Avoiding mycotoxins in corn feedstock and DDGS

Fusarium species are responsible for most of the mycotoxin contamination of corn harvested with 14%-plus moisture values in 2009, according to Dr. Frank Jones, professor emeritus and extension specialist with the University of Arkansas. This corn was harvested in areas that experienced high rainfall before and during harvest, said Jones, who recommends that feed manufacturers conduct mycotoxin assays on feed ingredients, particularly DDGS (dried distillers grains with solubles).
Although fusarium molds produce a wide range of toxins, deoxynivalenol—also known as DON or vomitoxin—is the most commonly encountered. Poultry are relatively resistant to DON at dietary levels of up to 10 parts per million. Swine, however, are extremely sensitive and will exhibit feed refusal at a level of one part per million.
DDGS derived from affected batches of corn can show up to three times the concentration of toxins when compared with the corn feedstock. Accordingly, most of the ethanol plants supplying DDGS implement some form of quality control using assays.
Despite these precautions, feed manufacturers—especially those supplying swine herds—are advised to conduct their own tests on ingredients and finished feed using available test kits for DON, aflatoxin and other specific toxins, as requested by clients.
Jones recommends a composite sample of at least 10 pounds to determine the specific mycotoxin content, derived using the U.S. Grain Inspection, Packers and Stockyards Administration recommendation of a single 12-foot probe from each railcar or 5- to 7.5-foot probes from a truck. This helps obtain a representative sample, since toxins may not be evenly distributed in consignments.