Mycotoxins in Poultry – How to Deal With it?

Common mycotoxins include aflatoxins, trichothecenes, fumonisins,
zearalenone, ochratoxin, and ergot alkaloids.

They can be present in agricultural products before or after harvest.

How Do Mycotoxins Harm Animals?

Mycotoxins’ effects on animals vary and can include carcinogenicity, hepatoxicity, neurotoxicity, impaired reproduction, digestive disorders, immunomodulation, and decreased performance. Although clinical signs may be visible at high levels of mycotoxin contamination, more commonly, we observe subclinical effects. Even moderate levels of mycotoxins, particularly during chronic exposure, can negatively affect the animals. Mycotoxins affect the immune system and the integrity of the gut barrier and act as predisposing factors for diseases.

Mycotoxins Are Highly Resistant

Mycotoxins are harmful substances that cannot be seen, tasted or smelled. They are chemically
stable, resistant to temperature and storage, and cannot be removed or detoxified during
normal feed processing. Therefore, managing the risk of mycotoxins is crucial, and it should
include detecting mycotoxins, providing other related services, and implementing solutions to
counteract the different types of mycotoxins present in the feed.

Mycotoxicosis In Poultry

Mycotoxins constantly threaten the poultry industry, as they regularly contaminate poultry feed
worldwide. Harmful mycotoxins are ingested by birds through typical feed ingredients, causing a
range of serious consequences.
While some fungi produce mycotoxins on the field, others produce them during the storage of
grains. It is important to uncover which specific mycotoxins are present in poultry feed to
understand the risks of mycotoxicosis in poultry better.
The most common poultry feed ingredients contaminated by mycotoxins include:

• Corn and corn by-products
• Wheat and wheat by-products
• Soybean meal
• Barley

How Do Mycotoxins Affect Poultry?
Mycotoxins mainly exert their effects through the following mechanisms:

• Feed intake reduction or feed refusal
• Reduced growth performance
• Compromised fertility
• Suppression of the immune system
• Damage to internal organs
• Reduced eggshell quality

Mycotoxins do play a significant role in the organ poultry and disrupt various body organs,
which are listed as follows,

Renal dysfunction

• Increased organ size
• Increased water consumption
• Promotion of inflammation

Fertility

• Decreased hatchability
• Decreased egg production
• Ovarian cysts
• Embryonic loss
• Delayed sexual maturation

Liver Health

•  Liver cancer
• Liver, spleen and bursa enlargement
• Change in the texture and colouration of the liver and gizzard
• Liver lesions

Other Common Complications

• Higher mortality
• Necrosis
• Vasoconstriction
• Teratogenic effects
• Dermal lesions
• Impairment of hematological parameters
• Decreased resistance to environmental stressors
• Neurologic effects

Gastrointestinal Effects

• • Gastrointestinal lesions (beak, oral cavity, intestinal tract)
  • Severe immunosuppression
  • Feed refusal
  • Decreased feed intake
  • Diarrhea
  • Impaired gut integrity
  • Impairment of haematological parameters
  • Reduced area for feed absorption

Effects Of Mycotoxins in Poultry
Poultry species differ in their sensitivity to mycotoxins, but all are affected by them.

Aflatoxins In Chickens
Aflatoxins can harm the liver of poultry and cause cancer in animals that are exposed to them.
Exposure to these toxins for a long time can damage the liver, lymphoid organs, and testes. In
cases of acute-subacute aflatoxicosis, the liver may become enlarged, pale yellow in colour, and
fragile. It is also common for the gall bladder to enlarge and fill with bile.

Several factors increase a bird’s susceptibility to mycotoxins, such as:

• Birds being placed in a hostile environment, e.g. high temperatures and humidity
• Poor ventilation
• High density
• Challenges from poultry diseases, e.g. coccidiosis and necrotic enteritis
• Leads to gut health issues > Leaky gut
• Impaired immunity at low mycotoxin contamination levels

Effects Of Mycotoxins in Week-Old Chicks
Even minor issues can significantly impact their short- and long-term health during the first week of a chick’s life. Developing their intestinal tract and immune system is crucial for a healthy life. However, early exposure to mycotoxins can jeopardise this foundation. Even lowlevel interference at this stage can have disastrous consequences later in life.

Low doses of mycotoxins can combine with environmental stressors,
sometimes out of the rearer’s control.

This combination can result in losses that are not immediately noticeable, with effects that may be subclinical, including invisible symptoms:

• Disruption of gut health
• Greater susceptibility to disease
• More serious immune problems in later life
• Further losses to economic performance
• Signs of infection

Clinical Signs
Mycotoxins can cause various clinical signs, depending on the type, quantity, and combination
of toxins present in the feed.

• Lack of reflexes and abnormal wing positioning
• Blood cell damage
• Increased water consumption and renal dysfunction
• Diarrhoea
• Impaired feathering, oral lesions & gizzard erosion
• Decreased feed intake and feed refusal, reduced daily weight gain
• Decline in egg production, size, weight, eggshell quality & hatchability
• Jaundice (yellow skin)
• Lower hatchability, increased number of rejected day-old chickens

Diagnosis Of Mycotoxicosis in Poultry
Mycotoxin contamination in poultry feed can be difficult to detect, but clinical signs and
pathological lesions on primary target organs can be used as an early warning system. To
counteract mycotoxins, the poultry industry tends to use toxin binders first, but clay mineral
binders are not effective against all major mycotoxins.

Biotransformation using microbes and enzymes is the most effective strategy, providing reliable
protection against mycotoxins by biodegrading them into non-toxic metabolites. Bio protection
is also important, and a variety of feed additives containing plant and algae extracts can provide
a hepato-protective effect to overcome the immune suppression caused by mycotoxins.

A combination of different strategies can counteract the negative effects of mycotoxins in
poultry more completely, especially in cases of multi-mycotoxin contamination with the poorly
absorbed fusarium mycotoxins in poultry feed.

Collecting and promptly submitting samples of feed and ingredients for
laboratory analysis is essential to ensure a definitive diagnosis.