Harvest moldy corn as soon as possible
Janet Kubat Willette
Date Modified: 11/19/2009 10:29 AM
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Agri News staff writer
Extension experts say it's best to harvest moldy corn as soon as possible and get it fermented or dried as soon as possible.
Dan Martens, Extension educator in Benton, Stearns and Morrison counties, said he's trying to find balance in his discussions about mold in corn. He doesn't want to create widespread panic, but he does want farmers to look at their fields and consider what the possibilities may be for using the crop. He wants farmers to be observant and aware, and work with their resource people to find solutions.
In general, the best plan of action is to harvest the grain and dry it to a low moisture that doesn't support mold growth, said Bill Wilcke, an Extension engineer. For corn, that's 14 percent or less if the corn is to be stored into summer. Corn may be dried to 15 percent for storage for winter into spring, he said.
While some mold is common every year, it seems to be more common this year. Moldy corn has the potential to contain mycotoxins, according to Noah Litherland, Extension dairy cattle nutrition specialist. Mycotoxins are toxic substances produced by fungi or molds that grow on grain or feed in the field or in storage, Litherland wrote in a paper, " Corn Quality Challenges Effects on Dairy Cattle: Fall Harvest 2009." Litherland says dairy producers should avoid feeding low quality feed to fresh and transition cows and cows that are immuno comprised or challenged. They should also avoid feeding low quality feed to weaned calves. Steers might be the best place to use the low-quality corn.
If the mold doesn't produce mycotoxin, producers may not be able to measure problems in cows, Litherland said. If mycotoxin is present, however, producers may consider adding mycotoxin binders or other feed additives. Producers can feed antioxidants to promote cow health and reduce disorders.
Producers need to remain vigilant, cautious and should sample the corn before feeding, he said.
Poultry producers, likewise, need to exercise caution when feeding moldy corn, said Sally Noll, Extension poultry specialist. Producers should pay special attention to the diets of very young birds and breeder birds, she said.
Molds and mycotoxins may also cause problems in hog and horse diets.
Some markets are very sensitive to mold levels and it might be worth separating grain if the ability exists, Wilcke said.
Down the road there could be demand for better quality corn, said Bob Zelenka, executive director of the Minnesota Grain and Feed Association.
Cladosporium and Trichoderma have been seen most often this fall, said Dean Malvick, Extension plant pathologist. They don't produce mycotoxins.
But just because Caldosporium and Trichoderma have been most common thus far, it doesn't mean it will stay that way, Malvick said.
He encourages producers to send in samples to the plant disease clinic to determine what type of mold they have. Thus far, most molds seem to be superficial and not causing a problem. If not harvested soon, the problem could escalate, he said.
Another issue is how to deal with ear corn.
Jerrold Tesmer, Extension educator in Fillmore and Houston counties, said he's been taking calls about what to do with earlage and ear corn. Mold growth should stop in corn that is dried by hot air to 15 percent, but ear corn isn't ran through a dryer.
Farmers with questions should call Tesmer.