Are we underestimating our mycotoxin risk?
To assess an operation’s mycotoxin risk, the mycotoxin type and concentration must first be determined. Mycotoxin testing types are generally classified into either rapid test methods or the more advanced laboratory-based detection. The primary rapid test methods include lateral flow devices (LFDs) and enzyme-linked immunosorbent assays (ELISA). Of the lab-based methods used for mycotoxin analysis, high-performance liquid chromatography and ultra-performance liquid chromatography with tandem mass spectrometry (UPLCMS/MS) are two of the most widely recognized.
The test method influences the risk assessment
As a greater number of mycotoxin types are analyzed, a better picture of the total mycotoxin risk can be determined. But what happens if a test only looks for a limited number of mycotoxins in the first place? Traditional mycotoxin guidelines that only consider one mycotoxin at a time are not always helpful for gaining a better understanding of the true risk of exposure for the animal.
This lack of information about the total risk is why the Alltech Mycotoxin Management team developed a tailored risk assessment method in 2012. Known as Risk Equivalent Quantity (REQ), this method provides feed and livestock producers with a unique way to identify the true risk associated with the presence of multiple mycotoxins in raw materials or finished feeds. Using the REQ value to compare the difference between assessing one mycotoxin, six mycotoxins or 54 mycotoxins, it is possible for producers to see how much they might be underestimating their risk if a test only analyzes the feed for a limited number of mycotoxins.
Mycotoxins in corn grain and the risk for monogastric animals
Based on samples analyzed by Alltech 37+ over a five-year period between 2018 and 2023 (Table 1), if aflatoxin (AF) was the only mycotoxin measured in the feed, the mycotoxin risk for sows would be underestimated by 96% (Figure 1). This makes sense, as aflatoxins were only detected in 9% of those samples, whereas other mycotoxins were detected more frequently.
In situations where the only option is to test for one mycotoxin, analyzing samples for deoxynivalenol (DON) is slightly better than analyzing for AF, as doing so led to an underestimation of 77% of the risk to sows. Still, there are many mycotoxins that are typically present in corn that are yet to be accounted for. When corn grain is analyzed for all six mycotoxins that can be detected through a rapid test method, the overall risk assessment is closer to what would be delivered by testing for an increased number of mycotoxins.
A similar underestimation of risk would occur for poultry. Using the same corn grain samples mentioned above, the risk assessment would be underestimated for broilers by 92% or 59% when the analysis only considered AF or DON, respectively (Figure 1), whereas an analysis of six mycotoxins reduces that risk underestimation to 21%. The presence of fusaric acid and other emerging mycotoxins would not be detected by rapid test methods, but many of the mycotoxins posing the greatest risk to pigs and poultry — such as DON, zearalenone and T-2/HT-2 — would be included.
Figure 1 – Differences in risk assessment in corn grain and corn silage (to broilers, sows and dairy cows)
Corn silage and dairy cows
Similar to grain, total mycotoxin risk assessment of corn silage can vary depending on the mycotoxins analyzed (Figure 1). In this case, assessment for only AF could result in a 99% underestimation of total risk for dairy cows, as AF was detected in only 9% of samples, with the majority of these containing very low concentrations (median <1 ppb). Sample analysis for only DON would be better — in this case, a 60% underestimation of total risk — but again, many key mycotoxin groups would not be detected. Assessment for 6 mycotoxins comes closer to the total risk assessed by the more advanced laboratory method, but this assessment in corn silage does not get as close to those results as the similar assessment in corn grain. This may be due to the higher occurrence and concentrations of mycotoxins such as fusaric acid, Penicillium mycotoxins and Aspergillus mycotoxins in corn silage.
Using readily available data, the comparisons in these examples were made using Alltech 37+ as the most comprehensive risk assessment method. This method identifies 54 individual mycotoxins. If other LMCS methods were used to identify an even greater number of mycotoxin types, the potential risk underestimation when only relying on rapid test methods would likely be amplified.
Mycotoxin testing plan
Although assessment of a limited number of mycotoxins by simpler analytical methods may not provide the full picture of an animal’s exposure to mycotoxins, these rapid test methods are still a valuable and accurate means of testing for mycotoxins. Many of these rapid test kits have been validated, with validation results published in scientific journals. The best mycotoxin management program is typically based on a combination of on-site rapid testing and laboratory-based analysis. Rapid tests can be used for routine testing where speed and cost are of concern, but periodic mycotoxin testing by laboratory-based methods can be used to learn about more complex mycotoxin mixtures.
Turning analysis into a control program
It is important to remember that at any point in time, the results of the average mycotoxin analysis can only show you a best-case scenario. In those cases, the mycotoxin levels will remain the same in the tested ingredient or ration — but they can continue to increase over time during storage. Equally, the total risk can be greater when multiple ingredient sources are brought together. Without knowing the full mycotoxin profile of a commodity or ration, developing a mycotoxin management program may be difficult. We also learned from the examples included above that analyzing samples for only one mycotoxin can lead to a significant underestimation of the total risk, even if the results for that particular mycotoxin type are accurate. Testing for a greater number of mycotoxins allows for the creation of a more accurate picture of the risk to the animal.
Determining the presence of multiple mycotoxins is important, but there may be a limit on the number of mycotoxins that can be assessed in a ration. More than 500 mycotoxin compounds have been identified, but it is sometimes not possible to routinely test for this number. Furthermore, it is still unknown how many of those mycotoxins impact animal performance and health. However, most mycotoxins are detrimental to animal performance, welfare and profitability.
To effectively combat the mycotoxin risk, a complete mycotoxin management program that focuses on identifying, quantifying and mitigating the risk level is needed. From a nutritional perspective, risk mitigation can be achieved directly within the animal through the use of Alltech’s Mycosorb® range of mycotoxin adsorbents, a family of products that contain yeast cell wall extract and can help to manage the collective mycotoxin challenge in the animal. Recently published meta-analyses with broilers and nursery and grow-finish pigs (Weaver et al., 2022; Weaver et al., 2023) reaffirm that when mycotoxins pose a problem, Mycosorb can play a role in improving performance, efficiency and livability. Mycosorb has even been linked to the improved environmental sustainability of broiler production.
To learn more about the tools and technologies offered by the Alltech Mycotoxin Management program, visit knowmycotoxins.com.
References are available on request.
This blog post is an updated version of an article published in All About Feed on October 23, 2023.