DAIRY farmers are being urged to stay informed about facial eczema risk as we head into the high danger period.
Facial eczema is a liver disease (often accompanied by photosensitisation) caused by the spores of a pasture fungus that multiply rapidly in warm and humid conditions.
As summer turns to autumn and rainfall returns, spore numbers will rise and so will the risk to cows.
Some high spore counts have already been recorded this summer, so even hot dry conditions are no guarantee that spore numbers will remain low.
To help dairy farmers manage the risk, Dairy Australia is once again funding the Facial Eczema Pasture Spore Monitoring Program with sentinel farms located in all major regions of Gippsland and the Bega Valley.
The aim of the program is to inform farmers, veterinarians and nutrition advisors when spore counts are rising so that preventative measures (such as supplementing the diet with zinc) can be taken before severe liver damage occurs.
Feeding the correct amount of zinc oxide in grain/concentrates in the bail at milking can be very effective for facial eczema prevention.
If cows are underdosed (e.g. incorrect rate, settling out of the supplement, competition between cows) there may be inadequate protection from facial eczema.
Blood testing of cows in 12 herds last season indicated that protective levels of zinc in the blood was most reliable when zinc oxide is fed in pelleted form.
More inconsistent results were achieved when zinc was fed via a mineral dispenser or in a powdered form.
It is recommended that farmers consider blood testing 10 cows in their herd 30-40 days after supplementation starts to check zinc levels are at the required level and adjust their program if required.
Experience in New Zealand indicates that accurate zinc supplementation at preventative levels is likely to be safe for up to 100 days. After this point, farmers should have blood testing repeated to minimise the risk of toxicity.
More information for farmers and advisors about the disease, current spore counts and facial eczema prevention can be obtained by speaking to your nutrition advisor or vet or by accessing the facial eczema information on the Dairy Australia website.
To subscribe to the Facial Eczema Monitoring Alerts, contact Dr Steph Bullen at firstname.lastname@example.org or on 0417 123 387 or by following the link on the spore counts page.
Be alert of facial eczema