News & Media

Check hay for annual ryegrass toxicity

Released on

Released on:
Friday, 29. March 2019 - 14:30

Livestock and horse owners in the Peel region are reminded to check that hay being fed to stock has been tested for annual ryegrass toxicity (ARGT).

ARGT is a serious, and often fatal, disease that occurs when livestock eat annual ryegrass seedheads that are infected with a toxin-producing bacterium.

Department of Primary Industries and Regional Development veterinary officer Kevin Hepworth said he was aware of five cases involving livestock in the region this year.

“Annual ryegrass is often present in oaten and meadow hay, so there is an associated risk that ARGT could be present,” Dr Hepworth said.

“At this time of year, seasonal paddock feed supplies are generally low and more hay is being fed to livestock and horses.”

ARGT is most often seen in spring when livestock graze pastures containing infected ryegrass seedheads, but the risk of ARGT remains when that pasture is turned into hay. Drying the grasses for hay does not eliminate the toxin.

“It is recommended that stock owners and feed sellers have hay containing annual ryegrass tested for the presence of the bacterium that causes ARGT, before they feed it to stock,” Dr Hepworth said.

“Whenever producers buy hay, they should obtain a commodity vendor declaration that states that the feed has been tested for ARGT and is classified as ‘low risk’. Horse owners buying hay from feed stores or a private supplier should ask to see a copy of a testing certificate.

“Owners should also note that while feed testing reduces the risk of ARGT poisoning, it does not eliminate it, as ARGT could be present in other untested parts of the bales.”

Signs of ARGT in livestock include trembling, clumsy gait, jaw champing and difficulty swallowing and drinking, followed by lying down and convulsions.

Dr Hepworth said the toxin accumulated slowly, so stock may not start to show signs of the disease until they had fed on the same hay source for several weeks.

Animals showing these signs should be slowly moved to a quiet area and disturbed as little as possible until veterinary advice has been sought.

More information on ARGT and hay testing can be found on the department website

Hay check reminder
Check that any hay being fed to livestock has tested low risk for annual ryegrass toxicity (ARGT).

Media contacts: 

Jodie Thomson, media liaison                        +61 (0)8 9368 3937