URBANA –This year’s drought has brought numerous challenges to cattlemen. Shortages of grass and water forced cow culling and sent many calves to the sale barn earlier than planned. The most recent challenge cattlemen are facing is high feed costs combined with the possibility of aflatoxin in the corn crop.
“It is a common misconception that the olive-green mold known as aspergillus automatically results in aflatoxin,” said University of Illinois Extension beef educator Travis Meteer. “This is not the case. If you find mold present on your corn, it needs to be tested for aflatoxin.”
Meteer cautioned that aflatoxin can also be found in Dry Distillers Grains with Solubles (DDGS) produced from infected corn. “Aflatoxin is concentrated in the fermentation process and thus the levels in DDGS can be dangerous,” he said. “Testing corn and corn co-products for aflatoxin is recommended.”
Livestock are usually the market for mycotoxin-infected commodities, he added. “Livestock can tolerate some level of mycotoxin, but levels above legal limits can cause problems in livestock. Reduced performance, immunosuppression, liver damage, and in extreme cases even death can be the result of feeding high levels of aflatoxin,” Meteer said.
The chart below illustrates the approved levels in livestock.
Intended Use Aflatoxin Level (ppb)
Finishing(feedlot) cattle < 300
Finishing swine < 200
Breeding cattle or swine < 100
Dairy cattle, young cattle or swine < 20
Intended use not known < 20
Human food < 20
Livestock, especially finishing cattle, will be the end user of much of the aflatoxin-infected corn, Meteer said. “Caution and management are crucial to ensure that negative results do not occur from feeding this toxin-bearing feed.”
Meteer recommends that the storage of corn that has aspergillus present needs to be dried down to less than 14 percent moisture to limit mold growth. Also, cool the grain down after drying and use aeration to control temperature. Mold inhibitors may also be applied to corn to reduce mold growth.
Test and monitor aflatoxin levels of corn to be fed to livestock. Blending aflatoxin-bearing corn with clean corn at the time of feeding can be a good practice to reduce aflatoxin levels in the diet.