Ergot (Claviceps purpurea) is an airborne fungus that affects grass seed heads. Wet, cool weather followed by high heat and humidity create ideal conditions for ergot growth according to Sarah Kenyon, agronomy specialist with University of Missouri Extension.
"Weather conditions this spring have been ideal for ergot development. Farmers should scout their fields and pastures for this disease," said Kenyon.
Ergot is identified by the presence of hard ergot bodies in the seed of grasses. The ergot bodies look like mouse droppings and are easily visible in the seed head of cereal grains such as barley, oats, wheat, triticale and rye, as well as many common grasses such as timothy, perennial ryegrass, and tall fescue.
"When livestock consume ergot they appear to suffer from extreme heat stress. Cattle may seek relief in shade or stand in water," said Kenyon.
Other symptoms might include rapid breathing, sloughing of the switches of tails and tips of ears, abortion, and decreased milk production. Livestock deaths may also result when large quantities are consumed.
"Ergot produces alkaloid compounds that are toxic to livestock and humans. The toxins constrict blood vessels, increasing respiration rates, raising core body temperatures, and limit blood supply to the extremities," said Kenyon.
Ergotism can be confused with fescue foot or fescue toxicosis because the symptoms are similar. However, ergot bodies (the ones that look like mouse droppings) have a thousand times more toxic alkaloids than those of fescue toxicosis. Because the toxin concentration is so much more, the animal symptoms appear quicker and are much more pronounced.
"If ergot is observed, producers should immediately move livestock from infected fields. Producers may also consider feeding other sources of feed to dilute the amount of ergot that is consumed," said Kenyon.
Farmers should also inspect hay for ergot bodies. If the hay is infested it can be destroyed or diluted with other feeds.
Ergot alkaloids are toxic to many species, including other ruminants, llamas and alpacas, horses, and even swine, dogs and humans eating infected grains. Ergot poisoning has been linked to human epidemics in the Middle Ages. The alkaloid toxins in ergot are chemically related to LSD, and some scientists suggest that bread made from infected rye may have played a role in the 17th-century witch trials in Salem, Mass., and even the French Revolution.
Source: University of Missouri Extension