5 Reasons why you need to consider subclinical mycotoxin contamination in your pig feed and how to mitigate it

In Brief:

• Subclinical mycotoxin contamination of pig feeds reduces herd performance in terms of growth, immunity and reproduction, often without any visible symptoms.
• Conventional mycotoxin control solutions are limited in their capabilities and are insufficient to tackle multi-toxin interactions.
• The next generation of mycotoxin management is through enzymatic detoxification.
• FUMzyme® and ZENzyme® transform fumonisins and zearalenone into harmless compounds in the gastrointestinal tract, improving feed efficiency, animal welfare and farm profitability.

Introduction

Mycotoxins are secondary metabolites produced by fungi when they infect cereal plants during growth and grain storage. They pose a persistent and complex challenge in pig production. Despite improvements in agricultural and storage practices, contamination of feed ingredients with mycotoxins such as deoxynivalenol (DON), zearalenone (ZEN), fumonisins (FUM), aflatoxins (Afla) and ochratoxin A (OTA) remains almost unavoidable.

While severe mycotoxin contamination of animal feeds leads to clear clinical signs including feed refusal and organ failure, low-level or subclinical exposure, even at levels below regulatory limits, can silently undermine animal health, growth and productivity, impacting herd profitability without presenting any visible symptoms.

Emerging research and industry data show that subclinical mycotoxin contamination is widespread, and that its effects extend far beyond the published regulatory guidelines for contamination levels. Fortunately, scientific advances, particularly in enzymatic detoxification, offer new strategies to mitigate these hidden costs and protect both animal welfare and farm profitability.

Understanding subclinical mycotoxin exposure

Subclinical exposure refers to toxin levels below official guidance thresholds, such as those defined by the European Union. At these concentrations, pigs show no obvious symptoms, yet physiological and metabolic disruptions occur. These often go unnoticed but can significantly impair performance and immune competence over time.

Mycotoxin contamination is rarely limited to a single toxin. Multi-mycotoxin contamination is the norm, not the exception. Data from the dsm-firmenich global survey program (January – September 2025) showed that 82% of the over 19,000 feed samples analyzed contained more than one mycotoxin. These toxins can interact additively or synergistically, amplifying the negative consequences, even when each toxin alone is at a ‘safe’ level.

Hidden impacts on pig health and performance

1. Growth and feed efficiency
   One of the earliest and most economically relevant consequences of low-level mycotoxin exposure is a reduction in average daily gain (ADG) and feed efficiency. Although pigs may continue eating normally, feed conversion rates decline subtly. Over time, this leads to lower final weights, longer finishing periods, and higher feed costs per kilogram of gain.
2. Gut integrity and function
   The intestine is a key target organ for many mycotoxins. Even low concentrations can increase gut permeability, alter villus morphology, and weaken barrier function. These changes allow bacteria and endotoxins to translocate from the gut into tissues or the bloodstream, fueling chronic low-grade inflammation that saps growth and immunity.
3. Immune suppression and vaccine response
   Subclinical mycotoxin exposure is known to impair both innate and adaptive immune responses. Pigs fed contaminated diets may show reduced lymphocyte proliferation, lower antibody titers after vaccination, and increased susceptibility to infections. The immune-modulating effects of DON have been widely documented, highlighting how hidden contamination can erode disease resilience in apparently healthy herds.
4. Organ and cellular effects
   Microscopic examination often reveals lesions in the liver, kidneys or lungs and oxidative stress at the cellular level. Such damage, though invisible in day-to-day herd management, can reduce organ function and limit the pig’s ability to metabolize other toxins or drugs.
5. Reproductive disruption
   Toxins with estrogenic activity, especially ZEN, pose specific risks for gilts and sows. Even at low levels, ZEN can disturb estrous cycles, delay puberty, lower conception rates, and reduce litter sizes. Chronic low exposure can therefore have cumulative reproductive costs across production cycles.

Chronic low exposure to mycotoxins can undermine animal performance

Why traditional mitigation is not enough

Conventional mycotoxin management strategies such as improved crop storage, toxin binders, and periodic testing have clear benefits but also limitations. Adsorbents are effective primarily against aflatoxins which bind readily to clays and other materials. However, most non-adsorbable toxins like DON, ZEN and FUM remain biologically active even in the presence of binders.

Given that low-level exposure is often undetectable and multi-toxin interactions are common, a more targeted and reliable approach that neutralizes toxins before absorption and supports the animal’s natural defense systems is required.

Enzymatic detoxification: the next generation of mycotoxin control

Recent advances in biotechnology have enabled the development of specific enzymes capable of irreversibly degrading mycotoxins into harmless compounds within the pigs’ gastrointestinal tract. Unlike general binders, these enzymes act through biotransformation, breaking down the toxin’s molecular structure and rendering it non-toxic.

The discovery process often begins with screening environmental microorganisms which naturally metabolize mycotoxins such as bacteria or fungi. Once identified, the enzyme responsible for this activity is isolated, expressed, optimized through enzyme engineering and formulated for stability in feed.

Cutting edge detoxification

Two enzymes now represent the cutting edge of enzymatic detoxification in pig feed: FUMzyme® and ZENzyme®.

FUMzyme® is a purified enzyme that catalyzes the conversion of fumonisins into its hydrolyzed form, that is far less toxic. Feeding trials have shown that adding FUMzyme® to contaminated diets significantly reduces fumonisin levels in feces. FUMzyme® is the first enzyme of its kind approved in both the EU and the US for use in pigs and other species.

Low doses of FUMzyme® (approximately 1.7 – 17 U/L) were capable of completely degrading 72.2 ppm FB1 (100 μM). An activity of 17 U/L completely hydrolyzed FB1 within the first 15 minutes of the reaction (Figure 1)

ZENzyme® is a purified enzyme that cleaves ZEN into a product with significantly reduced estrogenic activity. In animal studies, the enzyme effectively prevented the absorption of ZEN into the bloodstream, thereby reducing reproductive risks. Regulatory approval for ZENzyme® is currently pending in the EU and the US, with promising results already demonstrated in pigs. A dose of 20 U ZENzyme®/kg feed (which corresponds to 1 kg MPL 5.Z per ton of feed) achieves complete degradation of 10 ppm ZEN within just 2 minutes of incubation as shown in Figure 2.

Together these enzymes represent a targeted, science-based solution to a long-standing challenge in mycotoxin management.

Enzyme-based detoxification is a breakthrough in precision mycotoxin management

A holistic mycotoxin risk management strategy

Effective mycotoxin control requires a multi-pillar approach, combining prevention, detection and biological detoxification. Mycofix® embodies this integrated concept through three complementary mechanisms:

1. Adsorption – targeting aflatoxins using high-affinity binding materials
2. Biotransformation – employing enzymes such as FUMzyme® and ZENzyme® to detoxify tricothecenes, fumonisins and zearalenone
3. Bioprotection – supporting gut integrity, liver function, and immune resilience to mitigate residual effects

This layered defense ensures comprehensive protection even when complete toxin elimination from feed is impractical.

The economic and welfare benefits

Addressing subclinical mycotoxin exposure yields measurable returns. Producers who reduce toxin-related growth suppression and immune compromise can expect:

• Improved feed conversion and faster growth rates
• Better vaccine response and reduced medication costs
• Higher reproductive performance and litter consistency
• Lower chronic inflammation and improved animal welfare

Conclusion

Subclinical mycotoxin contamination in pig feed represents a hidden but substantial threat to productivity, health and profitability. Even when levels remain below legal limits, chronic low exposure can undermine gut function, immunity, organ health, and reproduction. Traditional mitigation strategies alone are insufficient to address the full complexity of multi-toxin contamination.

The advent of enzyme-based detoxification technologies such as FUMzyme® and ZENzyme®, marks a breakthrough in precision mycotoxin management. By directly and irreversibly neutralizing key toxins within the gastrointestinal tract, these enzymes protect pigs from the silent toll of subclinical exposure while enhancing overall performance and welfare.

As global feed contamination data continue to highlight the prevalence of multiple mycotoxins, integrating broad-based, scientifically validated solutions such as Mycofix® is no longer optional but essential for sustainable, high-performance pig production