Farmers in the Ozarks fear specific grass becoming poisonous in dry conditions

Johnson grass can be toxic to livestock in a drought
Johnson grass can be toxic to livestock in a drought(KY3)
Published: Jul. 28, 2022 at 10:19 PM CDT
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SPRINGFIELD, Mo. (KY3) - Farmers have another worry during this dry summer: Johnson grass.

The grass thrives in fields and landscaping, and animals and water easily spread its hard seeds. In normal conditions of regular rain, it poses little to no threat to livestock and is considered by many farmers to be great for grazing. When, however, the plant is under stress from a frost or a drought like we’ve been experiencing, it can become highly toxic to livestock and cause nitrite poisoning and prussic acid or hydrocyanic acid, better known as cyanide.

“I typically will wait until we’re in a severe drought, which we are, to worry the most about it.,” said Travis Merrick from Gleonda Angus Farms. “There are ways to avoid it. You can take some samples and get that tested for Nitrates and the prussic acid; however, we typically will try to graze that down early in the spring where the forage is grazed down to where it’s not an issue anymore.”

“We’ve noticed it in our roadways, we’re not able to obviously graze the roadways, and it’s not legal to spray them,” said Merrick. “And when that starts to take over, we see them start to creep from the ditches into the pastures.”

“It’s lush and green and is under 18 or 20 inches in height. That’s when we can run into problems with it,” said University of Missouri agronomy expert Tim Schnakenberg. “Sometimes in dry conditions, it just creates a situation where it’s almost toxic and can potentially kill a cow within just a few minutes of consuming it for the first time.”

Schnakenberg added that after a good rain, the toxin levels in the plants could be elevated, and it’s safest to wait five to seven days after rainfall before allowing cows to eat the plant.

He also said that this is not something to be very alarmed about, just something to watch.

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