Here's What You Need to Know About Mycotoxins and Swine Diets in 2022
By Joel DeRouchey, Mike Tokach, Jason Woodworth, Bob Goodband and Jordan Gebhardt
The 2022 grain growing season in many areas of the U.S. provided weather stress that may have allowed for mycotoxins to be present in harvested grains. Mycotoxins are toxic compounds produced by mold growth in feed ingredients. Although not all molds produce toxins, the most significant mycotoxins affecting swine are aflatoxin, vomitoxin, zearalenone, fumonisin and ochratoxin.
The only clear way to know if any mycotoxins are present is to sample and test ingredients such as corn, distiller's dried grains with solubles (DDGS), and bakery meal, or your complete feed if you do not have the ability to evaluate individual ingredients. While grain terminals and ethanol facilities generally do quick test screening, it may not tell the full story of levels present in feed delivered to your farm.
Detection and Sampling
Mycotoxins are not evenly distributed in grains or feeds. Rather, mycotoxins are often found at high concentrations in ‘hot spots,’ but at the same time may not be found at detectable amounts in other locations. Because of this, the ideal sample should be representative of all the grain or feed. Importantly, the presence or absence of visible mold growth is not a reliable indicator of mycotoxin contamination and should not be used as a sampling criterion.
Management of Mycotoxins
If mycotoxin contamination of grains or feeds is detected, some strategies for mitigation of mycotoxins in swine diets are available. Importantly, strategic feeding should be adopted in any instance of mycotoxin contamination by preferentially feeding finishing pigs instead of nursery pigs and sows, which are typically more susceptible to mycotoxins.
At high mycotoxin concentrations, grains can be blended with clean grains to reduce mycotoxin concentration. However, this strategy may be a challenge when mycotoxin occurrence is widespread in that area. Furthermore, the Food and Drug Administration does not permit aflatoxin-contaminated grains to be blended for commercialization. One important mitigation practice is grain can be screened and cleaned to remove broken kernels and reduce mycotoxin contamination. Misshapen and broken kernels are associated with higher mycotoxin concentrations.
In-Feed Mitigation Additives
The inclusion of mold inhibitors and mycotoxin binders in the feed can be used as a detoxification strategy. Mold inhibitors are used to control mold contamination and prevent mold growth, whereas mycotoxin binders or adsorbents are substances that bind to mycotoxins and prevent absorption through the gut. Mycotoxin binders are not effective against all mycotoxins and must be rather targeted to a specific mycotoxin. Always consult your nutritionist or feed supplier to assure you are targeting the correct mycotoxin with any additive used.
More information about mycotoxins in swine diets can be found in Kansas State University's swine nutrition guide.
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