Warning signs: the wide range of mycotoxin symptoms

Mycotoxins are toxic compounds produced by mould. Experts in the area of mycotoxin research have observed an increasing frequency of large-scale contamination events, and some of these events have been severe enough to influence the trading practices of raw materials. In New Zealand, whilst many view imported commodities as a source of risk, home-grown forages and conserved feed present their own challenges; local survey work screening for a wide range of mycotoxins confirms that mycotoxin contamination is commonplace in New Zealand.

What health problems can mycotoxins cause?

A brief review of symptoms that can be induced by various mycotoxins reveals a broad range of effects. Virtually all mycotoxins depress immunity in animals. This can be the underlying cause by which many secondary symptoms begin to present. Acidosis, retained placenta and metritis can all arise secondarily to immune suppression. Early embryonic mortality, abortions and a high number of services per conception can also be symptoms of mycotoxin challenge.

Diarrhoea, whilst having a number of possible causes, can also be due to contamination by a group of mycotoxins known as trichothecenes. Some mycotoxins can cause lesions by direct contact with the epithelium in the gut. Loss of appetite is associated with mycotoxins, particularly with a compound known as deoxynivalenol. This compound is the most common mycotoxin found in many surveys and is in the top three most commonly detected mycotoxins in New Zealand.

Further symptoms of mycotoxins include irregular oestrous cycles, lack of response to veterinary therapy, udder oedema, presence of ulcers/abscesses in the digestive tract, high somatic cell counts, lethargy, low milk production, gangrene, swelling of the vulva or feet, and lameness.

How can farmers tell if mycotoxins are a problem for their herds?

One of the difficulties of identifying mycotoxicoses is the nonspecific nature of many of the symptoms. Nonetheless, it is becoming clearer that mycotoxins are responsible for more adverse health events than they were previously credited with. Further investigation is often necessary when the above symptoms are presenting. Case history can sometimes add to the accuracy of diagnosing mycotoxicoses.

A common practice to help identify whether mycotoxins are influencing the herd is to include a broad-spectrum mycotoxin binder, such as Mycosorb^® from Alltech, in the feed.

Learn more about mycotoxins at www.knowmycotoxins.com.