ADM Releases Statement on South Carolina Horse Feed Incident

Horses feed manufacturer ADM Alliance Nutrition, a subsidiary of the Archer Daniels Midland, Co., is responding to recent news reports and social media posts about its potential connection to an incident in which three South Carolina horses died and another was sickened.

Farm owner Anne Kennedy told that in December, three horses residing at the farm were treated at the Edisto Equine Clinic in Yonges Island, South Carolina, for coliclike signs and later died. Another horse exhibiting similar clinical signs was also taken to the clinic for treatment, she said.

Kennedy subsequently sent a small sample of the ADM feed used at her farm to Michigan State University’s (MSU) Diagnostic Center for Population and Animal Health, in Lansing, for testing. She said the sample was “negative for ionophores (monensin),” but that a postscript included in the test results indicated the laboratory had identified monensin in trace quantities.

Ionophores are a type of antibiotic manufacturers sometimes add to cattle feed to promote weight gain. These substances, including monensin, can be toxic to horses. Monensin toxicity becomes apparent in horses in a number of ways, said Adrienne Bautista DVM, PhD, of the California Animal Heath and Food Safety Laboratory System at the University of California, Davis, School of Veterinary Medicine.

“Some horses go off their feed, some exhibit ataxia or weakness, some colic, and some simply die,” Bautista said. “When horses die, they generally die very quickly, and those are the horses we most often see.”

Kennedy said she shared the test results from her initial submission, including the postscript, with ADM representatives, who then visited her farm to gather five samples of the feed to test.

Kennedy also later sent eight additional samples of ADM feed to MSU for testing. According to the MSU test results Kennedy provided to on Jan. 6, the laboratory tested Kennedy's eight samples, including an untagged bucket of feed, several pelleted feed samples, and a feed designed for senior horses as a control sample. All of the samples were produced by ADM, she said.

In the test results, the toxicologist reported that “all of the submitted samples tested negative for the presence of monensin chromatographically and confirmed the finding by LC-MS/MS (liquid chromatography coupled with tandem mass spectrometry).”

The test results also showed that “monensin was observed in trace quantities of less than 0.2 ppm” in five of the samples, that “monensin was present at approximately 0.2 ppm” in one pelleted sample, and that “monensin was present at approximately 1.0 ppm” in another pelleted feed sample. The report said that monesin was “chromatographically negative” in the senior horse feed sample.

Bautista said the differences in the samples' test results could be attributed to "small differences in feed coming from the same bag.

“There could be 'hot spots' in the bag,” she said.

Kenneth Marcella, DVM, Dipl. AAT, of KLM Equine in Canton, Georgia, explained that there is a difference between a “toxic limit” and a so-called “allowable limit” of monensin in horse feed. At the same time, he said, the U.S. Food and Drug Administration has not set an allowable limit for monensin in horse feed.

But, “ideally, there should be no monensin in horse feed,” Marcella said.

But trace amounts of monensin can find their way into commercially produced horse feed during the manufacturing process, even if companies have policies and protocols in place to prevent such cross-contamination, Marcella said.

“If a company is producing horse feed one day and cattle feed the next on the same machine, it is possible that there could be some contamination, even though that machine is being broken down and cleaned,” Marcella said. “That contamination could be something very small that that been hidden in the machine for a long time and it does not mean that the company is not doing the right thing.”

In a Jan. 6 written statement, ADM said it is aware of “recent comments on social media and some news outlets concerning ADM Alliance 12% horse feed and its alleged link to deaths of horses.

“We take this matter very seriously and are working with authorities to investigate these horses’ deaths,” the statement continued. “We’re not aware that authorities have made any determination as to what caused the deaths, and based on our investigation to date, we have not found any evidence that our horse feed caused or contributed to these deaths. The (initial) single sample of our horse feed tested for our customer at Michigan State University was negative for ionophores (monensin) at the detection limits for the test. We have sent additional samples for testing and will share information as soon as it’s available.”

Customers with questions can contact the feed manufacturer at the statement said.

About the Author

Pat Raia

Pat Raia is a veteran journalist who enjoys covering equine welfare, industry, and news. In her spare time, she enjoys riding her Tennessee Walking Horse, Sonny.

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