The aerobic stability of the diet can affect feeding management and DMI of cattle. We evaluated the effect of 2 commercial products (Kemin, Brazil) at 3 dosages on the aerobic stability of a corn silage based TMR (50.5% MS, pH 5.52). Treatments were: Control (CTL), calcium propionate (CP. Shield Base Feedgrade Dry, 100% calcium propionate) at 1 (CP1), 1.5 (CP1.5), or 2 (CP2) kg/ton, or a liquid blend of microbial growth inhibitors (FC. Fresh Cut Plus Líquido. Acids acetic, benzoic, and propionic, ammonium hydroxide, polysorbate) at 1 (FC1), 1.5 (FC1.5), or 2 (FC2) L/ton. Water (CTL) or products diluted in water (30 mL) were mixed to 5 kg of TMR and placed into 6 buckets/treatment. A bucket with each treatment was placed on one of 6 shelves in a controlled environment room (29.1 ± 1.7°C) for 48 h. The temperatures of the TMR on each bucket and of the environment on each shelf were measured at 30-min intervals. Microbial counts (log cfu/g) were performed at 24 h. The statistical model contained the effects of shelf and treatment. Data obtained over time was analyzed as repeated measures. Contrasts compared CTL with other treatments. Treatments FC1.5 (1820 min) and FC2 (1825 min) delayed (P ≤ 0.05) the moment of maximum TMR temperature relative to CTL (1745 min). Maximum temperature (46.7°C) and aerobic stability (723 min for temperature of TMR + 2°C than environment) did not differ (P ≥ 0.28). Treatments FC1.5 (32.4°C) and FC2 (32.2°C) reduced the 0–24 h mean TMR temperature relative to CTL (34.8°C). Additives did not affect (P ≥ 0.63) the 24–48 h mean temperature (44.4°C). Counts of aerobic bacteria and spore forming bacteria were reduced (P ≤ 0.05) by CP2 (4.77 and 4.11) and FC1.5 (3.86 and 3.27) and tended (P ≤ 0.07) to be reduced by FC1 (4.98 and 4.24) relative to CTL (6.85 and 5.74). Yeast count tended (P = 0.09) to be reduced by FC1 (0.98 vs 2.71). Filamentous fungi count was 3.35 for CTL and was reduced (P ≤ 0.05) by CP2 (1.59), FC1 (1.37), FC1.5 (1.07), and FC2 (1.73) and tended (P = 0.06) to be reduced by CP1.5 (1.85). Product FC at the highest dosages reduced the 0–24 h TMR temperature and was more inhibitory of microbial growth than product CP.