Ryegrass staggers is not to be confused with grass staggers. Ryegrass staggers is caused by toxins produced by the endophyte fungus which naturally lives in perennial ryegrass. Levels of these toxins are usually highest during summer months. 

Sheep, cattle, horses, and alpacas can get ryegrass staggers and youngstock are often affected sooner or more severely than adult livestock. Affected stock can be nervous, uncoordinated, twitchy, and lack balance. These symptoms are often worse when stock are handled for shifting or yarding and calves can go down in the race during handling.Angus cattle grazing

Livestock will usually recover over time and there is no specific treatment for ryegrass staggers. Deaths may occur due to accidental injuries, becoming cast or drowning. When possible, provide paddocks that are relatively safe and allow more time to shift and handle stock.

There are ryegrass varieties available that have low levels of toxin-producing endophyte. Your crop and pasture agent should be able to give you more information on what may be suitable for your farm.