“Going hard and going early” on Facial Eczema

Facial Eczema (F.E.) can be one of the most insidious production-limiting conditions in sheep, cattle and deer. While fatal in worst case scenarios, it can wreak havoc at sub clinical levels keeping just below even the most vigilant farmers’ radars.

Tauranga-based ADAMA New Zealand Commercial Manager Bryce Simpson says with no cure for F.E. farmers are forced to be proactive. A mixture of herbs in pastures, dosing with zinc prophylactic products, monitoring spore counts, breeding using F.E. tolerant animals, and careful grazing management are all employed to minimise risk. Alongside those measures is the use of ADAMA’s broad spectrum fungicide Chief^®, which is proven to reduce the escalation of toxic spore numbers.

Toxic spores causing F.E.

Caused by the sporidesmin toxin produced by the spores of the fungus Pithomyces chartarum, F.E. thrives in the warm, moist conditions in the thatch in the lower sward of the pasture. When the spores are ingested the toxin, they release causes damage to animals’ livers. The highest levels of F.E. tend to be in the mid to upper North Island; Bay of Plenty, Waikato, King Country and Taranaki, with the highest risk period being January through to May.

At temperatures from around 18 to 20 degrees with 90% relative humidity spores can multiply very quickly, but Bryce says it is wisest not to make risk assumptions based on weather conditions alone.

“A farmer in Whanganui was having real trouble finishing lambs. He was grazing them in a little valley which created a microclimate as the dew tended to linger there. He’d never seen any clinical symptoms of F.E. And he couldn’t work out what the issue was. Finally, he was persuaded to spray with Chief and he found that the lambs put on an additional 2-3 kgs each. Once that spore count was brought down, finishing weights were a whole lot better.”

Bryce says in adult stock underlying F.E. can also be problematic. “Even when F.E. is sub clinical, it can take up to 18 months for animals to recover their full potential.” Reduced milk production in dairy herds and reduced fertility in sheep resulting from sub clinical F.E. have been reported with estimates of up to 25% productivity loss over a lifetime.

Early prevention with Chief

To borrow a phrase, Bryce says he always recommends “going hard and going early” with Chief. “It’s best to treat pasture in anticipation of danger. When spore counts start to approach 20,000 per gram of leaf, we’d recommend spraying then.” Bryce says the spores will still be present, but their rate of multiplication will be significantly slowed, and build-up will be prevented for up to six weeks.

He says animals can cope with spore counts of up to 20,000 but beyond that point liver damage will occur. “Once you’re over 100,000 the horse has well and truly bolted.”

When using Chief, he says it is important to ensure coverage of all areas likely to be grazed, including under and through fences, hedges and trees. A surfactant should also be added.

“In early February treat enough pasture for 14 days grazing then treat additional areas as required, timed so stock will be grazing 7-10 days after spraying.” In an emergency, stock can be grazed 24 hours earlier. Bryce says if heavy rain occurs within three days of treatment, the pasture should be resprayed.

During danger periods, stock should be grazed in treated areas only.

Bryce says in addition to efficacy Chief has the benefit of being very cost effective. “It’s a really important tool in helping fight the pathogen.”

For more information on spray timings and how to prevent F.E. with Chief click here.