Slaughter End Research Articles

Identification of risk profiles for Salmonella prevalence in pig supply chains in South Korea using meta-analysis and a quantitative microbial risk assessment model

International travel and the globalization of food supplies have increased the risk of epidemic foodborne infections. Salmonella strains, particularly non-typhoidal Salmonella (NTS), are major zoonotic pathogens responsible for gastrointestinal diseases worldwide. In this study, the prevalence and Salmonella contamination in pigs/carcasses throughout the South Korean pig supply chain and the associated risk factors were evaluated using Systematic reviews and meta-analyses (SRMA), and quantitative microbial risk assessment (QMRA). The prevalence of Salmonella in finishing pigs, which is one of the major starting inputs of the QMRA model was calculated through SRMA of studies conducted in south Korea in order to complement and enhance the robustness of the model. Our findings revealed that the pooled Salmonella prevalence in pigs was 4.15% with a 95% confidence interval (CI) of 2.56 to 6.66%. Considering the pig supply chain, the highest prevalence was detected in slaughterhouses (6.27% [95% CI: 3.36; 11.37]), followed by farms (4.16% [95% CI: 2.32; 7.35]) and meat stores (1.21% [95% CI: 0.42; 3.46]). The QMRA model predicted a 3.9% likelihood of Salmonella-free carcasses and a 96.1% probability of Salmonella-positive carcasses at the end of slaughter, with an average Salmonella concentration of 6.38 log CFU/carcass (95% CI: 5.17; 7.28). This corresponds to an average contamination of 1.23 log CFU/g (95% CI: 0.37; 2.48) of pork meat. Across the pig supply chain, the highest Salmonella contamination was predicted after transport and lairage, with an average concentration of 8 log CFU/pig (95% CI: 7.15; 8.42). Sensitivity analysis indicated that Salmonella fecal shedding (r = 0.68) and Salmonella prevalence in finishing pigs (r = 0.39) at pre-harvest were the most significant factors associated with Salmonella contamination in pork carcasses. Although disinfection and sanitation interventions along the slaughter line can reduce contamination levels to some extent, effective measures should be taken to reduce Salmonella prevalence at the farm level to improve the safety of pork consumption.

Treatment of thirst in broilers in a low-throughput abattoir

Thirst in broilers was satisfied by water provision while awaiting slaughter at a one-day-per-week poultry abattoir in England. Two consignments, of 7000 broilers in total, during high summer and in...

Occurrence and antimicrobial susceptibility of Campylobacter spp. on fresh and refrigerated chicken meat products in Central Italy.

This study investigated the presence and the level of Campylobacter spp. contamination in 41 thigh samples (with skin) and 37 skinless breast samples collected at the end of slaughter (T1) and after 10 day period at refrigeration temperature (4°C) (T2), corresponding to their commercial shelf life. The isolates were phenotypically classified as Campylobacter spp. and successively identified by conventional multiplex PCR. The antimicrobial susceptibility of the isolates from fresh thigh and breast samples was also determined via the microdilution method (MIC) in Eucamp microtitre plates with known scalar concentrations of: gentamicin (GEN), streptomycin (ST), ciprofloxacin (CIP), tetracycline (TET), erythromycin (ERY), and nalidixic acid (NA). A greater percentage of positivity for Campylobacter spp. (P<0.001) was observed in thighs and C.jejuni appeared to be the most common species identified at this level (P<0.001) followed from its association with C.coli. There was a global reduction of Campylobacter spp. in both thigh and breast samples at T2 (P<0.001) showing that the refrigeration was able to reduce Campylobacter count. The prevalence of resistance to CIP, TET, NA, and ERY was evidenced for C.jejuni and C. coli. The co (TET-NA, CIP-NA) and multiple resistant (CIP-TET-NA, CIP-TET- NA-ERY) isolates came from the thigh products. It should be highlighted the presence of Campylobacter spp. isolates resistant to ST occurred in breast samples, responsible for the ST-CIP co-resistance and ST-CIP-TE multi-resistance profiles, higher in breast than in thigh products (P>0.001). The presence of Campylobacter isolates resistant to ST can be further investigated since it is used for therapeutic treatment of several bacterial diseases in humans.

Variation in the effect of carcass decontamination impacts the risk for consumers

To enhance food safety, whole carcass decontamination during slaughter has been considered as a control measure to reduce pathogen concentrations on meat. The effect of such decontamination is usually measured in terms of the mean log reduction in concentration. However, the variation in this reduction may also contribute to the overall impact of the decontamination measure. Therefore, this study focuses on the relative contribution of mean and variation for the effect of decontamination in the slaughter-line expressed in terms of the effect on human health risk.A stochastic risk model is developed to assess the potential effects of pig carcass decontamination at the end of slaughter on the risk of salmonellosis for Danish consumers. Salmonella concentrations are represented by a lognormal distribution fitted to microbiological data, characteristic for Salmonella numbers on carcasses at the end-point of Danish slaughterhouses. Decontamination scenarios are represented by various gamma distributions with different means and standard deviations. The values chosen for these parameters are based on experimental data of the effect of real decontamination procedures applied to pork.Results show that the variation of decontamination has a relevant effect on risk reduction for the consumer: the higher the variation, the lower the overall risk reduction. This effect is particularly evident for procedures with a lower mean reduction (≤2.5 log10), but less so for highly efficient decontamination procedures (>2.5 log10 mean reduction). This difference is affected by the initial level of carcass contamination with Salmonella. With increasing mean and standard deviation of initial bacterial concentrations, it becomes increasingly relevant to account for the variation of the decontamination action, even if the mean decontamination effect is high.We conclude that for decontamination procedures with an overall mean reduction effect of 1–2 log10, it is important to consider the variation in effect: if the variation is large, the final effect of decontamination can be considerably smaller than expected on the basis of the mean only and efforts should be put in place to reduce the variation of the procedure. However, when a treatment of high mean reduction (>2.5 log10) is used, the impact of variation becomes smaller and may be negligible.

Prevalence of Salmonella in the Broiler Supply Chain in The Netherlands

This article presents detailed information on Salmonella prevalence throughout the broiler supply chain in The Netherlands, based on results from a national monitoring program. Data were collected during the period 2002 through 2005 and from six sampling points in the chain, covering hatchery up to and including processing. Trends in Salmonella prevalence over years and seasons were analyzed as well as the effect of slaughterhouse capacity on these trends. In addition, correlations between the occurrence of Salmonella at the various sampling points were calculated. The results showed a decreasing trend of Salmonella prevalence from 2002 through 2005 at all sampling points. A seasonal effect on the occurrence of Salmonella was found at the broiler farm, with a higher prevalence during the third and fourth quarter of the year (July through December). The higher the capacity of the slaughterhouse, the lower Salmonella prevalence on arrival at the slaughterhouse and the higher the prevalence at the end of slaughter and the end of processing. The detailed insights obtained in this study could be used to focus future field and experimental research on the prevention and control of Salmonella in the broiler supply chain. Results presented could also be used in risk assessment studies.

Management: The end of OTMS and casualty slaughter: What does it mean to you and your clients?

Management: The end of OTMS and casualty slaughter: What does it mean to you and your clients?

Verification of the level of Microbiological Control for the Slaughter and Cooling Processes of Beef Carcass Production at a High-line-Speed Abattoir

Methods are described which were used to verify the microbiological adequacy of the processes of production and chilling of carcasses at a high-line-speed abattoir. Ten excision samples (5 by 5 by 0.2 cm) were taken from each of 16 to 20 carcasses for each evaluation of these processes. Twelve monthly evaluations were made for the slaughter of steers, heifers, and cows and additional evaluations for each of the slaughter of cows and the chill process of carcasses. The ranges of the estimated mean log10 most probable number of growth units per square centimeter (LMPN, for 236 carcasses) and Escherichia coli per square centimeter (LEC, for 240 carcasses) enumerated by hydrophobic-grid membrane filter technology for the 12 monthly evaluations of the slaughter floor were 1.11 to 1.62 (LMPN) for single samples and 0.20 to 0.65 (LEC) for pooled samples. Based on a published advisory scale for the slaughter floor the aerobic bacterial counts reflect a cleanliness level of ”excellent” to “good.” For single evaluations of cow carcasses at the end of slaughter and of chilled carcasses the mean LMPN was 1.78 (“good”) and 1.40 respectively. From pooled samples of each of the 236 steer, heifer, and cow carcasses the pathogen E. coli O157:H7 was identified by polymerase chain reaction on one carcass whereas Listeria monocytogenes was identified on 14 carcasses. Verocytoxigenic E. coli (6 isolates) and L. monocytogenes were not isolated from the same carcasses. These low isolation rates dictate a large sample size and therefore these pathogens are excluded from use to routinely verify the workings of hazard analyses and critical control point (HACCP) systems for beef slaughter processes in Alberta. Alternatively the use of aerobic bacterial counts to directly measure cleanliness or of E. coli counts to indirectly measure fecal contamination appears to be more practical than the use of specific pathogen counts for regulatory agencies to verify the workings of quality control programs, including HACCP systems.

Reproductive Capacity of Dairy Bulls. II. Gonadal and Extra-Gonadal Sperm Reserves as Determined by Direct Counts and Depletion Trials; Dimensions and Weight of Genitalia

Summary Extra-gonadal sperm reserves (EGR) determined by direct counts averaged 69.4 billion for 15 sexually rested (SR) bulls, 73.5 billion for 15 sexually rested bulls depleted just before slaughter (SR-D), and 68.0 billion for five bulls ejaculated six or seven times per week for at least 6 wk. prior to slaughter (6–7 x). While total EGR, which included an average of 38.5 billion sperm collected on the day of slaughter from SR-D bulls and 10.5 billion from 6–7 × bulls, did not vary significantly among the three groups, sperm distribution was significantly different. Sperm counts of the caput, corpus, and cauda epididymis averaged 19.4, 4.7, and 37.6 billion for SR bulls, 16.2, 3.0, and 13.7 billion for SR-D bulls, and 22.6, 5.2, and 26.4 billion for 6–7 × bulls. Depletion removed 52.8 ± 2.3% of the total EGR of SR-D bulls; although the cauda epididymis was nearly emptied, partial replenishment with sperm from the caput and corpus occurred during the 60- to 90-min. interval between the end of depletion and slaughter. Daily sperm output for the 6–7 × bulls averaged 4.9 billion for 6 wk. The sperm content of the cauda epididymis was 25% lower than if they had been sexually rested. The ductus deferens and ampulla of SR bulls contained only 7.6 billion sperm. When corrected for preslaughter treatment, the EGR for the 35, 76 ± 5-mo.-old bulls averaged 72.6 billion sperm. Preslaughter treatment did not affect gonadal sperm reserves. Fifty testes, averaging 374 g., contained 20.2 billion sperm, or 54.8 ± 1.0 million per gram. Testis sperm numbers were highly significantly correlated (+ 0.62) with testis weight. The highly significant correlation (+ 0.87) between EGR and total sperm removed in a depletion should permit estimation of EGR in living animals by depletion trials of about 20 ejaculates. Gonadal sperm reserves were not significantly correlated to epididymal sperm reserves in SR bulls. The independence of testicular sperm production and storage of sperm in the excurrent duct system is stressed. Genitalia dimensions and weight for 55 bulls are presented by breeds and ages.