Ergot is a fungal disease that can infect open pollinated grass species. It is commonly found in cereal crops such as rye, triticale, wheat, oats, and barley. Grass species such as brome, wheat grasses, orchard grass, quack grass, and bluegrasses are also susceptible. The concerns are twofold: reduction in crop yield and the negative impact on animal health and performance.
Ergot is spread by ascospores that are released from sclerotia that grow on the ground surface. The spores are released into the air and infect seed heads when they are in the flowering stage. Instead of pollen fertilizing the seed embryo, it is infected by the spores. Cool conditions and plants with a longer pollination period have a greater risk of infection. It is common for brome and timothy found in ditches to be the first plants to be infected. The disease is then spread into pastures and cropland. Once seed is infected, ‘honeydew’ a liquid, develops. This liquid can be spread and infect more plants by the wind, bees, other pollinators, and wildlife walking through the pasture, hayfield, or cereal crop.
It is at this point of disease development that ergot alkaloids, the toxic compounds, form. The toxins remain in the seed as it matures to form the enlarged banana shaped seed. If cattle graze pastures with ergot, it can impair sperm motility and reduce cow fertility due to the high estrogenic content in the honeydew or infected seed. The alkaloids also reduce blood flow to the limbs, ears, tail, and outer regions of the body. In hot conditions, this reduces heat loss from the animal which results in panting. It will also reduce feed intake due to heat stress.
New research conducted at the University of Saskatchewan has determined that the 4 strains of ergot found in Western Canada are 2.5 to 3 times more toxic than strains reported in the southern USA. Duration of exposure and alkaloid concentration are key. Intake limits are much lower than previously reported. One of the first symptoms is a dramatic reduction in feed intake within 3 to 4 days of exposure. Monitoring animals and pastures is key to prevent serious problems.
For additional information on ergot, contact Barry at 403-741-6032 or bjyaremcio@gmail.com.
Photo credit: https://www.agric.wa.gov.au/mycrop/diagnosing-ergot