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Diverse Weather Setting the Stage for Mycotoxin Risk

Understand your mycotoxin risk from this years corn harvest is critical for reducing negative effects on production and performance.

If we learned anything from 2020, it is that we cannot control everything. For instance, we can’t control the weather, but we can work to control the mycotoxin risk it presents. Weather is the main influencing factor when it comes to mycotoxin risk, leading to a variation in risk levels across the U.S. This year is no exception to that trend, with mycotoxin levels having a wide distribution in the U.S. corn harvest. Mycotoxins can be responsible for the loss of production and efficiency in our animals — a duo we are not interested in.

What are mycotoxins?

Molds and fungi on crops naturally produce mycotoxins. Mycotoxins are ever-present on-farm but can vary in severity based on feed sources, storage and growing conditions. The three most common types of mycotoxins include Aspergillus, Fusarium and Penicillium. Aspergillus is responsible for aflatoxin B1, which can be more abundant with increased drought stress and dry field conditions. Trichothecenes and zearalenone are related to Fusarium. Trichothecenes are common field toxins in grain and silage, and swine are particularly impacted by this mycotoxin because they are considered a more sensitive species to deoxynivalenol (DON). T-2/HT-2 toxins and other trichothecenes are the most toxic for most species, while ochratoxins and citrinin are related to Penicillium. When an animal consumes mycotoxin-contaminated feed, there is risk of reduced production, immune suppression and decreased overall efficiency.

Learn more about mycotoxins at

2020 Harvest Analysis

Dr. Max Hawkins, Alltech’s mycotoxin and harvest expert, presented his analysis, giving an insider’s view on this year’s crop, during the 2020 U.S. Harvest Analysis.

Crops are influenced by weather as we go through the growing season, leading to regionalized mycotoxin risk based on weather patterns. The Corn Belt had moderate to severe drought conditions throughout the growing season, in addition to wind-storms, which also affected corn crops. The Eastern U.S. saw above-normal rainfall on heat-stressed and dry crops. It should be noted that while the overall risk is normal this year, where the risk is high, it is notably high. These risks can be manageable if we are able to feed the average, which is why we need to do testing to evaluate what the potential maximum levels are.

Mycotoxin risk breakdown by species:

The 120 corn samples that were analyzed by Alltech 37+ contained an average of 5.9 mycotoxins per sample, with 50% of these samples considered moderate- to high-risk and 50% low-risk. While corn in general is relatively low-risk, pockets of high-risk samples could be an increasing concern with lower corn yields. If we are not able to be as selective when feeding corn, we may get into feeding higher-risk corn, or higher-risk feed ingredients may be used to compensate for less corn in the diet.

  • Swine

The mycotoxin risk for sows is moderate to high, specifically related to DON and zearalenone, both of which present risks high enough to impact sow reproduction and performance. Grow-finish pigs are also affected by DON, which can impact gains, gut health and feed efficiency.

"sow mycotoxin risk chart"

  • Poultry

Overall, the samples showed a low to moderate mycotoxin risk for poultry, with the risk increasing the farther East the samples came from. Compared to swine, poultry are projected to have a lower risk from DON, but the risk presented by mycotoxins is still high enough to impact gains/feed efficiency and gut health.

  • Ruminants

The 273 samples of corn with a high moisture content (HMC) included an average of 6.1 mycotoxins per sample, creating a distribution of 60% low-risk and 40% moderate- to high-risk samples. On average, there is a low risk for beef and cattle; while the presence of mycotoxins has the potential to affect performance, overall, this risk is very manageable. Producers in the East and upper Midwest are projected to have the highest risk due to dry conditions followed by heavy rainfall.

The data from 2020 suggests much more prevalent and higher levels of aflatoxin B1, which should be of particular interest to dairymen. Dairy producers should monitor and test for mycotoxins in corn silage, especially if their operations are located in high-risk areas. Additionally, aflatoxin B1 can convert to aflatoxin M1, which can be excreted in the milk, leading to food safety concerns.

"dairy cow mycotoxin risk chart"

Managing mycotoxins

There will always be mycotoxins in feed, but knowing what they are and what risk level they pose is critical to mycotoxin management. The Alltech 37+ mycotoxin analysis test provides a realistic picture of the mycotoxins in feed ingredients or TMRs. This comprehensive test allows for quick diagnosis, effective remediation and planning for future control measures. To learn more about having a 37+ test completed on your farm, please visit the Alltech 37+ mycotoxin page.

Dr. Hawkins recommends testing each time you change your feed or introduce a new feed ingredient in order to properly measure your mycotoxin risk. Going forward, risk levels can change based on fermentation, and we need to watch out for “storage mycotoxins.” There have been forecasts of a dry spring, but the mycotoxin risk is fluid and always changing.

To watch the complete 2020 U.S. Harvest Analysis, click here.