Feeding High-Nitrate Hay This Winter Could Bring a Disaster

Make sure you test all your millet, oat, and cornstalk hay before feeding it.

Published on: Nov 27, 2013

Hay feeding season is not far away. Bruce Anderson, University of Nebraska-Lincoln forage specialist, has a warning: Don't let nitrate poisoning ruin your winter.

"I can't think of a much more sickening feeling than to watch a group of hungry cows start falling over dead after feeding them a fresh bale of hay," he says. "But that could happen to you this winter if you have high nitrate hay and feed it incorrectly to your animals."

Preventing a tragedy like this begins by testing all your millet and oat and cane and corn stalk hay for nitrates. "If you already tested them this summer, great," he says. "If you haven't, do it now, then keep your records close at hand and be sure you can match test results to bales."

Feeding High-Nitrate Hay This Winter Could Bring a Disaster
Feeding High-Nitrate Hay This Winter Could Bring a Disaster

Once you know the nitrate level is high in some of your hay, how do you feed it safely?  Your first step is dilution, Anderson recommends. Blend high nitrate hay with grain or low nitrate forages. Often this will require grinding and mixing various feeds together in the proper ratio. Do not feed free choice one bale of high nitrate hay and another bale of low nitrate forage. Cows will not adjust their diet correctly. "This practically guarantees that some cows that like the high nitrate hay best will be sick or dead the next day," he points out.

After blending, feed cows more often than usual. Frequent, small meals help cows adjust to high nitrate feeds and will allow you to slowly increase the amount of nitrate they consume each day.

You should especially avoid large meals to hungry cows, he warns. "Be extra careful if animals go off feed, like during a snow storm. Their first meal afterwards needs to contain well below their previous nitrate levels to avoid a sudden, large influx of nitrates into their system.

"High nitrates are scary but manageable. Keep your cows safe this winter," Anderson says.