In the Wars With the Spores: Monitoring Facial Eczema on Your Farm this Summer

With humidity and temperatures rising, we are once again on the lookout for facial eczema. FVM uses four monitoring farms across the Matamata area to monitor trends in spore levels, so that you can time preventative treatment appropriately. Click through to the article to check out our suggestions for monitoring and preventing this disease.

What is facial eczema?

Facial eczema is actually a toxicity. The spores we are counting are responsible for releasing a toxin, sporedesmin, which causes liver damage. When the liver is damaged enough, it can’t keep up with the body’s demands, leading to the accumulation of break down products in the blood stream. These break down products are what cause the skin damage we observe as clinical facial eczema. However, we can also see signs of subclinical facial eczema due to liver damage, which may be affecting more of your herd than you know. There is an increased risk of developing facial eczema when spore counts rise above 30,000. 

Spores of fungus Pithomyces chartarum, producing the toxin sporidesmin, which causes liver damage.

What are the Risk Factors?

The main risk factors are anything that favours the sporulation of the fungus. These include

·         High humidity

·         Warm overnight temperatures (over 12oC) for at least three consecutive nights

·         Pasture with high amounts of dead litter (ie ryegrass)

Monitoring on Farm

Multiple studies have demonstrated that spore count not only varies by farm, but also by paddock. Therefore, relying on our monitoring farms may not paint a true picture of your farm’s risk. We offer spore counting for $30 (for four paddocks) at the clinic over the risk period, so if you would like to assess your farm’s risk, please feel free to bring us some samples.

Collecting a grass sample

·         Collect from the same paddock each time.

·         Cut a handful of grass with scissors or a knife, at 1cm above the ground level (grazing level) and place into your sampling container.

·         Repeat the procedure at least 10 times, from random areas at least 10 steps apart in the paddock.

·         Avoid parts of the paddock sheltered by trees and hedges and try not to contaminate the sample with soil and roots.

·         Bring to the clinic for testing

Signs to look out for in cattle

·         Drop in production

·         Skin lesions (ie sunburn, sloughing of the skin)

·         Kicking at gut (‘colicky’ signs)

·         Swelling of eyelids or vulva

·         Blood in urine

Prevention

When spore counts begin to trend towards 30,000, it is time to start supplementing with zinc. Zn supplementation must be initiated 2-3 weeks before the risk period. Zn works by damaging the toxin before it can affect the liver. For your cows, we recommend supplying multiple sources of Zn (ie both in the meal and dosatron). Four young stock we have plenty of FaceGuard Zn bullets in the shop to provide protection for six weeks, so you can effectively set and forget.

Another approach taken by some farmers is to spray high risk paddocks with a fungicide, or graze alternative forages over the risk period.

But what about copper?

Copper binds zinc in the body, thereby making it ineffective. Therefore, it is counterintuitive to be supplementing them together, as copper will limit the effect of the zinc. We recommend stopping copper supplementation and resuming at the end of the risk period.