Mycotoxins are toxic substances produced by fungi that grow on plants. These toxins have the potential to cause liver and kidney damage, feed refusal, reproductive failure and immune suppression. The immune suppression can make a disease outcome much worse. The toxin producing fungi belong to three main groups. Aspergillus, Fusarium and Penicillium
fungi are all capable of producing a variety of mycotoxins. Mycotoxins normally need to reach a minimum threshold level before they can cause damage on their own. Multiple mycotoxins working in concert can work together such that small amounts of individual toxins can add up to a bigger problem.
Preventing the initial production of mycotoxins in the field can be difficult in years where the weather is very wet. It is just too easy for the fungi to grow in the field crops. Mold has the potential to continue to grow in storage. This can make an already bad situation even worse. Separating highly contaminated component materials such as “red dog” can help to minimize the amount of mycotoxin that is in the grain as it is harvested. Removing moldy grain from storage facilities between batches can reduce the level of contamination of bin liners and dust. A spray disinfectant can be used between batches on all inside surfaces in order to reduce fungus carry over. The University of Nebraska- Lincoln Extension shares the following sanitation practice:
- Apply an effective disinfectant mix for fungal contamination on non-porous surfaces like grain bins eg. 1/2 gallon of household bleach to 10 gallons of water.
- Wait several days and then rinse the area where the mixture was applied.
Note – Chlorine vapors are dangerous. Make sure that there is lots of ventilation when
working in the bin and never mix bleach with ammonia or vinegar!
It stands to reason that keeping corn cool and dry will also go a long way to minimizing mold growth. Running aeration fans in dry grain storage systems is one way to accomplish this when the climate is colder. The eventual goal in northern climates is to cool grain to less than 30°F (-5°C). Mold inhibitors can also be used in storage to assist in controlling the growth of mold. Mold inhibitors can not eliminate the toxins that have already been produced but can reduce the amount of additional toxins while in storage. Organic acid blends such as propionic, acetic, sorbic and benzoic acids can be used as mold inhibitors.
Sometimes, some of the mycotoxins that have already been produced can be neutralized. Activated charcoal, montmorillonite/bentonite, zeolite, hydrated sodium calcium aluminosilicates (HSCAS), and yeast cell wall-derived agents have been reported to reduce the effective levels of some mycotoxins. The other strategy of course is to blend the problem grain with clean grain. The “solution to pollution is dilution”. In a year like this, however,
finding clean grain can be much easier said than done.
Take Home Message
Eliminating highly contaminated feed components such as “Red Dog” can reduce overall toxin levels.
Some toxin binders may help with some toxins but this is not a silver bullet
The “Solution to Pollution is Dilution” providing that you can find some clean grain.
Submitted by Brent Jones, DVM