients of DM, OM, CF, EE and NFE, TDN and feed intake as  DM and TDN increased (P<0.05) with increasing CS level, however, CP digestibility, DCP value and CP and DCP intake increased (P<0.05) with increasing SBTS level. The pH value and NH₃-N concentration increased (P<0.05) with increasing SBTS level of, however TVFA's concentration in rumen liquor (RL) increased (P<0.05) with increasing CS level. Buffaloes fed R3 recorded (P<0.05) the highest milk and 7% FCM yield, however, those fed R1 had the lowest yield. The percentages of fat, lactose and total solids (TS) in milk increased (P<0.05) with increasing CS level, however, the percentages of protein, solids not fat (SNF) and ash increased (P<0.05) with increasing SBTS level. Animals fed R3 showed the lowest amounts of DM and TDN  required per kg 7% FCM while R4 showed the lowest amounts of CP and DCP required per kg 7% FCM. however, those fed R1 revealed the highest amounts (P<0.05). Buffaloes fed R3 showed the lowest feed cost/kg 7% FCM and the highest price of 7% FCM and economic efficiency, but those fed R1 had on opposite trend (P<0.05).