Zinc is still the best short-term preventative for facial eczema in cows writes Federated Farmers Bay of Plenty Sharemilkers' Section chairperson Richard Fowler.

There's more to zinc than the '90s craze of smearing children's faces with brightly coloured sun protection.

Last week I attended a DairyNZ discussion group on facial eczema's impact on stock.

It was a great refresher on the cause, effect and prevention options for the disease and included some new information on the effectiveness of different treatment options farmers use.


Some of the key points from guest speaker, Emma Cuttance from VetEnt, were that facial eczema is caused by the spores of the Pithomyces chartarum fungus which get to elevated numbers over the warm, humid periods of summer.

Read more from Federated Farmers here.

Facial eczema is a disease of the liver despite many people thinking it's a skin disease.

Severe sunburn and skin peeling are definitely clinical signs of facial eczema, but, it's the loss in milk production and lack of weight gain that really hit farmers in the pocket - up to $100,000 per year in some cases.

Only 5 per cent of cows will show clinical signs so even if you're not seeing sunburn on the animals, there's a good chance your herd is still being challenged.

Long term approaches to managing facial eczema include breeding facial eczema tolerant animals and growing pasture species that are less likely to host the spores, but the best short-term preventative is still using zinc - although not the stuff you stick on your nose.

Zinc can be given to stock directly as a bolus, as a drench or indirectly by mixing it with animal feed or water.

All methods have their pros and cons but the key to it all is monitoring.


Te Puke Vet Center can spore count your pasture samples and can blood test your animals for zinc levels.

Trials have shown that as few as 30 per cent of animals in a herd can have effective levels of zinc in their system despite the best efforts of a farmer.

My take home message from the discussion group was that the first step in getting control of facial eczema is getting your animals' blood tested to check the effectiveness of your own zinc treatment programme.