Aspergillus ochraceus was grown on wheat (20 kg) in several
500 ml conical flasks and moistened by the addition of distilled
water to obtain a moisture value of 40% (v/w); then, the wheat was
incubated in a thermostatic chamber at 30 C for 2 weeks. Successively,
the sample was desiccated at 60 C overnight and ground
using a cyclone hammer mill (1 mm sieve) (Pulverisette, Fritsch
GmbH, Idar-Oberstein, Germany). Four aliquots were analysed for
OTA content using HPLC with fluorescence detection. Finally, the
contaminated wheat was homogenised into the pig ration to give
the required OTA concentrations in the diets.