Many producers will be busy making corn silage during the next few weeks.

Greg Lardy, North Dakota State University Extension Service beef cattle specialist, has some tips for harvesting high-quality corn silage.

One is to harvest the silage at the correct moisture level.

“Depending on the storage structure you are using, corn silage should be harvested at 65 percent to 70 percent moisture for optimum results,” Lardy says.

Moisture levels that are too low result in less favorable fermentation and poor packing characteristics in the silage, whereas moisture levels that are too high result in silage that has greater effluent losses (loss of nutrients in the water that oozes from the pile) and in a “sour” fermentation. Corn silage can be harvested at slightly lower moisture levels for upright, oxygen-limiting structures.

Cutting height is another important factor because it impacts both the quality and quantity of silage produced, according to Lardy. Harvesting at a lower cutting height increases dry-matter yield, but does so with the addition of lower-quality forage material (lower portions of the stalk). Raising the cutter bar height will increase the quality of the silage slightly, meaning lower proportions of neutral detergent fiber and acid detergent fiber and a slightly more digestible silage, but it will decrease the overall dry-matter yield.

Lardy also advises packing the silage correctly. Excluding oxygen is a very important aspect of making good-quality silage. Proper packing ensures that oxygen is driven out.

Adequate packing involves a number of factors, including the correct chop length for a particular silage crop, as well as having the appropriately sized tractor for the amount of silage being placed in the pile. Because wheeled tractors exert more pressure per square inch, compared with crawler or track-type tractors, wheeled tractors are preferred for packing silage.

“Be sure to use caution when packing silage,” Lardy says. “The weight of the tractors used and the height of many bunker silos make this a job for experienced tractor operators. Add thin layers of material and pack adequately as the silo is filled.”

One often overlooked item is the value of sharp knives during the chopping process. Sharp knives produce a uniform chop length and improve packing in the bunker. Take time before and during harvest to sharpen the knives. It will pay dividends in improved silage quality.

Making silage properly also includes covering the silage bunker after packing is complete because it ensures that spoilage and potential damage from rodents and other wildlife will be kept to a minimum, Lardy says. He recommends using black or white plastic to cover the pile and plenty of tires to adequately hold the plastic on the bunker silo.

For more information about ensiling corn, visit the NDSU Extension Service’s Web site at http://www.ag.ndsu.edu/procrop/crn/silage.htm.

NDSU Agriculture Communication