There are more than 400 different mycotoxins described in the research literature, but only 20 to 50 of them can be analyzed. And, with no correlation between visible mold growth and mycotoxins, it can be challenging to determine if you have a mycotoxin problem, says Duarte Diaz, ruminant research manager at Novus International.

Conversely, Diaz warns, the absence of molds does not guarantee the absence of mycotoxins. Toxins can be present long after the death of toxin-producing molds. Diaz has been studying mycotoxins for more than 10 years and says that people make the assumption that mycotoxins are a corn problem. But, he says, it only seems that way because corn is tested more than any other crop. Mycotoxins can be present in all feeds, including byproducts. Byproducts are often wet, allowing mycotoxin producing molds to grow during transport and storage. Grazing systems are not immune from mycotoxins either. Diagnosis of a mycotoxin-related disease is difficult because of nonspecific symptoms, difficulties in feed sampling and analysis, and interactions with other stress factors. However, Diaz says mycotoxins should be considered as a possible causative factor when unidentified problems exist. Methods for detection of mycotoxins have improved in accuracy and cost.

Check with your lab to make sure it has experience with mycotoxins before sending samples.