Extension and Ag Research News


Turn Frost-damaged Corn into Silage

NDSU’s dairy specialist offers advice on using frost-damaged corn for silage.

This year, late-seeded corn destined for grain may have been damaged by frost, but it still can be used.

“The weather continues to complicate the farming and ranching scene,” North Dakota State University Extension Service dairy specialist J.W. Schroeder says. “If your corn doesn’t make grain, then silage may be an option, providing ruminant livestock exist in the area to consume it. Make sure you put the corn up right to avoid losses due to spoilage from improper storage.”

Corn silage is a popular forage for ruminant animals because it is high in energy and digestibility, and it is easily adapted to mechanization from standing crop to time of feeding.

“While the quality of weather-damaged corn will not be as high as corn that has reached the dent stage, feeding value will depend upon the stage of plant development and how it is handled after the damage has occurred,” Schroeder says.

Corn silage should have a light, pleasant smell with only a slight vinegar odor. It should be slightly brown to dark green. If it is dark brown or has a fruity, yeasty, burned or rancid (butyric acid) odor, excessive heating or improper fermentation has occurred.

The greatest problem with this type of silage is a lack of energy, which is the result of less grain formation and improper fermentation due to excessive dryness of a damaged plant.

Frosted corn should be cut as soon as possible because it will dry quickly and lose leaves, Schroeder says. Producers may need to add water to establish airtight conditions in corn that has frosted and become too dry to pack well.

As a rule of thumb, add 4 gallons of water per ton of silage for each 1 percent of desired rise in moisture content. Add this water as the silo is being filled. If water is added to a silo after it is filled, the water tends to seep down the silo walls and does not permeate the silage mass.

A bit more precise and more frequently used calculation when adjusting total mixed rations for dryness is: added water (lbs) = (ay-az)/z, where a = batch size in pounds, y = percentage of dry matter (DM) of dry mix and z = percentage of DM desired for the mix.

If the combination of feeds results in a mixture that is too dry (for example, a total mixed ration, or TMR, that is 80 percent dry matter) and the desired or target moisture content that would result in greater intake or reduced dustiness is 65 percent DM, then for a 1-ton (2,000-pound) batch, use the following formula: (2,000 x 80) - (2,000 x 65)/65 = 462 pounds of water.

Water typically weighs about 8.35 pounds per gallon, so you would need 55 gallons of water for each ton of TMR (462 divided by 8.4).

Compared with the rule of thumb (4 gallons), this formula requires about 3.7 gallons for each 1 percent of change in dry matter for every ton.

NDSU Agriculture Communication

Source:J.W. Schroeder, (701) 231-7663, jw.schroeder@ndsu.edu
Editor:Ellen Crawford, (701) 231-5391, ellen.crawford@ndsu.edu
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