Successful Zinc Supplementation

It is common knowledge the role zinc has to play when it comes to facial eczema. However, the success of zinc supplementation is one to deep dive into, to ensure that each animal is getting the right amount of zinc. The key steps to mitigation are to firstly manage pasture quality, watch animals for signs of facial eczema and have a zinc program ready.

Zinc is a preventative measure for facial eczema. It is important to be aware it can take up to 3 weeks after the start of treatment before enough reserves are built up in the liver for supplementation to be effective. Implementing a program to protect cattle from the damage of facial eczema requires identifying the high-risk period and taking early preventive measures. The ideal conditions for facial eczema spores to increase are when humidity is high and overnight temperatures are above 12 degree C for three consecutive nights and generally from December through to May.

Facial eczema results from stock ingesting spores of Pithomyces chartarum, a fungus that is found in many ryegrass pastures. The spores of the fungus release a potent mycotoxin known as sporidesmin in the gastrointestinal tract of the animal. In warm moist summer and autumn conditions the fungus can rapidly multiply within the sward, thus increasing the risk to animals. 

Initial signs of a problem include reduced dry matter intake which leads to a drop in milk production and weight loss. Subsequently animals, may be irritated and seek shade due to photosensitivity, which presents as reddening and flaking skin on hairless areas and white skin areas exposed to the sun i.e. skin along the back, under front legs, udder, teats and around the eyes, ears, and nose. However, skin damage is secondary to liver damage and many cows will not show external symptoms of facial eczema, but they can still suffer liver damage.  

Pasture with more dead matter in the base tends to have higher spore counts, as this helps to trap moisture and provides ideal growing conditions for the fungus. Good pasture management can complement zinc supplementation in the control of facial eczema. Carefully managed pre- and post-grazing helps reduce the toxicity of pasture as dead matter levels are low, minimising the potential for high spore counts. 

Complementing farm mitigation practises, by supplementing with zinc in the herd’s water is an easy option. SealesWinslow Zincmax+ is an effortless product to use, dissolving easily and with a unique peppermint flavour to overcome the bitter taste of zinc. It is important to disguise the taste as the bitterness discourages cows from drinking enough water to receive the full dose of zinc to treat facial eczema. The addition of organic copper helps offset the depletion effect of prolonged use of zinc at high levels and allows stock to maintain healthy copper levels. 

To ensure the zinc product is right for your farm contact your local SealesWinslow Technical Sales Representative.





For the prevention and treatment of facial eczema in dairy cows. Zincmax+ is a peppermint flavoured blend of water soluble zinc, combined with organic copper.