Know the truth about mycotoxin dangers

Thursday, September 24, 2020

Know the truth about mycotoxin dangers


Neil Michael, DVM, Manager, Ruminant Technical Services, Arm & Hammer Animal and Food Production


Mycotoxins are host to a range of issues in both dairy and beef cattle. Caused by molds and fungi in feed, mycotoxins damage the intestinal tract and interfere with digestion. The devastating effects include reduced feed consumption, lower reproductive performance and diminished overall productivity.


But because symptoms of mycotoxin contamination vary widely, the dangers of mycotoxins are often overlooked or misunderstood by producers. To managing mycotoxins effectively, don't be fooled by these five mycotoxin myths:


MYTH: Mycotoxins are only a problem in wet years.

TRUTH: During the growing season, temperature and humidity fluctuations often lead to growth of different types of molds. Some molds prefer cool, wet environments and others like hot and humid conditions. Under stressful conditions due to weather extremes, insect damage or poor storage, molds produce toxic secondary metabolites known as mycotoxins. Thus, mycotoxins always need to be on your radar regardless of environment, growing year or location.


The fact is, mycotoxin contamination may be even more common than you realize. In a global survey, 88 percent of feed was contaminated with at least one mycotoxin.


MYTH: If mycotoxin tests are negative, there's no need to worry.

TRUTH: Feed analyses might not reveal the whole picture because not all mycotoxin species show up in testing. Analyses also may be hindered because of inconsistent mold growth and mycotoxins not being uniformly distributed within a feedstuff. Often it is difficult to obtain representative samples for accurate testing. In fact, sampling error accounts for 90 percent of inaccuracies in mycotoxin analyses.


More importantly, research shows that multiple mycotoxins at "non-significant" or undetectable lab levels can have a cumulative effect, creating chronic, negative impacts on the animal. The ingestion of low-level toxins may cause an array of metabolic, physiologic and immunologic disturbances.


In addition, realize that the mycotoxin testing process is often expensive and time-consuming. While you wait for results, mycotoxins could already be at work damaging your animals and compromising productivity. Considering the potentially severe impact of mycotoxins, producers should assume mycotoxins are present and proactively manage the herd to make animals more resilient against their negative effects.


MYTH: The rumen detoxifies mycotoxins.

TRUTH: Ruminants do have some ability to detoxify consumed mycotoxins, but the process has a negative impact on rumen bacteria populations. During detoxification it is possible for the bacteria to create even more toxic byproducts, known as conjugated mycotoxins. These altered mycotoxins can impact normal function in both the rumen and intestines.


Also, due to a faster rate of passage in high-performing animals, many consumed mycotoxins can escape the rumen before being detoxified and damage the lower intestines.


Even if the rumen bacteria successfully detoxify mycotoxins, the presence of mold in feed may increase refusal rates, reducing nutrient utilization and performance in a herd. Mycotoxins have been associated with various factors that reduce performance including irregular estrous cycles, embryonic mortalities, pregnant cows showing estrus and decreased conception rates.


MYTH: Dilution is the solution to mycotoxins.

TRUTH: A common strategy to manage mycotoxins on many farms is to mix contaminated feeds with good quality feedstuffs and hope that dilution is enough to mitigate the harmful effects. However, because the rumen isn't always successful in detoxifying mycotoxins, even one bite of contaminated feed can significantly impact the intestines.


The single layer of intestinal lining cells and associated immune cells is the primary target for ingested mycotoxins. Once exposed, inflammatory compounds are released, causing local damage to the intestine's lining. These toxins compromise the GI tract and can decrease the surface area available for nutrient absorption. This opens the door to growth of pathogens like Salmonella, Clostridia and E. coli. Inflammatory cytokines released into the bloodstream can cause inflammation to liver, lungs and other organs.


Although not all mycotoxin challenges result in clinical disease, any mycotoxin exposure reduces performance as a result of the additional energy required to manage the immune response and repair the gut integrity. The moral of the story is to protect the gut every day, with every bite—not just when clinical cases occur.


MYTH: Feeding clay solves mycotoxin problems.

TRUTH: Clay and other binders can successfully bind some types of mycotoxins, but not others. Researchers have identified more than 400 different types of mycotoxins, so traditional binders may leave the animal vulnerable. In addition to their effectiveness being limited to certain mycotoxins, binders do not protect the gut from their harmful effects.


A more advanced alternative is feeding Refined Functional Carbohydrates™ (RFCs™), which are natural carbohydrates that are biologically active in the gut to reduce pathogen impacts and prepare the immune system ahead of environmental challenges so animals can respond quickly. Regardless of the specific mycotoxin involved, RFCs protect the gut and prevent mycotoxins from being absorbed and entering the blood circulation. The toxins then pass harmlessly through the digestive system and are excreted without negatively affecting animal performance.


Research shows that immune challenge caused by mycotoxins can be avoided by beta 1,3/1,6 glucans and mannans present in RFCs, allowing the cow to further protect itself against pathogens. In addition, nutrient uptake is maintained, leading to better feed efficiency and animal performance.


This level of protection enables animals to devote energy to all functions instead of staving off infections or struggling to maintain nutrient uptake in the face of mycotoxin contamination. RFCs can help producers manage unseen threats from mycotoxins and other pathogens, building a resilient immune system that protects animals from the ill effects of these challenges.



Don't fall victim to complacency about mycotoxins. Understanding and addressing the dangers of mycotoxins can keep them from robbing your cattle of immunity, feed efficiency and performance.



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Article made possible through the contribution of Neil Michael and Arm & Hammer Animal and Food Production