Warm, wet and worrying for facial eczema

With NIWA’s seasonal weather outlook through to December signalling warm, wet conditions across the North Island, farmers are being encouraged to include preventive measures against facial eczema in their summer farm management plans.

Above average temperatures and rainfall are ideal conditions for the fungus which causes facial eczema to thrive. Spore production occurs when soil temperatures exceed 12 degrees for three consecutive nights and soil moisture is favourable or air conditions are humid.

“After reduced milk production through the spring, the last thing farmers need is another potential brake on it as summer progresses. Prevention is the best approach and starting early with zinc supplementation is a good tactic to get the best protection,” says SealesWinslow Science Extension Officer, Natalie Hughes.

“It takes time to build up protective levels of zinc in animals, so dosing should start two to three weeks before you would expect spore counts to rise. Given NIWA’s outlook for warm wet conditions through to the end of the year, supplementation could be needed in early December.”

Zinc can be sprayed on pasture, dispensed in water, given in boluses or mixed into feed. Long-term use can lead to copper deficiencies in the herd’s diet, which also leads to lost production.

“This can be overcome by using a product like SealesWinslow ZincMax+ which contains organic copper, as well as a peppermint flavouring to offset the bitter taste of zinc which can often make cows reluctant to drink the dosed water.”

Good pasture management can also help guard against rising spore counts. Matching the rotation to feed supply will help ensure that grass growth is optimised. When grass becomes too long, dead matter can accumulate at the base of the sward which will increase facial eczema risk.

Facial eczema is estimated to cost the country around $200 million annually with affected stock suffering liver and skin damage, reduced fertility, reduced milk and meat production.

What to look for:

• The first sign of facial eczema in cows is a drop in milk production occurring soon after the intake of toxic spores.
• Cows are restless at milking time, seek shade, and lick their udders.
• Another drop in production occurs when physical symptoms become obvious.
• Check unpigmented or thin skin which thickens and peels because of sun sensitivity.