When wheat prices dip below corn values, some pork producers have turned to wheat as an attractive feed alternative to corn. Reuters reported this summer that The Maschhoffs were already buying more wheat for its animals and reformulating feed rations, and others in the industry have followed the trend.
Feeding wheat to pigs isn’t without concerns. In addition to grinding the wheat a little coarser than corn to avoid ulcers in pigs, wheat can also be infected with the mycotoxin Deoxynivalenol (DON), also known as vomitoxin, which can make pigs sick.
A Closer Look at DON
According to the University of Minnesota in a report, mycotoxins are compounds found in grains caused by molds or fungi. There are as many as 400 known mycotoxins identified to date, but only a few mycotoxins are known to cause detrimental health and performance issues in pigs, including DON. Though it can be found in other grains, DON in wheat occurs when the plant is infected by Fusarium head blight or scab. Fusarium head blight infects grain heads when wet weather occurs during the plant’s flowering and grain-filling stages of development. Finding Fusarium head blight does not necessarily mean DON is present, but a high level of scabby kernels in harvested grain can indicate DON is likely present. Read more here.
Feeding DON-Contaminated Wheat to Pigs
Concentrations of DON are expressed in parts per million (ppm). For example, 1 ppm is equivalent to 1 wheat kernel in 80 lbs. of wheat. Bob Thaler with South Dakota State University reports DON does not cause health or reproductive problems in swine, however, when the total concentration of DON in the diet reaches above 1 ppm, pigs will eat less feed. The animals can also vomit and stop eating completely. This decrease in feed results in slower gains but not death.
If producers want to use DON-contaminated wheat, Thayer stresses producers should take samples from several locations in the bin or load and send them to a certified lab for analysis on how much mycotoxin is present. With the results in hand, blend the contaminated grain with the clean grain to keep DON levels below 1 ppm.
“For example, if the wheat contains 2 ppm DON and it is included in the diet at 25% of the total ration, the final diet should only contain .5 ppm DON if the other ingredients are clean. At this level, pig performance will not be affected,” Thaler says.
Of course, if the results show significant levels of DON, producers may want to heed this advice from Aaron Gaines, vice-president of technical resources and support operations with The Maschhoffs. He says, “At a certain level we'll reject that grain and not feed it at all because it's more costly in terms of animal performance versus the value of grain.”