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Effects of co-ensiling high moisture corn stover with co-products on spoilage, aerobic stability, nutrient composition, and in situ digestibility
Objectives of this study were to determine the effects of co-ensiling high moisture corn stover (HMCS) with co-products on pack density, spoilage, aerobic stability, nutrient composition, and in situ digestibility. Plastic barrels (n = 4) were used to ensile 5 combinations: 1) CON; HMCS only, 2) CCDS; HMCS and corn condensed distillers solubles, 3) MIX30; HMCS and Mix30 liquid supplement (Agridyne, LLC, Springfield, IL), 4) MWDGS; HMCS and modified wet distillers grains and solubles, 5) STEEP; HMCS and corn steep water. Each combination was individually mixed in a feed truck and then manually packed into barrels. Barrels were packed to the same height then covered with plastic. Barrels were stored in an open-sided building for 183 d. After storage, the spoilage depth was measured and weighed. Pack density was calculated for each barrel. A subsample from each barrel was placed in an open bucket at room temperature. Subsample temperatures were assessed every 12 h for 4 d to determine aerobic stability. Additional subsamples were dried at 55C, ground through a 4 mm screen, and incubated in 2 ruminally fistulated steers for 12, 24, and 48 h to determine in situ DM disappearance (DMD) and NDF disappearance (NDFD). Pack density, spoilage, aerobic stability, nutrient composition, DMD, and NDFD were analyzed using the MIXED procedure in SAS (SAS Inst. Inc., Cary, NC), with repeated measures for aerobic stability, DMD, and NDFD. There were no differences (P≥0.21) in spoilage. Pack density was greater (P<0.01) for all co-ensiled combinations compared to CON. There was a combination by time interaction (P<0.01) for aerobic stability. At 96 h, STEEP had the greatest (P<0.01) temperature, CCDS and CON were intermediate, and MIX30 and MWDGS had the lowest temperature. Samples of CON had greatest (P<0.01) NDF and ADF concentrations whereas CCDS, MIX30, and STEEP had least; MWDGS was intermediate and different from CON. The CP concentration differed (P<0.01) among treatments (6.4, 11.7, 12.7, 14.1, and 14.8% for CON, CCDS, MWDGS, STEEP, and MIX30, respectively). The MWDGS DMD was greater (P=0.01) than STEEP, CCDS, and MIX30, with CON being intermediate and not different. However, CON and MWDGS had greater (P=0.03) NDFD than MIX30, with STEEP and CCDS intermediate and not different. Co-ensiling high moisture corn stover with co-products reduced fiber concentration, increased protein concentration, and increased pack density of the mix. Co-ensiling with Mix30 liquid supplement and MWDGS improved aerobic stability.
Keywords: co-ensiling, co-products, high moisture corn stover