The 2012 corn crop delivered many of the problems that were foreseen throughout last year’s growing season. Decreased yields, variable quality and mycotoxins have affected livestock production throughout North America. However, this crop may still be causing trouble as we dig deeper into the storage bins.

Alltech’s 37+ Program surveyed 329 samples from July 1 through Dec. 31, 2012. Only one percent of the samples analyzed were free of mycotoxin contamination; 94 percent were contaminated with two to 10 mycotoxins. In corn grain samples, 95 percent contained Fumonisin and 48 percent contained DON. In corn silage, 90 percent contained Fumonisin and 84 percent contained DON. The DDG samples contained 100 percent of both Fumonisin and DON. In all samples tested, aflatoxin was present in 18 percent.

At harvest time, it was recommended for mycotoxin contaminated grain to be dried to 14 percent moisture within 24 to 48 hours to stabilize mold growth and ensure adequate grain storage. By limiting mold growth, mycotoxin production can be stabilized, but any mycotoxins already present would remain.

As temperatures remained warm in the fall, many growers aerated the bins and discovered that the mold and mycotoxin levels increased rapidly. As storage facilities have been emptied this spring, high levels of mycotoxins have been found in the lower levels of the facilities, where the fines and cracked kernels tend to concentrate.

Recommendations for producers using the last of their 2012 crop:

• Only run aeration fans during the coolest times of day or night. Hold grain at 50 degrees Fahrenheit or less and 14 percent moisture or less.
• Mold growth in storage is greater where there are leaks in facilities and where fines and damaged kernels are concentrated.
• The south side and tops of grain bins warm quicker as daytime temperatures begin to increase.
• New mold growth will increase temperature and moisture in surrounding grain.
• Continually monitor stored grain for temperature, moisture and mycotoxins.