Addition of a Silage Preservative Reduces Spoilage in Wet Brewers Grain1

Two experiments were conducted to compare the deterioration of wet brewers grains (WBG) treated with a commercial preservative (Silo-King GPX, Agri-King Inc., Fulton, IL). Wet brewers grains were divided into 3 piles for Exp. 1 and 6 piles for Exp. 2, weighing an average of 975 and 988 kg, respectively. The preservative was added to WBG at 0 (control), 0.45, and 0.9 kg/900 kg. The WBG were stored in wooden bins for 28 d (all piles uncovered for Exp. 1; 1 pile/treatment covered for Exp. 2). Samples were taken every 2 d for wet chemistry analysis. In Exp. 1, the preservative-treated piles had numerical increases in acetic acid and fat concentrations and decreases in starch and mineral concentrations. Treated piles had numerical decreases in pH and logarithmic colony-forming units of yeasts, molds, and clostridia. In Exp. 2, preservative addition resulted in numerical increases among treatments for DM and lactic acid, whereas the logarithmic colony-forming unit counts for yeasts and molds decreased numerically with treatment. Untreated piles had numerically decreased starch concentrations. This study indicates that using a commercial preservative may reduce spoilage of WBG.