At the Fair Feeding Symposium Prof. Johanna Fink-Gremmels pointed out that mycotoxins are still an underestimated danger in the dairy and cattle industry. After the symposium we spoke to Prof. Fink-Gremmels about this important issue.

Why are fungi unwanted?
More than 100.000 types of fungi exist on earth. If you put the biomass of fungi on one side of the weighing scale and the biomass of the total population on the other side, then the fungi would win. Not all fungi are unwanted. A number of fungi are essential for the transport of nutrients throughout the soil. The unwanted and harmful fungi are those that form mycotoxins.

What are mycotoxins?
Mycotoxins are toxins that are harmful to both humans and animals. The difficulty with mycotoxins lies in the fact that they are invisible and can not be removed from the feed. Mycotoxins affect the immunsystem and organ function of cows. This makes them susceptible to infections. Fertility can also be affected, as toxins might disrupt the hormonal balance.

To which type of fungi should farmers be alert?
First of all Fusarium spp, this fungi is not only harmful to plants but also to livestock. As this fungi forms mycotoxins. In recent years we have seen an increase of these toxins in many animal feed ingredients both in Europe and abroad. Secondly every dairy farmer should know the toxins: DON (deoxynivalenol) and ZEA (zearalenone). These toxins are mostly present in roughage. Additionally Fusarium fungi produce a number of toxins (Enniatins) that have an unwanted antibiotic characteristic which can affect the rumen flora.

In what other ways can cows get exposed to fungi?
Funghi are present at every farm, even on tools, but most of all in silage. This is usually the Penicillium spp, this a storage fungi. First it is white and then it slowly turns blue. Penicillium grows at a low temperature, low pH and requires only minimal oxygen.

You mention the Fusarium and Penicillium fungi, are there any other fungi that are present at a farm?
Yes, the fungi Aspergillus fumigatus, it can be found in the soil and storage locations. Traces of this fungi are present in the particulate matter in the stables, that is why cleanliness is of great importance. Keep everything clean and leave no feed residues. This fungi is able to access the intestines of a cow through the the rumen, where it can cause a lot of damage. This fungi also forms toxins.

As you said earlier fungi can negatively affect the health of a cow. Is it possible to recognize if a cow is exposed to mycotoxins?
You can recognize a lot from the CowSignals. In fact a cow does not show any sickness right away. Signals such as a sudden loss of milk, claw problems, an increased somatic cell count or a bad rumen function (undigested manure) all point towards a presence of fungi and toxins in feed. These signals are often associated with infections, and that’s when antibiotics are administered. However, if toxins are present and they are given no attention, then a treatment with antibiotics does not provide permanent results.

In what way can farmers decrease the effects of toxins?
First of all, acknowledge the risks! Fungi and toxins cannot be avoided entirely, but the risks are manageable. When you pay close attention to the silage, the feeding speed, the cleanliness and food-hygiene at a company then these risks can be kept under control. When you suspect a problem, examine the feed and based on the outcome trace the source of the contamination. A toxin binder can also offer support when the toxin contamination is high.