Using the on-farm data in the project, scientists were able to show the relationship between the levels of fungi, spores, larvae etc, and the poor live weights of stock.
when the NIV and DON levels in pasture are at 0.8 mg/kg DM, it is likely that the toxic result caused (trichothecenes) will be reducing live weight gain (LWG) by 40g per day in lambs and 200g per day in cattle. Urine patches may have very high levels of fungi (200 times higher than inter-urine patches), although this hypothesis requires further research.
318 pasture samples were collected as part of the project and around 70% of samples were shown to have fungi that produce toxins. However, the presence of toxic fungi does not mean that toxins are being produced, as was shown in further tests where fungi were present and growing, but no toxins could be detected. Trace elements:
in sheep, predicting live weight gain suppression is possible using blood tests for selenium and cobalt but not for copper. This is not possible in cattle.
The degree of live weight gain suppression was not able to be accurately linked with: • the level of eggs in a FEC, although live weight gain will start to be suppressed if above 500 eggs per gram (epg) in lambs and 300epg in young bulls; • the level of copper in a liver test. The good news is that the biggest causes of ill-thrift (parasitism and pasture quality) can be reduced by management (eg, providing stock with higher quality pasture, management to reduce larval contamination of pastures, worm control products). It is best that farmers eliminate these causes first, before tackling the more complex pasture fungi issues.
If you suspect your stock have issues, talk to your vet and work with them to get more information through testing.