February 8, 2013
The Department of Agriculture and Food is reminding producers to check their livestock for signs of annual ryegrass toxicity (ARGT). Department principal veterinary toxicologist Jeremy Allen said the first cases of ARGT for the season had been reported in late October and early November in the Moora and Three Springs areas. “November is the peak month for ARGT cases, but the disease also occurs in January and February when stock are moved onto stubbles,” Dr Allen said. “Producers feeding bought-in hay to stock should also check if their hay has been tested for toxic ryegrass contamination. “Signs of ARGT may appear from four days to several weeks after animals are introduced to toxic paddocks or hay, so it is important to check stock daily in paddocks containing annual ryegrass. “Stock losses can be high if producers do not identify the signs early and act. “To check if livestock are affected by ARGT, run the animals for 200 to 300 metres. If any animals stagger or run with a rocking-horse gait or fall, immediately move the mob quietly to a paddock with good water, safe feed, shade and, if possible, no ryegrass.” Dr Allen recommended that producers ask a veterinarian to investigate stock deaths to determine the cause, especially if ARGT is new to the farm or to the district. “Don’t rely on looking at ryegrass seed heads for bacterial slime or distorted seed heads to assess whether ARGT is present,” he said. “If there is any possibility that pastures are toxic, samples should be tested in a laboratory before introducing stock.” ARGT incidence can be reduced over a number of years by treating paddocks with a commercial twist fungus inoculum from May to early July. The inoculum should be ordered by the end of February and order forms are available at agric.wa.gov.au, from agricultural supplier Becker Underwood or from local merchandisers. ARGT can also be controlled by pasture management and chemical manipulation. Another option for long-term control of ARGT is to sow a variety of ryegrass called Safeguard. This variety is resistant to the nematode that carries the toxic bacteria into the developing seed head.