The effect of three microbial inoculants (Lactobacillus plantarum CCM 4000, L. fermentum LF2, and Enterococcus faecium CCM 4231) on the fermentation and nutritive value of orchard grass (Dactylis glomerata) silage was studied under laboratory conditions.Overall, microbial inoculants generally had a positive effect on orchard grass silage characteristics in terms of lower pH and higher lactic acid concentration. The inoculants significantly increased the lactic to acetic acid ratio in inoculated silages. The total concentration of acids (acetic, propionic, n-butyric, lactic acid) was 2-3 times higher in inoculated silages compared to control silage. The percentage proportion of fatty acids (saturated, unsaturated, short-chain and medium-chain) was similar in all grass silages. Only the proportions of long-chain fatty acids – alpha-linolenic acid were significantly lower while those of oleic acid and linoleic acid were significantly higher in inoculated silages in comparison with contro.