[Hyperestrogenism in swine due to natural poisoning with zearalenone]

A field case is described in which all prepuberal swine of a group of 20 pigs and 11 sows showed marked estrogenic effects. These consisted of enlarged mammary glands, swelled tumefacient vulva, and greatly enlarged internal reproductive organs. The corn used to feed these animals was found to contain 56 ppm zearalenone. Deoxynivalenol (4.9 ppm) was found in the corn; T-2 toxin, nivalenol, fusarenon-X, diacetoxyscirpenol, aflatoxins and ochratoxins were absent. Identity of Z was confirmed by TLC in four solvent systems, behavior of the suspected spots under UV light of different wavelengths, change of fluorescence from green to blue after spraying with 5% AlCl3 in alcohol and heating at 110 degrees C during 5 minutes, and by its UV spectrum. A zearalenone producing strain of Fusarium oxysporum was isolated from the suspected grain. Histopathology of uterine tissue showed typical changes produced by zearalenone: hyperplasia, hypertrophy, and metaplasia of the myometrium. Feeding of the grain to a prepuberal sow under controlled conditions reproduced all the effect found in the farm animals. This is the first field case of zearalenone poisoning reported in Argentina.