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Ochratoxicosis is caused by ingestion of ochratoxin A (OTA), a type of mycotoxin, which has nephrotoxic, hepatotoxic, teratogenic, and immunotoxic effects on several animal species. Mycotoxins are secondary metabolites produced by a wide range of filamentous fungi which have adverse effects on humans, animals and crops that result in illnesses and economic losses. Mycotoxins are estimated to contaminate 25% of the world's grains that are used for food (FAO 2001), particularly in grains used as ingredients in commercial feed for livestock such as chickens. OTA is produced by different species of Aspergillus and Penicillium such as A. ochraceus, A. carbonarius, P. verrucosum and P. nordicum. However, A. carbonarius is considered to be the main producer of OTA on coffee and grapes.
The resulting toxic effects of chickens consuming OTA contaminated feed include:
  • Inhibition of protein synthesis
  • Induction of lipid peroxidation
  • Impairment of calcium homeostasis
  • Oxidative stress
  • DNA damage
  • Increased incidents of food allergies
  • Reduced blood coagulability
  • Destruction of digestive enzymes
  • Reduced immunity, leading to increased susceptibility to invasion by harmful pathogens
  • Circulatory system damage
Recent research suggests that several Essential Oils (E.Os) have shown to be beneficial at inhibiting production of A. carbonarius, the fungi responsible for producing OTA. The E.O of fennel (Foeniculum vulgare), at 5 µL/mL was found to be the most effective.

Clinical Signs

Rapid weight loss
Decreased appetite
Increased thirst
Reduced egg production
Poor hatchability
Thin-shelled eggs
Egg yolk w/blood or meat spots
Decreased body temperature
Excessive urates
Yellow diarrhea


  • History
  • Clinical signs
  • CBC
  • Ochratoxin Quantitative Analysis


Supportive careIsolate the bird from the flock and place in a safe, comfortable, warm location (your own chicken "intensive care unit") with easy access to water and food. Limit stress. Call your veterinarian.
Removal of moldy feed from diet
L-carnitine + vitamin EAdded to feed at 1 g/kg (L-carnitine) and 200 mg/kg (vitamin E)Abidin Z et al., 2013
ProbioticsSpecifically containing several species of lactobacillus bacteriaSlizewska et al., 2014



  • Probiotics: Adding probiotics can reduce the amount of OTA by 55% : Slizewska et al., 2014
  • Purchase quality poultry feed
  • Properly store poultry feed, for no longer than a month in duration and in an air-tight container that is free from moisture accumulation and not exposed to sunlight, insect contamination, or rodents.
  • Inspect feed daily : Look over quality of feed prior to giving to birds.
  • Do not feed anything to birds that is suspected of contamination with mold, insects, spoiled, or has been continuously refused by your chickens.

Scientific References

Risk Factors

  • Purchasing poor quality (cheap) poultry feed
  • Not storing feed correctly.