In maize, brown midrib phenotype is associated with 6 loci and bm1 to bm4 are spontaneous mutants, influencing cross-linkages between cell wall and lignin. Although several studies report higher digestibility of bmr mutants, field results often report lower yield and sensitivity to stresses. Few information exists evaluating fermentation and aerobic stability (AS). To test ensiling conditions, we compared bm3 (F2F379 and F2F499), bm1 (PO238XR), and non-BMR hybrids (PO533AM1 and TMF2Q419) grown in a randomized complete block design. Ensiling was performed following inoculation (INO: Lactobacillus buchneri NCIMB 40788 (150000 cfu/g) and Lactobacillus hilgardii CNCM-I-4785 (150000 cfu/g) compared with control (CON). After 60 and 120 d of incubation in mini-silos (5 repetitions; 7 L; 222 kg DM/m³), we measured fermentation parameters, VOC, and aerobic stability (AS). Statistical analysis was performed using a 5 × 2 factorial (hybrids x inoculation). The fermentation profile for INO was typical of heterofermentation, with a pH slightly higher to CON due to transformation of lactate to acetate, and synthesis of 1,2-propanediol. INO improved starch by 2.4% units, ADF (0.59% unit), NDF, and reduces fresh matter losses (fermentation + AS). Difference in AS was important between hybrids in CON were bmr hybrids had high intrinsic AS (over 186h to reach +2°C over ambient) versus non-BMR (lower 90 h). In CON, concentration of 1,2-propanediol was similar among hybrids (1.01 ± 0.25%DM, P = 0.363) and not related to AS. In INO over CON, 1,2-propanediol was increased for all hybrids at 60 and 120 d (P = 0.001 and 0.016). By 120 d, 1,2-propanediol concentration ranged from 0.70 to 2.37%DM and accumulation of propionate was observed in all hybrids. Improvements of AS in BMR hybrids could be linked to higher total VFA and lactate, improved in bm3 over bm1 and non-BMR. Some of the observed differences for lactate, ethanol, propionate, ammonium, and pH would be related to difference in germplast between hybrids, not to the bmr mutation. BMR mutation and inoculation improved ensiling parameters, aerobic stability, and some nutritional parameters.