“The cattle were struggling,” recalls Tony Scott, Ph.D., partner with Cattlemen’s Nutrition Services and consultant to a feedyard in the Southern Plains where the nightmare occurred.
“Over a period of just two to three days, we saw a severe depression in feed intake. At the same time, feed intake went down, the pull rate went up. Riders were pulling way too many cattle, especially at higher weights where you don’t expect health issues.”
Lab tests confirmed what Scott suspected. Mycotoxins had contaminated the feed. These metabolites of mold and fungi attack the gut and rob cattle of immunity, feed efficiency and average daily gain.
The feedyard was not alone in fighting the effects of mycotoxins. In tests of the 2017 U.S. corn crop across 23 states, 91 percent of grain, silage and corn byproduct samples contained mycotoxins. These unseen enemies also contaminate oilseeds, byproduct feeds, protein concentrates, wet brewers grains, food wastes and forages.
What are mycotoxins?
Mycotoxins can form wherever molds exist – in the field, at harvest, during storage and processing, and at feedout. Most fungi produce several mycotoxins simultaneously, and there are thousands of different species.
When feedstuffs contain multiple mycotoxins, their impact is not as simple as 1 + 1 = 2. Mycotoxins can have a cumulative effect, creating an even greater risk of cattle performance loss.
Growing conditions can affect the severity of mycotoxin contamination. Fusarium toxins are more common in the cool, wet weather of the Northeast and Midwest, while aflatoxins produced by aspergillus occur frequently in the heat and humidity of the South and West.
If you are bringing in feedstuffs from other regions, it’s not safe to assume rations are mycotoxin-free just because certain mycotoxins are not prevalent in your area.
Plus, it’s often difficult to spot mycotoxin contamination because symptoms are so wide-ranging and often seem unrelated.
Ripple effects
Researchers are learning more about the ties between mycotoxins, gut health and overall immune function. This is of key interest, because immune suppression is one of the ways mycotoxins affect cattle health and production.
The intestines are the first areas of the body to be exposed to mycotoxins and often at higher concentrations than other tissues. Maintaining a healthy gastrointestinal tract is crucial as it ensures nutrients are absorbed at an optimum rate and protects the body against pathogens through its own immune system.
Mycotoxins affect the animal at the point of attack (locally) and throughout the body (systemic) when inflammatory compounds reduce overall immune function. A ripple effect opens the door for opportunistic diseases that negatively impact animal performance.
Gut protection
At the Southern Plains feedyard, immediate action addressed the mycotoxin problem and restored cattle health.
At Scott’s recommendation, the yard began feeding refined functional carbohydrates (RFCs) to counteract mycotoxins in the feed. RFCs work by preventing mycotoxins from being absorbed through the gut and into the blood circulation.
Unlike mycotoxin binders such as bentonite, which inactivate some strains of mycotoxins after ingestion by the animal, RFCs actually protect the gut from mycotoxin damage.
In addition, immune suppression caused by mycotoxins can be reversed by beta 1,3/1,6 glucans and mannans present in RFCs, allowing the animal to further protect itself against pathogens.
Ultimately, the increased protection from RFCs enables animals to devote energy to body maintenance and growth – instead of staving off infections or struggling to maintain nutrient uptake. That means animals are better able to weather the ill effects of mycotoxins.
RFCs worked quickly to mitigate the mycotoxin crisis in the Southern Plains.
“Within 24 to 48 hours, intake had started to creep back up, and in a week to 10 days, we recaptured the vast majority of the feed intake depression,” Scott says. “Energy and activity started improving rapidly, and the cattle quickly bounced back.”
Proactive approach
Although his client’s feedyard experienced clinical impacts from mycotoxin contamination, Scott points out that subclinical cases are common in all types of operations. “Any one or a combination of mycotoxins are invasive at the gut level and can cause negative effects when it comes to immunity and general thriftiness across all cattle,” he says.
Considering the prevalence of mycotoxins across the country, producers should assume mycotoxins are present in the feed and manage accordingly to prevent economic losses. Your goal should be to make your cattle resilient against the pervasive risk of mycotoxins – on every day and in every bite.
With high odds that mycotoxins will threaten animal health, feed efficiency and gain, now’s the time to take steps to boost the resiliency of your cattle to fight back against mycotoxins. 
PHOTO: Make it your goal to build resiliency against mycotoxins in your cattle. Staff photo.
References omitted but are available upon request. Click here to email an editor.
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Neil Michael
- Manager, Ruminant Technical Services
- Arm & Hammer
- Email Neil Michael
