Drought-weakened corn crops in our neighborhood are turning out to also be infected with aflatoxins this year. This group of chemicals are a product of fungal infections on the drying ears.
The problem is wide-spread enough that our local elevator is testing every load. If the aflotoxin levels are too high, the infected corn is blended with less-infected corn to meet the FDA standard. At $25 per test, a single 5 kernel sample is used to determine the fate of a whole semi-truck load of grain, meaning that the results could easily over- or under represent the real threat.
The FDA limits aflatoxin contamination to 0.5 parts per million (ppm) in milk and 20 ppm in human food and animal feed. Feedlot cattle, on the other hand, can be fed corn with up to 300 ppm as a sole ration with the idea that they will be hamburger before the cancer takes them down.
What will become of all the infected corn? The federal regulations won't allow it in the food supply for either people or livestock, but the ethanol plants won't take it either since their byproducts are marketed as animal feed.