Extension News

Don’t Use Flood-soaked Grain for Feed or Food


AMES, Iowa -- Floodwaters have soaked many grain bins on farms and at commercial elevators. With only a few exceptions, flood-soaked grain is not useable for feed or food, said Charles Hurburgh, Iowa State University professor of agricultural and biosystems engineering and professor in charge, Iowa Grain Quality Initiative. Flooding affects both the stored grain and the storage structures.

Grain and Grain Products

“Flood damaged grain is adulterated grain because of the potential for many contaminants to enter through the water,” Hurburgh said. “This grain should be destroyed, never blended. Contact local public health and sanitation officials to determine the best disposal process for your area.”

Water coming up from tiles, pits, etc., is just as suspect because storm and sanitary sewers are usually compromised in floods, he said. Even field tile water contains animal waste products, high chemical levels and other contaminants. 

He offered these additional comments on flood-damaged grain.

  • Corn will stay at 30 percent moisture after the water drains off; soybeans about 25 percent moisture.
  • The moisture will not travel more than a few inches above the floodline.
  • Good grain on top of flooded grain must be removed from the top or side, not down through the damaged grain. Remove all the good grain possible before doing anything with the bad portion.
  • Mycotoxins are likely in rewetted grain. Warm, wet conditions are ideal for mold growth.  Soaked grain will spoil within a day or two at summer temperatures. The heat and moisture given off from spoilage moves upward, rapidly affecting the rest of the grain.
  • Rain damaged grain – such as what might be found in a grain bin that’s roof was removed during strong winds — can be saved by drying and cleaning. This grain should be tested for mycotoxins before use. Use reconditioned grain immediately.
  • Do not track or mix mud, gravel, etc., from flooded grounds into good grain during salvage operations. These materials are potentially toxic for the same reasons as the floodwaters.
  • FDA allows for reconditioning (washing and drying at high temperatures) in cases where the floodwater did not remain long and it is known that the water did not contain contaminants. However, knowing that floodwater was clean would be a rare situation. The National Grain and Feed Association (NGFA) has summarized the requirements for reconditioning. (See the  NGFA Newsletter, Volume 60, Number 13; June 19, 2008.)


Hurburgh offered these tips on dealing with grain structures.

  • Grains swell when wet so bin damage is likely; more so with soybeans. Bolts can shear or holes elongate. Look for signs such as stretched caulking seals, doors misaligned or bolt holes open.
  • Check bins with stirring devices carefully; the bin must be perfectly round for them to work correctly.
  • Bin foundations can shift, float or deteriorate from flooding. Inspect structures and foundations carefully, and have an engineering evaluation for larger bins.
  • Expect electric wiring, controls and fans to be ruined. Do not energize wet components.  Be sure the power is off before touching any electrical components of flooded systems.
  • Wood structures will be hard hit and may retain mold and contaminants.
  • Do a thorough safety inspection before returning facilities to operation, to assure that debris, mud and contaminants have been removed. Maintain cleaning records.


In the rare situations where the water was not contaminated, the grain may be reconditioned, noted Dan Loy, ISU Extension livestock specialist. For that grain to enter commerce, it has to be reconditioned with the written consent of FDA. For feed on site, producers have three alternatives.

  • Dry the grain, then feed it immediately.
  • Feed it immediately as wet grain to their livestock
  • Ensile the grain for livestock feed.

Decisions need to be made quickly, Loy said. The good grain should be removed immediately, again, not down through the soaked grain. No flooded grain can be sold to the market without approval of FDA, to document its reconditioning and intended use. Uncontaminated soaked corn can be used as a livestock feed within a day or two. Replace the corn in the animals’ current diet with the wet corn and adjust amounts fed for moisture.

Wet, whole soybeans can be fed to cattle if the soybeans are limited to 10 to 12 percent of the ration’s dry matter, Loy said. Soybeans substitute well for the protein in soybean meal, but they need to be fed with a vitamin-mineral-additive premix if substituted for a complete protein supplement. It is not necessary to heat-treat the soybeans for cattle. If adding whole soybeans to diets high in distillers’ grains, pay attention to the total ration fat content. For hogs, raw soybeans can only be fed to mature sows. The soybeans need to be heat treated if fed to younger pigs.

For more information on drying or ensiling the grain, contact your Iowa State University Extension county office.


Contacts :

Charles R. Hurburgh, Extension Agricultural and Biosystems Engineering, Iowa Grain Quality Initiative, 515-294-8629, tatry@iastate.edu

Daniel Loy, Animal Science, (515) 294-1058, dloy@iastate.edu

Laura Sternweis, Extension Communications and External Relations, (515) 294-0775, lsternwe@iastate.edu