Who knows what’s in store for us this season. The weather has been all over the place with unseasonal dry spells, humidity and the odd massive down pour. With such uncertainty it’s impossible to make any bold predictions with regard to facial eczema this season. So for that reason we have re-printed the FE article that appeared in our newsletter this time last year. If you aren’t on our Spore Counts e-mail list let us know and we will add your details
The Problem:
During periods of warm humid weather a fungus called ‘sporidesmin’ builds up in pasture. When eaten this toxin damages the liver, which in turn results in the build up of waste products that circulate around the body and react to sunlight resulting in the classic signs of facial eczema. FE can be very severe and may kill animals. Usually these signs are quite visual but once they are obvious the animal is already severely affected.
Signs:
Marked drop in milk production
Restlessness at milking time (kicking off cups etc)
Actively seeking shade
Licking of the udder
Obvious redness (“sunburn”) of affected areas, particularly white areas, inside hind legs, udder and teats, tongue, lip margins and vulva.
Dramatic peeling of ‘dead’ skin from affected areas
Likely toxic conditions:
Prolonged periods of warm humid weather
High humidity
Light rain or heavy dews in conjunction with grass minimum temperatures above 12-13 degrees C.
North facing sheltered paddocks, under hedges etc are generally the most likely to have high spore counts
Risk levels:
Spore counting is still the best way to get a handle on likely risk. It is highly variable between paddocks but as a guide:
Low risk: < 20,000
Slight: 20,000 – 35,000 (start water treatment once we get to 20,000 if not already)
Moderate: 35,000 – 70,000 (if you were drenching this is when you would generally start)
High: > 70,000
Care for affected stock:
Dry off milking cows
Make shade readily available
Treat infected skin lesions
Access to plenty of quality feed and water
B vitamin injections, zinc cream for affected areas and ‘Eczema Oils’ or ‘Manderson’s Mix’ to aid recovery
Seek veterinary advice
Management and Prevention Tips:
Make early preparations (around here that means starting to make plans in January usually)
Spore count regularly to find out what the situation is on your property and where the most dangerous paddocks are (regional monitor farm counts are at best a trend indicator for the region)
Never graze stock into the base level of pastures. The fungus grows on the litter at the base of the plant and spores are concentrated there (watch out for re-growth paddocks after hay and silage making)
Prevention Options:
Fungicidal Sprays – they certainly work but timing is an issue and around here where FE is sporadic it might be hard to justify cost. (In the Waikato where FE seems to occur every year, it would just about be a no-brainer). If you were planning on using them they need to be applied before spore counts rise so you would be applying them now
Zinc is still the most workable and cost-effective choice for this part of the world. There are various ways to supplement zinc depending on your situation:
Water treatment- as this is not a direct method you would need to start adding zinc to the water supply in small amounts early (i.e. before spore counts get high and so that cows get used to the taste). Effective in low to moderate conditions; less effective once counts get to danger levels
Drenching- individual drenching is the method of choice once spore counts get high because then you know the cows are actually getting the required dose for protection. Not possible in some situations depending on your shed and so on
Zinc boluses – very useful option for stock away grazing, young stock and so on. At least two versions are available with protection of about 4-5 weeks. Probably not cost-effective in lactating animals due to their size and therefore cost of treatment
For all your zinc requirements and options our Trading manager John Larkin is the man to talk to. Give him a bell