AMES, Iowa – Farmers are being advised to take the necessary steps to ensure good quality grain for livestock this spring, starting with the very first precaution: personal safety.

“First, let’s stay safe by not entering grain bins to check whether over-winter grain is still safe for feeding,” said Dirk Maier, Iowa State University professor of agricultural engineering. “Second, if you have multiple bins with stored corn, be sure you are taking corn out of all bins if you grind your own to make feed, or if you haul loads to the elevator.

“Keeping grain flowing, removing the core of fines under the loading spout, and un-peaking peaked corn are simple practices to keep corn from crusting over, and creating unloading problems,” he added. “Third, we prefer to keep cold grain that has been cored and un-peaked cold as long as it is not showing any signs of warming, or spoilage.”

Moreover, he said turning on the fan for a few minutes and sniffing the exhaust air out of the manhole is a quick way to check whether your corn is in good shape or not.

“We highly recommend using a handheld CO2 meter to check air exhaust because it will detect the onset of spoilage better than a temperature cable,” he said. “As long as CO2 readings remain stable in the 400-600 parts per million range, corn will continue to store well.”

He added, “If you have been observing birds perching comfortably on the roofs of some of your bins and not others, chances are you have stored grain going out of condition and giving off heat. Any bins that ended up with rain or snow on the grain surface will likely end up with some spoilage and surface crusting.

“Do not enter the bin to check but instead run the fans and smell the exhaust air,” he said. “Also consider running some grain out of the bin to break up crusting grain surfaces early. That helps to avoid plugging unload wells.”

Kristina TeBockhorst, Iowa State University field agricultural engineer in Iowa City, said good quality grain stored dry and kept cool in the bin through the winter should not have quality issues for livestock.

However, she said it will be important to keep grain cool when temperatures rise in the spring to prevent spoilage.

“Damaged grain with broken kernels or fines, or grain with insects would pose the most risk for spoilage and quality loss in the spring,” she said.

“Mold growth is something to keep a close eye on for those feeding grain,” she added. “Animals have varying levels of sensitivity to mold, but it can make grain unpalatable, and be a respiratory irritant.”

In addition, mycotoxins can be present in clean or moldy grain, so testing will be required when regional grain quality experts believe previous growing conditions favored mycotoxin development, she said.

“Test weight is another factor that may impact feeding quality of the grain,” she said. “Testing grain is the only way to know the quality and digestibility of the grain.”

She agreed with Maier regarding personal safety, adding farmers should check for signs that the grain has gone out of condition and use extreme caution when handling out-of-condition grain to avoid grain engulfment, unloading equipment entanglement, or other potentially fatal accidents.

“A few indicators that grain has gone out of condition include musty, moldy or sour smells coming from the first flush of air pushed through the grain with a fan, carbon dioxide (CO2) monitor levels rising above 600 parts per million, surface crusting, or warm and damp spots found by probing the grain,” she said.

“Do not enter a bin if surface crusting is suspected as a hollow space may be present under the surface,” she added.

She also advised farmers to check grain condition at least weekly as temperatures start to rise in the spring.

“Use aeration to keep grain 40 degrees or cooler and temperatures in the bin even,” she said. “This means running the fan during cool weather in the spring, such as when the average between the daytime high and nighttime low are near 35-40 degrees, rather than during warm sunny weather.

“Run aeration fans long enough to complete a cooling cycle, which takes nearly a week with a small aeration fan with around 0.1 cubic feet per minute per bushel air flow rate, or less than a day for larger drying fans with 1 cubic feet per minute per bushel, or more,” she added.

She advised farmers to “use the University of Minnesota fan selection program, found at: https://bbefans.cfans.umn.edu/ to estimate the airflow rate per bushel based on your fan, grain bin size, and grain depth. Only warm grain back up to 40 degrees if it was stored well below freezing through the winter, such as 20 degrees, to prevent excessive condensation and ice in warmer weather.”

When grain is stored in bins too wet through the winter, she said it is essential to finish drying it, or to move it as temperatures start to rise in the spring and spoiling begins.

“The recommended moisture content of corn is 15 percent when stored just through the winter,” she said, “but to store safely into warmer weather in late spring and summer, it is recommended to store corn at 13 percent moisture content. Get rid of corn stored above 20 percent through the winter as soon as possible.”

Maier said, “Keep rotating among bins by taking some corn out of them for feed grinding and/or delivery to the local elevator. This keeps grain flowing in all bins and prevents grain from crusting over and setting up. Keep checking CO2 readings weekly, or bi-weekly.

“As long as readings stay stable, stored grain is in good shape. If readings go up from week to week in a bin, keep taking corn out of that bin until readings stabilize again. Then go back to your rotation among multiple bins. Above all, stay out of bins. Don’t risk your life.”