Providing consistent, high quality forage is a strategic goal on dairy farms. The value of top yields of high quality forage can be lost if storage conditions and feeding management reduce forage quality and quantity. In 2004 an on-farm study was initiated on dairy farms in south-central PA to measure corn silage bunker and pile dry matter (DM) densities. Eighty bunkers and piles were sampled at 12 points using a gas operated drill with a 2 inch corer. This study found average density ranging from 8.3 – 16.8 lb.DM/ft³. Lowest densities, by location, were found on the highest levels and edges of the piles. In 2006 a second study was conducted to examine the effect of time and location on forage quality and aerobic instability during feedout from a 7,000 ton silage pile utilizing a multi-pass feedout system. DM densities, moisture levels, forage analysis, acidity profile, and mold/yeast counts were measured and statistically analyzed from samples collected monthly (March – July), at 4 levels and 3 positions, along the silage feedout edge. Significant variation in density and forage quality was observed during this period and at different levels within the pile. There was significant effect of the interaction between time and position. Distance from the exposed edge of the pile had no consistent negative effect on silage quality. Significant variability existed within the silage pile. Variability was likely due to differences in hybrids, harvest moistures, localized growing conditions, harvesting factors and packing variability. Feed managers need to consider variability within any silage structure, take steps to reduce it and make use of frequent forage analyses. Based on this study, it is possible to utilize a multi-pass feedout program to maintain high levels of forage quality.