Mycotoxins are toxic secondary metabolites produced by fungi growing on crops in the field, during handling and in storage. Molds produce mycotoxins under a wide range of conditions. They enter animal production system through feed (concentrate, silage or forage) or through bedding. Some toxins tend to be more common in temperate or tropic climates, but most fungi and mycotoxins are found worldwide. Mycotoxins unconstructively affect animal performance, animal health and product quality.

Mycotoxin control is critical for production economics and product quality.

Known mycotoxins, the mold that produced them and the grains affected.

Mycotoxin

Produced by Fungi

Commodities affected

Systems affected

Maximum Tolerable level

Aflatoxin

Aspergillus flavus
Aspergillus parasiticus

Corn, cotton seed, peanuts, soy

 Liver necrosis, fatty infiltration of the liver, immune-suppression

< 20 ppb for human use, dairy feed, feed for immature animals

Ochratoxin A

Aspergillus ochraceus
Aspergillus nigri
Penicillium verrucosum

Wheat, barley, oats, corn, others

 Renal nephropathy, immune-suppression

< 200 ppb has been associated with organ damage

Trichothecenes T-2

Fusarium graminearum
Fusarium culmorum

Corn, wheat, barley

 Vomiting, intestinal lesions, immune-suppresion

< 1 ppm

Vomitoxin (DON)

Fusarium graminearum
Fusarium culmorum

Corn, wheat, barley

 Feed refusal, vomiting, reduction in feed consumption

 <5 ppm on grain (contaminated feed should not exceed 20% of diet)

Zearalenone

Fusarium graminearum
Fusarium roseum

Corn, wheat, barley, grass

 Hyperestrogenism, abortion, infertility, prolapses, ulceration

 < 1 ppm for young pigs
< 2 ppm for breeding herds
< 3 ppm for finishing pigs and young boars

Mycotoxins show their effects four different ways:

  • Intake reduction or feed refusal
  • Alteration in nutrient content of feed in terms of nutrient absorption and metabolism
  • Effects on the endocrine and exocrine systems
  • Suppression of the immune system

Mycotoxins display a range of biological outcomes:

  • Liver and kidney toxicity
  • Malfunction of the central nervous system
  • Fertility and reproduction problems
  • Effect on immunity

Mycotoxins are also deposited in the food supply chain (e.g. milk, eggs, meat) and therefore a risk for human health.

Long range goals should be to decrease the amounts of mycotoxin exposure by using mold inhibitors and checking your sources of feed. It is important to remember that mold inhibitors cannot destroy mycotoxins.

Chart of Mycotoxins

Swine

 

  • Reduced feed intake
  • Poorer growth rate
  • Decreased feed conversion efficiency
  • Rectal / vaginal prolapse
  • Sudden death
  • Pale / weak pigs
  • Bloody feces
  • Reduced sow productivity
  • Abortion
  • Increased fetal re-absorption

     

 

  • Inconsistency of sow body condition
  • Delayed puberty in gilts and boars
  • Reduced libido
  • Poorer semen quality
  • Reduced fertility
  • Higher incidence of liver and/or kidney disease
  • Poor semen quality
  • Low sperm concentration
  • Reduced numbers born and milking ability
  • Sudden deaths
  • Erysipelas

     
Beef Cattle

 

  • Liver damage
  • Depressed immune function
  • Disease outbreaks
  • Rectal straining

     

 

  • Prolapsed rectum
  • Reduction in mild yield
  • Reduced growth rate

     
Dairy Cattle

Sub-clinical:

  • Reduced fertility
  • Unsettled cows
    Clinical:
  • Inconsistent milk yield
  • Low butterfat levels
  • Higher cell counts
  • Variable intakes
  • Acidosis-type symptoms

     

 

  • Loose and variable feces
  • Bloody feces
  • Lethargy
  • Impaired immune function
  • Poor rumen function
  • Lower leg / teat swelling
  • Poor performance without any alternative explanation

     
Poultry

 

  • Reduced health
  • Reduced weight gain
  • Poor fertility
  • Low egg production
  • Poor hatchability
  • Poor egg shell quality
  • Tibial dyschondroplasia
  • Embryonic mortality
  • Mortality
  • Poor vaccine response or
    vaccination failure
  • Immunosuppression
  • Poor feathering
  • Listlessness 

     

 

  • Huddling
  • Diarrhea
  • Tremors
  • Lesions of the beak
  • Liver/Kidney & bone disorders
  • Increased downgrades
  • Higher disease incidence
  • Reduced egg size
  • Reduced feed conversion
  • Leg problems
  • Carcass condemnation
  • Mouth lesions
  • Intestinal lesions
  • Increased feed passage

     
Equine

Sub-clinical:

  • Increased susceptibility to disease
  • Hypersensitivity
    Clinical:
  • Reduced growth rates
  • Decreased appetite
  • Poor performance

     

 

  • Colic
  • Respiratory problems
  • Reduced reproductive performance
  • Brain lesions, neurological disorders
  • Organ damage especially liver, kidneys
  • Paralysis

     

Chart of Animal Symptoms

Aflatoxin

 

  • Reduced weight gain
  • Reduced milk production
  • Decreased feed intake
  • Decreased feed conversion efficiency
  • Reduce fertility
  • Mortalities at very high exposure levels gain
  • Liver lesions with congestion and bleeding
  • Fatty acid accumulation in the liver, kidney and heart leading to encephalopathies and oedemas.

     

T-2
(Trichothecenes)

 

  • Oral and skin lesions
  • Reduced feed intake
  • Reduced weight gain
  • Reduced milk production
  • Diarrhea
  • Emesis
  • Reproductive failure
  • Mortality
  • Gastro-enteritis and lesions
  • Intestinal hemorrhage 

     

Zearalenone 

 

  • Abortions
  • Decreased embryo survival
  • Infertility and mammary gland enlargement of virgin heifers
  • Oedema and hypertrophy of the genitalia in pre-pubertal females
  • Vaginitis
  • Vaginal secretions
  • Feminisation of young males
  • Infertility of young males

     

Ochartoxin

 

  • Pulmonary oedema
  • Increased mortality at very high inclusion levels (e.g. 3ppm)
  • Kidney damage
  • Reduced feed intake

     

Deoxynivalenol (DON)

 

  • Feed refusal, vomiting