Effectiveness of Ensiling Wet Brewer's Grains

The objective of this study was to evaluate the effectiveness of ensiling Wet Brewer’s Grain (WBG) sourced from a craft brewery with or without a low quality roughage and a corn silage inoculant (11C33; Dupont Pioneer^®, Johnston, IA, USA). Treatments consisted of WBG (W), WBG + inoculant (WI), WBG + ground corn stalks (WS), and WBG + ground corn-stalks + inoculant (WSI). Corn stalk bales were ground through a vertical tub grinder to an average particle length of 15cm or less, and mixed in a reel-type mixer with WBG on a 50% dry matter basis to achieve a calculated mixture dry matter of approximately 34%. Treatments were stored in ~208.3L cylindrical drums, lined with plastic liners (to achieve a 6ml thickness), filled to approximately 72L, and ensiled for 30d. Twenty-four (n=24) observations were utilized in four treatments with six replications per treatment. Samples from each treatment, approximately 0.45kg, were collected before and after ensiling and analyzed for physical composition, nutrient profile, and fermentation quality measures. Crude protein (CP) content was not altered during ensiling, regardless of treatment (P = 0.3375). Significant differences were observed in crude fat % (CF) (P = 0.0037) following ensiling. Declines in dry matter % and moisture were less in W and WI than WS and WSI treatments (P = 0.0037). Inoculant use increased extent of pH decline in W treatments, but did not increase extent of decline in WS groups. No significant differences were observed in lactic acid, 1,2-propanediol, lactic acid (% of total acids) and lactic:acetic acid (P > 0.05) regardless of treatment. Acetic acid content increased less in W than in WI and WSI (P = 0.01). Ammonia (%CP) and ammonia (as CP) were significantly greater in WS and WSI following ensiling (P < .0001). Ethanol content significantly differed between treatments (P = 0.0308). WI exhibited greater loss of propionic acid than WS (P = 0.0361). WSI displayed greater increases in total acid than W (P = 0.0232). 1-propanol, 2-butanol, butyric acid, iso-butryric acid, and methanol were not detected after analyses. Data from this pilot study indicates that WBG may be successfully ensiled similar to conventional feeds. However, further research on the effectiveness of ensiling WBG sourced from craft brewing in a production scale ensiling system is needed to determine feasibility and cost-effectiveness.