In the previous two articles in this series, the focus was on the prevention of mycotoxin contamination, and the value of mycotoxin analyses. Mycotoxins can cause a lot of problems without a well-thought-out prevention strategy in place. In fact, even with a good strategy, toxins will still be present. The aim is not to prevent all contamination, but rather to limit mycotoxin contamination as far as possible.
The golden rule
A good rule of thumb is to accept the fact that toxins are present, despite visual appearance and test results. Material that is visibly heavily infected should obviously be removed and destroyed and should under no circumstances be used as animal feed. If it is used, it can lead to deaths in the short term and cause production losses in the long run.
The vast majority of mycotoxin contamination cannot be seen with the naked eye and is not necessarily identified by tests and analyses. If test results do show that toxins are present, it is normally already a bigger problem than the test indicates. As discussed previously, tests can be of limited value if the information is not correctly applied. A positive test for one toxin is not a guarantee that there are no other toxins present, because toxins always occur together with others.
Subclinical mycotoxicosis
Mycotoxins act synergistically when more than one type is present. In other words, one plus one often adds up to more than two. Long-term exposure to low levels of different mycotoxins will have various negative impacts on production and the general health of animals, which may go unnoticed. It is this subclinical mycotoxicosis that can cause huge losses in the long run.
A relatively simple way to monitor the general health of a herd is by measuring and monitoring somatic cell count (SCC). Rapid and sudden increases in the SCC associated with changes in the ration, for example, feed from a new silage bunker or a consignment of lucerne, can indicate a problem. In the same manner, continually high counts may indicate a constant exposure to mycotoxins. A high SCC is not a specific symptom of mycotoxicosis, but it does indicate a systemic infection and inflammation that can have various causes, of which mycotoxins are one.
Basic binders
The most basic mycotoxin binders are specific types of clay that bind polar toxins to a greater or lesser extent. These are, however, inefficient against non-polar toxins. Enzymatic mechanisms are used to break down non-polar molecules, including various remedies from natural extracts, bacterial enzymes, and probiotics. The cheaper, clay-based binders have limited efficiency, while more expensive binders use a variety of mechanisms to bind toxins, detox, and counteract consequences.
There are also some good, multifunctional mycotoxin eliminators that do not only bind toxins and detox them, but also support the immune system of the animal to counteract the consequences of mycotoxins and, therefore, help to lower the SCC and to limit unseen losses. The biggest loss is the one that passes unnoticed, as a slightly lowered pregnancy rate, a few more false heats, a few more multiple inseminations, and a litre of lost milk here and there.
All these little jackals work together and can cause huge losses in the long run. Mycotoxins have a direct and lasting effect on the milk cheque. It is completely worthwhile to invest in a good mycotoxin management strategy, with a good mycotoxin eliminator as a last line of defence to limit mycotoxin contamination.
Download the full article in Afrikaans in PDF format here, as published in the July 2021 issue of The Dairy Mail.
Heinrich Jansen van Vuuren holds a BSc in animal science from the University of Pretoria and is the team lead for amino acids, companion animals, and aquaculture at Chemuniqué.