By TIM ALEXANDER
Illinois Correspondent

SPRINGFIELD, Ill. — The Illinois Department of Agriculture (IDOA) issued a reminder last week to the state’s farmers to be vigilant concerning proper storage and handling of grain to protect against mold development.

“Mold is a greater concern this year because of the unseasonably cool, wet weather we’ve experienced,” stated Jim Larkin, IDOA bureau chief of agricultural products inspection, on Nov. 23.

“Mycotoxins, which are toxic substances that molds produce, thrive in moist environments and can spread in poorly-ventilated grain bins, causing not only grain losses, but also potential health risks.”
In addition to recommending that farmers keep their grain as dry as possible to reduce the chances of mold growth, Larkin said grain should be screened before storage to remove damaged seeds and kernels that may harbor mold. Crops that are stored outside should be covered with tarps and moved off the ground as soon as possible, he added.

Crop disease experts agree that the chances for mold growth in corn are greater this year due to October’s rainy, cold conditions combined with an above-normal year for rainfall and a cool summer. “Farms that feed their own corn absolutely need to test this year to avoid these problems,” says Missouri swine specialist Marcia Shannon. Shannon warned that if corn has more than 5ppm of vomitoxin, pigs will become ill and refuse to eat, causing breeding disruptions within the herd.

The concentration of mycotoxins animals can tolerate varies according to the animal’s species and age, according to Larkin. Therefore, all livestock producers, dairy farmers and horse owners should strongly consider testing their feed grain. A seven-point screen for mycotoxins in feed grain can be purchased from the IDOA’s Centralia Animal Disease laboratory for $60, Larkin said.
Moldy corn reduces bushel weight, corn quality and nutrient content and increases the risk of mycotoxin formation, according to a University of Illinois (UoI) Extension news release in November warning of mold and mycotoxins. 

“Mycotoxins associated with cool and wet conditions are zearalenone, T-2 toxin, umonison and deoxynivalenol, also called DON or vomitoxin,” stated Mike Hutjens, UoI Extension dairy specialist. “Signs of mycotoxin in dairy cattle include rumen disorders and reduced microbial digestion, loose fecal discharges, reduced dry matter intake, decline in fertility, hormonal-like changes such as udder development and fertility, and immune suppression where cattle do not respond to disease challenges.”

Hutjens said diluting contaminated feed grain with clean feed may reduce mycotoxins to acceptable levels, but warns that contaminated feed can vary greatly in concentration. Like Larkin and Shannon, Hutjens recommends testing feed grain that shows signs of mold development. 

Mold can continue to develop in harvested grain as it awaits drying, Hutjens warned. High-moisture corn could increase the risk of additional mold growth until the pH of the fermented corn decreases, but drying corn below 15 percent moisture prohibits further toxin development, he said.

“Adding a grain inoculant to speed up fermentation and stabilize the wet corn is recommended,” said Hutjens. “Also, distillers’ grain produced from ethanol production can concentrate the level of toxins in the feed.”

Adding propionic acid at the time of ensiling can also help reduce mold development in wet corn, Hutjens concluded.

Jeffrey Brooks, manager of Grainland, Inc., a grain elevator in central Illinois (Woodford County), said that while grain moisture remains at around 25 percent, mold associated with excessive moisture has not been a factor with most of his customers’ grain. “We saw a little bit of Diplodia (ear rot) early on, but we haven’t noticed it as much as harvest winds on,” Brooks said. “I haven’t heard anyone really talking about mold, and it has not been an issue as I’ve seen it.”

A Peoria County farmer, Gerald Noe, said he’s seen no evidence of mold or ear rot in his corn crop, which he was still harvesting the weekend after Thanksgiving. Noe is encountering higher than usual moisture, he acknowledged.

The UoI’s Bulletin website features an in-depth article with photos entitled “Dealing With Moldy Corn and Mycotoxin Risks,” authored by Hutjens and colleague Carl Bradley. It can be accessed at http://ipm.illinois.edu/bulletin/print.php?id=1244

For more information and some tips on preventing mold contamination in grain, the IDOA recommends calling the Bureau of Agricultural Products Inspection at 217-782-3817.