Zearalenone toxicosis

It is an estrogenic toxin that appears in the maize and is produced by Fusarium graminearum, which requires high levels of moisture for the propagation and production of the toxin.

Alternative names: Micotoxins, zearalenone, F-2 toxin, ZEA, Fusarium graminearum, Fusarium roseum


Zearalenone is a toxin with estrogenic effects. It is produced during periods of high humidity and changes of temperature between day and night . This mycotoxin can also be produced during storage of grain / feed. Its clinical condition affects primarily females.




  • The sperm can be affected if there are levels in feed above 30 ppm but it does not affect fertility. Higher levels can lead to a decrease in libido, edema of the foreskin and hair loss.


  • Variable duration of estrus.
  • Anoestrus may be associated with pseudo gestation due to the retention of the corpus luteum. The F2 toxin will not usually cause abortion.
  • If sows are exposed during the implantation period, the litter size can be reduced.
  • Female piglets may develop increased size of the vulva during lactation.
  • Effect on gestation: when levels are above 30 ppm, there is complete loss of embryos between implantation and thirty days, followed by pseudo gestation. Low levels may not affect the first half of the gestation but in the final stages, it can slow the growth of piglets in the womb. Some of them may have an increased size of their vulvas.
  • Effect on lactation: Low levels have no effect during lactation but the interval between weaning and mating can be lengthened.

Nursery and fattening (only females)

  • Swelling and redness of  vulva, enlargement of nipples and mammary glands. In young growing sows, a rectal and vaginal prolapse can be observed.


Causes / Contributing Factors

  • Crops affected by high humidity levels and low temperatures.



  • Clinical condition, especially redness of vulva in young females. Identify the presence of the toxin in grain or feed.



  • Removal of suspected feed.
  • Maintain low humidity prior to and during storage.
  • Use adsorption products in feed.

Atlas of pathology

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