Overcoming the Risk of Ryegrass Staggers
Illness of animals expressed from consuming ryegrass with toxic levels of endophyte is often referred to as Perennial Ryegrass Toxicosis (PRGT).
PRGT can be a serious problem during summer and autumn months. The overwhelming threat is from the syndrome known as ryegrass staggers which can lead to animal losses though ill-thrift and death.
These alkaloids can cause production losses as well as leading to potential injury or death of the animals. Even if the livestock do not seem to be under the effects of the endophyte, there may be sub-clinical effects that are lowering milk or meat production, without the animals seeming to suffer.
There are also often animal welfare concerns. Heat stress may also be observed, but appears less common in the main.
There is no specific treatment for PRGT. Toxic pastures can however be addressed through good management and can readily be replaced with safe alternatives.
Avoiding Ryegrass staggers:
- Do not use ryegrasses with wild-type endophyte - other options are readily available
- Plant/over-sow a diverse pasture mix, and manage it to reduce any (toxic) ryegrass component
- Adopt a program to replace staggers-causing paddocks that should include reducing the soil weed-seed burden
- Develop a number or ‘staggers-safe’ pastures, specifically reserved for the threat period, particularly for younger stock
- Introduce supplementary feeding before the staggers season
- Avoid feeding hay or silage made from wild endophyte pastures through the staggers season
- Avoid introducing hungry stock to the first ryegrass shoots of the autumn, and offer enough pasture to reduce the grazing pressure, thus reducing the inclination to graze the grass hard in the crown
- Avoid contamination of staggers-free pasture from seed sources such as brought-in hay
If Ryegrass staggers occur:
- Monitor stock during periods of stressed green-pick through summer and autumn
- Quietly move affected animals to safe pastures or confinement areas with shade and water
- Prevent access to dams or waterways to prevent drowning; provide water via troughs
- Avoid using dogs or loud/swift vehicles
- Use of narrow ditches to set sheep upright
- Animals may improve over 1 – 2 days, although toxins can remain in their system for a week or two.