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Virginia Cooperative Extension - Knowledge for the CommonWealth

Silage Density

Dairy Pipeline: November 2006

Bennet Cassell
Extension Dairy Scientist, Genetics & Management
(540) 231-4762;

Forage quality is one of the most important factors affecting the level of milk production. Some of the factors affecting forage quality, like weather, are outside of our control. Other factors like forage variety, proper planting and harvesting time can be controlled. Silage density through proper silo packing is another of the factors that can be controlled.

After getting a good crop harvested it is extremely important to ensure it is properly stored. Proper packing to ensure good silage density is extremely important. Silage density in a trench or bunker silo is related to many factors. These factors include: forage dry matter, packing time, weight of the tractor, silo filling rate.

Good silage density is important for many reasons. Oxygen is the enemy of good silage fermentation. The more densely packed the silage is the less oxygen that will be present. Dry matter loss greatly increases as silage density goes down (see table 1).

In order to see how good a job Virginia’s farmers are doing packing silos, extension has purchased a special corer. By taking samples from various places in the silo silage density can be calculated. If you are interested in testing the silage density of your silo please contact your local dairy extension specialist to schedule a visit.

Corn Silage dry matter loss in bunker silos
Silage Density lbs DM/ft3
Dry Matter loss at 180 days (%)
Table 1. Ruppel et al 1992 JDS

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