2. Mycotoxins
The word mycotoxin derived from the Greek word "mykes",meaning
mould, and "toxicum" meaning poison.
Mycotoxins are toxic secondary metabolite produced by the fungus
(mold) that causing disease and death of animals.
Aspergillus, Fusarium and Penicillium.
3. Characteristics of Mycotoxins:
• There are hundreds of known mycotoxins.
• They are chemically different.
• They vary greatly in their severity.
• Their molecular weight ranges from 200 to 500 kD( kilodalton)
• In the field
• During storage
4. In the field
Field fungi invade the seeds while the crop is still in the field.
They require high moisture conditions (20-21%).
• Fusarium Specie
5. Storage Fungi
They invade grains or seeds during storage.
They need less moisture than field fungi (13-15%)
Temperature over 14-30°C
Usually do not present any serious problem before harvest.
Storage fungi include species of:
• 1. Aspergillus
• 2. Penicillium
6. Types of Mycotoxins
Although several hundred mycotoxins are known, the mycotoxins of
most concern, based on their toxicity and occurrence, are:
• Aflatoxin
• Trichothecenes (DON, T-2 toxin, DAS, etc)
• Ochratoxin A
• Zearalenone
• Ergot alkaloids
• Fumonisin
8. Mycotoxins Fungi Effect of birds Maximum Limit
Aflatoxin Aspergillus flavus, Aspergillus
parasiticus
Hepatotoxicity, carcinogenic and
teratogenic effects
200-300 ppb
Trichothecenes Fusarium graminearum,
Fusarium sporotrichioides/
culmorum
immunologic effects, hematological
changes, digestive disorders, edema
100 ppb
Zearalenone Fusarium graminearum estrogenic effects, atrophy of ovaries
and testicles, abortion
200-300 ppb
Ochratoxin Aspergillus ochraceus,
Penicillium verrucosum
nephrotoxicity, hepatotoxicity, 3 ppm
Ergot alkaloid Claviceps purpurea, Claviceps
paspaspali
nervous or gangrenous syndromes No restriction set
Fumonisin Fusarium verticillioides,
Fusarium proliferatum
leukoencephalomalacia,
nephrotoxicity, hepatotoxicity
5 ppm
9. Aflatoxins
• Aflatoxins are a type of mycotoxin produced by Aspergillus species of fungi,
such as A. flavus and A. parasiticus.
• The aflatoxin refers to four different types of mycotoxins produced, which
are B1, B2, G1, and G2.
• Aflatoxin B1, the most toxic, is a potent carcinogen and has been directly
correlated to adverse health effects, such as liver cancer, in many animal
species.
• Among poultry, ducks are the most susceptible to aflatoxin,
followed by turkeys, broilers, laying hens and quail
10. • Aflatoxin affects:
• Reduce weight gain
• Reduce feed intake and FCR
• Decrease egg production
• Decrease male and female fertility
• Tissue degeneration
• Liver cirrhosis
• lesions in the liver, reddened due to necrosis and congestion or
yellow due to lipid accumulation
• hemorrhages in liver and other tissues
11. Ochratoxins A (OTA)
• Ochratoxins are quite toxic to poultry, as nephrotoxins produced
chiefly by Penicillium viridicatum and Aspergillus ochraceus in grains
and feed. Ochratoxicosis primarily causes renal disease but also
affects the liver, immune system, and bone marrow.
• Ochratoxin A is the most important of the ochratoxins.
• Ochratoxicosis causes:
• decreased weight gain and poor feed conversion
• reduced spontaneous activity, hypothermia and huddling
• diarrhea, rapid weight loss, and death due to renal failure
• decreases in carcass yield, egg production, fertility and hatchability
12. Trichothecenes (T-2 toxin, diacetoxyscirpenol (DAS),
deoxynivalenol (DON), HT-2 toxin, etc)
Trichothecenes are typical field mycotoxins.
They are produced on crops entering the feed via contaminated
ingredients.
Poultry are most sensitive to T-2 toxin and DAS.
13. • Signs
• Oral lesions, dermatitis and intestinal irritation.
• Gizzard erosion - Necrosis of proventricular mucosa.
• Immune suppression
• Reduced egg production - Poor shell quality.
• Regression of ovaries.
• Reduced female fertility and hatchability of fertile eggs
14. Zearalenone
Zearalenone often occurs with DON in naturally-contaminated
cereals.
Zearalenone is responsible for reproductive disorders due to
its estrogenic effect at high concentrations.
ZEA has limited toxicity to birds.
At high concentrations, the following symptoms have been
observed:
1. Vent enlargement
2. Enhanced secondary sex characteristics
15. Fumonisin
• Broilers and turkeys are resistant to acute fumonisins toxicity.
• Spiking mortality (paralysis, extended legs and neck, wobbly gait,
gasping)
• Reduced growth rate.
• Increased organ weights.
• Hepatocellular hyperplasia.
16. Prevention
• Proper storage (dry place)
• Moisture 10-12 %
• Temperature below 15 °C
• Proper ventilation
• Insect free place
• Drying grains in sunshine
• Toxin binders
• Bentonite, Zeolite
• HSCAS
