Dry matter loss, fermentation profile, and aerobic stability of wet brewers grains ensiled with various amounts of dry ground corn

Abstract

ABSTRACT Storage of wet brewers grain (WBG) for longer periods is challenging, and alternative techniques are required. The objective of this experiment was to evaluate the fermentation profile, dry matter loss, and aerobic stability of WBG ensiled alone or with various concentrations of dry ground corn (DGC). Samples of DGC and WBG were weighed separately and mixed forming 3 treatments: WBG alone (23% DM), a mixture of 25% DGC and 75% WBG (as-fed basis) to achieve a DM concentration of 35%, and a mixture of 46% DGC and 54% WBG (as-fed basis) to achieve 50% of DM. Samples were allowed to ferment for 0, 14, or 28 d in triplicate laboratory silos (3.78 L per bucket). Concentration (DM basis) of CP decreased (P = 0.001) with both the inclusion and the level of inclusion of DGC in the mixture. Concentration (DM basis) of water-soluble carbohydrates decreased (P = 0.001) with the inclusion of DGC in the mixture. A treatment × storage length interaction was observed (P = 0.001) for pH, but the change in patterns differed among treatments. Both, the inclusion (P = 0.01) and greater amounts of inclusion of DGC to the mixture (P = 0.001) decreased lactic acid concentration. Mixing WBG with DGC increased (P = 0.02) acetic acid concentration. Aerobic stability tended (P = 0.08) to be 12 h longer for both mixtures of WBG and DGC. Under the conditions of the present study, averaged across storage lengths, mixing WBG with DGC did not significantly speed acidification, decrease the final pH, or prolong aerobic stability of WBG.