The objective of this experiment was to investigate the influence of addition active dry yeast, bentonite or their mixture to lactating buffalos' rations on digestibility, milk yield, milk constituents, some blood metabolites, feed efficiency and economic efficiency. Eight lactating buffalos were used in double 4×4 Latin square design where their live body weight was (612.5±41.19 kg on average) and previous milk yield recorded (8.92±0.47 kg/day on average). Animals were fed individually according to Kearl requirements (1982) requirements, as follows: 40% of their energy requirement as total digestible nutrients (TDN) was covered from concentrate feed mixture (CFM), while the other 60% of energy requirement was covered from Egyptian berseem (Br), with an extra amount of rice straw (RS) was offered at 0.5% of animal's body weight T1 (control ration), while the tested rations were included the control ration plus 10 g/h/d yeast (T2) or 20g bentonite /kg DM intake (T3) or the combination of the two additives (T4). Results showed that positive significant effects respecting most nutrient digestibilities for all supplemented rations based on those control ration, being the better values were mostly occurred with T4. The feeding values as TDN was significantly (p<0.05) increased with supplemented rations compared with that of control one. Similar trend between experimental rations regarding DCP values were observed with the best value was also associated with (T4). The average daily actual milk yield (AMY) was significantly higher (p<0.05) when animals fed the supplemented rations (T2, T3 and T4) in comparison with those fed the free from additives ration (T1). The fat corrected milk (7% - FCM) was behaved the same trend of (AMY), but there were no significant differences among the experimental rations. There were no significant differences between the experimental diets regarding milk composition. The total dry matter intake and TDN intake showed no significant differences among the experimental rations, while, the values of DCP intake was significantly (P< 0.05) better when animals fed T4 ration than those fed the control one. There were no significant differences among experimental rations regarding the measured blood metabolites. The best economic efficiency was occurred with T3 and T4 rations. Generally, from the obtained results, it could be concluded that supplementation of dry yeast or bentonite or both of them to rations of lactating buffaloes had, favorability significant effects on digestibility, feeding value, milk production and composition and economic efficiency.