Abstract:
The objective of this study was to demonstrate the possible correlation of visible carcass
contamination and abattoir aerosol quality with microbial hygiene criteria. A total of 279 bovine
carcasses were analyzed on 23 different working days. The aerobic colony count and total coliforms
on the carcasses were calculated together with the presence of Escherichia coli. To determine the
visible contamination of carcasses, we used a 100 cm2 sheet of transparent, adhesive plastic material,
applied to the side of the carcass, to collect all the particles, which were then counted against both
black and white backgrounds. The daily particulate index in the abattoir aerosol was determined
using an air sampler device. The results showed that aerobic colony counts, which ranged from
1.41 to 2.40 log cfu cm−2, total coliforms (from 0.00 to 0.73 log cfu cm−2), and E. coli presence (from
0.00% to 60% of the sampled carcasses per day) are not correlated with the carcasses’ visual dirtiness
or the aerosol quality. The factor analysis showed a correlation between the three groups of variables
investigated: group 1, representing “aerosol quality”, group 2, representing the “microbiology of
the carcass”, and group 3, the “visual dirtiness of the carcass”. Thus, even though microbiology
analysis is useful in diagnosing the microorganisms which the official veterinarian is unable to detect
during the post-mortem inspection, it is ineffective in evaluating slaughtering procedures. Aerosol
monitoring and the visual classification of carcass dirtiness, instead, could provide good indications
of the slaughtering process and the quality of the abattoir environment, and guarantee control of
manufacturing practices, protecting both animals’ and operators’ health.
