Mycotoxins are present in the 25% of the worldwide grain production. They cause significant economic losses in livestock production and some of them where identified to have carcinogenic and teratogenic effects on humans due to their transfer and accumulation in milk and meat.
Clinical symptoms are time and dose dependent. When feedstuff is contaminated with more than one mycotoxin, the toxic effects are additive and sometimes synergistic. Clinical symptoms of known mycotoxins are usually subclinical or chronic but with significant impact on productivity.
The table below enlists the symptoms that can be recorded in swine herds.
| Mycotoxins | Effects/ mode of action | Clinical symptoms | Susceptibility of swine |
| Aflatoxins | Immunosuppression, Reduced feed consumption |
Increased disease susceptibility. Poor growth rate. Abortion-agalactia. |
High |
| Zearalenone | Mimic of estrogen. | Anestrous. Pseudopregnancy. Swelling of the vulva and mammary glands. Abortion. Reduced fertility. Increse of non-productive days. Reduced litter size and piglet vitality. Reduction of libido, semen production and life-span and the size of the testicles. |
High |
| Trichothecenes | Irritation of skin and oral cavity, Immunosuppression. |
Reduced feed consumption Vomiting, digestive problems, Increased FCR. |
High |
| Ochratoxin A | Lesions in nasal cavity, Immunosuppresion. |
Reduced growth rate, Polydipsia. |
Moderate |
| Ergot | Reduced feed consumption. | Reduced growth rate. Reduced weight of born piglets. Agalactia. |
Moderate |
| Fumonisin | Reduction in the number and synthesis of red blood cells. | Pulmonary edema. Respiratory distress/failure, Reduced feed consumption. |
High |
High temperature and pressure during drying and processing of grains can help in reducing the fungi load but mycotoxins are resilient in temperatures that destroy fungi and can remain in feedstuff without the present of active fungi. Most mycotoxins are chemically stable and remain so for a long time after fungi death.
Some areas are in greater risk for the development and presence of several mycotoxins due to warm and wet weather conditions, rime, air currents and insect infestation.