Facial eczema is a cause of major production losses in dairy herds.

When moisture, high ground temperatures and humidity all occur together, the offending fungus present all year round becomes a problem. Under these conditions the fungus grows rapidly and spores are produced containing the toxin Sporidesmin which damages the liver and prevents removal of chlorophyll break down products from the body. This ultimately causes photosensitisation or ‘sunburn’ when the cow is exposed to sunlight. This is usually seen 10 days after exposure to the spores. The first thing you may notice is a drop in milk production and affected cows may seek shade, have swollen legs or brisket, fat ears, red skin or burnt teats.

KEY STRATEGIES TO FE PREVENTION:
1) GRAZING

• Spore counting & then selectively grazing safe paddocks – obtain spore count information from your local vet or get spore counts done on pasture samples from your own farm and send them to your vet for testing
• Avoid hard grazing of paddocks as the toxin is concentrated at the bottom of the sward
• No topping of grass as this allows build-up of leaf litter
• Provide alternative feeds (maize, silage, brassica crops, hay) during high risk times

2) ZINC DOSING

Zinc forms a stable complex with sporidesmin preventing damage to the liver. For best protection zinc dosing should be started 2-3 weeks before spore counts start to rise (December – January.)