This document provides an overview of mycotoxins in poultry. It discusses fungi species that produce mycotoxins, conditions needed for their growth, and factors affecting mycotoxin formation in crops and storage. The key mycotoxins of concern for poultry are described as aflatoxins, trichothecenes, ochratoxin A, zearalenone, and fumonisin. Aflatoxins specifically produced by Aspergillus fungi are more common in warm, humid conditions and negatively impact liver function and health in poultry.

1. Mycotoxin In Poultry
General Overview

2. Plan Of Talk
 Introduction
 Fungi species
 Fungi growth
 Agronomic factors affecting mycotoxin formation in the field
 Principle factors influencing mycotoxin production
 Mycotoxin types

3. Plan Of Talk
 Introduction
 Fungi species
 Fungi growth
 Agronomic factors affecting mycotoxin formation in the field
 Principle factors influencing mycotoxin production
 Mycotoxin types

4. Mycotoxins … Human First Discovery
 Human cases of ergotism or
St. Anthony's Fire have been
described in Europe since
the Middle Ages.
 It is known now to be caused
by alkaloids produced in rye
by the mould Claviceps
purpurea.

5. Mycotoxins … Avian First Discovery
England 1960,
An outbreak of Turkey X disease and the
subsequent discovery of the aflatoxins
stimulated great interest in the field of
mycotoxin research (Bullerman, 1979).
Since then, many more mycotoxins, such as
trichothecenes, zearalenone, ochratoxins
and fumonisins have been discovered.

6. What Are Mycotoxins?
 The word mycotoxin stems from the Greek word "mykes",
meaning mould, and "toxicum" meaning poison.
 Mycotoxins are toxic secondary metabolites produced by
fungi growing on crops whether;
1. In the field
2. During handling
3. During storage

7. Cont. …
Characteristics of Mycotoxins:
1. There are hundreds of known mycotoxins.
2. They are chemically different.
3. They vary greatly in their severity.
4. Their molecular weight ranges from 200 to 500 kD.

8. Mycotoxins Host Affinity
All poultry species are affected by
mycotoxins.
– Species differences have been
reported.
– Ducks for example are particularly
sensitive towards aflatoxin.

9. Mycotoxin Affection
Mycotoxins enter the animal
production system via:
1. Feed (concentrate, silage or forage)
2. Bedding.

10. Mycotoxin Negative Effect
Mycotoxins negatively affect:
1. Animal performance
2. Animal health
3. Product quality
Mycotoxin control is crucial for:
1. Production economics
2. Animal welfare
3. Product quality
4. Food safety

11. Cont. …
Mycotoxins exert their effects through 4 primary mechanisms:
1. Reduction of feed intake or feed refusal.
2. Alteration in nutrient content of feed in terms of nutrient absorption
and metabolism.
3. Effects on the endocrine and exocrine systems.
4. Suppression of the immune system.

12. Cont. …
1. Poor growth
2. Reduced egg production
3. Reduced feed conversion
4. Increased mortality
5. Poor egg shell quality
6. Reduced fertility
7. Leg problems
8. Carcass condemnation
9. Increased susceptibility to disease

13. Diagnosing Mycotoxicosis
 Mycotoxicosis often lead to unspecific symptoms, which can
also be caused by many other factors, making if difficult to
diagnose mycotoxin problems.
– Moderate mycotoxicosis has general unspecific symptoms as:
• Reduced performance
• Impaired immunity
– Sever mycotoxicosis has more specific symptoms.

14. Cont. …
 Further difficulties in mycotoxicosis diagnoses can be caused
by secondary symptoms resulting from opportunistic disease
related to the suppression of the immune system following
mycotoxin exposure.

15. Cont. …
 In order to effectively identify mycotoxicosis, experience with
mycotoxin-affected animals is important.
 This experience, combined with adequate feed and tissue
analyses, provide the basis for the most accurate diagnosis of
mycotoxicosis.

16. Plan Of Talk
 Introduction
 Fungi species
 Fungi growth
 Agronomic factors affecting mycotoxin formation in the field
 Principle factors influencing mycotoxin production
 Mycotoxin types

17. Fungi Species
Fungal species are often divided into two groups:
1. Field fungi
2. Storage fungi

18. Field Fungi
 Field fungi invade the seeds
while the crop is still in the field.
 They require high moisture
conditions (20-21%).
 These include species of:
1. Fusarium
2. Alternaria
3. Clodosporium
4. Diplodia
5. Gibberella
6. Helminthosporium

19. Storage Fungi
 They invade grains or seeds
during storage.
 They need less moisture than
field fungi (13-18%)
 Usually do not present any
serious problem before harvest.
 Storage fungi include species of:
1. Aspergillus
2. Penicillium

20. Plan Of Talk
 Introduction
 Fungi species
 Fungi growth
 Agronomic factors affecting mycotoxin formation in the field
 Principle factors influencing mycotoxin production
 Mycotoxin types

21. Fungal Growth
 Moulds grow by producing long
filaments called hyphae
 Hyphae form a network.
 The network is responsible for
cementing kernels together.
 This complex forms clumps of grain that
cannot be separated.
 Grain-mould fungi also produce spores
capable of aerial dispersal in the field.

22. Cont. …
 Masses of these spores give the mould a characteristic colour.
 Spores can lay dormant for months or years until the proper
conditions for fungal development are available.

23. Predisposing Factors
For Fungal growth
Under field conditions,
Stress and subsequently reduced
vigour often predispose plants to
infestation and colonization by
toxigenic fungi.

24. Cont. …
In stored grain,
Fungal infection and mycotoxin production result from a complex
interaction between:
1. Moisture
2. Temperature
3. Substrate
4. Oxygen (O2)
5. Carbon dioxide (CO2) concentration
6. Fungal abundance
7. Insect presence
• Insects can influence a differentiation of fungal species, that is a specific
insect determines the presence of a specific fungal species.

25. Fungi Ideal Growth Conditions
The ideal growth conditions are:
1. Environmental humidity
2. Temperature
3. pH and Oxygen

26. Environmental Humidity
 The most interesting benchmark for fungal growth is humidity
or free water.
 According to the behavioral differences related to water
availability, fungi species can be classified as follows:

27. Cont. …
Hydric
• The spore can only germinate at free water levels above
90%.
• The optimal growth takes place at 100%.
Medium
level
• The spores germinate at free water levels between 80% and
90%.
• The best and optimal growth takes place at 95% - 100%.
Xerofile
• The spores germinate at free water levels less than 80%.
• The best and optimum growth takes place at 95%.

28. Cont. …
61% The minimum level for all fungi.
78% The minimum level for
Toxigenic species.
7%
Fungi can grow only in grains
with high levels of oil (e.g.
peanuts)

29. Temperature
 The ideal temperature: 15 - 30°C.
 Optimal values of 20-25°C.

30. Cont. …
Low Temperature Exception
1. Cladosporium herbarium have an
apparent growth at -6°C.
2. Penicillium can develop in frozen fish at -
20°C.
3. Rhizopus nigricans, Mucor mucedo,
Aspergillus niger, Aspergillus glaucus can
persist after immersion for 77 hours in
liquid hydrogen at -253°C and for 492
hours in liquid air at -190°C.

31. Cont. …
High Temperature Exception
1. Aspergillus fumigatus, can
contaminate respiratory tract
at body temperature.
2. Monilia sitophila can survive at
35-40°C (typical contaminant of
bread)

32. pH and Oxygen
pH
 Ideal pH: 4 - 8.
 Some moulds can grow at lower
or higher values by modifying
the acidity of the medium
during their development.

33. Cont. …
O2
 Moulds are generally aerobic organisms that
develop above the surface of the medium.
 Some species can however develop in deep
mediums or in liquid mediums such
as Stachybotrys, with a low oxygen rate.

34. Plan Of Talk
 Introduction
 Fungi species
 Fungi growth
 Agronomic factors affecting mycotoxin formation in the field
 Principle factors influencing mycotoxin production
 Mycotoxin types

35. Agronomic Factors
Affecting Mycotoxin Formation In The Field
 As temperature and moisture levels
are key factors for fungal growth and
subsequent mycotoxin production, the
climate plays a key role in the
occurrence of mycotoxins.
 Crop surveys show large variations in
contamination levels from one year to
another due to varying climatic
conditions.

36. Cont. …
 In addition to climatic conditions, agronomic practices also
have a pronounced effect on mycotoxin formation as they
affect:
1. Presence of fugal spores in the field.
2. Fungal growth.
 Three key agronomic factors have been shown to affect
mycotoxin presence and concentration significantly:
1. Crop presence and rotation:
2. Soil cultivation:
3. Crop and crop variety

37. Cont. …
1. Crop presence and rotation:
 Monocultures (planting of closely
related crops one after the other)
will enhance the risk of mycotoxin
formation.
 Spores will transfer to the
subsequent crop and thus allow
fungal growth to establish quickly
and strongly.

38. Cont. …
2. Soil cultivation:
 Ploughing harvest residues will
reduce spore contamination of
the subsequent crop and thus
reduce fungal infestation and
mycotoxin formation.
 No-till systems will enhance
the risk.

39. Cont. …
3. Crop and crop variety
 Crop varieties that are more resistant to fungal foliar
diseases reduce fungal infection and thus mycotoxin
formation of the crop.

40. Cont. …
 Mycotoxins are very stable.
 They will persist during storage as they are independent of
storage conditions.
 Because there are no efficient decontamination procedures
are available today, most of the mycotoxins that are present
at the time of harvest will reach the final animal diet during
feed consumption.

41. Plan Of Talk
 Introduction
 Fungi species
 Fungi growth
 Agronomic factors affecting mycotoxin formation in the field
 Principle factors influencing mycotoxin production
 Mycotoxin types

42. Principal Factors Influencing Mycotoxin
Production
These factors are;
1. Intrinsic factors, connected to the fungal stock.
2. Extrinsic factors, i.e. environmental conditions.

43. Intrinsic Factors
Intrinsic factors, connected to the fungal stock
1. The power of generating toxins
– It varies inside each fungi from 1 to 103-104.
2. The fungal species
– It determines type of mycotoxin produced.
3. The initial contamination
– It influences the amount of mycotoxins produced.

44. Extrinsic Factors
1. Chemical, physico-chemical and physical factors.
2. Biological factors.

45. Cont. …
Chemical, physico-chemical and physical factors such as:
1. Humidity
2. Free water
3. Temperature
4. Substrate
5. Gas composition (atmosphere)
6. Mechanical damages to the caryopsis

46. Cont. …
Biological factors, such as:
1. Insects
– Act as a vectors of fungal spores.
– Acts as vectors responsible for mechanical damage to the caryopsis,
favoring the entry of moulds.
2. Microbiological flora
3. Competition between mycological strains
4. Plant stress

47. Chemical, Physico-chemical And
Physical Factors
Chemical, physico-chemical and physical factors;
1. Level of free water (humidity)
2. Temperature
3. Oxygen
4. Type of substrate

48. Cont. …
1. Level Of Free Water
 Toxin production is improved by levels of free water of
90%.
 Aspergillus flavus can start to produce aflatoxin at 83%.
 A. ochraceus needs at least 97% to produce ochratoxins.
 The humidity of the substratum is the principal factor to
be considered in the prevention of contamination and its
control has become fundamental in feed production.

49. Cont. …
2. Temperature
 It is difficult to define temperature values to control
mycotoxin production.
 Aspergillus flavus produces aflatoxins at 10°C - 25°C.
 Fusarium tricinctum produce T2 toxin at 1°C - 4°C, up to
15°C.
 Aspergillus ochraceus produces ochratoxin from 12°C -
20°C up to 30°C.
 Penicillium viridicatum produces ochratoxin between 4°C -
31°C.

50. Cont. …
3. Oxygen
 Oxygen concentration and the acidity of substratum are
not relevant for mycotoxin production.

51. Cont. …
4. Type of substrate
Some types of substrate may help improve mycotoxin
production;
1. Vegetal, more than the animal substrates.
2. Starch.
3. Zinc, only referred to the aflatoxin production.
4. Cereals, oleaginous seeds and dried fruit are the foods most
frequently contaminated by aflatoxins.
5. The more frequent products contaminated with mycotoxins are
maize, peanuts and cotton seeds.

52. Plan Of Talk
 Introduction
 Fungi species
 Fungi growth
 Agronomic factors affecting mycotoxin formation in the field
 Principle factors influencing mycotoxin production
 Mycotoxin types

53. Types Of Mycotoxins
Fungi proliferate Grow colonies
Mycotoxin levels
become high
then then

54. Cont. …
Cocktails of mycotoxins
Storage
fungi
Field
fungi

55. Cont. …
Although several hundred mycotoxins are known, the
mycotoxins of most concern, based on their toxicity and
occurrence, are:
1. Aflatoxin
2. Trichothecenes (DON, T-2 toxin, DAS, etc)
3. Ochratoxin A
4. Zearalenone
5. Fumonisin
6. Fumonisin
7. Moniliformin

56. Cont. …
Mycotoxin Fungi Produced Commodities affected
Aflatoxin
Aspergillus flavus
Aspergillus parasiticus
Corn, cotton seed, peanuts, soy
Ochratoxin A
Aspergillus ochraceus
Aspergillus nigri
Penicillium verrucosum
Wheat, barley, oats, corn, others
Trichothecenes (DON,
T-2, DAS, etc)
Fusarium graminearum
Fusarium culmorum
Corn, wheat, barley
Zearalenone Fusarium graminearum Corn, wheat, barley, grass
Fumonisin
Fusarium verticillioides
Fusarium proliferatum
Corn
Moniliformin Fusarium moniliforme Corn
PR toxin, patulin Penicillium roqueforti Silage, Grass

57. Aflatoxin

58. Aflatoxin
 Aflatoxins are of concern in warm and humid climatic
conditions.
 Although aflatoxins are not considered to be a major problem
in cold or more temperate regions, caution must be exercised
in colder climates when using feedstuffs imported from warm
and humid countries.

59. Host Sensitivity
 Among poultry, ducks are the most susceptible to aflatoxin,
followed by turkeys, broilers, laying hens and quail.

60. Effects
Aflatoxins are hepatotoxic
1. Fatty changes - causing hepathocyte degeneration - Hepatic necrosis
2. Altered liver function.
3. Suppression of hepatic protein synthesis is the main factor resulting
in growth suppression and reduced egg production.
4. Interfere with vitamin D metabolism, contributing to reduced bone
strength and leg weakness.
5. Reduce bile salt production, and in turn negatively affects lipid
digestion.
6. Reduce metabolism of other minerals including iron, phosphorus and
copper.

61. Cont. …
Blood vessels
 Increases the fragility of capillaries
 Reduce prothrombin levels.
 Due to the transfer of aflatoxin into edible products and its
carcinogenic effects, most countries have set upper legal
limits for aflatoxin in feed.

62. Clinical Signs Of
Aflatoxin Toxicity
1. Decrease weight gain - anorexia – increase FCR
2. Fatty liver - Liver necrosis - Bile duct hyperplasia
3. Increased mortality
4. Immune suppression - increased disease susceptibility
5. Specific visceral haemorrhage
6. Leg weakness and reduced bone strength
7. 'Pale bird syndrome'
8. Increased incidence of bruising and downgrading
9. Embryo toxicity - Reduced fertility and hatchability
10. Decreased egg production

63. Ochratoxin

64. Ochratoxin
 Ochratoxins are important storage toxins.
 They are produced by different fungi and are prevalent in
temperate as well as in tropical regions.
 Ochratoxin A is the most important of the ochratoxins.

65. Effects
 Ochratoxin A is nephrotoxic
– Proximal tubules are mainly affected and the kidney is pale and grossly
enlarged.
– In acute cases, mortalities occur due to acute renal failure.
 As with aflatoxin, fatty liver can also occur due to ochratoxin
exposure.
 In young chicks, ochratoxin A is approximately three times
more toxic than aflatoxin.

66. Clinical Signs Of
Ochratoxin Toxicity
1. Reduced feed intake - Reduced growth rate – Reduced egg
production.
2. Reduced feed conversion efficiency.
3. Mortality due to acute renal failure - Pale and grossly
enlarged kidney.
4. Polyurea with large volumes of wet faeces.
5. Fatty liver.

67. Cont. …
6. Urate deposition in joints and abdominal cavity (at high
exposure levels)
7. Depletion of lymphocytes and with strong suppression of
cellular immunity.
8. Poor egg shell quality and higher incidence of eggs with
blood spots.
9. Reduced embryo viability - Decreased hatchability.
10. Reduced feathering.

68. Trichothecenes

69. Trichothecenes
(T-2 toxin, diaceptoxyscripenol (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.

70. Clinical Signs Of
Trichothecenes Toxicity
1. Trichothecenes are proven tissue irritants
– Oral lesions, dermatitis and intestinal irritation.
2. Loss of appetite
– Reduced feed intake - Reduced weight gain
3. Oral lesions: circumscribed proliferate yellow caseous
plaques occurring at the margin of the beak, mucosa of the
hard palate and the angle between the mouth and the
tongue.
4. Gizzard erosion - Necrosis of proventricular mucosa

71. Cont. …
5. Immune suppression
– It affects cellular immune response by direct effects on
bone marrow, spleen, lymphoid tissues, thymus and
intestinal mucosa, where actively dividing cells are
damaged.
– Reduced vaccination response.
6. Reduced egg production - Poor shell quality.
7. Regression of ovaries.
8. Reduced female fertility and hatchability of fertile eggs.
9. Tibia dyschondroplasia.
10. Increased liver weight.

72. Zearalenone (ZEA)

73. Zearalenone (ZEA)
 Zearalenone often occurs with DON in naturally-contaminated
cereals.
 Zearalenone is responsible for reproductive disorders due to
its oestrogenic 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

74. Fumonisin

75. Fumonisin
 Broilers and turkeys are resistant to acute fumonisins toxicity.

76. Clinical Signs Of
Fumonisin Toxicity
1. Spiking mortality (paralysis, extended legs and neck, wobbly
gait, gasping)
2. Reduced growth rate.
3. Increased organ weights.
4. Hepatocellular hyperplasia.
5. Poor vaccination response.