Untersuchungen zum Vorkommen von Salmonellen-Antikörpern bei Mastschweinen im Einzugsgebiet des Schlachthofes Karlsruhe im Hinblick auf die Einführung eines staatlichen Salmonellen-Monitoring

For this study between January and April 2003 meat samples from
diaphragm pillars of 1920 finisher pigs out of 57 farms were taken
on the slaughter line. After freezing and subsequent thawing the
thus obtained meat juice was analysed for antibodies against
salmonella by means of ELISA, in order to determine the salmonella
status of the fattening pigs, respectively of the fattening farms
in the area of the slaughter-house Karlsruhe via antibody
detection. In addition, the farm owners were asked about some of
the farm’s management factors in a telephone interview by means of
questionnaire; the answers were correlated to the ELISA antibody
results and were discussed. 125 out of 1920 meat juice samples were
tested positive regarding their salmonella antibody result and an
overall antibody prevalence of 6.51% was detected in the total of
the samples. This result is within a percentage range which is
comparable to other studies’ results from Germany, which stated
antibody prevalences ranging from 0.74% (HARTUNG, 2001 and 2002) to
1.6% (CZERNY et al., 2002) to values of 7.3% (VON ALTROCK et al.,
2000) to 8.9% (LUDEWIG and FEHLHABER, 2001). Investigation results
from the Netherlands showed slightly higher, such from Denmark
lower values. Based on the results of this study, 48 (84%) farms
could be classified in category I (< 20%
Salmonella-antibody-positive samples), 7 farms (12%) in category II
(20-40% Salmonella-antibody-positive samples) and only 2 farms (4%)
in category III (> 40% Salmonella-antibody-positive samples),
corresponding to the guidelines of the German Ministry of Food,
Agriculture and Forestry outlining a Salmonella surveillance
programme. The evaluation of the questionnaire yielded that 47
(82.45%) farms had more than 200 fattening pigs, four (7.02%) had
between 101 and 200 and six (10.53%) farms between 46 and 100
finisher pigs. Only five (8.77%) of the farms included in the study
slaughtered their animals exclusively at the slaughterhouse
Karlsruhe, twelve (21.05%) farms worked with an in/out-management,
45 (78.95%) with continuous stabling. 29 (50.88%) farms bought
their piglets, 28 (49.12%) reared their animals on their own, 54
(94.74%) farm owners had knowledge about the concept “Salmonella
monitoring”, three (5.26%) had no idea of this topic and twelve
(21.05%) of the farms did already take part in a Salmonella
monitoring programme at the time of questioning. The total of the
57 farms yielded an average antibody prevalence of 7.97%.
Further-more, the average prevalences for groups of farms with the
same management factors were determined in order to investigate if
individual management factors in-cluded in the questionnaire had an
influence on the antibody prevalence of the farms. Smaller farms
(46-100 slaughter pigs), farms which bought their piglets and farms
which did not take part in a Salmonella monitoring programme showed
a tendency towards higher average antibody prevalences. A better
evaluation of farms with in/out management could not be confirmed.
In general, Salmonella monitoring seems to be sensible. Yet, for
the successful implementation of such a programme the establishment
of a legal foundation is essential, in order to oblige all farm
owners to participate in these control measures and in order to
achieve more uniformity in the German quality insurance.
Unfortunately, the low grade of organisation in the German pork
production chain impedes both the feasibility of such a programme
and the successful establishment of certain measures to reduce the
entry of salmonella into the food chain.