Pigs fed Fusarium-infected maize containing zearalenone and nivalenol with sweeteners and bentonite

In a 29-day growth trial 48 pigs were fed on diets based on mouldy maize (715 g/kg) and supplemented with sweeteners (raw sugar or dehydrated molasses) or bentonite (a natural alumino-silicate clay) 20 or 50 g/kg. Maize was naturally infected with Fusarium graminearum [Gibberella zeae] and contained mycotoxins zearalenone (ZEA, 3.0 mg/kg) and nivalenol (NIV, 11.5 mg/kg). A positive control diet, identical to the basal diet other than for the substitution of mouldy maize with sound maize, was also fed. Pigs given diets containing mouldy maize showed marked feed rejection typical of trichothecene toxicity and some scouring and vomiting were also observed. Females exhibited signs of precocious oestrus typical of ZEA toxicity. The performance of pigs fed on the control diet was better (P<0.01) than those fed on mouldy diets. None of the additives was effective in overcoming the oestrogenic or reduced performance effects of mouldy maize. Although sweeteners and bentonite may be useful in situations where moulds cause non-specific unpalatability, they seem to be ineffective where feed refusal is due to direct effects on appetite.