Summertime brings with it an increased risk of poisonings that impact beef cattle, according to Eldon Cole, livestock specialist with University of Missouri Extension.

Cole says he has had inquiries about johnsongrass and wild cherry leaves as the source of potential toxins and cattle deaths.

“The toxin involved in these two plants is the same, cyanide. It comes from cyanogenic glycosides contained in the plants. Besides wild cherry and johnsongrass, the compound is found in sudan, sorghum-sudan crosses, peach and elderberry,” said Cole.

Most of the time cattlemen do not worry about cyanide or prussic acid poisoning.

“Conditions of both the plant and animal have to be just right for death losses to occur,” said Cole. “Conditions that accentuate the risk in plants include heavy nitrate fertilization, herbicide treatment and drought.”

Cattle do seem to be more susceptible to cyanide or prussic acid poisoning than sheep. The amount of foliage or grass consumed is a factor, also.

University of Missouri Extension centers in Missouri do not test the forage or leaves to determine the degree of risk.

“I recommend when turning cattle into a pasture containing significant amounts of johnsongrass that you only turn a couple of head in initially. If there’s likely to be a problem you’ll know it in 30 to 45 minutes,” said Cole. “Be sure you know how to contact a veterinarian immediately if the sentinel animals go down. Immediate treatment can save them.”

The stage of maturity or height of the johnsongrass and sorghum-sudan plants tend to be factors as well. As a rule, the short, immature plants, less than 18 to 20 inches in height, are more troublesome.

Cattle that graze johnsongrass-containing pastures from early spring throughout the summer, generally do not experience death loss.

“The greatest risk with fallen wild cherry trees occurs after a storm when the leaves are easily accessible for the cattle to eat large amounts of them. Farmers should check pastures after storms for downed trees. Once the leaves dry, the poisoning risk is minimal,” said Cole.

For more information, contact any of the MU Extension livestock specialists in southwest Missouri: Eldon Cole in Mt. Vernon, (-417-466-3102; Gary Naylor in Dallas County, 417-345-7551; and Dona Funk in Cedar County, 417-276-3313.