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2016 Weather Impacted Mycotoxin Levels Across USA

09 January 2017


US - As another harvest season is now complete, dairy producers are looking towards the quality of their crops during winter storage months.

Varying weather patterns across the U.S. during the 2016 growing season proved to provide ideal conditions for the development of deoxynivalenol (DON) and aflatoxins (AFB1) in corn crops across various regions, posing a threat to feed quality.

Dryness during pollination, due to mild to severe drought conditions across the plains and southern states was a major cause in aflatoxin levels. According the Neogen Mycotoxin Report, confirmed reports of mycotoxins were found in Kansas, Oklahoma, Texas, Louisiana, Alabama, Georgia, South Carolina and North Carolina. The most severe cases were found in Texas with corn testing above 150 parts per billion (ppb) and in North Carolina above 200 ppb. According to the U.S. Food and Drug Administration, feeds may not exceed more than 20 ppb of AFB1 or 0.5 ppb of AFM1 to dairy cows before milk must be discarded. AFB1 can cause a number of symptoms in dairy cows ranging from a decrease in feed intake, an increase in somatic cell count to lowered milk production, ultimately affecting profitability.

The Neogen Mycotoxin Report also indicated reports of high DON levels across the plains and northeast states in both the corn and wheat crop due in part to excess rain during late summer and fall. Confirmed reports were found in Nebraska, Iowa, Wisconsin, Illinois, Indiana, Ohio, Michigan, Pennsylvania and New York ranging from three to more than five ppb.

According to Wendy Vandenboom, Nutriad mycotoxin specialist, mycotoxins can have many effects on dairy cows. From simple feed refusal resulting in a lack of nutrition to serious detrimental effects on the body. Cows can suffer reproductive problems such as poor heats, infertility or embryonic losses. Milk production can also decline significantly. Intestinal health can be compromised as well, compounding nutritional deficits. In severe cases, mycotoxin ingestion can also lead to mortality.

“In addition, we are seeing these high levels of mycotoxin in silage stalks, soybean stubble and even some straw,” says Vandenboom. “When these products are used for bedding, we have to be aware that the cows will often eat this as well, which means we have to account for possible mycotoxin ingestion in all cows including neonatal calves.”

Neonatal calves are often overlooked when we are dealing with mycotoxin exposure because the usual sources of contamination are forages. When mycotoxin levels are as high as reported this year, calves must also be assessed and managed for mycotoxin effects at they can become more susceptible to the risk of diseases caused due to a less developed immune system. Ingestion of mycotoxins can also impair growth rates in calves as their dry matter intake decreases.

Proper mycotoxin management programs are crucial to ensuring herd health and performance is not altered due to contamination. Steps involved in dealing with mycotoxins should include:

  • Testing and analyzing feedstuffs for the presence of mycotoxins.
  • Practicing proper feed and storage management strategies to minimize ingestion levels.
  • Utilizing mycotoxin management solutions proven to not only minimize the effects on cows, but also to aid in the recovery and healing due to the damages already done.

“Mycotoxins can increase overtime if feeds are not stored properly. Producers should utilize mycotoxin identification tests to help determine specific sources of contamination to allow for a tailored response to meet the needs of individual herds,” says Vandenboom.

Nutriad delivers products and services to over 80 countries through a network of sales offices and distributors. These are supported by four application laboratories and five manufacturing facilities on three continents. Find out more at


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