Pathological effects of dietary zearalenone and/or tamoxifen on female mink reproductive organs.

The efficacy of dietary tamoxifen (TAM) to alleviate the hyperestrogenic effects of the mycotoxin zearalenone (ZEN) was assessed by pathologic examination of the reproductive organs of female mink (Mustela vison). Mink were fed 20 mg/kg ZEN, 10 mg/kg TAM, or 20 mg/kg ZEN + 10 mg/kg TAM from about 2 mo prior to breeding until the kits reached 3 w of age. All female mink fed ZEN mated, but only 25% whelped. No mink fed TAM or TAM + ZEN mated. Postmortem examination revealed moderate to severely distended uteri filled with caseated necrotic substances in the TAM, ZEN and ZEN + TAM fed mink. Histologic examination revealed mild to severe endometrial hyperplasia to uterine atrophy, endometritis, metritis and pyometra. Ovarian follicles were atrophied and degenerated. TAM was not effective in alleviating the hyperestrogenic effects of ZEN but was a potent estrogen agonist in mink.