Mycotoxin management in dairy cows: enhancing health, performance and milk safety

Mycotoxins are toxic compounds produced by molds, such as Aspergillus, Alternaria, Fusarium, Penicillium and others.

Mycotoxigenic molds can grow on multiple agricultural commodities (e.g. grains, conserved forages [silage and hay] and pastures) (Jouany et al., 2009; Schatzmayr and Streit, 2013; Santos Pereira et., 2019).

Although moulds and mycotoxins are ubiquitous, high humidity and improper storage practices can exacerbate the level of contamination of feed and animal-derived food (especially dairy products!) (Fink-Gremmels, 2008).

It has been widely assumed that the resistance of ruminants to mycotoxins is a fact.

However, current studies demonstrate that these toxins affect dairy farms performance and profit enormously.

Dairy farmers worldwide still underestimate the negative consequences of mycotoxins (Fink- Gremmels, 2008a; Rodrigues, 2014).

Mycotoxins in dairy cow feed: a threat to animal health

Current research on mycotoxins clearly shows that dairy cattle are consistently exposed to mixtures of multiple mycotoxins, including aflatoxins, zearalenone (ZEN), deoxynivalenol (DON), fumonisins, enniatins, beauvericin, ergot alkaloids, among others (Penagos-Tabares et al., 2021, 2022a, 2022b, 2023a, 2022b, 2024).

Such “mycotoxin cocktails” can induce adverse effects in the dairy industry.

Although acute mycotoxicosis is rare in ruminants, chronic exposure to mycotoxins can have multiple impacts on cattle with unspecific effects, representing a real diagnostic challenge for veterinarians, nutritionists, consultants, and farmers (Fink-Gremmels, 2008a).

Among the main adverse effects of mycotoxins in cattle are:

• ⇰ Feed intake reduction
  
• ⇰ Rumen microbiome disruption
  
• ⇰ Nutrient absorption impairment
  
• ⇰ Liver damage
  
• ⇰ Immune and reproductive function alterations

Moreover, increased prevalence of diseases such as laminitis, mastitis and others have been linked to mycotoxin exposure.

The mentioned disturbances in the physiological status of the cows will be reflected in reduced milk production, poor growth performance, and higher veterinary costs, which will reduce the economic profits of dairy farms (Gallo et al., 2015).

AFLATOXIN M1: a hazard for human health and the dairy industry

Mycotoxins, such as aflatoxins, can seriously threaten the food safety of dairy products.

The hazard starts with feeds contaminated with aflatoxin B1 (AFB1), produced by Aspergillus spp., considered the most potent natural hepatocarcinogenic agent in mammals and classified as a group 1 human carcinogen by the International Agency for Research on Cancer (IARC 2012; Marchese et al. 2018).

Once cows ingest AFB1-contaminated feed, they metabolize it into aflatoxin (AFM1), which can appear in milk within hours and persist for several days, even after contaminated feed is removed from their diet (Fink-Gremmels, 2008b).

The carry-over rates from feed to milk range from 1 to 6% of AFB1 to AFM1 (Zentai et al., 2023).

Since milk is a staple in many diets, including infants and children, AFM1 represents a critical risk to food
safety, particularly in populations dependent on dairy as a dietary staple.

Regulatory agencies, such as the European Union (EU) and the United States Food and Drug Administration (FDA) have set stringent limits on AFM1 levels in milk to protect public health.

The EU, for example, has established that the maximum allowable level of AFM1 is 0.05 μg/kg in raw milk (EC, 2023).

However, even low levels of AFM1 exposure over time can pose long-term health risks, including liver cancer and immunosuppression.

Although other mycotoxins, such as ZEN, DON, fumonisins and emerging mycotoxins, have not been shown to be secreted into milk in large quantities (Fink-Gremmels, 2008b), these toxic compounds can still impact cow health and productivity, reducing milk yield, increasing somatic cell counts, impairing reproduction and compromising overall herd health (Gallo et al., 2015).

Signs of mycotoxin exposure in cows can range from subtle and unspecific issues like decreased appetite and weight loss to more severe problems such as liver damage, immunosuppression,

In addition to the health implications, the economic losses from reduced milk production and treatment costs can be substantial for dairy farmers (Fink-Gremmels. 2008b; Rodrigues, 2014; Santos and Fink-Gremmels, 2014; Gallo et al., 2015).

Integral management of mycotoxins in dairy feed

Minimizing exposure to mycotoxin mixtures will protect animal health and optimize performance.

Reduction in total aflatoxin intake will reduce both adverse effects on cows and the AFM1 contamination in milk, improving the safety of derived dairy products and protecting the health of human consumers.

A holistic mycotoxin management in dairy feeds involves several strategies, such as:

• ⇰ Good agricultural and feeding practices: ensuring crops are harvested at the right time, appropriately dried, and stored under appropriate conditions that prevent mold growth can significantly reduce the risk of mycotoxin contamination. Remove moldy spots of conserved forages (silages and hay) and concentrate feeds. Sensory feed evaluation can help prevent the inclusion of low-quality feeds in animal diets (Santos and Fink-Gremmels, 2014, Penagos-Tabares et al., 2022a).

• ⇰ Regular multi-mycotoxin feed analysis
  (exposure monitoring): since mycotoxicoses are a diagnostic challenge and commercial biomarkers are usually unavailable, analyzing feeds/rations for mycotoxin contamination is crucial for mycotoxin management. Regular feed analysis is ideal for objective monitoring and risk assessment, especially during high-risk periods such as wet seasons and summer (in temperate regions) (Penagos-Tabares et al., 2022b; Muñoz-Solano et al., 2024).

• ⇰ Use of anti-mycotoxin feed additives: incorporating adsorbents, detoxifiers, natural hepatoprotectors, and immunostimulants into dairy cow diets is one of the most effective strategies for preventing and mitigating the absorption and harmful effects of mycotoxins (Jard et al. 2011; Gallo et al., 2015; Marin y Taranu. 2023).

MYCORAID: a holistic solution for mycotoxin management

MYCORAID is a multi-action mycotoxin control product designed to address the challenges posed by a wide range of mycotoxins, including AFB1, fumonisins, and ZEN.

It offers several protection mechanisms through adsorption, biotransformation, and immune support.

1. Adsorption

MYCORAID integrates specialized minerals, scientifically validated to adsorb a wide range of polar and less polar mycotoxins in the gastrointestinal tract.

⇰ This adsorption prevents the absorption of harmful toxins into the bloodstream.

2. Biotransformation

The product includes Bacillus sp., which can biotransform mycotoxins into less harmful compounds.

⇰ This is particularly important for AFB1, as Bacillus can help reduce its conversion to AFM1.

3. Hepatoprotection

MYCORAID also contains herbal extracts such as Silymarin from milk thistle (Silybum marianum), which protect the liver from toxin-induced damage.

4. Immunostimulation

The cell walls included in MYCORAID are rich in β-glucans and mannan oligosaccharides, which play a pivotal role in immunostimulation.

• ⇰ β-glucans act as immune modulators by stimulating innate and adaptive immune responses. They activate macrophages, dendritic cells, and natural killer (NK) cells, enhancing the cow’s ability to combat infections and resist the detrimental effects of mycotoxins.
• ⇰ Mannan oligosaccharides, on the other hand, bind to pathogenic bacteria, preventing their attachment to the gut mucosa and helping to establish a balanced gut microbiota.

CONCLUSION

Compared to monogastric animals, dairy farmers worldwide have neglected and underestimated mycotoxins.

The control of mycotoxins in dairy cow feed is not just an animal health and welfare issue but a critical food safety concern with significant economic implications in the global dairy industry.

With the growing awareness of the dangers of AFM1 in milk, farmers must take proactive steps to minimize mycotoxin contamination in their dairy cow diets.

References

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