Spoiled silages can harbor pathogenic and antimicrobial-resistant microbes. The potential of some antimicrobial additives to inhibit certain pathogenic and antimicrobial-resistant bacteria in air-exposed silage was measured using pure and mixed bacterial cultures. With pure cultures, laurate and monolaurin (5 mg·mL⁻¹) caused decreases (P < 0.05) of 4 to >7 log₁₀ colony-forming units (CFU)·mL⁻¹ in Listeria monocytogenes and Enterococcus faecalis compared to controls. Ten-fold higher amounts of these inhibitors were needed to equivalently decrease staphylococci. 2-Nitropropanol (1 mg·mL⁻¹) decreased (P < 0.05) E. faecalis and L. monocytogenes 2.9–3.8 and 2.4–7.2 log₁₀ CFU·mL⁻¹ after 6 and 24 h incubations, respectively. In air-exposed whole-plant corn silage the inhibitors caused decreases, although not necessarily significant, of 0.7–2.2 log₁₀ CFU·mL⁻¹ in L. monocytogenes, staphylococci and culturable aerobes after 24 h incubation, with modest yet significant (P < 0.05) inhibition (<0.1–0.3 log₁₀ CFU·mL⁻¹) of yeasts and molds. Tests for carry-over effects against ruminal microbes revealed laurate, monolaurin, and 2-nitropropanol inhibited methanogenesis by >50% (P < 0.05) after 24 h incubation and inhibited L. monocytogenes and enterococci. The antimicrobial activities exhibited by these compounds may yield opportunities to optimize their use to rescue spoiled silages.