Ergot infections in common Missouri pasture grasses have led to cattle deaths, says Craig Roberts, University of Missouri (MU) Extension forage specialist. He urges producers to immediately move any livestock from infected fields. There’s a chance that stored hay could also contain the toxin.
The ergot fungus produces alkaloid compounds toxic to livestock and humans. The toxins constrict blood vessels, increase respiration rates, raise core body temperatures and limit blood supply to extremities. Ergot poisoning appears to be prevalent statewide, Roberts says.
Ideal ergot growing conditions have been forming this spring and summer, beginning with wet, cool weather followed by high heat and humidity, says Roberts. “With that amount of moisture in the ground and in the plants, once it gets hot, the state turns into an incubator.”
A northeastern Missouri farmer reported four of his cattle died in early July after moving them to tall-fescue pasture in seed-head stage, says Tim Evans, an MU toxicologist. The farmer said the cattle appeared to suffer from extreme heat stress.
Cattle may seek relief in shade or stand in water. Other symptoms might include overall malaise, rapid breathing, sloughing of the switches of tails and tips of ears, abortion, and possible decreased milk production.
Ergot bodies, which look much like small rodent droppings, are easy to see in the seed heads of cereal grains, including barley, oats, wheat, triticale and rye, as well as in grasses like timothy and tall fescue.
Ergot bodies could be in stored hay, which should be inspected. Evans says. If hay is infested, destroy it or dilute with other feed.
Ergot toxin levels may be reduced if hay is ammoniated, but little published research has been done on this method, warns Roberts. At least half of the alkaloid concentration would remain even if the hay were field-cured and stored more than a year, he adds.
Ergot alkaloids are also toxic to llamas, alpacas, horses, swine, dogs and humans eating infected grains.