Mold, which is present in much of the Midwest this year, can produce toxins that can reduce livestock weight and value because some animals won't eat poor-quality grains.
It can also create birthing problems and lead to low birth weight and suppress the immune systems in poultry, said Ken Eck, Purdue University's extension educator for Dubois County.
As much as 40 percent of the corn in fields Eck has looked at in southwestern Indiana have been affected by mold. Mold and toxins won't harm humans because of the high quality demanded for produce sold for human consumption, Eck said.
Eck said some farmers sell low-quality grain to ethanol plants. They get less money that way but can recoup some of their investment.
Richard Stroshine, a professor with Purdue's department of agriculture and biological engineering, said some ethanol plants are separating low-quality grain in the distilling process or rejecting it altogether.