Reducing Aflatoxin in Grain Corn

— Written By and last updated by

Aflatoxins are a type of mycotoxin that is produced by Aspergillus flavus which has a worldwide impact on human and animal health. They are particularly dangerous to animals because their diet usually has less variety than humans. Aflatoxins can be passed through dairy feed into milk that is consumed by humans. Many foods such as milk, corn, and peanuts are tested for mycotoxins at processing. Even though they occur frequently in nature, it is important to mitigate them as early as possible to prevent illnesses and food waste. Learn about how sound post-harvest practices can reduce or prevent contamination or buildup once the crop is harvested and stored by watching the video below.

Most Aspergillus contamination occurs on corn with broken and damaged kernels and in foreign material. Heat and drought stress can cause seed coat fractures and increase the chances of infection. Even if corn was previously free of aflatoxin, when under these conditions in the presence of mold and fungi, aflatoxin can develop in corn within 24 hours. Proper harvest, handling, and storage of grain can reduce and prevent contamination.

Pre-Harvest:

  • Clean out harvest, handling, drying and storage equipment.
  • Check and repair grain bins.
  • Use an approved insecticide to treat bins before filling.
  • Mow around storage bins.

Harvest:

  • Set combines to maximize cleaning of grain and minimize grain damage.
  • Set fans higher to clean out lightweight cracked grain and undeveloped kernels.
  • Don’t pick up ears in contact with the ground.

Storage:

  • Do not hold high moisture grain in wagons or trucks longer than 6 hours.
  • Keep moisture below 12-13%
  • Cool grain below 60°F with outside air as soon as temperatures permit.
  • Aerate stored grain when grain is 10°F warmer than outside air temperatures and the humidity is below 65%.
  • Inspect and probe grain every 3 to 4 weeks

Additional Resources:

Aflatoxins and Animal Food Safety – NC State Extension

Reducing Aflatoxin in Corn During Harvest and Storage – University of Georgia Extension

Aflatoxins: Occurrence and Health Risks – Cornell College of Ag. and Life Sciences