Mycotoxins in Cattle Feed: Effects on Cow Health, Milk Yield and Fertility

Every farmer knows that healthy cows are the foundation for healthy profits. But what if something invisible is quietly draining your herd’s performance, lowering fertility, damaging milk quality, and forcing you to spend more on veterinary treatments?

That invisible enemy has a name: mycotoxins. These toxic by-products of fungi can be found in crops and stored feed. They are not a new problem, but they are an increasingly serious one — especially as weather conditions shift and feed storage becomes more challenging. Fortunately, there are effective ways to manage this challenge — and they provide reliable and efficient protection.

The silent threat

More than 400 different mycotoxins have been identified by scientists. Fortunately, only a small group is especially harmful to livestock. However, even at levels below EU guidance values, these toxins can quietly damage animal health and farm profits.

Aflatoxins in milk are especially risky, since they are toxic and carcinogenic and can directly affect human and animal health.

Even small amounts in the feed can be transferred to the milk as aflatoxin M1, making it undeliverable to the dairy processing plant. In addition, aflatoxin B1, the precursor of M1, damages the liver, further threatening animal health and performance. Other common mycotoxins may not stop the milk from being collected, but they silently compromise cows’ health.

The most common culprits include:

• Deoxynivalenol (DON) – also known as vomitoxin, reduces feed intake and damages the digestive tract.
• Zearalenone (ZEN) – an estrogenic mycotoxin, leading to fertility problems and miscarriages.
• Ochratoxin A (OTA) – harmful to the kidneys and the immune system.
• T-2 toxin – affects the skin, mucous membranes and central nervous system.
• Endotoxins – toxic components derived from bacterial cell walls. They become especially dangerous in combination with mycotoxins, as mycotoxins reduce gut mucin production and increase intestinal permeability, allowing both mycotoxins and endotoxins to enter the bloodstream.

The result? Less feed intake, reduced milk yield, fertility issues, rough coats, higher somatic cell counts, miscarriages and, in young calves, stunted growth. In other words: more costs, less income.

The rumen is not as safe as you think

It is said that the rumen protects cows from mycotoxins. There is some truth in that — rumen microbes can degrade some toxins to a certain extent.

But modern dairy farming puts enormous pressure on this natural protection:

• Concentrate-rich diets can lead to rumen acidosis, which impairs the rumen environment and reduces the number and activity of the microorganisms involved in mycotoxin degradation.
• Multiple mycotoxins often occur together, creating a synergistic effect: 1 + 1 = 3. This means that their combined impact on animal health is greater than the sum of their individual effects.

The outcome? Mycotoxins that would once have been neutralized now pass into the bloodstream, often together with bacterial endotoxins. This double impact causes systemic inflammation, weaker immune defenses, and invisible but costly production losses.

The economic impact of mycotoxins

Research has shown that herds exposed to even moderate mycotoxin contamination face:

• Reduced milk production – even small decreases in production can have significant economic consequences.
• Fertility issues – lower insemination success, more abortions, longer calving intervals.
• Higher veterinary costs – more mastitis, fertility treatments and metabolic problems.
• Animal losses – in severe cases, abortions, stillbirths or culling due to poor performance.

In fact, some farms suffer losses of several hundred euros per cow annually — often without recognizing mycotoxins as a serious contributing factor.

The smarter way forward: MycoProtec

At Josera, we know prevention is the smartest investment. That’s why we developed MycoProtec – a powerful, broad-spectrum solution for mycotoxin problems in dairy and beef cattle.

How it works

MycoProtec combines multiple active ingredients for maximum protection:

• Bentonite-montmorillonite – binds a wide range of mycotoxins, locking them safely in the gut so they are excreted harmlessly.
• Yeast cell walls: MOS (mannan-oligosaccharides) and β-glucans – bind both mycotoxins and harmful bacteria such as E. coli, stimulate the immune system and improve digestion.
• Natural herbs – support feed intake, stimulate digestion and help cows cope with stress.

The result: a healthier gut, a stronger immune system, better liver function and reduced toxin absorption into the bloodstream.

Real farm results

On a dairy farm with 3,200 cows producing nearly 9,700 kg of milk per cow per year, feed analysis showed 800 ppb DON and 38 ppb ZEN in the TMR. A significant portion of the herd (53.4%) was affected by mastitis.

MycoProtec was used as follows:

After adding MycoProtec to the ration, the farmer observed:

• A 30% reduction in udder infections within just three months.
• Improved overall herd health.
• Increases in both milk yield and reproductive performance.

The benefits at a glance

MycoProtec effectively controls mycotoxins, leading to measurable improvements:

• Healthier cows – fewer udder infections, stronger immunity, reduced metabolic stress.
• Better fertility – improved insemination efficiency, fewer abortions, healthier calvings.
• Higher productivity – more milk per cow, better feed intake, improved fiber digestion.
• Lower costs – reduced veterinary bills, fewer animal losses.
• Stronger profits – more animals sold, higher milk yield and better milk quality (lower somatic cell counts).

It’s not just about preventing losses. It’s about unlocking the full potential of the herd and safeguarding the farm’s profitability. It’s the smart, simple way to turn a hidden risk into a managed challenge. Because in the end, cows deserve the best — and so does the dairy business itself.