Twelve 7 month old male Friesian calves with an average body weight of 111+ 8.4 kg were used is this study. Calves were distributed into three groups similar in number. The experimental rations were formulated as follows : ration 1 (R1) 64% concentrate feed mixture (CFM) + 36% clover hay (CH) (control), ration 2 (R2) : 64.12% CFM + 34.36% CH + 1.52% sodium bicarbonate (SB) and ration 3 (R3) : 60.61% CFM + 36.19% CH + 3.2% SB. The digestibility coefficients of DM, OM, CP, NFE, NDF and ADF and the value of TDN, ME, (Mj / kg), NE (Mcal / kg), DDM% and RFV were higher (p<0.05) for R2 than R1 and R3, while there was no significant difference between R1 and R3. The CF and NFC digestibility coefficients were increased (p<0.05)  when feeding on R2 compared with R1, while there was no significant difference between R1 and R3 or between R2 and R3. The predicted values for starch and sugar fermentations using CNCPS were (640 and 274 g/d, respectively) with feeding R1,(475.8 and 276.8 g/d, respectively) for R2 and ( 431.7 and 267 g/d, respectively) for R3 , and the total microbial protein was 815 , 825 and 775 g/d when feeding on R1 , R2 and R3 , respectively. The DM intake was increased when feeding on R2 than R1 or R3 because the passage rate was higher when feeding on R2 (8.5 %/h) than feeding on R1 (7.6 %/h) or R3 (7.8 % g/h).    The mean values for total  VFA were higher (p<0.05) with feeding R1 or R2 than R3. The mean values were 9.67, 9.88 and 8.05 ml eq / 100 ml RL for R1, R2 and R3, respectively. The mean values for NH₃-N concentration decreased (p<0.05) when feeding R2 than R3, but without significant effect with feeding R1. the mean values were 10.96, 9.36 and 13.5 mg/100ml RL when feeding on R1, R2 and R3, respectively. The mean values of blood parameters were not significantly affected by feeding R1 or R2 or R3. The mean values of ADG were 0.62, 0.69 and 0.66 kg for steers fed on R1, R2 and R3, respectively. Concerning to the amino acids composition of the tested rations, the AAs composition were less than the requirements except for tryptophan. The mean balance AA values (% of requirement) were 70.45 , 68.14 and 71.73 with feeding on R1, R2 , R3 , respectively. The production efficiency was lower when feeding on R2 than feeding on R1 or R3 (16.77, 18.74 and 18.85% respectively), and the economic efficiency, was also lower when feeding on R2 than feeding on R1 or R3. In general, the data indicated that feeding ration at a level 64.12% CFM + 34.36% CH + 1.52% sodium bicarbonate  for growing Friesian calves increased the nutritive values of the ration than using 3.0% sodium bicarbonate.