Fifteen growing buffalo calves (3.73 months old and 104 kg body weight) were used to study the effect of adding live dried baker's yeast (Saccharomyces cerevisiae, LDY) and Gustor natures (GN) on their performance. The calves were allocated randomly and equally on the basis of age and weight to one of three treatments. All treated groups were fed according to the allowance recommended by Animal Production Research Institute, Egypt. Treatments consisted of a basal ration without additives (control), control ration plus live dried baker's yeast (LDY) 5g /h /d (R2) or with added Gustor natures (GN) 5g / h / d (R3). Experimental period lasted 5, monthsوthe main results showed that each of DM, OM, CP, CF, NFE, digestibility and feeding values (TDN, DCP) were similar for LDY and GN fed groups being better (P<0.05) relative to the control. While, EE digestibility was not affected by treatments. The DM intake was almost similar due to additives compared to the control . Daily gain and feed conversion (DM,TDN and DCP) were almost similar with the two additives (GN or LDY). However, both two supplemented groups were superior (P< 0.05) relative to the control. While , relative economic efficiency due to LDY or GN inclusion in the ration was 111.15 and 126.98 % , respectively as compared to the control. The pH values of rumen liquor was not affected by treatment. While, VFA and NH3-N were improved (P<0.05) due to the addition of the two additive (GN or LDY) compared with the control. Inclusion of GN in the ration increased plasma total protein (p < 0.05) relative to the other groups. Plasma globulin of the two additive groups was similar and was higher (P<0.01) relative to the control. The, A/G ratio and GPT activity were also similar for the two additive groups which were lower (P<0.01) relative to the control . Plasma albumin, GOT activity and urea concentration were not affected by treatments. From this study, it could be recommended to supplement 5g / h / d from live dried baker's yeast LDY or 5 g / h /d from gustor nature GN to the daily rations of growing buffalo calves to improve final body weight, total gain, daily gain. Also, they improve feed conversion and economic efficiency.