As farmers consider what the next step might be for any corn damaged by drought, one idea is harvesting the crop for livestock feed to salvage some of its value and help livestock producers supplement short forage supplies. Purdue Extension forage specialist Keith Johnson says that corn does have some good value.
“It can be harvested as it traditionally is as silage. It can also be green chopped and that’s less common today as compared to what it was several decades ago, but those are really the two major options individuals have.”
Johnson says most studies indicate feed value of drought-stressed corn to be 80-100 percent that of normal silage.
“For individuals who haven’t utilized corn silage before I think they would be quite surprised to know that the quality is actually fairly close to what with grain good yielding silage would be. First of all you’re going to have lesser yield. From a quality standpoint we’re going to find that there is a little bit more fiber. You’re going to find in the drought damaged crop actually has a little bit, 1-2 percent more protein is going to be more common on a dry matter basis. So it’s a feedstuff that is available for possible use.”
Before growers make any decisions about what to do with drought-damaged corn, Johnson said it is imperative that you talk with your crop insurance agent.
“We want to make sure that individuals that do have crop insurance, before they just go out and start harvesting the corn, that they need to seek the advice and counsel of their insurance agent and follow the protocol that’s appropriate for that.”
Purdue University studies showed little or no difference in feedlot gain or milk production when beef and dairy cattle were fed normal or stressed corn silage. One of the most influential factors is moisture content at harvest.
“Ideally, the crop should contain 60-70 percent moisture at harvest,” Johnson said. “For upright silos, to avoid seepage, growers should harvest at 60-65 percent, whereas for bunker silos, harvesting at 65-70 percent moisture will result in better packing and storage qualities.”
He said producers often tend to harvest the damaged crop too soon, meaning silage has too much moisture, which can result in poor fermentation and ultimately lower feed value.
Stalks of plants with brown leaves and stalks with small ears or little grain content will be higher in moisture.
“A quick way to determine if the plant contains too much moisture is to hand-squeeze a representative sample collected from the forage chopper,” Johnson said. “If water drips from the squeezed sample, the corn is too wet for ideal fermentation.”
Livestock producers using drought-damaged corn for silage need to make sure they have the feed tested for nitrate. Nitrate levels can be higher in drought-damaged corn. While the potential for nitrate toxicity after fermentation is reduced, Johnson said it’s still a good idea to have the feed analyzed.
Producers with short pasture and stored feed supplies might also consider harvesting drought-damaged corn as green chop.
“There are two major concerns with this practice,” Johnson said. “One is the potential for nitrate toxicity and the second is the potential to founder animals.”
Animals with founder, or laminitis, have an inflammation of the soft tissue around the hoof bone that can cause permanent damage to the foot.
He offered a series of steps to help avoid these problems:
* Raise the cutter bar to 12 inches the first few days of chopping.
* Gradually introduce animals to green chop.
* Use other feeds that are low in nitrate as part of the ration.
* Feed green chop in small quantities throughout the day, rather than large quantities once per day.
* Don’t allow green-chop forage to set on a wagon overnight.
* Feed 2-3 pounds of grain with high nitrate feeds.
* Take extra precautions during the first 2-3 days following rain because nitrate levels tend to increase during this period.
“As plants mature, nitrate levels decline, so animals become acclimated and the chances for toxicity decrease over time,” Johnson said.
Corn growers looking to sell drought-damaged corn for silage, and livestock producers looking to purchase it, need to understand how to properly price the crop.
The value of the corn as silage can be determined using either of the following free Purdue Extension Publications: https://www.extension.purdue.edu/dairy/articles/ValueCornSilage.pdf or
Because yield varies widely based on moisture content, Johnson said moisture content will greatly affect pricing. More information is available in Johnson’s Web-based publication, Drought-Damaged Corn as Livestock Feed available free of charge.
He also noted that herbicides and insecticides applied to the corn crop throughout the season have feeding restrictions. Growers need to pay close attention to herbicide and insecticide labels and be in touch with chemical suppliers to make sure the crop is harvested and fed safely.[audio:https://www.hoosieragtoday.com//wp-content/uploads//2012/07/Keith-Johnson-on-drought-damaged-corn-for-silage.mp3|titles=Keith Johnson on drought damaged corn for silage]
Source: Purdue Ag Communications