Preliminary study to assess mycotoxin concentrations in whole corn in the California feed supply

Mycotoxins are naturally occurring environmental contaminants recognized worldwide in a variety of food and feed products. Produced as secondary metabolites by filamentous fungi, mycotoxins can have acute and chronic effects. Differing seasonal weather patterns and harvesting and storage conditions put corn grain at high risk for mycotoxin contamination. The objective of this study was to assess the risk of mycotoxin exposure posed to California livestock from whole corn. Random samples (n=50) of whole corn were collected and analyzed for 6 different mycotoxins, including aflatoxins, fumonisins, ochratoxins, trichothecenes (deoxynivalenol and T-2 toxin), and zearalenone. The samples represented a cross section of the corn entering California from various corn-growing states (n=43) as well as additional samples from California-grown corn (n=7). The experiment was a randomized sampling design. Over the course of a 6-mo period, 16 trains in California (100-110 railcars) and 5 California grain elevators were randomly sampled. Aflatoxins were detected in 14 samples, with 1 sample containing a concentration of 41.3 μg/kg (as-is basis), which was above the action level of 20 μg/kg for corn fed to dairy cattle. The average concentration of aflatoxins for the 13 samples below the regulatory action level was 8.69 μg/kg (range 4.67 to 13.82 μg/kg). Deoxynivalenol was found in 15 samples and averaged 553 μg/kg (range 340 to 1,072 μg/kg), which was below the federal advisory level of 5,000 μg/kg for grain fed to dairy cattle. Fumonisins were found in 38 samples and averaged 1,687 μg/kg (range 435 to 4,843 μg/kg), which was below the federal guidance level of 30,000 μg/kg in corn for dairy cattle. Ochratoxins, T-2 toxins, and zearalenone were not detected in any samples of whole corn. Fumonisins were the most prevalent mycotoxins found.