RESUMO
Following the use of sugar beet pulp that was retrospectively found to be predominantly contaminated with zearalenone (ZEN) in diets of reproducing sows largely exceeding the EU-guidance value for critical ZEN concentration of 0.25 mg/kg, farmers did not report any changes in the reproductive performance of sows. Thus, the aim of the study was to verify this guidance value in a dose-response setup by using sugar beet pulp as a ZEN source hitherto not considered a risky feedstuff additionally characterized by comparatively low levels of deoxynivalenol. A total of 90 sows was equally allocated to one of the three feed groups during experimental lactation 1 and up to 40 days after insemination: CON with a minimal ZEN concentration, ZEN1 with a target concentration of 250 µg ZEN/kg feed, and ZEN2 with a target concentration of 500 µg ZEN/kg feed. Thereafter, all sows received the same feed without ZEN for the rest of gestation, and the following lactation for testing of putative carry-over effects resulting from previous ZEN exposure. Exposure of sows to ZEN with blood serum as an indicator was linearly related to dietary ZEN concentrations. Reproductive and zootechnical performances of sows were only affected by ZEN exposure at weaning weight. Clinical-chemical parameters indicated no clear effect of ZEN exposure. An influence of ZEN on the occurrence of tail and ear injuries (not necrosis) in piglets and lesions on the mammary complexes in sows is possible. The influence of a ZEN concentration above the EU guidance value on the study farm can therefore not be neglected.