Forty-five male Friesian calves averaging 309.86 kg live body weight
(L.B.W.), were divided into three similar groups (15 in each) and used in feeding trial which lasted 172 days. Animals were assigned to receive 2% of L.B.W. concentrate feed mixture which containing dried distiller grains with solubles (DDGS) at the rate of 0%, 10% and 20% in rations A, B and C, respectively. All animals offered rice straw at the rate of 1.0% of L.B.W., plus 2 kg berseem hay/day. In addition, three digestibility trials (3 calves in each) were conducted to determine the digestibility coefficients of all nutrients and feeding values of experimental rations. The results obtained showed significantly (P<0.05) higher digestibility coefficients  and nutritive value of ration C (containing 20% DDGS) than the control ration (ration A). Average daily gains were 0.898, 0.955 and 1.110 kg for animals fed rations A, B and C, respectively. Animals given ration C grew significantly(p<0.05) higher than those given ration A or B. Significant (P<0.05) improvements were recorded for animals fed ration C with respect to feed conversion efficiency expressed as kg, DM, TDN, SE or DCP/kg gain. Results of ruminal measurements of animals fed rations B and C containing 10% and 20% DDGS showed high pH, NH₃-N and VFA's concentrations. At the same time, serum blood parameters (Total protein, albumin and globulin) showed similar trend. Moreover, animals fed rations containing both 10% and 20% DDGS grew faster and had lower cost of feeding with better economical efficiencies, than the control group.