Facial Eczema the Downside to Humid Weather

The recent humid weather that has Waikato farmers smiling over grass growth could return to haunt them with more facial eczema outbreaks in the New Year.

Facial eczema is caused by stock eating pasture with high levels of the toxin sporidesmin from fungus spores typically found in dead pasture. This damages the animal’s liver and causes facial lesions and can lead to death or reduced production for cattle and sheep.

Morrinsville Animal Health Centre vet Scott McDougall said rainfall and high humidity this week had raised the risk of spore growth and farmers needed to prepare treatments.

“By the time you see the typical sunburn signs of facial eczema you are already two weeks down the track from the outbreak.”

Mr McDougall said last autumn had shown some high spore counts and the practice would begin spore counts on monitor farms in the New Year to contribute to regional tallies. Spore counts could differ widely on individual farms and paddocks so farmers should make their own counts and reduce the risk of infection by using silage or other feed supplements to reduce reliance on “hot” paddocks.

Facial eczema expert Neale Towers said warm weather could lead to the facial eczema starting up to two weeks earlier than its usual end of January season.

La Nina weather conditions featuring humidity and high temperatures were likely to contribute to a rise in facial eczema.

Of the five La Nina years that occurred between 1975 and 1999, four resulted in higher than normal facial eczema occurrences.

Dr Towers said prevention with zinc oxide dosing in summer was crucial but farmers needed to ensure they gave the correct dose either individually or to stock through their drinking water.

Dr Towers said in severe cases facial eczema could lead to stock losses of 20-30 per cent, while survivors faced lower weight gain and fertility for meat stock and milk yield for dairy cows.

Source: http://www.stuff.co.nz/stuff/waikatotimes/4333115a6415.html