Effect of mycotoxins in the nutrition of farm animals

• secondary metabolites of fungi• fungi start to produce them under stress conditions• some of them are produced on the field (fusarium toxins), others

during the storage (ochratoxin) • not only mycotoxins are harmful, but also their metabolites,

produced in their digestion and metabolism in the animals

• They have an influence :• on the health and immune system of the animals• on the cell metabolism, • the reproduction processes,• the function of liver and kidney,• the production traits.

• They also mean a potential food safety risk

AflatoxinProducing: – Aspergillus flavus, A. parasiticus

Effects: – binds to the DNA and protein of the cells, – cause mutation, cancer, cell toxicity– the liver is damaged first time

The most important metabolite is aflatoxin B1 (AFB1).

The most dangerous toxin for both human and animals (excreted also in the milk)

Produced mostly under warm temperature conditions

Potential sources groundnut, soybean, corn

OchratoxinProducing: – Aspergillus alutaceus, Penicillium verrucosum

Effects: – inhibits the protein synthesis (PHE - tRNS)– increase the lipid peroxidation– decrease the cell respiration, gluconeogenezis, the ATP

level of the cells– damages mostly the kidney

The more frequently produced metabolite is ochratoxin A (OTA).

Produced in the storage period

Can be found also in animal products (egg, meat, liver),

potential food safety risk factor

Zearalenon (ZON), F-2 toxinProducing: – fusarium species (F. graminearum, F. culmorum, F.

avenaceum, F. poae, F. moniliforme)

Effects: – oestrogenic effect– increase the plasma oestrogen level, causing

dysfunction in reproduction– increase the lipid peroxidation– bleedings in the liver

Poultry species are resistant to ZON, but causing serious reproduction problems in pigs, beef and horse.

Deoxynivalenol (DON, vomitoxin)Producing: – Fusarium species

Effects: – inhibiting the protein synthesis and cell proliferation– damages the liver fat metabolism– decrease the success of vaccination– stimulates the synthesis of B-limphocytes.

Pigs refuse to eat DON contaminated diets, In horses it decreasing the plasma immunoglobulin

levelIn cows decrease the milk production and milk fat.Poultry species are not so sensitive for DON

T-2 toxinProducing: – Fusarium species

One of the most harmful toxinsEffects:– decrease protein synthesis and cell proliferation – producing lesions around the mouth– animals refusing food intake– poor feather production– worse egg shell strength– increase the lipidperoxidation in the liver– increase the death rate after infections– decrease milk fat

FumonisinsProducing: – Fusarium species (Fusarium moliniformin)

Effects: – increase the weight, but decrease the fat content of liver– impaired function of the immune system

The most common form is fumonisin B1 (FB1),Can be found mostly in cornDecreasing milk production in ruminants, damages

the liver Horses are especially sensitive for this toxin

(softening of the brain, giddiness, lameness).

Interaction among different toxins

Mostly more mycotoxins can be found at the same time.

Their interaction depends:– on the type of toxin– on their concentration– on the investigated parameter

The interaction of OTA, FB1 and DON are additive on the weight gain, but it is synergetic on the plasma asparatic acid aminotransferase enzyme.

Food safety aspects• According to the investigations of Institute of

International Cancer Research:– carcinogenic: AFB1– potential carcinogenic: OTA– probably not carcinogenic: ZON, FB1, T-2– not enough information: DON, NIV

• Some of them are metabolised already in the enterocytes of the intestine.

• Therefore their metabolites are also important (ZON α-ZOL, β-ZOL , AFB1 AFM1)

• Absorbed quickly, after 6 hours reach their highest concentration in the blood.

Food safety aspects

• The half-life time of ZON is the longest (12-28 hours), therefore it can be found in the egg and liver)

• 4-5 mg/kg of DON was not detectable from the tissues

• 30 mg/kg of FB1 detectable also from the kidney, liver and egg.

• Small concentration of OTA and T-2 toxins were found in eggs and other animal tissues

Chances to feed toxin contaminated feedstuffs

Possibilities:– dilution with toxin free feedstuffs– feeding with not so sensitive animal species and adults

(beef cattle – milking cow; pig – poultry)– using toxin binders

Toxin binders:– a bentonit, a zeolit, sodium-kalcium-aluminium-

hydrosilicates, glukomannans, binders containing enzymes can be used efficiently (60-90%) against AFB1

– Their affinity for fusarium toxins (ZON, DON, T-2) is however, poor (10-60%)

– They also bind some other bioactive substances (vitamins, amino acids, minerals etc.)

Effects of feeding mycotoxin contaminated diets and different toxin binders on the weight gain of broiler chicks

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