Four sites on each of 720 dressed carcasses (360 bovine and 360 porcine) were sampled (2,880 samples in total) in a single commercial
abattoir slaughtering cattle and pigs using two separate slaughterlines. The carcasses were sampled before HACCP (pre-HACCP;
960 samples) and after HACCP implementation (post-HACCP; 1,920 samples) and Total Viable Count (TVC), Enterobacteriaceae count
(EC) and Salmonella spp. prevalence were determined. During the pre-HACCP period, mean TVC levels on four tested sites varied on
bovine carcasses between 3.03 and 4.19 log10 cfu/cm2 and on porcine carcasses between 3.73 and 3.99 log10 cfu/cm2. During the
post-HACCP period, TVC levels on all tested sites on carcasses were further signicantly reduced, by 0.33-1.64 log and 1.13-2.04 log
on bovine and porcine carcasses, respectively, compared to the pre-HACCP period. Both the EC occurrence in samples and EC levels in
EC-positive samples somewhat decreased during post-HACCP as compared to pre-HACCP period, but the reductions were not statistically
signicant due to large proportion of EC-negative samples and very low counts in EC-positive samples. Salmonella spp. was not
detected in any of bovine or porcine carcass samples, regardless of whether they were taken pre- or post-HACCP. Overall, the processhygiene-
improving eects of non-intervention HACCP have been proven through reduction of TVC on carcasses, but could not be
veried in the present study through similar reductions in EC and/or Salmonella, because of their low levels and/or absence
