FE outbreak triggers warning

Dairy Australia says current and forecast weather conditions put cows at risk. The recommended action is to either monitor spore counts on farm paddocks weekly or begin preventative strategies such as zinc supplementation if this isn't already in place.

Dairy Australia's Feed2Milk programme leader, Dr Steve Little says this month the FE spore monitoring programme had detected increasing pasture toxicity levels across Gippsland, Victoria.

"The average spore count is now more than 20,000 spores per gram which is the trigger level for farmers to take action," Little says.

Continued exposure of animals to pasture containing more than 20,000 spores per gram of pasture can result in liver damage for which there is no specific treatment.

"The greatest cost of FE to dairy farmers is from the 80% of cows with liver damage but no skin lesions. These cows will have lower milk production and fertility," says Little.

Dairy Australia introduced a spore monitoring programme this summer/autumn, prompted by a widespread outbreak across Gippsland last season, with the likelihood of favourable conditions again this year. Its website has the latest spore monitoring results and information on preventing the disease. The industry-good organisation is also offering tips to farmers to tackle FE.

When the FE spore monitoring programme indicates spore counts in an area are trending upwards of 20,000 spores per gram, Dairy Australia recommends monitoring pasture spore counts on paddocks weekly or starting prevention strategies such as zinc supplementation.

FE is caused by toxic levels of spores from the fungus, Pithomyces chartarum.

Commonly mistaken for a skin disease, it is caused by ingestion of spores of the fungus Pithomyces chartarum which lives mainly on ryegrass. These spores release a toxin in the cow's gut which damage the liver, and in some cows, cause skin lesions (photosensitisation).

The greatest cost of FE to dairy farmers is from the 80% of cows which have liver damage but no skin lesions. These cows will have lower milk production and fertility.

The risk of FE is greatest in late summer and autumn when periods of rain or high humidity occur in combination with high night time minimum temperatures. However, weather alone is not an accurate way to predict pasture toxicity.

The recommended management is to monitor pasture spore counts and take preventative action when levels reach 20,000 spores per gram.

Zinc supplementation can be effective for preventing facial eczema if well managed. The most commonly used approach for milking cows is the inclusion of zinc oxide in the grain/concentrate fed in the dairy.