Producers urged to watch for pimelea

Livestock producers are urged to be alert to the potential emergence of toxic pimelea plants, with current seasonal conditions conducive to their growth.

In years where light winter rain follows a relatively dry summer, the threat increases of the pimelea group of plants thriving. The plants, commonly known as flaxweed, are poisonous to grazing animals and cause what’s widely known as St George or Maree Disease.

Symptoms to watch out for include chronic diarrhoea, loss of condition, characteristic fluid swelling under the jaw and down the neck and brisket, and prominent pulsing jugular vein in the neck.

MLA Program Manager Health, Welfare and Biosecurity Johann Schroder said outbreaks in 2015 and 2017, when seasonal conditions were similar to now, saw numerous cattle deaths and production losses in Queensland herds.

While all animals can be susceptible, poisoning is more likely to occur in those that are new to an area, he said.

“There’s currently no effective vaccine or antidote, but MLA is continuing to fund research into solutions to treat livestock poisoning from the potentially fatal plants,” Johann said.

“A key project is seeking to produce a rumen inoculum containing microbes able to detoxify the pimelea toxin.”

Prevention and control

To avoid pimelea poisoning, producers should undertake careful monitoring of livestock during high-risk seasons and implement management strategies to minimise contact between susceptible stock and pimelea plants.

Key management considerations include:

• Pimelea is unpalatable to stock with full bellies. Animals that have been reared in pimelea country generally learn to avoid eating the plants.
• Inadvertent ingestion of pimelea can occur where remnants of the plant are caught up in a tussock of grass which is being grazed.
• Where animals are regularly exposed to a small amount of pimelea in an adequate total feed intake, they will probably develop a tolerance and retain that for some time.
• The likelihood of pimelea poisoning appears to be increased if pasture availability is limited. Pasture management could be an important feature for reducing herds’ susceptibility, maintaining stocking rates that allow retention of adequate pasture condition throughout the year.

For further information, and photographs for identification, visit:

• MLA’s pimelea fact sheet
• Understanding pimelea poisoning of cattle

Contact:

Johann Schröder
E: jschroder@mla.com.au