Probiotics are live microbial feed supplements, providing beneficial effects on the host animal by improving balance of microorganisms in digestive tract. This study aims to examine the benefits of liquid multi-microbe probiotic supplementation on nutrient digestibility and economical production of beef cattle. The treatments were including ration control using fresh forage of King grass (Pennisetum purpureum) + 350 g of URPS-Block without liquid probiotic supplement (T0), fresh forage of King grass (Pennisetum purpureum) + 350 g of URPS-Block + liquid probiotic supplement of 2.0 cc/liter fresh water (T1), fresh forage of King grass (Pennisetum purpureum) + 350 g of URPS-Block + liquid probiotic supplement of 4.0 cc/liter fresh water (T2) and fresh forage of King grass (Pennisetum purpureum) + 350 g of URPS-Block + liquid probiotic supplement of 6.0 cc/liter fresh water (T3). Experimental design applied the Randomized Block Design involving 24 male cattle, divided into six groups of animal ages and four liquid multi-microbe probiotic doses. Parameters were feed dried matter consumption (DMC), average daily gain (ADG), feed conversion and income over feed costs (IOFC). The data were analyzed by variance analysis continued by Duncan test. Results showed that liquid multi-microbe probiotics supplementation of 2.0 to 6.0 cc/liter fresh water and URPS-Block of 350 g/day added into forages increased significantly (P<0.05) production of cattle indicated by significant higher ADG of 510 to 570 g (P<0.05) compared with those of control ration producing ADG of 380 g. The increase of animal production was supported linearly by the increasing drinking water consumption supplemented with liquid probiotic levels of 2.0 to 6.0 cc/liter fresh water of animals. Cattle supplemented with liquid probiotic of 2.0 to 6.0 cc/liter fresh water/animal/day also produced higher IOFC, equivalent with increases of 55.67 to 80.87 percents IOFC compared with the animals fed the control ration without liquid probiotics.