Slaughterhouse carcasses
At the slaughterhouse, the monitored flocks were processed as
the first three batches on the scheduled day, with C. jejuni negative
flock(s) having priority over the others. Ten carcasses per batch
were selected at the entrance to the evisceration room, with an
approximate 5-min time interval between them, each distinctively
marked and then sampled sequentially down the slaughter line in
the evisceration room. The same carcasses were also sampled after
the cooling and freezing steps. Approximately 2 g (2e4 cm2 ) of
neck-skin from each individual carcass was taken to analyse for
presence and genotype of C. jejuni and to assess the C. jejuni
contamination level of each carcass at three successive sampling
positions in the evisceration room: at carcass entry immediately
after scalding and plucking (post-plucking, pPL), immediately after
the evisceration step (post-evisceration, pEV) and after the finalrinse before leaving the evisceration room and the start of the dry
air-cooling step (post-final rinse, pFR). To analyse the effect of
refrigeration and freezing, five of the ten monitored carcasses were
neck-skin sampled and C. jejuni -analysed after three days of
refrigeration and the other five after three days of freezing.