Density and Losses in Pressed Bag Silos

The objective of the study was to monitor the filling and emptying of bag silos at three research farms to determine the variation in density and losses in pressed bag silos. Twenty five bags were filled over the 2000 harvest season, and 15 of those bags have been completely emptied. Dry matter (DM) densities in alfalfa silages were approximately 200 kg/m when the crop was at 40% DM, and densities declined approx. 3 kg/m-% DM in wetter crops. With one bagger, densities were 3 to 8% lower in corn silage whereas densities were 16 to 35% higher in another bagger. Densities declined 5 kg/m-% DM in wetter corn silages. Average DM losses were 8.4% gaseous/seepage loss and 5.8% spoilage loss for a total of 14.2% loss. The average spoilage and total losses were inflated by three bags with substantial spoilage (26 to 38% total loss). Removing those from the average reduced average total losses to 9.7%. Total losses increased with low feed out rates and with drier, more porous silages.