ZEARALENONE

Toxin Characteristics

Zearalenone, also known as RAL and F-2 toxin, is a potent estrogenic metabolite produced by some Fusarium species.

Several Fusarium species produce toxic substances of considerable concern to livestock and poultry producers: namely, deoxynivalenol, T-2 toxin, HT-2 toxin, diacetoxyscirpenol (DAS) and zearalenone.

Crops and Weather Conditions

Zearalenone production does not seem to occur in significant amounts prior to harvest, but under proper environmental conditions, it is readily produced on corn and small grains in storage.

Alternating low and moderate temperatures in storage promote production of this toxin. Temperatures between 53-57° F induce the enzymes involved in biosynthesis of this toxic substance, and optimum production occurs at 81° F.

The toxin is heat-stable, and it is not destroyed by long storage, roasting, or by the addition of propionic acid or mold retardants.

Impact on Animal Health

Zearalenone is the primary toxin causing infertility, abortion or other breeding problems, especially in swine.

When contaminated rations are consumed by animals, they develop a condition known as hyperestrogenism.

Swine are most sensitive to zearalenone.

As a general rule, rations exceeding 0.5 ppm of zearalenone should not be fed to swine.

Prepuberal gilts are more susceptible than mature swine.

Abortions and uterine prolapse may occur as a result of consumption of zearalenone-contaminated feeds.

Zearalenone has been associated with infertility and abortion problems in dairy cattle in the Midwestern U.S.

Conception rates may be reduced in dairy heifers when fed greater than 12.5 ppm zearalenone.

Poultry in general are more tolerant than swine to zearalenone.