Fig. 1 implies another interesting notion: at the sampling positions
pPL and pEV there was an obvious rise in the CFU numbers
when the three succeeding batches were compared at a specific
sampling position, both in the spring and autumn samples. The last
monitored batch on a particular day's schedule always had the
highest Campylobacter numbers at pPL and pEV while the first
batchwas always the least contaminated. In otherwords e the later
the batch was slaughtered, the higher were the CFU numbers
recorded at pPL and pEV, which could be indicative of accumulation
of campylobacters somewhere on the slaughter line before pPL.
Because of negative results of Campylobacter analyses for the
scalding water post-slaughtering samples both in spring and
autumn, the most probable critical points remain the stunning
water tank and/or plucking stage machinery. Unfortunately, these
hypotheses could not be verified because these locations were
either not sampled (plucking machinery) or not quantified (stunning
water tank). At pFR, this trend was not observed, probably due
to intensive carcass water spraying/rinsing/washing after the
evisceration step. This water cleansing carcass procedure, being
apparently effective, should therefore be applied or intensified also
after the plucking stage or immediately at the entrance into the
evisceration room. This could reduce the initial carcass contamination
load and contribute to lower Campylobacter CFU numbers at
the end of slaughtering and consequently also later at a retail level.
Our results regarding C. jejuni carcass contamination dynamics
during slaughter line processing correspond almost perfectly to the
picture given by Guerin et al. (2010) in their systematic review.