Beware dangers from freeze-damaged grasses
High Plains Journal
Cattlemen should be aware of the dangers certain grasses pose to cattle after a freeze, warns Mark Keaton, Baxter County staff chair with the University of Arkansas Cooperative Extension Service.
“Usually in October, the first killing frost visits Arkansas,” he said. “Crops such as Johnson grass, Sudan grass, sorghum-Sudan grass, grain sorghum and other sorghums are sensitive to temperatures below 32 degrees. Plant cells of these crops are damaged by frost, and hydrocyanic acid, or prussic acid, is formed.”
Keaton said there’s a chance cattle can be killed by eating only a few pounds of forage from these grasses if they’ve been killed by frost.
Hydrocyanic acid is more abundant in sorghum leaves than in stems. Since young shoots and suckers consist mainly of leaves, they’re more hazardous to eat than mature plants that contain large stems. That’s because stems dilute the harmful effects of this potentially lethal compound found in sorghum leaves, Keaton said.
