Zearalenone (ZEN) is a toxic metabolite produced by fungi of the Fusarium genus. These species contaminate cereals and become quite relevant in high humidity and mild temperatures (25±10°C).

ZEN is a natural contaminant of cereals as wheat, barley, rice and predominantly corn in different countries. The toxin may produce estrogenic effects when contaminated cereals or derivatives are ingested.

Swine present the highest sensitivity. Clinical signs of intoxication may occur with exposure to low levels of ZEN, such as vulvovaginitis, litters with weak piglets and dead born, infertility and rebreeding. In cattle there may also be a relation with infertility. Birds are less susceptible, and there are no reports on alteration in laying hens productivity; nonetheless, association of ZEN with other mycotoxins may negatively affect performance. 

Clinical signs caused by ZEN and species sensitivity: