When drought occurs in Butler County, Ohio, as it did in 1983, 1988, 2002 and this year, people are interested in feeding corn, stalks and all, to livestock.

If drought-stressed corn is green-chopped, it should be tested for nitrate concentration prior to feeding. When drought conditions prevent normal plant growth, the cornstalk may contain abnormally high levels of nitrate, which, if fed in excessive amounts, can cause animals to go off feed or die. Under most feeding situations, the nitrate level in feed must be over 2 percent to cause a problem. Nitrate testing of feed is especially important if high rates of nitrogen fertilizer or manure were applied or if the soil has a high organic matter content.

A return to non-stressed conditions following substantial rainfall should decrease nitrate accumulation, but chopping should be delayed for three to five days.

We recommend you raise the cutter bar to leave 10 to 12 inches of the stalk in the field. Nitrate tends to accumulate in the lower portion of the stalks of drought-stressed corn.

Ensiling stressed corn is preferred to green chopping or grazing. The potential for nitrate toxicity is practically eliminated during the fermentation process. If nitrate toxicity is a concern, testing for nitrate should be done after the forage has gone through the ensiling process.

Before drought-stressed corn is chopped for silage, test the moisture percentage. Even though lower leaves may be brown, plants can contain 75 to 90 percent water, which is too wet for acceptable silage fermentation. If drought-stressed corn has pollinated, it is best to delay harvest as long as some green leaf and stalk tissue remains and the black layer has not formed on kernels.

As with any new feed, livestock should be fed small amounts of drought-stressed corn forage at first so the rumen bacteria can adapt to it. Before making and feeding silage, be sure that all pesticides applied to the crop are cleared for silage use. The interval between final application and allowable harvest may differ for silage and grain. Be sure to check the label of any chemical that was applied.

Ensiling high-nitrate forage can result in production of various nitrogen oxide gases. These gases are highly toxic to humans and livestock.

The danger of silo gas can exist from ensiling time to four weeks later. During this period, do not enter a silo without first running the blower for 15 to 30 minutes.

For more information on drought options, go to: www.agcrops.osu.edu and click on “Drought Information.” If you don’t have access to the Internet, call the Ohio State University Extension Office in Butler County at: 513-887-3722.