Mycotoxins: The Invisible Profit Killer

Part 2 – Harvest Insights for your Operation

While mycotoxins are rarely the first factor considered when evaluating potential reasons for losses in growth performance, reproductive efficiency, or health outcomes, we are strong advocates for awareness of this “silent killer” in feedstuffs and associated potential negative consequences in livestock. With 2022 corn harvest in the Midwest just weeks away, and albeit likely later than “normal”, now is the time to begin planning and penciling the economic benefits of testing, awareness, and mitigation strategies for the business. With Increased variety in feed ingredients, from cereal grains to DDGS, bakery product or forages, diligence should be done to minimize the economic impact mycotoxins will likely have on your business.  

Weather, why does it matter to my feeding program? 

As discussed last month, environmental conditions are a major player in the development of disease, mycotoxin pressure, and ultimately have a large influence on economic losses in livestock and crop production. Weather models leading up to harvest indicate 2022 is in a similar pattern to 2018, the warmest La Niña summer on record to-date and a substantial mycotoxin year. La Niña is when the sea surface temperature along the equator in the eastern Pacific Ocean is at least 0.5°C cooler than the long-term average. That is something that we have seen during the last two winters: 2020-2021 & 2021-2022, causing highly variable conditions to occur throughout the northern half of North America (  With these highly variable conditions throughout most of the corn belt, we rely on these models to anticipate the impact mycotoxins may have on production. National Weather Service models indicate the warmer and drier than normal pattern is expected to continue through the first half of the meteorological autumn (Sep 1 – Nov 30) which opens the door for increased risk of aflatoxins and fumonisins (Drought monitor). Still, the variability remains, as some regions of North America continue to experience wetter than normal conditions, leading to increased risk of trichothecenes (including deoxynivalenol aka “vomitoxin”, nivalenol, etc.) and zearalenone this harvest year. is a useful tool for tracking current conditions in your area. 

(Climate Prediction Center, National Weather Service, 2022) 

(La Nina: How does it impact our winter locally, 2022)

(National Weather Service, 2022) 

(National Weather Service, 2022)

Market volatility  

It is no secret that the strength in the grain and oilseed markets has been cause for heartburn over the course of the last year. This volatility creates an even greater sense of urgency for awareness as to what is in the field, how it translates to the bin and what mycotoxins are going to need to be mitigated in the next 12 months. The trade is moving into what feels like a seasonal shift as the global markets prepare for North America harvest timelines.  Demand for US goods will drive the trade as it seems the lower US corn yield has been factored into the market. These factors, combined with higher priced inputs offer us the opportunity to encourage livestock producers to be aware of the multiple factors of mycotoxins in their feed ingredients of choice, and the factors that play into affecting ruminant and monogastric species, alike.  

How to know if mycotoxins are present

Visual inspection alone is not a reliable indicator of mycotoxins, so screening your grain is an important step in understanding the level and type of contamination present in your feed.  Rapid test kits are available that can be administered locally and quickly to help inform your operation of the mycotoxin pressures in your raw feed ingredients. Submitting samples for analysis to a mycotoxin service lab is another option to screen feeds which can provide a broad-spectrum analysis using advanced methodologies that are validated on complex feeds.  

Potential consequences in livestock

Although mycotoxin contaminated feedstuffs may not be the first factor considered when evaluating potential reasons for poor health, growth, or reproductive performance in livestock, fungal metabolites can impact all these areas. According to reported US mycotoxin surveys, there have been a variety of mycotoxins detected in cereal grains, oilseeds, by-products, silages, pasture grasses, and harvested hays in all regions of the US in recent years. The frequent occurrence of mycotoxins in feedstuffs suggests that exposure to mycotoxins is likely more common than many people realize. Therefore, the consideration of mycotoxins as contributing factors in cases of poor health and performance of livestock is justified. 

The clinical signs and financial costs of mycotoxins can vary depending on the level and duration of exposure, the type of mycotoxin(s) present, the age/sex/breed, and the presence of other health challenges. Additionally, the presence of multiple mycotoxins can lead to synergistic effects, resulting in more severe outcomes compared to individual toxin exposure. Therefore, the outcomes following consumption of mycotoxin contaminated feeds vary when it comes to the signs observed on farms and the extent of the economic impact as well. 


Mycotoxins can impact pigs in different ways. From reproductive impairment to digestive disorders, respiratory issues, and ear and tail necrosis. We see swollen vulva in the newly born piglets, and piglets born with splay legs due to the mycotoxins in sow feed that are carried over through the placenta and milk. Ear and tail necrosis caused by various toxins can contribute to vices like ear and tail biting. Additionally, mycotoxins can cause immune dysfunction which can decrease vaccine efficacy and increase susceptibility to various diseases. They can increase the severity of health challenges for example PRRS, PED, and E. coli challenges. Therefore, there are other health concerns with mycotoxins that we need to consider beyond feed refusal and reduced growth. Losses due to mycotoxins can potentially reach $1,000 per sow and the number can multiply quickly when adding the losses on piglet growth. 


Although poultry are considered more resilient to mycotoxins than some other livestock, they are not immune to the harmful effects. As with other livestock species, the negative effects of high concentrations of mycotoxins in poultry diets are two pronged: direct and indirect. Direct effects include lesions and inflammation of the gastrointestinal tract (e.g., necrosis in oral mucosa), which can lead to diarrhea, impaired feed intake, and sub-optimal nutrient digestion and absorption which can ultimately weaken feed conversion ratio. For breeders, mycotoxins such as zearalenone can directly affect the reproductive tract and reduce egg production, fertility, and hatchability.  Indirect effects include predisposing birds to bacterial infections such as necrotic enteritis, Salmonellosis, BCO lameness, etc., because of compromised gastrointestinal integrity and immunosuppression that can lead to vaccine failure. With increasing feed costs, these negative impacts on performance and health can carry a hefty financial consequence.    


Ruminants are often thought to be less sensitive to mycotoxins due to natural detoxification in the rumen. However, the extent of protection depends on the type and concentration of mycotoxin present and may be limited by increased passage rate in high-producing cows as well as low rumen pH. Therefore, toxins can persist, and cause negative effects in the cow. The severity of negative effects from mycotoxins in cattle is influenced by several factors including the type of mycotoxin, age of the animal, health status, and the duration and degree of exposure. Animals exposed to a high level of mycotoxins and/or long duration of exposure may show clinical signs of mycotoxicosis, which range widely from reduced feed intake, poor growth, immunosuppression, impaired reproduction, or even death. Low to moderate levels of toxins may cause subclinical signs that are not readily observable, but can still cause poor growth and reproductive performance, leading to economic losses.  

In many livestock operations, mycotoxins are only considered as a potential contributing factor to herd or flock health once other causes of have been ruled out or addressed. Whereas proactive screening of feeds can identify potential mycotoxin challenges early and guide development of a comprehensive mycotoxin risk management strategy which can help limit losses on-farm. As we move into 2022 harvest, if you would like to learn more about the services and mitigation options dsm-firmenich offers, including the first and only FDA-approved product for degradation of fumonisins in swine and poultry feed, our sales and technical teams would be happy to discuss options to minimize the financial impact mycotoxins can have on your operation through testing and addressing risk in your operation. 

Climate Prediction Center: ENSO Diagnostic Discussion (

2018 - hottest La Niña year ever recorded » Yale Climate Connections

Published on

19 September 2022


  • Swine
  • Poultry
  • Ruminants
  • Mycotoxins

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