OSU Extension agriculture educators have received reports of cattle deaths this summer due to prussic acid toxicity. Producers should take caution to protect their herds.
Commonly linked to the consumption of Johnsongrass, prussic acid toxicity occurs in certain plants of the sorghum family when temperatures rise and the ground dries out.
Johnsongrass, one of Oklahoma’s most invasive plants, is high in prussic acid, but the nitrate toxicity of other sorghum plants such as Foxtail millet is low. Ranchers should first identify the toxicity level of any sorghum variety intended for grazing purposes.
Symptoms of prussic acid poisoning in cattle can include muscle tremors, excess salivation, staggering, breathing difficulties, convulsions and collapse.
What ranchers should know:
– Prussic acid levels are higher in the leaves of young plants, with the upper leaves containing the most toxin.
– Plant stress from drought and other extreme conditions can increase levels of prussic acid.
Methods to prevent prussic acid toxicity:
– Contact your county’s OSU Extension office to have your forage tested before grazing.
– Never turn hungry cattle onto a new pasture.
– Take soil samples and fertilize accordingly.
– Rotate pastures to prevent cattle from consuming lush regrowth.
– Place one or two cows in a pasture and observe before turning in all cattle.
Learn more about keeping your herd safe from prussic acid toxicity 
