Facial eczema is caused by the ingestion of toxic spores produced the Pithomyces chartarum fungus, that grows in the dead pasture litter layer of the pasture. Monitoring of the numbers of these spores is a useful tool to help with the timing of preventative measures.
Regular testing is a proactive tool that gives a good indication of the overall disease challenge that your animals face. Results may range from zero to several hundred thousand spores per gram of pasture.
The disadvantage with pasture spore counting is that it can be difficult to sample in exactly the same manner as your animals graze. There can be large variations in the spore count between different parts of the same paddock and between paddocks.
The sampling site depends on the type of farm and the management policy. If all the animals are in one group only the paddocks due to be grazed need be sampled. If set stocked then sample the dangerous paddocks.
Points to note
Take samples at least 3 times a week, more often if the weather favours spore production. Spore numbers will rise in the absence of rain if the weather is humid, particularly late in the season. Numbers do not always rise immediately after rain and the peak may occur up to a week after the last fall.
Traditional monitoring of facial eczema has relied on counting fungal spores in the pasture. However, this method can be unreliable because of large variations in the spore count between different parts of the same paddock, between different paddocks and different farms. It is also very difficult to sample in exactly the same manner as what the animals are going to graze.
Faecal spore counting involves counting the spores that have actually passed through the animal (they pass through the intestinal tract unchanged). This gives a very accurate assessment of actual spore intake by the stock and avoids the variability seen with pasture spore counting.
Once the risk to stock has been assessed, then appropriate measures can be taken. High frequency monitoring means that problems can be detected before significant production loss sets in.
Our faecal spore counting service is available to farmers though Ravensdown. This is accessed via a special faecal spore counting test kit (similar to a self-sampling soil test kit).
Samples collected by the farmer will be sent in the courier pack and results will be relayed back to the farmer via one of the Ravensdown animal health team.
Full instructions are included on the submission form in the sampling kit.