ST. PAUL, Minn. — On a crisp autumn morning in Kentucky, a hemp farmer kneels in his field, running a hand over the golden stalks swaying in the breeze. A few years ago, these fields were filled with soy and corn. Now, they hold a crop with enormous promise—hemp.
Farmers across the U.S. are eyeing hemp’s potential in animal feed, drawn to its high protein content, essential fatty acids, and fiber. If approved for livestock diets, hemp could reduce feed costs, improve farm sustainability, and introduce new revenue streams for struggling farmers.
But there’s a catch—one that has nothing to do with the plant itself. It’s a microscopic threat, a hidden danger that could upend hemp’s future in animal agriculture.
The Silent Threat: Fusarium and Mycotoxin Contamination
On the surface, hemp looks like an ideal addition to livestock feed. But beneath that nutrient-rich exterior, a fungal menace could jeopardize the safety of meat, dairy, and eggs.
Fusarium, a common agricultural pathogen, has long haunted grain crops like wheat and corn, causing devastating yield losses and contaminating animal feed with dangerous mycotoxins. The same threat now lurks in hemp.
When Fusarium infects hemp, it produces toxins such as deoxynivalenol (DON) and zearalenone (ZEA)—both of which are known to:
Weaken immune function in livestock Stunt growth and reproduction Contaminate consumer food products
Farmers worry that without clear regulations, contaminated hemp feed could unknowingly enter the food supply, damaging the reputation of livestock industries and creating serious economic consequences.
What Research is Revealing
Scientists are now racing to understand just how big this problem could be.
A 2023 survey published in Plant Health Progress found Fusarium head blight (FHB) in four out of five major plant disease diagnostic regions in the U.S.. Another study identified high levels of mycotoxin-producing Fusarium species in post-harvest hemp material.
Yet, despite these warnings, there is no national requirement for toxin testing in hemp feed. Instead, individual states are left to decide their own policies, creating a regulatory patchwork that frustrates farmers and industry leaders alike.
A Lesson from Corn’s Costly Mistakes
If there’s any doubt about what could happen next, the history of corn offers a sobering lesson.
In 1989, Fusarium contamination in corn led to one of the worst livestock feed disasters in U.S. history. Over 1,100 swine in Iowa died after consuming contaminated maize. Elsewhere, horses suffered severe neurological disorders, and entire shipments of grain were rejected by global markets.
It was a financial catastrophe for farmers and feed producers—one that took years to recover from.
Only after these costly mistakes did the U.S. Federal Grain Inspection Service (FGIS) implement strict mycotoxin testing protocols for corn. These regulations restored market confidence and protected livestock health, but they came too late to prevent the initial crisis.
Hemp, still in its early stages as an animal feed option, has the chance to avoid a similar fate—but only if regulatory clarity comes before disaster strikes.
The Struggle for Consistent Regulation
Unlike corn and soy—both of which have strict federal safety standards—hemp remains in regulatory limbo.
The Association of American Feed Control Officials (AAFCO) has provided some guidance, but so far, it has primarily focused on THC and CBD levels rather than mycotoxin risks. While the Hemp Feed Coalition found that 68% of farmers and feed producers see regulatory uncertainty as a major roadblock, there is still no national mandate for Fusarium testing in hemp feed.
A 2022 FDA report highlighted the danger of this inconsistency, warning that without national safety guidelines, hemp feed could introduce supply chain risks and undermine consumer confidence in livestock products.
The Science is Catching Up—Can Policy Keep Pace?
Researchers aren’t waiting for regulations to catch up—they’re already working on solutions.
At the University of Kentucky, plant pathologists have been studying Fusarium head blight in hemp since 2020, searching for ways to reduce mycotoxin risks before they reach livestock feed.
Some of the most promising strategies include:
Using molecular diagnostics to detect Fusarium before symptoms appear • Tracking environmental factors like humidity and temperature that increase fungal outbreaks Evaluating crop rotation and cover crops to reduce Fusarium spores in hemp fields • Testing biological and chemical treatments to limit Fusarium spread
These strategies could help mitigate risks, but without national safety standards, farmers are left guessing which protocols to follow.
What’s Next for Hemp in Animal Feed?
Hemp’s future in livestock feed depends on science and regulation working together. Addressing these challenges will not be easy, but potential solutions include:
Establishing federal mycotoxin testing standards for hemp feed to ensure consistent safety measures Expanding research into Fusarium mitigation strategies to provide farmers with effective management options Creating voluntary certification programs to help producers demonstrate compliance with safety guidelines Developing transparent tracking systems to monitor the hemp supply chain and detect contamination risks
Conclusion: A Critical Crossroads
Hemp represents a new frontier in sustainable agriculture, but its path forward is not yet clear.
If properly regulated, it could transform livestock feed, benefiting farmers, consumers, and the environment. However, without safety measures, the risks could outweigh the rewards.
The opportunity is here, but the window to act is narrowing. If hemp is to fulfill its potential, the time to address these regulatory gaps is now.
Henry S. SmithDepartment of Plant Pathology
Martin-Gatton College of Agriculture, Food and Environment
University of Kentucky
and member of The American Phytopathological Society (APS)
Natacha RousseauScientific Societies
The American Phytopathological Society (APS)
This article is part of the APS Outreach Project, an initiative of the American Phytopathological Society (APS). APS is a nonprofit professional organization with over 3,600 scientists dedicated to advancing global plant health. Representing academia, government, industry, and private practice, APS members drive innovation in the accuracy and speed of field disease diagnostics and deepen our understanding of plant pathology through fundamental research. APS publishes peer-reviewed, reliable information in its scientific journals and translates research into actionable solutions for growers through the APS Outreach Project and Grow: Plant Health ExchangeSM (planthealthexchange.org), a knowledge base for plant health management professionals.
Explore additional practical resources and insights for managing plant health from APS at www.apsnet.org.
–American Phytopathological Society
