Aflatoxin is not typically a big problem in the Midwest corn crop, especially coming directly from the field. However, this year's hot and dry growing conditions were ripe for the toxin's development, according to the American Farm Bureau Federation.

Consumed at high enough levels, aflatoxin– which is a mold– can be deadly to young animals and can cause reproductive problems in swine breeding herds. Livestock-feed tolerance levels range from 100 to 300 parts per billion.

Aflatoxin is more commonly found in the southern Midwest and the Plain states, prompting grain handlers there to test newly harvested corn. So far this year, aflatoxin has been found in the heart of Corn Belt including southern Illinois, southern Indiana, southeastern Nebraska, southwestern Iowa and northeastern Kansas.

"I'm hopeful that the majority of the crop is OK," said Don White, a University of Illinois plant pathologist. "I don't think it will be as bad as 1988." That marked the last severe Midwest drought, and with it came a fairly widespread aflatoxin break. For the most part, aflatoxin has not been a problem in Midwest corn since, he notes.

The aflatoxin-producing fungus, Aspergillus flavus, likes hot days and nights with temperatures near 90 F or higher. Affected fields look scorched, infected ears appear moldy and growth is usually stunted.

"Aflatoxin is showing up and the impact is difficult to tell at this point. We're still early in our harvest," notes Jim Stack, a University of Nebraska plant pathologist. Many Midwest elevators had not been testing for the mold, but, according to AFBF, will likely start.

Texas has been the U.S. state hardest hit by aflatoxin, with reports as high as 500 to 800 parts per billion.

The October issue of Pork magazine has a feature article outlining the problems that aflatoxins present to swine herds. The article also offers guidance in terms of testing and using the affected grain.

The American Farm Bureau Federation