Metabolism of high concentrations of dietary zearalenone by young male turkey poults.

Six male turkey poults (3 weeks of age) were fed a starter ration artificially contaminated with 800 mg zearalenone/kg for a 2-week period to examine zearalenone metabolism and residues in various tissues, excreta, and blood plasma. Zearalenone had no effect on either feed consumption or body weight gain. All the birds fed zearalenone frequently showed strutting behavior, displayed an increased size and coloration of caruncles and dewlaps, and had swollen vent tissue. None of these signs were seen among six control birds fed uncontaminated starter feed. Hormone analysis, however, revealed that the testosterone concentrations in blood plasma were the same in both controls and treated birds. Analysis after 14 days of feeding showed that most of the dietary zearalenone had been metabolized into alpha-zearalenol. Levels of zearalenone and alpha-zearalenol were: blood plasma 66 +/- 27 and 194 +/- 80 ng/ml, excreta 182 +/- 33 and 644 +/- 86 micrograms/g, lung 56 +/- 45 and 202 +/- 161 ng/g, heart 57 +/- 40 and 238 +/- 121 ng/g, kidney 122 +/- 25 and 477 +/- 53 ng/g, and liver 276 +/- 54 and 2715 +/- 590 ng/g, respectively. Only traces of beta-zearalenol could be detected in plasma, excreta, and the various tissues. The percentage alpha-zearalenol of total zearalenone plus alpha-zearalenol rose significantly in both blood plasma and excreta during the experimental period. Almost all zearalenone and alpha-zearalenol was found conjugated in blood plasma, and the conjugates consisted of both glucuronides and sulfate conjugates. Approximately 65% of all zearalenone and alpha-zearalenol in excreta was found to be conjugated.