Much has been written this past year about increased efficiency and minimizing waste. However, not all waste is easy to see or measure.
With the corn silage harvest just around the corner, dairy producers need to pay special attention to the packing of their corn silage in a bunker silo. Getting adequate density on the silage will prevent air infiltration and reduce dry-matter (DM) losses.
For optimum storage and minimum dry-matter loss, the standard producers should aim for is a silage density of 15 pounds of DM per cubic foot.
A general guideline for the amount of packing equipment needed to match up with high harvesting rates is 800 pounds of packing weight per ton of silage delivered. For a 50 tons-per-hour harvest rate, a producer would need 40,000 pounds (50 x 800), or 20 tons, of packing equipment to achieve high-density levels. Harvesting equipment can overwhelm packing capacity very easily at the bunker.
Forage expert Brian Holmes, an agricultural engineer at the University of Wisconsin-Madison, has studied what factors affect silage density levels. The following factors all influence silage dry-matter density in the bunker silo:
- Delivery rate - making sure the rate is matched to packing time
- Dry-matter content - not too wet or dry
- Depth of silage in the bunker silo - lower portions of the silo are higher in density
- Increased tractor weight - more is better
- Reducing the packing layer thickness - consider 6 inches versus 12 inches
- Packing time - matched to delivery rate
Furthermore, researchers at Cornell University found that tractor weight and packing time were the most important factors affecting density.
Silages are very valuable feedstuffs on the dairy and one of the more costly sources of nutrients when not stored properly. Reducing spoilage by accounting for these factors will help reduce shrinkage and increase efficiency on the dairy.