What do recent studies reveal about mycotoxin co-occurrence across grain, feed ingredients, and finished feed?

Introduction

Grain, feed ingredients, and finished feed are routinely tested for mycotoxins to support quality, compliance, and risk management decisions. Recent peer-reviewed research suggests that the question may no longer be whether mycotoxins are present, but whether testing programs capture the full range of contaminants present in a sample.

Many monitoring programs have historically focused on individual contaminants, such as aflatoxin, deoxynivalenol (DON), fumonisins, or zearalenone. While these toxins remain important, a growing body of literature indicates that frequently multiple mycotoxins occur together. Testing programs only report the mycotoxins measured, which may not provide the full picture. In other words, a result can be accurate and still be incomplete.

Across both grain and feed systems, multiple mycotoxins are increasingly understood to be the norm rather than the exception.

This has practical implications across the supply chain, where materials are evaluated at multiple points as they move from grain to finished feed. Decisions at intake, in the laboratory, and in formulation are based on the data available at that moment. When that data is limited in scope, the picture guiding those decisions may not always be complete.

Co-occurrence begins in grain

Large-scale survey data indicate that co-occurrence is common at the earliest stages of the supply chain. In a seven-year study of corn grain and corn silage in the United States, Weaver et al. (2021) reported that 90.2% of corn grain samples and 96.8% of corn silage samples contained two or more mycotoxins, with an average of 4.8 and 5.2 mycotoxins per sample, respectively.

Regional data reinforces these findings. Fusilier et al. (2022), analyzing maize grain harvested in Michigan, reported that every sample contained multiple mycotoxins, with at least four detected in one year and six in another, with several toxins frequently occurring together rather than in isolation.

These results indicate that co-occurrence is not an isolated condition. It is a consistent feature of grain entering feed and food supply chains. Identifying a single mycotoxin therefore does not necessarily characterize the contaminant profile of the sample.

Co-occurrence extends beyond harvest

Co-occurrence does not end at grain intake. It continues through feed ingredients and finished feed, where contamination may reflect a combination of field conditions, storage environments, and ingredient blending.

Pokoo-Aikins et al. (2026) evaluated poultry feed and feed ingredients across more than 570 samples and reported fumonisins in 86% of samples, DON in 45%, zearalenone in 36%, and aflatoxin in 10%. All corn and finished feed samples contained at least one mycotoxin, and more than half contained multiple contaminants.

Importantly, the study found that co-contamination patterns were consistent in both corn and finished feed. This indicates that mycotoxin risk is not confined to a single stage of the supply chain but persists throughout it.

When incomplete screening becomes visible

The limitations of single-analyte testing are not always apparent at the point of initial screening. In many cases, they become visible when materials are evaluated again in a different context.

A shipment may meet criteria for one mycotoxin while other contaminants remain unexamined, or an ingredient may be accepted for use based on partial information. In some cases, additional testing is triggered later or materials already in process are reconsidered as new information becomes available.

In practice, this often means that a result initially considered acceptable may need to be revisited when additional information becomes available.

In these situations, testing has not failed. It has provided a view aligned to the scope of the assay performed. For operations responsible for grain quality, formulation, and production, that distinction becomes operationally significant.

Operational impact and economic context

At the operational level, the effects of mycotoxin contamination are not abstract. They can appear as discounts, rejected loads, additional testing requirements, and adjustments to ingredient use or production plans.

Recent studies continue to demonstrate how frequently these decisions occur under real market conditions. For example, Postma et al. (2023) reported that only about 41% of harvested maize fell below the 20 μg/kg threshold, while 38% fell between 20 and 300 μg/kg—a range that may trigger discounting or rejection at the grain elevator.

The implication is straightforward. Incomplete visibility does not eliminate risk. It can shift when and where that risk becomes visible, often at the point where a decision must be confirmed, reconsidered, or delayed.

Expanding insight within operational constraints

The prevalence of co-occurrence is well established. The challenge for many organizations is how to respond without introducing additional operational burden.

Expanding monitoring scope can require additional extractions, increased testing time, and greater laboratory workload. For facilities managing high sample volumes, those constraints are significant.

As a result, the priority is not simply broader testing. It is broader understanding that remains practical within existing workflows. Approaches that allow multiple mycotoxins to be evaluated from a single extraction can expand visibility without proportionally increasing complexity.

A practical path forward

The question facing feed and grain operations is no longer whether multiple mycotoxins are present. The question is whether current testing approaches provide a complete enough picture to support confident decisions.

A result may be accurate for the analyte tested, but still incomplete in the context of co-occurrence. Bridging that gap requires approaches that align analytical capability with operational reality.

Expanding mycotoxin monitoring with Waters VICAM Solutions

In a supply chain where multiple mycotoxins are common, the most important risk may still be the one that hasn’t been measured. The evidence is clear: multiple mycotoxins are frequently present within the same sample. The remaining challenge is not awareness, but how to expand visibility without adding time, complexity, or additional testing steps.

Waters VICAM Myco 5-in-1 PLUS workflow, used with the Vertu Touch platform, enables the analysis of six mycotoxins from a single extraction. By consolidating multiple assays into one workflow, food safety and quality teams can reduce total testing time while maintaining precise, quantitative results.

Results are delivered in less than 10 minutes per assay, excluding sample preparation, allowing decisions to be made within the same workflow rather than across multiple testing steps.

The ability to evaluate multiple mycotoxins in a single method reflects a shift toward testing strategies that better align with the reality of co-occurrence.

Take the next step

Expanding the scope of mycotoxin testing does not require expanding complexity.

With Waters VICAM, one extraction enables a more complete mycotoxin profile without adding additional steps, time, or complexity.

• One extraction, six mycotoxins

• Reduced testing time by eliminating separate assays

• Quantitative results delivered rapidly within a single workflow

Multi-mycotoxin monitoring enables a more complete view of contamination risk while preserving the speed and efficiency required for everyday operations.

Visit VICAM.com or connect with a VICAM representative to learn more about Myco 5-in-1 PLUS.

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References

1. Weaver, A.C., Weaver, D.M., Adams, N., & Yiannikouris, A. (2021). Co-Occurrence of 35 Mycotoxins: A Seven-Year Survey of Corn Grain and Corn Silage in the United States. Toxins, 13(8), 516.

2. Fusilier, K., Chilvers, M.I., Limay-Rios, V., & Singh, M.P. (2022). Mycotoxin Co-Occurrence in Michigan Harvested Maize Grain. Toxins, 14(7), 431.

3. Pokoo-Aikins, A., Mitchell, T.R., Read, Q.D., Shanmugasundaram, R., & Glenn, A.E. (2026). Mycotoxin Occurrence in Poultry Feed and Feed Ingredients. Journal of Applied Poultry Research.

4. Postma, K., et al. (2023). Economic benefit of co-regulation to manage aflatoxin risk in maize. Heliyon.