Occurrence of zearalenone, α- and β-zearalenol in biles of breeding sows in relation to the reproductive performance

Although zearalenone-induced reproductive disorders and the clinical appearance of hyperestrogenism were reproduced and documented quite often the role of zearalenone-contaminated fodder as a cause for fertility problems in sow breeding is still discussed controversial. Therefore the correlation of zearalenone and zearalenone-derivatives in bile (n = 794) and feed (n = 158) with fertility problems of unknown origin was investigated in this study. For the analysis of zearalenone and its derivatives in bile a HPLC/EIA combination was used. On the one hand, this procedure guaranteed the quantitatively reproducible detection, on the other hand, the investigation expenditure could be kept small with regard to a later effort in the routine diagnostics. The detection limits for zearalenone, alpha- and beta -zearalenol in bile were at 1.0 ng/ml, 1.0 ng/ml, and 3.0 ng/ml, respectively. Results were confirmed by GC-MS. Zearalenone and zearalenone-derivatives were detected in almost every bile analysed. The contamination rate was 96.2 %. In opposition to recent investigations beta -zearalenol was perceived as a relevant metabolite in swine. The contamination rate of feeding stuffs was 25.9 %. Incubation of samples with beta -glucosidase did not elevate the detected amounts of zearalenone. As the measurable concentrations in bile and fodder were only slightly correlated the analysis of bile represents a reasonable alternative for fodder investigation. However, a correlation between the occurrence of zearalenone, alpha- and beta -zearalenol in bile of sows and noninfectious reproductive disorders could not be established at the loading level found. These results are in line with those statements obtained in feeding experiments regarding the risk evaluation of zearalenone in sow reproduction.