In a trial lasted for 90 days to assess the impacts of a saponin plus glyco components (defaunator and ammonia binder) containing plant extract SCPE without or with fresh compressed (Baker's) saccharomyces cerevicia yeast culture (FSCYC) ( a probiotic) were used as feed additives to enhance rumen fermentation in buffalo heifer rations. Twenty  buffalo heifers of an average weight of  (248 ) Kg were allotted to four  groups of five animals in each according to age and assigned at random to receive one of four dietary treatments. The treatments were: T1, received the basal ration BR (Control ) that consisted of concentrate feed mixture:  Egyptian berseem : rice straw (50:25:25 on dry matter basis), T2, received the BR plus 800 mg of saponin containing extract, T3, received the BR plus 800 mg saponin plus 10 g (FSCYC), and T4 received the BR plus 800 mg saponin plus20 g FSCYC.                 Results of the supplementation with saponin only (T2) improved (P<0.05) digestibility of organic matter (OM) , ether extract (EE) and nitrogen free extract  (NFE), while  the introduction of  FSCYC at10 or 20 g rates improved (P<0.05) nutrients digestibility for all nutrients in T4, and T3 as compared to T2 and the control. The T4 group maintained its superiority (P<0.05) above all groups for all nutrients except for DM digestion. Ruminal fluid pH tended to decrease with the introduction of additives in heifers rations where T4 was the lowest (P<0.05).    Ruminal ammonia-N concentration for the saponin only, T2 group, exhibited the  lowest (P<0.05) ruminal pH, while the control group was the highest.  Total volatile fatty acids (TVFA's) highest concentration was recorded for T4 while the control group was the lowest (P<0.05). Heifers rations enrichment with SCPE and the FSCYC increased (P<0.05) blood serum total proteins, albumin (A) and globulin (G) and A/G ratio, where T4 was the highest and the control was the lowest. However additives introduction in the rations decreased (P<0.05) serum urea, creatinine, cholesterol,  GOT and GPT, where T4 was the lowest (P<0.05) and the control was the highest (P<0.05).                  It could be concluded that ration supplementation with saponin containing natural plant extracts plus 10 or 20 g's of FSCYC for buffalo heifers positively increased nutrient digestibility, with ruminal and blood serum indicator parameters were within the normal  ranges for these biologics in buffaloes.