Deer hunters and wildlife enthusiasts are urged to use caution this fall when feeding corn to wildlife, paying special attention to product labeling. Failing to do so could pose a potential health threat to Texas wildlife.
Fumonisin, a mycotoxin that is produced almost exclusively in corn and can be harmful or fatal to some wildlife species, has been found in samples from the 2002 corn crop harvested in certain portions of Texas. Samples of new crop corn analyzed by the Office of the Texas State Chemist and the Texas Feed and Fertilizer Control Service have been found to contain high concentrations of fumonisin in excess of five parts per million (ppm).
Grain containing fumonisin above these levels can cause health problems in horses and rabbits, and it is likely that they can also affect wildlife, says Dr. Neal Wilkins, Texas Cooperative Extension wildlife specialist.
"Because of their complex ruminant digestive system, deer may not be as susceptible to the effects of fumonisin as other animals. In particular, quail, turkeys and other birds that tend to consume wildlife corn may be at higher risk," Wilkins said. "In addition, this toxin may impact squirrels, rabbits and feral hogs that consume corn at wildlife feeders. Corn having concentrations greater than five parts per million of fumonisin should not be fed to wildlife."
Fumonisin is produced in corn by the mold Fusarium [verticillioides (formerly F. moniliforme).]
"The fungus can infect kernels that are damaged by insects or drought stress," said Dr. Tom Isakeit, Extension plant pathologist. "The fungus can also grow into the ear via the silks and this is favored by rain. Infection of corn does not automatically result in toxin production, and visual examination cannot detect corn containing fumonisin. In most cases corn containing unacceptable levels of the toxin may not exhibit any external mold damage. The corn will look good. Factors affecting the production of toxin in corn are not well understood."
Fumonisin should not be confused with aflatoxin, which is another toxin produced by several molds of the genera of Aspergillus and Penicillium that can occur in corn and also in whole cottonseed, peanuts, grain screenings and the meals made from the oil extracted seed. Aflatoxin contamination is favored by drought conditions and occurs primarily in corn kernels damaged by insects and drought.
"Based on what appears to be high rates of deer corn on the market contaminated with fumonisin, and considering the potential biological risks, our best advice is to avoid feeding corn to wildlife until certain of the corn's source," Wilkins said.
When buying deer corn for feeding to wildlife, buyers should find out if corn has been tested for fumonisin and aflatoxin.
"Deer corn should test below 50 parts per billion aflatoxin and five parts per million fumonisin," Wilkins said. "If it's not possible to confirm that the corn has been tested, or it is not labeled, then the best advice is to not feed it. Some of the deer corn on the market is advertised 'cleaned' or 're-cleaned,' but cleaning does not ensure removal of the kernel contaminated with these mycotoxins."
The Office of the Texas State Chemist is continuing to survey new crop corn. For updates and further information, contact the Office of the Texas State Chemist/Feed and Fertilizer Control Service at 979-845-1121 or at http://otsc.tamu.edu. For specific questions about wildlife, contact Wilkins at 979-845-7726 or by e-mail at firstname.lastname@example.org.