Mycotoxins produced by Aspergillus flavus and A. parasiticus.


[affected.gif] Animals most affected
Poultry, pigs, sheep, cattle, dogs (especially juveniles).


[etiology.gif] Etiology
Ingestion of contaminated harvested crops
or cereals (the fungus proliferates on peanuts, cotton, sorghum, oats, barley, soya), especially when the crops have been harvested and stored under poor conditions (warm and humid).


[toxic.gif] Toxicity
Aflatoxin is hepatotoxic, carcinogenic, teratogenic and an immunosuppressant. The toxicity is due to flavocoumarins of which AFB1, AFB2, AFGl and AFG2 are the most important. AFB1 produces toxic metabolites which interfere with DNA, causing immunosuppression and carcinogenesis. All the compounds are highly hepatotoxic. Attention should be paid to the metabolite AFM 1, which may pass into milk.

Toxic doses in mg/kg:

LD50 rats, ducklings 1
  turkeys, rabbits, dogs 1
  sheep 2
  chickens 6.3
  pigs 10
  calves 10


[clinical.gif] Clinical features
Acute form
Poultry chicks are the most sensitive of birds and animals to the compound.

Turkeys

Pigs

Sheep

Cattle

Subacute or chronic form

Pigs

Sheep


[lesions.gif] Lesions
Acute

Chronic
Uniquely affects the liver, causing adeno-carcinoma, nodules, fibrous atrophy.


[treatm~1.gif] Treatment
Remove the cause or source of the intoxication.

Prophylaxis and prevention
The amount and concentration of aflatoxins in different animal feedstuffs should be monitored and regulated; for example the levels should be kept below 0.2 ppm in feed for adult poultry.