Chopping corn for silage provides a quality feed option for beef and dairy cattle, and during a drought year it can salvage a suffering crop.
“Corn silage generally is an excellent high-energy feed for all classes of beef cattle,” University of Missouri Extension livestock specialist Gene Schmitz says.
Iowa State University Extension dairy specialist Larry Tranel says silage can help maximize performance.
“For dairy producers, it’s probably the cheapest source of energy — highly digestible energy,” he says.
This year, widespread drought could mean many corn fields are chopped for silage as potential yields drop. Schmitz says even drought-stressed corn can make for decent feed.
“In a drought year, the quality is inhibited, but it’s still a good feed source,” he says.
Also, Schmitz says with dry conditions decimating hay yields and pasture growth, corn silage could play a crucial role this winter.
“It’s a very valuable feed,” he says. “In a lot of the drought-stressed areas, I think it’ll be the thing that gets us through the winter.”
The timing of the silage chop and getting it packed tightly and covered are keys to getting the best-quality silage.
“We have a good feed source here so we don’t want to mess it up,” Schmitz says.
The experts say chopping silage when the corn is in the 65 to 70% moisture range is ideal. Iowa State University Extension dairy specialist Fred Hall says producers should test corn to see when the moisture is just right for silage chopping.
Hall says aiming for a three-quarter inch cut when chopping silage is a “magic number.”
“That’s vital that we have that three-fourths inch cut,” he says. “Damage as many kernels as possible — hopefully all the kernels.”
Schmitz says when corn gets too dry, it doesn’t pack as tightly. He says a tight silage pack keeps oxygen out.
“It’s all about oxygen exclusion,” he says.
This allows for good fermentation of the silage. Schmitz says it is important to get silage packed in tightly even if producers are putting it in a bag or bale instead of a pit.
Hall says when silage chopping loads are coming in quickly, it can pressure the silage packer to hurry, but it is important to be thorough.
“We’re trying to get as much air out of it as possible,” he says.
Hall says silage packers should avoid making turns on top of the pit to avoid air in the pack, instead driving straight up and over and then coming back.
“There’s an art form to it,” he says.
He adds it is good to get silage covered quickly, right after getting it packed down.
“If you want the most pounds of milk, the most pounds of beef, you’ve got to cover it quickly,” Hall says.
Tranel’s key steps to preserving silage as a nutritious, energy-rich feed are “harvest it quickly, get it packed tightly ASAP, and cover it quickly,” he says.
When cutting drought-stressed corn, there are a few additional considerations. Schmitz says if it was a field initially intended for grain, producers should check with their crop insurance agent for an assessment before chopping to avoid causing issues with insurance claims. If the agent cannot get an assessment done before the ideal time to cut, producers can talk with them about leaving a representative sample standing in a field.
Also, drought corn can mean higher levels of nitrates.
“With drought-stress corn, you’ve got to be very careful about the nitrate levels,” Tranel says.
Chopping higher up on the plant can help with this.
“Most of the nitrates that are in the plant are in the lower part of the stalk,” Schmitz says.
Producers can cut drought corn higher, around 12 to 18 inches, and reduce the nitrates in the silage by 30 to 50% while still preserving the best parts of the plant for feed.
“It can still be a very high-quality feed source,” Schmitz says.
Hall says when deciding to chop drought-damaged corn, producers should inspect it to see if pollination is happening, and if so they can let it stand and develop what kernels it can before chopping.
He says forages are the cheapest nutrients available for a dairy herd, and given the narrow margins in the industry, it is good to get the most out of silage cutting.
After giving silage a month or so to ferment, Schmitz recommends testing silage nitrate levels and also the nutritional information, and then producers can supplement cattle diets as needed.
“We can find out what nutrients are missing and how to supplement in the most cost-effective way,” he says.
