EFFECT OF MICROBIAL INOCULATION OF HIGH-MOISTURE CORN ON FERMENTATION CHARACTERISTICS, AEROBIC STABILITY, AND CATTLE PERFORMANCE

Two trials were conducted to evaluate the effects of microbial inoculation for preservation of high-moisture corn (HMC). In Trial 1, three concrete, upright silos were filled with 83 t of HMC that was treated with either a dry microbial inoculant (DI), reconstituted liquid microbial inoculant (RLI), or an untreated control (CON). The CON or RLI-treated HMC were placed in two silos in Trial 2. Both inoculants were applied to supply 2 x 10(6) colony-forming units (cfu)/g of wet corn. Samples were collected from the bottom two doors of each silo for 21 d (Trial 1) or 40 d (Trial 2) postensiling and during feedout to evaluate fermentation changes over time. Dacron bags buried at four elevations within each silo were recovered during feedout to determine DM losses and chemical composition changes during the fermentation period. In both trials, concentrations of soluble N (SN) increased over time. Acetate content was higher in DI than in CON in Trial 1 and ethanol was greater (P < .05) for RLI than for CON in Trial 2. Acidity declined faster (P < .05) and soluble carbohydrate was reduced for RLI during the feedout phase in Trial 2. Dry matter recovery tended to be greater with CON (P < .10) than with RLI-treated HMC in Trial 2. Aerobic stability was evaluated on corn from silos in Trial 2 by placement in styrofoam containers. Temperature and microbial numbers increased (P < .05) during the 5-d aerobic incubation period for both HMC treatments. The population of microorganisms was greater for RLI on d 3 than for CON. In feeding studies, ADG were similar for all treatments in both trials; however the CON and DI-treated HMC were consumed to a greater extent (P < .05) than RLI-treated HMC in Trial 1. Inoculation of HMC with lactic-acid-producing bacteria before ensilement did not show an increase in lactic-acid-producing bacteria or a lower pH. Weight gains and feed conversion efficiencies were similar.