Mycotoxins

Mycotoxin
About Mycotoxins

Mycotoxins are toxic compounds which are produced naturally from fungal species or moulds. The majority of mycotoxins are derived from three main mould groups: Fusarium, Aspergillus and Penicillium. Penicillium and Aspergillus derived mycotoxins are often associated with the storage of feedstuffs and ensiled forages. Penicillium based mycotoxins can often affect the sensory quality of the forage and can affect the palatability of forages, often leading to a reduction in feed intakes. In addition, we have seen an increase in plant head blight this year which has led to a rise in Fusarium mycotoxins (such as deoxynivalenol and zearalenone) in wheat crops in specific areas of the country. "A number of factors increase the risk of mycotoxins contamination of grains" says HGCA scientist Simon Oxley. "These include the previous crop present, for example maize is a high risk crop, and the type of cultivation used as well as high levels of rainfall at flowering and harvest." To help farmers assess the likelihood of mycotoxins contamination, HGCA have developed an online risk assessment tool which is available from www.hgca.com/mycotoxincalc.


Symptoms of mycotoxicosis
With around 500 different types of mycotoxins, the effects of mycotoxin poisoning are often diverse and hard to isolate from other issues. Fusarium derived mycotoxins such as zearalenone have been found to impact on animal fertility reducing embryo survival, decreasing conception rate and causing abortions. Likewise deoxynivalenol, another common Fusarium mycotoxin has been associated with reductions in milk production. In addition, Penicillium based mycotoxins are particularly harmful to rumen health and often weaken the animal's immune system making it more susceptible to other diseases.
If you suspect that mycotoxins may be a problem on your farm it is advisable to test your forages and any home-grown cereals for mycotoxins. New technology has meant testing for mycotoxins has become much cheaper (<£10 per sample). More information on testing can be found on the HGCA website at www.hgca.com/publications/documents/cropresearch/FusariumGuide-Testing.pdf.


 Dealing with mycotoxins
If you have identified high levels of mycotoxins on your farm, introducing rumen buffers, mycotoxins absorbers or particle binders may help alleviate this problem. Alltech's Graeme Smith offers this helpful advice when selecting mycotoxins binders:
• Avoid clay based products: Clay is ineffectual against Penicillium mycotoxins and binds vitamins and minerals, preventing their use by the cow. 
• Select broad spectrum binders: to deal with the broadest range simultaneously.
• Choose fast acting products: in the blood stream within 20 minutes.
• Select scientifically proven products. 
• Be aware of the European Animal Feed Regulations (legislation 767 2009)
• Beware of products purporting to bio-transform mycotoxins.  This can be more harmful than the original mycotoxin.