Mycotoxin Survey in US corn: August 2019 update

Our August update from the annual Biomin® PROcheck mycotoxin survey in corn harvested in 2018 includes 691 samples from 32 states. Of the sample pool 67% are corn samples (466 samples), 21% are corn silage (146 samples), and 11% are corn by-product (79). Of the total sample pool 97% tested positive for at least one mycotoxin vs. 91% in 2017, while 74% of samples had more than one mycotoxin compared to 47% in 2017. Below we discuss trends of each of these feed ingredients regarding mycotoxin prevalence and contamination levels. 

Corn 

  • 98% of ground corn samples are positive for at least one mycotoxin, vs 89% in 2017
  • 74% of samples have more than one mycotoxin, vs 47% in 2017
  • Aflatoxin prevalence in dry corn increased to 9% vs 4% in 2017, with average contamination levels increasing over seven fold.
  • Deoxynivalenol (vomitoxin) prevalence rose to 78% vs 70% in 2017, with average contamination level increasing by 41%
  • Fumonisin prevalence jumped to 79% vs 52% in 2017, with average contamination levels increasing by 33%
  • Zearalenone prevalence increased to 46% vs 25% in 2017, with average contamination levels remaining steady.

Corn By-Product

  • 96% of samples are positive for at least one mycotoxin, vs 100% in 2017
  • 91% of samples have more than one mycotoxin, vs 94% in 2017
  • Aflatoxin prevalence decreased to 3% vs. 9% in 2017, both years with similar and low contamination levels.
  • Deoxynivalenol (vomitoxin) prevalence decreased slightly to 94% vs 99% in 2017, with average contamination level increasing by 39%
  • Fumonisin prevalence is 89% vs 91% in 2017, with average contamination levels remaining steady.
  • Zearalenone prevalence is 84% vs 80% in 2017, with average contamination level nearly 2.5 fold.

Corn Silage

  • 94% of samples are positive for at least one mycotoxin, vs 91% in 2017
  • 66% of samples have more than one mycotoxin, vs 30% in 2017, a drastic increase in co-contamination.
  • Aflatoxin prevalence is 1% with low average contamination levels.
  • Deoxynivalenol (vomitoxin) prevalence has increased slightly to 91% vs. 85% in 2017, with average contamination level more than doubling.
  • Fumonisin prevalence increased to 25% vs 12% in 2017, with average contamination levels increasing by 7%
  • Zearalenone prevalence jumped to 61% vs 26% in 2017, with average contamination level more than doubling.

These contamination levels present MEDIUM to HIGH risk for all livestock and poultry species depending on toxin and feed ingredient type. Overall, producers in the Midwest should be on the lookout for the impacts from deoxynivalenol and zearalenone, while Southern states should be vigilant regarding fumonisin and aflatoxin contamination.