Monitoring mold and mycotoxins in stored grain
The devastating flooding in the Midwest has led not only to human loss but has also destroyed infrastructure, homes and farm buildings — not to mention the additional financial loss due to flooded grain facilities. The images of ruptured grain bins and flooded grain show only a portion of the destruction caused by this disastrous event.
Grain that has been subjected to flood damage is considered contaminated for food and feed use.
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| How to prevent mycotoxins in grain |
Grain that was stored in the same facility but did not come in contact with floodwaters can be utilized as normal, but precautions should be taken. Grain from the upper portion of the bin must be removed from the side or the top; due to potential contamination, it cannot be removed through the bottom of the bin. Make sure the electricity is disconnected, as there will be a greater risk of potential shorts and damaged electric motors. Once removed, grain can be handled in various ways, including flat storing and bins.
Flat-stored corn should be closely monitored for temperature and moisture, as moist grain can sometimes flare up in “hot spots” and warm temperatures. When the temperature inside the grain pile reaches 150° F, the grain begins to compost, so it should be mixed or stirred. If the temperature reaches 170° F, the grain may begin to smolder and has the potential to catch fire. Monitor pile temperatures with deep probes or by driving pointed pipes into the pile, followed by lowering in a thermometer. Since this grain could be subjected to rainfall, it is important to continue monitoring it until the grain can be moved or covered.
Grain that is moved to bins will also need to be monitored. Aim for the recommended grain moisture level of 14 percent moisture for storage. Some producers utilize standard natural air bin drying systems with perforated floors and high-capacity fans. Supplemental heat can also help speed up drying time, but take caution not to raise the air temperature more than 10°–15°F.
Along with moisture, grain must also be monitored for mold and mycotoxins. Molds may or may not be visible and, as such, the grain should be analyzed. Mold can produce mycotoxins that impair animal performance and health while also reducing the grain’s nutritional value by lowering its energy level. Propionic acid can help control and maintain mold levels in stored grains, but application rates will vary based on the grain’s moisture level and the percent of propionic acid used in the product.
If it has not been contaminated by floodwaters, grain from flood-damaged facilities can be salvaged and properly removed, monitored for health and moisture in a new storage facility, and analyzed for mold and mycotoxins.
The recent flooding speaks to a larger concern for grain producers in the Midwest, where some areas experienced the wettest 12 months (April 2018 to April 2019) in 127 years. Overall, corn planting in the United States is 6 percent behind the five-year average — but some Midwestern states are even further behind than that. Of the top 18 corn-producing states, five had not begun planting by April 21. Topsoil moisture is at a 29 percent surplus for the entire U.S., with subsoil at a 26 percent surplus. A wet, delayed spring planting can put crops in jeopardy of pollinating and maturing in a more challenging environment. These trials could also subject the plant to mold and mycotoxin infestation.