The research aimed at assessing the effects on nutrient digestion and ruminal fermentation by goats of a complete feed block (CFB) that incorporated agro-industrial by-products that were high in fibre and cellulolytic bacteria. Three Kacang goats, a native Indonesian breed, were used in a 3 × 3 Latin square experimental design with i) CFB without microbes (control), ii) CFB containing 1% Pseudomonas aeruginosa and 1% Acinetobacter baumannii, and iii) CFB containing 2% P. aeruginosa and 2% A. baumannii. Microbes in the CFBs consisted of lactic acid bacteria, yeast and cellulolytic bacteria that ranged from 106 to 108 cfu/g. The goats were fed each day at 08h00 and 16h00. The inclusion of P. aeruginosa and A. baumannii at 2% level reduced both neutral detergent fibre (NDF) and acid detergent fibre compared with other treatments. Goats fed on CFB with microbes had higher (P <0.01) digestibility of organic matter (OM) and NDF compared with control. The addition of P. aeruginosa and A. baumannii at 2% level increased (P <0.05) ruminal ammonia nitrogen (N-NH3), acetate, and total VFA. However, goats fed on CFB with microbes had lower (P <0.05) urinary N excretion, which improved (P <0.05) N retention compared with the control. It was concluded that a combination of lactic acid bacteria, yeast and cellulolytic bacteria in the CFB could modify fermentation in the rumen and increase the use of nitrogen in goats.