Improved Fermentation and Aerobic Stability of Ensiled, High Moisture Corn with the Use of Propionibacterium acidipropionici

Abstract

This study evaluated the effects of a bacterial bio-inoculant that produced propionic acid on fermentation characteristics and aerobic stability of ensiled, high moisture corn. Addition of Propionibacterium acidipropionici DH42 (previously isolated from ensiled, high moisture corn) increased propionic acid content [0.35 vs. 0.03 g/100 g of dry matter (DM)] after ensiling for 42 d. In addition, corn treated with P. acidipropionici DH42 had a greater acetic acid concentration, a lower pH, lower numbers of yeasts and molds, and a higher recovery of DM after ensiling for 42 d. The temperature of control corn increased after 3 d of aerobic exposure, and the temperature of corn treated with P. acidipropionici DH42 remained unchanged from the ambient temperature. After 5 d of aerobic exposure, pH and numbers of yeasts, molds, Acetobacter spp., and total aerobic bacteria increased for the control corn, indicating poorer aerobic stability. Propionic acid concentration was higher (0.61 vs. 0 g/100 g of DM) after 5 d of aerobic exposure in high moisture corn ensiled with P. acidipropionici DH42. In addition, recovery of organic matter from inoculated corn was greater after 5 d of aerobic exposure. Inoculation of high moisture corn with P. acidipropionici DH42 improved fermentation during ensiling and reduced the aerobic instability of ensiled, high moisture corn.