Toxic grass kills cattle

GrandLakeNews:  SOUTHWEST CITY, Mo. - Cattleman John Hamilton turned his back on his herd while moving them to another pasture this week. When he turned back to his cattle, ten of them were convulsing on the ground within 15 minutes.

The reason? Cyanide poisoning. What cattlemen in this area call "johnson grass bloat".

“Severe drought conditions will cause grass to emit prussic acid that can cause death within a few minutes after ingestion,” said Veterinarian Dr. Ken Leach with the Southwest City Veterinarian Clinic.

Hamilton said he was moving his herd from one pasture to another across the road earlier this week. He turned back to pick up a few cattle left straggling behind and within 15 minutes, he had 10 cows down on the ground.

“It didn't take but just a few minutes for my cows to get sick. I graze my cattle on both of these properties and treat the pastures exactly the same. They didn't die on my field, but when I moved them to the other field, they got sick. I've lost four, and the other six are still recovering,” Hamilton said.

According to Dr. Leach, the culprit is Johnson grass that has been cut and is growing back.

“These grass conditions are a stress related problem due to the dry, hot weather. A rain will help for a while and the solution is for the grass to start growing again,” Dr. Leach said. “We have an antidote that works if we can get to the sick cattle in time. At last count I estimate we've lost 15 cows in Northwest Arkansas and Northeast Oklahoma.”

The deadly grass is not restricted to our area. Some cattlemen have lost their entire herds in Texas to toxic bermuda grass.

Dr. Leach said another danger to cattle is nitrate poisoning.

“Nitrate will stay in hay forever. I have a friend who has some grass that tests positive for nitrate and it's now 12 years old,” Dr. Leach said.

There's no way to determine an estimated time of death for cattle who consume the poisoned grass.

“It all depends on several factors as to the time between eating it and the time they die. It's dose related. Depends on how much they eat, their size, or how toxic the grass is,” Dr. Leach concluded.

“For a cattleman like Hamilton, losing four cattle is a blow,” said Dr. Leach. “The only recommendation I can make to livestock owners is to not turn them into a field full of Johnson grass.”