Aflatoxin contamination is greater in corn that has been produced under stress conditions. Thus, drought, heat, insect, nematode, and fertilizer stress are all conducive to high levels of aflatoxins. Seed companies are in the process of developing corn hybrids with some level of resistance to the fungus or that have less tendency to accumulate the toxin. Although these hybrids will tend to have lower levels of aflatoxin than others grown under the same conditions, complete resistance is unlikely. Management practices such as irrigation, good insect control and timely fertilization may reduce stress to the corn plant and thus lower aflatoxin levels.
Aflatoxin can also appear in milk of lactating animals fed aflatoxin-contaminated feed.
The allowable limit in milk is 0.5 ppb. Fumonisins in Corn Fumonisins are a group of mycotoxins produced by fungi in the genus Fusarium . Fusarium moniliforme usually appears white to salmon colored, although it may not be visible on the corn kernel. The visual absence of mold, however, does not mean that kernels do not contain the toxin. Intact corn kernels may contain the fungus and the toxin but show no sign of the fungal contamination.