Aflatoxin is definitely on the radar screen this year. The key number to remember when quantifying aflatoxin contamination is 20 parts per billion (ppb). This is both the Food and Drug Administration's Action Level for feeds whose intended use is unknown, and the low end of the range in which a total mixed ration will cause milk contamination to be greater than the FDA allowable level.

As with most years, the majority of samples that are tested for aflatoxin contain only very low levels. However, being aware of potential aflatoxin sources and monitoring contamination levels will become increasingly important. Particular caution should be applied to corn and corn silage stored in bags or vertical silos, since these feeds can make up a large portion of the diet and these storage structures will have as much variation in contamination as the fields from which they were harvested.  

For more information about aflatoxin, proper sampling instructions and interpretation of results, as well as up-to-date mold and toxin summaries, visit

Source: Dairyland Laboratories Inc.