Effects of immunizing gilts against zearalenone on height of vaginal epithelium and urinary excretion of zearalenone

Two experiments were conducted to develop a vaginal epithelium bioassay for zearalenone (Z) and to determine whether immunization against Z would prevent Z mycotoxicosis. Eleven gilts were ovariectomized and allotted by weight to dietary doses of 50, 150 or 350 micrograms Z/kg BW daily for 3 d. All doses of Z increased height of the vaginal epithelium. Height of the vaginal epithelium in gilts fed 150 or 350 micrograms Z/kg BW increased more than that in gilts fed 50 micrograms Z/kg BW. Twenty-four gilts then were ovariectomized and allotted to be immunized or not immunized. A Z-bovine serum albumin conjugate was injected into gilts to achieve immunization. Ten weeks after initial immunization, antibodies to Z were detected after a 1:10(7) dilution at greater than .1 absorbance units using an enzyme-linked immunosorbent assay, and gilts were allotted by weight to diets with no Z or 150 micrograms Z/kg BW daily for 3 d. Immunization alone had no effect on height of vaginal epithelium, but after 3 and 10 d, immunized gilts fed Z had higher vaginal epithelium than did nonimmunized gilts fed Z. Immunized gilts excreted a larger percentage of ingested Z than nonimmunized gilts did. Therefore, immunizing gilts against Z potentiated both the estrogenic effects of Z and urinary excretion of Z equivalents.