Mycotoxins damage the intestinal wall of poultry by directly affecting epithelial cells, weakening the barrier function, and triggering inflammatory responses. This leads to reduced nutrient absorption, increased susceptibility to infections, and significant production losses. In this article, we answer the most frequently asked questions about mycotoxins and the gut health of chickens.
How do mycotoxins damage the intestinal wall of poultry?
Mycotoxins damage the intestinal wall of poultry by weakening tight junction proteins, reducing villus height, and causing oxidative stress in intestinal epithelial cells. The result is increased intestinal permeability, also known as “leaky gut,” whereby harmful substances and pathogens more easily reach the bloodstream.
The intestinal wall of a chicken consists of a thin layer of epithelial cells held together by tight junction proteins such as occludin and claudin-1. Mycotoxins disrupt the production and structure of these proteins, reducing the sealing function of the intestinal barrier. At the same time, they damage the microvilli, the small projections that increase the absorption surface, which directly leads to poorer nutrient utilization.
In addition to structural damage, mycotoxins also cause oxidative stress in intestinal cells. This accelerates cell death and slows the recovery of the intestinal epithelium. With chronic exposure, the cells become exhausted and the intestinal wall gradually loses its ability to renew itself, resulting in long-term damage. This makes gut health in poultry a priority for every livestock farmer who wants to optimize performance.
Which mycotoxins are most harmful to the intestines of chickens?
The most harmful mycotoxins for the gut health of chickens are deoxynivalenol (DON), fumonisins, T-2 toxin, and ochratoxin A. These mold toxins occur most frequently in cereal crops and feed raw materials, and each has a specific target site in the gastrointestinal tract.
An overview of the most problematic mycotoxins for the gut:
- Deoxynivalenol (DON): Directly affects enterocytes, inhibits protein synthesis, and causes inflammation of the intestinal mucosa. DON is one of the most common mycotoxins in corn- and wheat-based feeds.
- Fumonisins: Disrupt lipid synthesis in intestinal cells and damage the mucosal barrier. They occur mainly in corn and are particularly problematic in warm, humid harvest conditions.
- T-2 toxin: A trichothecene with strong cytotoxic effects. T-2 causes necrosis of the intestinal epithelium and strongly inhibits cell renewal.
- Ochratoxin A: Affects the kidneys, but also has a negative effect on intestinal integrity and the immune system in the gut.
The risk increases significantly with simultaneous exposure to multiple mycotoxins, a situation that occurs frequently in practice. Combinations of DON and fumonisins amplify each other’s harmful effects, meaning the threshold values for visible damage are lower than with single contamination.
What are the visible consequences of mycotoxin damage in poultry?
Visible consequences of mycotoxin damage in poultry include wet droppings, reduced growth, poorer feed conversion, increased mortality, and deteriorated litter quality. These symptoms cannot always be unambiguously attributed to mycotoxins, which complicates diagnosis.
In the barn, mycotoxin damage is often first noticed through fecal consistency. Wet, watery droppings indicate disrupted fluid absorption in the gut and reduced absorption capacity. Wet litter subsequently increases the risk of footpad lesions, pododermatitis, and secondary bacterial infections.
At the performance level, the consequences are measurable through the following indicators:
- Lower average daily gain (ADG) due to reduced nutrient absorption
- Deteriorated feed conversion ratio (FCR) due to inefficient utilization of the ration
- Increased mortality, particularly in young chicks with an immature immune system
- Reduced carcass weight and lower breast muscle yield in broilers
- Decline in egg production and shell strength in laying hens
Chronic, low-grade mycotoxin exposure often gives more subtle signals than acute poisoning. Farmers then notice a gradually deteriorating technical performance without clear disease symptoms, making the cause difficult to trace.
How do mycotoxins affect the immune system in the gut?
Mycotoxins suppress the gut-associated immune system of poultry by inhibiting the production of immune cells, reducing the production of protective antibodies, and disrupting the balance of the gut microbiota. This makes chicks significantly more susceptible to bacterial and viral infections.
The intestinal mucosa of poultry contains a large portion of the total immune system. Mycotoxins disrupt this system at multiple levels. First, they inhibit the proliferation of lymphocytes, the white blood cells that recognize and attack pathogens. Second, they reduce the concentration of secretory IgA, the antibody that protects the intestinal wall against pathogenic bacteria and viruses.
In addition, mycotoxins cause dysbiosis: a disruption of the microbiome balance in the gut. A healthy microbiome is characterized by eubiosis, with a stable and diverse bacterial population dominated by beneficial bacteria such as Firmicutes and Bacteroidetes. Mycotoxins reduce this diversity and promote the growth of pathogenic bacteria, particularly from the Proteobacteria group. This significantly increases the risk of secondary infections such as Clostridium-related necrotic enteritis.
The immunosuppressive effect of mycotoxins also has practical implications for vaccination programs. Chicks exposed to mycotoxins develop protective immunity less effectively after vaccination, undermining the effectiveness of standard vaccination protocols.
How can mycotoxin damage to the gut be limited?
Mycotoxin damage to the gut of poultry can be limited through a combination of preventive measures in feed production, the use of mycotoxin binders in the ration, and strengthening the intestinal barrier through targeted feed additives. No single measure is sufficient on its own.
The first line of defense is prevention at the source: good harvesting and storage practices, rapid drying of raw materials, and regular analysis of feed raw materials for mycotoxin content. In practice, however, complete avoidance is not realistic, especially in years with unfavorable weather conditions.
Additionally, mycotoxin binders in the feed can reduce the absorption of toxins in the gut. These bind mycotoxins in the gastrointestinal tract and promote their excretion via the feces. Effectiveness varies by type of binder and by mycotoxin, meaning the choice of binder must be tailored to the specific contamination profiles in the ration.
In addition to binding, strengthening the intestinal wall itself is an essential strategy. Ingredients that support tight junction proteins, reduce oxidative stress, and restore microbiome balance help make the gut more resilient against the damage mycotoxins cause. View our range of drinking water and feed additives for an overview of available solutions. Drinking water is a particularly attractive delivery vehicle: water intake is more reliable than feed intake during stress and illness, and the dosage is fully controllable by the farmer.
How Jodoco helps with mycotoxin damage to the gut of poultry
We at Jodoco develop feed and drinking water products that actively support the gut health of poultry, even under the challenging conditions that mycotoxins create. Our approach combines multiple mechanisms of action in one formula, aimed at restoring and protecting the intestinal barrier.
Our products deliver a holistic combination of active ingredients:
- Natural betaine: Strengthens tight junction proteins, reduces oxidative stress, and protects the intestinal wall during infection or toxin exposure
- Slow-release butyrate: Strengthens intestinal integrity and reduces intestinal inflammation
- Medium-chain fatty acids (MCFA): Have a strong antimicrobial effect against gram-negative and gram-positive bacteria
- Yeast cell walls (beta-glucans and MOS): Support immune modulation and promote eubiosis in the gut microbiota
- Organic acids and essential oils: Improve feed and water hygiene and support technical performance
With products such as Grovax, we offer a concrete solution for livestock farmers who want to protect the gut health of their flock, even during periods of increased mycotoxin pressure. Want to know which approach best suits your situation? Contact us and we will be happy to think along with you.
