Watch for 'moldy corn' experts warn

The late harvest, wet weather and high moisture corn have contributed to reports of moldy corn across the state, and producers should pay careful attention before handling, storing or feeding the crop to livestock, University of Minnesota Extension experts warn.

“If the corn is not harvested and dried properly, various fungi may continue to grow,” said Extension plant pathologist Dean Malvick. “Both types of mold—superficial growth on the surface of the kernels and significant ear and kernel rots—may cause greater problems.”

“Both molds and the mycotoxins produced by molds can cause health problems in livestock,” said Extension livestock specialist Jim Linn. At heightened risk for mold and mycotoxin health and disease problems are young animals, breeding animals and lactating dairy cows, with swine and poultry species more susceptible to these problems than ruminants. Mycotoxins in large doses can cause acute health, reproduction and production problems. However, the most likely scenario with feeding of moldy and/or mycotoxin containing feeds is a higher incidence of general, chronic health problems, poor reproduction and overall poor animal growth or milk production.

“In general, livestock producers should avoid feeding grain or grain silages containing colored molds (pink, blue green),” said Linn. Mycotoxins, on the other hand, are not visible and their presence depends on the type of fungus present and the storage environment. Livestock producers should test grains and silages for mycotoxins before feeding.

To diagnose and help identify mold and kernel infection, producers can send samples to the University of Minnesota Plant Disease Clinic.