Monitoring natural feed contamination in beef cattle by measurements of urinary zearalenone concentrations after oral administration of mycotoxin adsorbents as a top dressing

To investigate the effects of supplementation of mycotoxin adsorbents (MAs) in top dressing of cattle feed with respect to concentrations of urinary zearalenone (ZEN) and its metabolites, alpha-zearalenol and beta-zearalenol, Japanese Black cattle herds for breeding (2 herds) and fattening (2 herds) were provided with similar feeding conditions. Two types of MAs were tested, and the maximal recommended dose of each MAs was supplemented in the feed as a top dressing for 2 weeks. Urine samples were collected from cows (n = 6 7) on day 0 and 14. The urinary concentrations of ZEN and its metabolites were found to be variable in all herds. This might reflect significant natural ZEN contamination of the feed at the farm level. However, the urinary concentrations of ZEN and its metabolites after supplementation with MAs for 2 weeks were not significantly different. Additionally, our results suggest the possibilities that supplementation of the feed with MA may affect the absorptivity of mycotoxins from the gastrointestinal tract or limit the binding of MA to mycotoxins.