Take steps to reduce the risk of annual ryegrass toxicity in livestock

Producers are reminded to take steps to reduce the risk of annual ryegrass toxicity (ARGT) occurring in their livestock.

Department field veterinary officer Hayley Hardwick said ARGT occurred when stock ate hay or pastures containing annual ryegrass seed heads infected with the bacterium, Rathayibacter toxicus.

“ARGT causes serious disease and death in livestock including sheep, cattle, pigs and horses,” Dr Hardwick said.

“Testing your pasture and hay for ARGT before feeding it to your livestock can help to minimise the risk.

“If buying hay, always ask hay sellers for a commodity vendor declaration and a certificate that shows the hay sample tested is low risk for ARGT.

“However, it is important to understand that a low-risk test result does not guarantee the pasture or hay is completely safe as the toxin may be present in other areas of the bale or paddock that were not tested.

“The toxin accumulates in the body and a small dose continually consumed will reach a toxic level over time.

“That is why it is vital to monitor livestock daily when on hay or pasture containing annual ryegrass, as affected animals can recover from ARGT if removed from the feed source early.”

Signs of ARGT include muscle tremors, walking unsteadily, dullness, being unable to stand and death. Stress or movement make the disease signs worse.  Another typical sign is if left undisturbed animals in the early stages will get up and walk off appearing as if they have recovered.

“Always call a veterinarian for advice when livestock show disease signs or die unexpectedly to ensure a correct diagnosis,” Dr Hardwick said.

“Sheep and cattle affected by ARGT show signs similar to some exotic emergency animal diseases and some of these cases may qualify for a rebate under the Significant Disease Investigation Program.”

More information is available on the 'Annual ryegrass toxicity in livestock' webpage.