Although the spore counts have been zero to low in the last two months, there seem to be some signs of facial eczema around. How can this happen?
If you are grazing turnips, rape or swedes as a summer feed there is a chance you see photosensitisation signs, the same as with facial eczema. This doesn’t have to be caused by facial eczema spores but rather caused by progoitrin (a compound in turnips and rape).
Normally this progoitrin is broken down in the rumen. BUT if animals are suffering from rumen acidosis (a lower pH in the rumen) this is not broken down and it affects the liver the same way as facial eczema does. If the liver is damaged, chlorophyll (the green stuff from pasture) cannot be broken down in the liver and it will react with sunlight in white skin.
Yes, liver enzymes go up and there will be skin lesions. Zinc supplementation would do nothing to prevent this photosensitisation from rape or turnips though.
Changes in diet and/or management, to prevent rumen acidosis and an overload by individuals, help prevent these photosensitisation cases in your stock.
If you have any skin issues while feeding turnips or rape, please ring the clinic!
We can distinguish what is the cause and can treat and prevent more cases.