Iowa Farmer Today

Farmers may have to beware of mycotoxin-causing mold this season because of high amounts of stored grain.

Moldy grain can cause a number of mycotoxins. At different levels or mixtures, mycotoxins can cause reproduction problems, weight loss, and death in livestock.

Twenty-five percent of the world's grain is contaminated, said Alan Harrison, coordinator for field research for Alltech, a nutritional technology company in Lexington, Ky.

Producers should beware of unexplainable lack of appetite in livestock because it is a natural reaction to avoid consuming mycotoxins, he said.

Mycotoxins are "invisible thieves," said Peter Surai, head of antioxidant research at Alltech. "Sometimes, you don't see them but they'll take away productiveness," he told a group of dairy producers during Alltech's North American Lecture Tour stop in Cedar Rapids this past week.

In Iowa, deoxynivalenol (DON) could be a problem because last season was cooler-than-normal, which DON thrives in, said Gary Munkvold, research coordinator for pathology and entomology specialists at Pioneer Hi-Bred International.

Harrison calls DON a "milk thief." High levels of DON cause milk production levels to drop. DON is also known as vomitoxin.

Swine can tolerate DON at five parts per million (ppm) and beef cattle at 10 ppm, Munkvold said.

DON is a product of many Fusarium fungi species.

Producers should beware of T-2, another product of Fusarium, which Harrison calls a "digestive tract" thief. It is more toxic at much lower levels.

"I hope that none of you will experience T-2. It will kill cows," he said.

Signs of T-2 are inflammation of the digestive tract, vomiting, uncontrollable bleeding, decrease in milk production and loss of appetite in cattle and weight loss and feed refusal in swine, Munkvold said.

Harrison calls Zearalenone the "repro thief" because it tends to cause infertility, abortions or other problems, especially in swine.

Feed contaminated with more than .5 ppm of Zearalenone should not be fed to swine. Conception rates for dairy cattle may be affected if feed exceeds 12.5 ppm, Munkvold said.

Another well-known mycotoxin is aflatoxin, which commonly causes liver damage and reduced growth rates in swine and cattle. However, it is not common in the Midwest, Harrison said.

If there is a high level of one mycotoxin, there are probably others, Surai said.

Most research has been focused on one type of mycotoxin at a time but the problems producers face in the fields are usually a "cocktail of mycotoxins," Harrison said.

"We see things in the field that we don't see in research." he noted.

Much of the research on mycotoxins concludes certain levels are harmless. But, the problem is it doesn't address the other levels of mycotoxins in the "cocktail," Harrison says.

Munkvold suggested producers test their grain for mycotoxins and levels of contamination.

"If you can't remove (contaminated grain), the next step is to analyze and test for mycotoxins," he said.

The results may encourage farmers to sell their grain, if it is not too damaged, or they may want to blend it with "clean" grain to lower contamination levels, he said.

But, there are some setbacks in testing for mycotoxins because it is hard to get an accurate sample, Munkvold said.

"Blending is tricky," he said. "In reality, the sample may not be representative and mycotoxins could be higher. When it is blended with clean grain, you can end up with more contaminated grain."

Another option is to experiment with mycotoxin-binding agents. Farmers can experiment with levels of the product and pay attention to production reactions, Harrison said.

Using a mycotoxin-binding agent at 10 to 20 grams per day can be cheaper a grain test, he said

"The best thing is to try to prevent the problem. But, if you can't remove it, you try to deal with the problem," Harrison said.

He advised trying different levels of an agent and looking for a reaction.

"The cows never lie," Harrison noted.

Munkvold recommended farmers get their grain tested. Then they can look for a binding agent that is designed for the mycotoxin found at high levels in the test.

"Generally, I would want to have my test results and to see proof that the binding agent protects against the specific mycotoxins that are in my grain," he said.

E-mail: Hannah.Fletcher@IowaFarmerToday.com