| This study aimed to evaluate the effects of the heterofermentative Lactobacillus brevis (MF098783) strain on the fermentation characteristics, aerobic stability, chemical and microbiological composition, and in vitro digestibility of wheat straw silage. Wheat straw was ensiled with three different concentrations of L. brevis (10⁶, 10⁸, and 10⁹ cfu/g), forming the treatment groups (WSLB6, WSLB8, WSLB9), and these were compared with a control group (WS). A total of 64 silage samples were fermented under anaerobic conditions for 90 days. After fermentation, physical (pH, temperature, color), chemical (DM, CP, EE, CF, ADF, NDF, etc.), microbiological (LAB, yeast, mold), energy, and in vitro digestibility parameters (IVOMD, GP, ME, NEL) were analyzed. Statistical analyses were performed using ANOVA and Duncan’s multiple range test with SAS software. The L. brevis inoculation significantly reduced the pH values of the silages (P< 0.001), indicating improved fermentation quality. The WSLB6 and WSLB8 groups showed increased crude protein and ether extract contents, and significantly lower ADF, ADFom, and crude fiber values (P< 0.05–0.001) compared to the control. These groups also demonstrated higher metabolizable energy (ME), net energy (NEL, NEM), and in vitro digestibility. Microbiological analyses revealed reduced yeast counts and no mold growth in the inoculated groups, whereas the control had higher yeast levels. Post-aerobic stability assessments confirmed better preservation and microbial control in WSLB6 and WSLB8, reflected by lower pH and yeast counts. In conclusion, Lactobacillus brevis inoculation, particularly at 10⁶ … |