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Mycotoxins could be holding your herd back from top productivity

Dr. John Doerr, Vice President Science and Technology - Agrarian Solutions

Knowing mycotoxin symptoms and having a plan to correct them leads to a healthy herd.   

MIDDLEBURY, Ind. – Healthy cows, smooth transition periods, high milk production and reproductive success. It’s the ideal situation on any dairy farm, but it’s not always reality. “Why not?” is the next logical question, and there might be many reasons – but one reason could be a result of overlooking the effects of mycotoxins.


“When herd performance isn’t where it should be, mycotoxins could be at work,” says Dr. John Doerr, Ph.D., Vice President, Science and Technology, Agrarian Solutions. “It might be one symptom, like cows off feed, or it might be a whole host of symptoms – either way your cows could be telling you that you have a mycotoxin challenge to solve.”

Know the mycotoxin symptoms

Knowing the signs of a mycotoxin issue is the first step towards a diagnosis. Here are symptoms commonly associated with mycotoxins:

  • Reproductive symptoms:
    • Decreased heat detection rates
    • Silent/weak heats
    • Mammary development in virgin heifers
    • Cystic ovaries/follicular cysts
    • Off-cycle heats
    • Decreased pregnancy rates
  • Health symptoms:
    • Elevated somatic cell count
    • Intestinal hemorrhages
    • Increased death loss
    • Inconsistent manure
  • Transition symptoms:
    • Displaced abomasum
    • Ketosis
    • Off feed
  • Production symptoms:
    • Reduced milk production
    • Reduced milk fat
    • Erratic feed intakes

Whether your herd has one symptom or many, it’s essential to test your feed and determine if mycotoxins are at fault and, if so, which mycotoxins are present. Feed test results will give you the information you need to choose the appropriate direct-fed microbial (DFM) solution to add to diets.

The right direct-fed microbial (DFM) solution, in the right amount

When a mycotoxin issue is to blame, Doerr says it’s important to use the right DFM solution, in the right amount.

“The right DFM solution will enhance a cow’s immune system when a mycotoxin issue arises,” says Doerr. “Farmers should consider a DFM solution that contains L-form bacteria because it is the most effective against multiple mycotoxin issues. Unlike other feed additives, L-form bacteria influence the overall health of animals and metabolism of the intestinal cells.”

Equally important is using the DFM solution in the right amount.

“The degree of mycotoxin levels in your feed will determine the amount of DFM you need. And mycotoxin levels can fluctuate over time, especially from harvest to harvest,” says Doerr. “Feeds with mycotoxins in the medium-level range will require a standard DFM dose, whereas a high-level range could indicate you need a double dose of the DFM solution.”

Don’t let economy dictate performance

Incorporating a DFM solution to tackle mycotoxin issues is just as important as having a milking procedure to help prevent mastitis. It can save performance and profit in the end.

“In an economy like we’re in and with the wet harvest conditions we had this past fall, sampling for and preventing mycotoxin issues are steps you don’t want to skip,” concludes Doerr.

Contact your local Select Sires representative or visit to get a free feed sample analysis.


Since 1996, Agrarian Solutions has been a global leader in providing L-Form bacteria-based technologies for dairy cattle, swine and poultry. Agrarian’s cutting-edge L-Form bacteria technology functions inside of animal cells, populating the cells lining the intestinal tract. There, the L-Form bacteria perform specific functions like balancing intestinal immune function, reducing the burden of pathogenic bacteria or combating feed-borne toxins – challenges animals and their owners face every day. Learn more about Agrarian products and technology at