Measures Advised to Mitigate Annual Ryegrass Toxicity in Livestock

Annual Ryegrass Toxicity: Risk Reduction Measures for Livestock

Information has been provided regarding steps producers can take to reduce the risk of Annual Ryegrass Toxicity (ARGT) in livestock.

Annual Ryegrass Toxicity occurs when livestock consume hay or pastures containing annual ryegrass seed heads infected with the bacterium Rathayibacter toxicus. This condition can lead to severe illness and fatalities in various livestock species, including sheep, cattle, pigs, and horses.

• Pasture and Hay Testing: Testing pasture and hay for ARGT prior to feeding can assist in minimizing risk.
• Hay Procurement: When purchasing hay, producers are advised to request a commodity vendor declaration and a certificate indicating a low-risk test result for ARGT.
• Test Limitations: It is noted that a low-risk test result does not guarantee complete safety, as the toxin may be present in untested sections of a bale or paddock.
• Toxin Accumulation: The toxin accumulates within the animal's body, meaning continuous consumption of small doses can eventually reach toxic levels.
• Daily Monitoring: Regular daily monitoring of livestock consuming hay or pasture containing annual ryegrass is indicated. Animals affected by ARGT may recover if removed from the contaminated feed source early.

Signs of ARGT include:

• Muscle tremors
• Unsteady gait
• Dullness
• Inability to stand
• Death

Stress or physical movement can exacerbate disease signs. A characteristic observation is that undisturbed animals in early stages may rise and walk, appearing to have recovered.

In cases where livestock exhibit disease signs or experience unexpected deaths, immediate consultation with a veterinarian is recommended to ensure an accurate diagnosis. It is noted that ARGT symptoms in sheep and cattle resemble those of certain exotic emergency animal diseases. Some such cases may qualify for a rebate under the Significant Disease Investigation Program.

Further details are accessible on the 'Annual ryegrass toxicity in livestock' webpage.