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Knowledge Nuggets
  • Ergot is a plant disease that is caused by a fungus called Claviceps purpurea found in rye, triticale, wheat, barley, bromegrass, wheatgrass, bluegrass, quack grass, orchardgrass, meadow foxtail and wild rye.
  • Ergot is most easily recognized by the hard, black bodies that replace the kernels on the seed head. If the bodies are broken open, they are grey in color.
  • Ergot overwinters as black, grain-sized fungal structures. In the spring, they germinate and form mushroom-like structures that produce spores which are carried by the wind to flowering cereals and grasses.
  • Cool, damp weather in late spring and early summer increases ergot germination because of the longer flowering time of cereals and grasses.
  • Ergot contains numerous toxic alkaloids that cause four different syndromes in livestock: gangrenous ergotism, convulsive/nervous ergotism, reproductive ergotism and hyperthermic ergotism. The gangrenous and nervous forms are most common.
  • General symptoms of ergot poisoning include lameness, excitability, belligerence, weight loss and loss of appetite. It can take 2-8 weeks for these symptoms to become visible.
  • Gangrenous ergotism is associated with longer term ingestion of ergot. Ergot alkaloids cause small blood vessels to constrict reducing the blood supply to limbs, tails, teats and ears. If blood flow is restricted for long periods of time, the tissues become oxygen deprived and die. Hooves can slough off and in cold weather ears freeze off.
  • Convulsive or nervous ergotism is more common in horses and sheep and is the acute form of ergotism. Symptoms include dizziness, drowsiness, convulsions, paralysis and death. These symptoms usually disappear about 3 to 10 days after the ergot is removed.
  • Reproductive ergotism is caused by high levels of estrogen in the ergot bodies. This can lead to abortions or lowered fertility due to abnormal cycling. Once the ergot is removed, it takes a long time for estrogen levels to return to normal.
  • Hyperthermic ergotism results from long term exposure to ergot. It is made worse on hot and humid days with no shade. Animals pant and lose weight.
  • If your pastures have a history of ergot, make sure to graze so the plants don’t head out or mow them to prevent the ergot bodies from developing.
  • The upper feeding limit of ergot in older, non-pregnant cattle is 0.1% by weight of feed consumed. However, ergot could still have a negative impact on cattle health at this level. Pregnant, breeding and lactating animals are the most sensitive to ergot and should not be fed any ergot.
  • Ergot levels in screenings from seed cleaning plants can be very high. Do not buy screenings with any amount of ergot unless they can be appropriately diluted with ergot free feeds. competitive.

Fact Sheets

Ergot (NDSU)


Ergot of Cereals and Grasses

Ergot of Small Grain Cereals and Grasses and its Health Effects on Humans and Livestock

Ergot Update

What is ergot poisoning?

Research Papers

Effect of rye ergot on the pregnant sheep

Endogenous toxins and mycotoxins in forage grasses and their effects on livestock

Intake, digestion and N metabolism in steers fed endophyte-free, ergot alkaloid-producing endophyte-infected, or non-ergot alkaloid-producing endophyte-infected fescue hay.

Online detection and quantification of ergot bodies in cereals using near infrared hyperspectral imaging - available in PDF format only

Physiologic responses of livestock to toxic plants

Productivity of cow-calf pairs grazing tall fescue pastures infected with either the wild-type endophyte or a nonergot alkaloid-producing endophyte strain, AR542

Validation and transferability study on a method based on hyperspectral imaging for the detection and quantification of ergot bodies in cereals - available in PDF format only
  For more information about the content of this document, contact Grant Lastiwka.
This information published to the web on August 2, 2012.
Last Reviewed/Revised on March 2, 2017.

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