Evaluation of zearalenone, α-zearalenol, β-zearalenol, zearalenone 4-sulfate and β-zearalenol 4-glucoside levels during the ensiling process

Zearalenone-producing Fusarium species can contaminate maize before ensiling and cause reproductive problems in animals. Suspect feeds are only routinely analysed for zearalenone (ZEA), not considering other oestrogenic metabolites or masked derivatives. The aims of the present study were to monitor the levels of ZEA, α-zearalenol (α-ZOL), β-zearalenol (β-ZOL), zearalenone-4-sulfate (ZEA-4S) and β-zearalenol-4-glucoside (β-ZOL-4G) in artificially contaminated maize silage and determine the effect of the ensiling process on these toxins. A laboratory silo model was designed using polystyrene bags filled with previously contaminated chopped whole-plant maize, stored in a dry and cool room and sampled at days 7, 45, 90, 120 and 127. ZEA, α-ZOL, β-ZOL, ZEA-4S and β-ZOL-4G levels were quantified by liquid chromatography – tandem mass spectrometry. Chemical and physical analysis indicated silage maintained good quality in all stages. pH was reduced favourably (P