High levels of deoxynivalenol (DON), a mycotoxin commonly known as vomitoxin, are being found in grain across the Corn Belt, including eastern Iowa.
Contaminated corn is an issue, especially in dried distillers grains plus solubles (DDGS), according to Erin Bowers, mycotoxin sampling and analysis specialist with Iowa State University.
“This is problematic because we have a huge swine industry in Iowa, and swine are very sensitive to DON,” Bowers said. “When you feed DDGS contaminated at even three parts per million to swine in addition with other contaminated grains, you’re going to start seeing health and productivity issues.”
DON is produced by molds of the genus Fusarium, most commonly Fusarium graminearum. According to the Food & Drug Administration, advisory levels for livestock consumption of DON are as follows:
* 5 ppm of DON on grains and grain byproducts destined for swine, with a recommendation that these ingredients not exceed 20% of their diet.
* 10 ppm of DON on grains and grain byproducts intended for chickens, with a recommendation that these ingredients not exceed 50% of the diet.
* 10 ppm of DON on grains and grain byproducts (on an 88% dry matter basis) destined for ruminating beef and feedlot cattle older than four months, and 5 ppm DON for ruminating dairy cattle older than four months.
* 5 ppm of DON on grains and grain byproducts destined for all other animals, with the added recommendation that these ingredients not exceed 40% of the diet.
“In the eastern Corn Belt right now, we are seeing base corn levels around 1 ppm,” Bowers said. “As soon as you make DDGS out of them, you start pushing the boundaries of some feeding limits. Grain receiving locations should be testing for these levels or at least be aware that we are seeing higher levels this year. Having a good strategy for managing their grain supply and marketing it appropriately can increase its safe use.”
There are solutions to utilizing DON-contaminated grain. Beef cattle are much more tolerant of this mycotoxin and can be fed higher levels of contamination without seeing negative health or productivity effects. DON also can be blended, but steps should be taken to carefully test a representative sample of blended grain.
The Iowa Grain Quality Initiative has developed a set of online learning modules to help producers learn about mycotoxin sampling and handling. The Iowa Grain Quality Mycotoxin Development Module (CROP 3083F) and Iowa Grain Quality Best Practices in Handling & Testing Module (CROP 3083G) were produced in cooperation with the Iowa Grain Quality Initiative and Crop Advisor Institute.