Awareness of the threat from mycotoxin contamination has substantially increased in the equestrian community and it’s now increasingly common to try to quantify this threat using commercially available tests.
There are numerous methods to detect and identify mycotoxins ranging from the rapid and cheap to the more extensive and, of course, more expensive. The rapid and cheaper options include tests, such as Enzyme-Linked Immune-absorbent Assays (ELISAs). ELISAs are used for detecting many different compounds, not just mycotoxins, but are what is called qualitative (present/not present) as opposed to quantitative (how much is present). Each ELISA is specific to only one mycotoxin so you need multiple ELISAs to test for a range of mycotoxins and not all the relevant mycotoxins have a commercially available ELISA.
Additionally, ELISAs are not hugely sensitive so struggle to detect low levels of mycotoxins. Another aspect of mycotoxin detection is the presence of masked mycotoxins – these are mycotoxins that are bound to molecules, such as sugars and are often missed by traditional detection methodology, such as ELISAs. Ultimately, this means the actual level of challenge and, therefore, the risk to the animal, is under-reported.
More comprehensive and quantitative methods for detecting mycotoxins are chromatography (liquid (LC) and gas (GC)) and mass spectroscopy (MS). Both these methods can detect multiple individual compounds in one go by looking at the structure of molecules present in samples. These methods require some, often complicated, sample preparation so take longer than more simple tests but they give a better idea of the overall threat from contamination. During sample preparation for LC/GC and MS analysis, masked mycotoxins can be released from the sugar making it ‘visible’ for detection.
The ability to detect and quantify multiple mycotoxins in single samples, such as hay or grass, allows us to better understand mycotoxin exposure. In temperate climates, such as the UK, animals are usually exposed to low levels of multiple mycotoxins rather than high levels of just one, hence, it’s important to ensure that any sample analysed for mycotoxins can detect low levels of a range of different mycotoxins.
One of the most comprehensive commercially available tests for mycotoxin contamination is Alltech’s 37+. Using the latest sample preparation and detection techniques, the 37+ test can test for over 40 mycotoxins at once and is now a routine management tool in many large yards. A combination of LC and MS can detect minute quantities of numerous, relevant mycotoxins, including masked mycotoxins.
One of the unique things about the 37+ is the reporting. Not only are the levels of each mycotoxin reported but an idea of the relative risk to the animal to which the feed sample is being fed (Figure 1). A Risk Equivalency Quantity (REQ) is allocated according to the perceived risk to that particular species and stage of life (e.g. growing, pregnant, lactating). A traffic light system for individual mycotoxins and groups of mycotoxins present is also presented. A list of levels of mycotoxins is near enough meaningless unless it is put into context, which is what the REQ and reporting system does.
Although testing is preferable, it is not cheap and for owners with one or two horses, the addition of an effective mycotoxin binder, such as Forage Guard, can be a useful diagnostic tool. Forage Guard is a natural feed material produced from yeast cell wall, which specifically binds mycotoxins and removes them from the gut. It offers many advantages over the alternative – clay binders – which require high inclusion rates and can also remove key nutrients in the diet.
Ultimately, the threat of mycotoxin contamination is everywhere but the 37+ test, together with other management tools, can be used to make informed decisions about the risk from mycotoxin exposure.
A 5kg tub of Forage Guard® retails at £39 and contains a 100 day supply.
For further information please visit www.lifeforcehorse.co.uk or telephone 01780 764512.