Impact of the Salmonella status of market-age pigs and the pre-slaughter process on Salmonella caecal contamination at slaughter

Abstract

-The aim of this study was to evaluate the impact of the pre-slaughter process on Salmonella caecal contamination of pigs at slaughter. An observational study was carried out in 2001 on 101 conventional farrow-to-finish pig farms. On each farm, one batch of contemporary pigs was followed from the end of the fattening period until slaughter. The Salmonella bacteriological status of the batches was assessed by environmental samples of faecal material. The serological Salmonella status was obtained on 30 individually identified market-age pigs using an indirect ELISA test. At the slaughterhouse, 25 g of caecal contents were taken from 10 of the identified pigs. Faecal and caecal material were analysed according to a classical bacteriological method. A questionnaire was designed to obtain information about the type of feeding during the fattening period (dry versus wet), the duration of fasting on the farm before leaving for the slaughterhouse, the duration of transport between the farm and the slaughterhouse, the holding time in lairage at the slaughterhouse and loading and unloading conditions on the farm and at the slaughterhouse. To assess the relationships between these factors and the Salmonella caecal status of the pigs and the batches, two logistic models were fitted at the individual and at the batch level, respectively. The first analysis was performed using a random effects logistic regression model. The second analysis was based on a cumulative logit model with a positive caecal rate classified into three classes as the outcome variable. The results showed that the Salmonella status of market-age pigs assessed on the farm either by serological or bacteriological examinations and the time spent in lairage before slaughtering played a crucial role on caecal contamination. In the light of these results, actions should be considered both on the farm and at the slaughterhouse to decrease the risk of Salmonella contamination of the caecal contents.

Phage Therapy To Reduce PreprocessingSalmonellaInfections in Market-Weight Swine

“…It is clear that multiple intervention strategies are needed to effectively reduce the incidence of Salmonella contamination in processing plants (1,3,26). Toward this end, we hypothesized that phage therapy would prove very useful, as other groups have shown that phages can be used against difficult-to-treat infections, such as those caused by Pseudomonas and antibioticresistant tuberculosis (6,10).…”

Pre-harvest risk factors for Salmonella enterica in pork production

“…Several studies have shown that the proportion of pigs infected with Salmonella increases between the farm and the abattoir (Beloeil, Chauvin, et al, 2004;Gebreyes et al, 2004;Hurd et al, 2002). These observations reveal an effect of the pre-slaughter process, which includes handling, transportation, and lairage.…”

Prevalence and serovars of Salmonella enterica on pig carcasses, slaughtered pigs and the environment of four Spanish slaughterhouses

“…In general, S. Typhimurium was the most frequently isolated serovar followed by S. Rissen, a relevant serovar in Spanish pig farms (EFSA, 2008a;García-Feliz et al, 2007;Vieira-Pinto et al, 2005). S. Derby, a common serovar in other slaughterhouse studies (Beloeil et al, 2004;Botteldoorn et al, 2003;EFSA, 2008a;McDowell et al, 2007;Vieira-Pinto et al, 2005), and the monophasic variant of S. Typhimurium S. 4,[5],12:i:-, which has increased in prevalence in the latest decade (EFSA, 2010b;Hopkins et al, 2010), were also identified in a relevant number of samples. S. Bredeney was the fourth serovar identified in our study, although it should be pointed out that the 72 S. Bredeney isolates were all found in the same visit to slaughterhouse D (more than 70% of the Salmonella isolates recovered in that visit).…”