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Stored Grains and Flooding

Originally authored by Alvaro Garcia, former SDSU Extension Agriculture & Natural Resources Program Director.

According to the Food and Drug Administration (21 U.S. Code § 342 - Adulterated food), grain inundated by watercourses is considered adulterated and must be destroyed. The portion of the grain that not affected by the water can still be salvaged for its use (see point 4 below). The FDA thus considers the grain adulterated, only when the flooding is the result of the “overflow of watercourses” (i.e. rivers). The issue is that floodwater could have brought with it all class of contaminants from one or more of chemical, human, plant, and animal sources. Examples are sewage, chemicals (i.e. fertilizers and herbicides), heavy metals, pathogenic animal bacteria or other organic or inorganic contaminants. Flooding resulting from rain or melting snow around a storage structure or “pooled water” does not carry contaminants from other locations, and the grain just need drying in order to feed it to livestock.

One thing to keep in mind is that the moisture accumulated after either type of flooding could very likely lead to the development of molds that can affect animal health. Making sure corn or any other cereal grain is safe to be fed to livestock is the responsibility of both crop and livestock growers.

Actions to Take

three grain bins in a flooded farm yard. Photo by John Shea, FEMA
Photo by John Shea, FEMA

If the grain bins are in an area threatened by flood, the first option to consider is to remove and relocate as much grain as possible. Granted, this is not usually easy since it requires time to coordinate transportation, and finding an alternative storage site. Paying for transportation and storage however will always be more economical than having to destroy flooded grain. If the flooding has already happened however, the first thing is to assess the extent of the damage. Below are the logical steps to follow to deal with the situation once the flooding has receded:

  1. Before any visual inspection in or around the bins, an electrician should check out any electrical components to make sure there is no danger of electrocution. It is more than likely that these will need replacement depending on the extent of the damage.
  2. Moist grain swells exerting undue pressure on the weakest points of the storage structure, which increases the risk of it bursting open. Be aware of this potential hazard to prevent accidents when assessing the damages around the bins.
  3. Call your insurance agent/company for an on-site inspection to be in compliance if you are going to report losses.
  4. According to Iowa State University research, the moisture travels a foot above the highest floodwater line; grain below that line retains roughly 30% moisture, the FDA considers it adulterated, and needs to undergo destruction. Local DNR officials can provide guidelines on how to handle this.
  5. Grain above one-foot height can still serve as livestock feed within your farm. For use outside the farm, it needs FDA clearance. This will require some additional information regarding its safety according to certain standards. Testing for mycotoxins and pesticides is required if it is going to be sold, and highly recommended if used as feed in the farm of origin. Once cleared it is also advisable to feed it as soon as reasonably possible in either case.
  6. If we do not want to dry the moist grain above one foot, it is possible to ensile it as high moisture corn (HMC) for future use. Before ensiling, test for moisture to make sure it has at least 24%. If drier, one can always add water to take it to the recommended level. Since we are starting with dry shelled corn, the addition of a fermentation enhancer could potentially help with its preservation. Follow the usual guidelines for feeding HMC at feed-out to minimize aerobic deterioration.

If you have doubts on how use safely this corn as livestock feed, contact your local SDSU Extension Field Specialists or SDSU Extension Veterinarian.