Comparison of GN Hajna and tetrathionate as initial enrichment for salmonellae recovery from swine lymph nodes and cecal contents collected at slaughter.

An epidemiologic survey was conducted to determine the prevalence of salmonellae in swine from 5 farms of an integrated swine operation. The purpose of this study was to evaluate the recovery efficiencies for salmonellae from swine lymph nodes and cecal contents when GN Hajna and tetrathionate were compared as initial enrichments. Salmonellae were isolated from 61% of 645 pigs at slaughter; 324 positive cultures were from lymph nodes, and 224 were from cecal contents. Frequently, pigs had salmonellae isolated from both the lymph nodes and cecal contents. Total isolations, regardless of source, were similar for GN Hajna (247) and tetrathionate (301). There was no difference (P > 0.05) in the number of isolations from lymph nodes when GN Hajna enrichment was compared with tetrathionate enrichment (174 vs. 150). However, there was a significant (P < 0.05) advantage of utilizing tetrathionate when compared with GN Hajna for isolations from cecal contents (151 vs. 73).     

Time series analysis of mycobacteriosis in California slaughter swine

Records of a California abattoir were reviewed for the 46-month period August 1977 through May 1981, and data were collected for 23 ranches which only marketed hogs born and raised in California. Passed for cooking (PFC) rates (per 100 000 animals slaughtered) due to lymph node lesions listed as TB (mycobacteriosis) by inspectors were roasters (32–50 kg) 0, market hogs (82–105 kg) 243, and sows (> 145 kg) 125. Effective exposure to disease-causing factors seemed to have taken place at 2–3 months of age or earlier. Time series analysis of hog PFC rates for the 23 California ranches combined demonstrated statistically significant, regular cycles of 6 and 24 months duration with seasonal peaks of PFC rates in June and December. Based on an estimated incubation period of 4–6 months, animals were at greatest risk of effective exposure to factors associated with lymph node lesions during the periods December–February and June–August.     

Microbiological and serological study of leptospirosis in horses at slaughter: first isolations

A bacteriological survey of kidneys from 145 abattoir horses was performed, which resulted in the isolation of two Leptospira strains. The isolates were serologically typed as belonging to serogroups Australis and Pomona, and REA identified them as L. interrogans serovar Bratislava and L. kirschneri serovar Tsaratsovo, respectively. These are the first Leptospira isolates obtained from horses in Portugal and the Bratislava strain is the first serogroup Australis strain to be isolated in this country. The 145 horses were also serologically tested for leptospiral antibodies, and 37% had MAT titres #10878;1:10.     

Effect of withdrawing feed from swine on meat quality and prevalence of Salmonella colonization at slaughter

OBJECTIVE: To determine whether withholding feed from pigs prior to slaughter had any effects on meat quality, percentage of pigs with Salmonella spp in cecal contents during slaughter, or percentage of pigs with lacerations of the gastrointestinal tract during slaughter. DESIGN: Split-plot design. ANIMALS: 873 pigs. PROCEDURES: At the finishing barn, pigs were assigned to 30 pens. Feed withdrawal times were assigned to pens at random, and pigs in each pen were marketed in 3 groups. The first marketing group consisted of the 10 heaviest pigs in each pen, the second consisted of the next 10 heaviest pigs, and the third consisted of all remaining pigs. RESULTS: Withdrawing feed improved the redness score assigned to the meat but did not have any other significant effects on carcass composition or meat quality. The percentage of pigs with Salmonella spp in the cecal contents decreased from the first (73%) to the second (64%) to the third (52%) marketing group. However, isolation of Salmonella spp from cecal contents was not associated with feed withdrawal time or with pen prevalence of Salmonella shedding during the 2 months prior to slaughter. Feed withdrawal time and marketing group did not have any significant effects on overall prevalence of gastrointestinal tract lacerations. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that withdrawal of feed from pigs prior to slaughter does not increase the prevalence of Salmonella colonization or the risk of carcass contamination associated with gastrointestinal tract lacerations during slaughter but only slightly enhances meat quality.     

Bacteria isolated from lymph nodes of California slaughter swine

Lymph nodes from 280 slaughter swine from 9 California ranches were examined for the presence of aerobic microflora. Genera of interest which were isolated (and percentage of animals from which they were isolated) included Salmonella (4.3%), beta-hemolytic streptococci (8.2%), Mycobacterium avium-complex (6.4%), Corynebacterium pyogenes (0.4%), and Aeromonas hydrophila (5.7%). Patterns of bacterial isolations from swine herds may be of assistance in predicting herd health problems.     

Low occurrence of pathogenic Yersinia enterocolitica in pig tonsils at slaughter in Southern Brazil

Tropical Animal Health and Production - Yersinia enterocolitica is a foodborne pathogen and pigs are the main reservoir of it in their tonsils. As Brazil is a large producer and exporter of pork...     

Prevalence of lesions and body condition scores among female swine at slaughter

OBJECTIVE: To determine prevalence of foot lesions, dermatitis, shoulder lesions, mammary gland abnormalities, and visceral lesions, and body condition scores among culled female swine at slaughter. DESIGN: Observational study. ANIMALS: Culled gilts and sows killed during a 1-week period at a Midwest slaughterhouse. PROCEDURE: Carcasses were examined, and lesions were recorded. Body condition was scored on the basis of standard criteria. RESULTS: 58.9% (1,029/1,747) of the carcasses had foot lesions, 67.3% (1,178/1,751) had dermatitis, and 4.6% (80/1,751) had shoulder lesions. Body condition score was significantly associated with detection of dermatitis and shoulder lesions. Mean +/- SE number of teats (n = 1,432 carcasses) was 13.86 +/- 0.02. Mean numbers of normal-appearing teats in the left and right mammary chains were 6.57 +/- 0.02 and 6.58 +/- 0.02, respectively. Feet from 48% (688/1,433) of the carcasses were condemned. Visceral lesions were found in 48.8% (624/1,278) of the carcasses; of the carcasses with lesions, 412 (66%) had liver spots, and 268 (42.9%) had pneumonia. CLINICAL IMPLICATIONS: Lesions that potentially could have adversely affected production were found in a large percentage of culled gilts and sows at slaughter. Knowledge of lesions commonly found at slaughter may help direct changes in herd health programs.     

Lesions in the carcasses and viscera of very young slaughter calves condemned at post-mortem meat inspection

The carcasses of 370 very young slaughter calves condemned for various diseases and defects at routine post-mortem meat inspection were subjected to further and more detailed macroscopic examination as well as histopathological examination of some tissues. Of the carcasses examined, 138 were condemned for navel ill, and in the majority of these cases the lesions extended beyond the umbilicus, particularly involving the umbilical vein and the urachus. Enzootic pneumonia was the most common cause of pleuritic lesions in the carcass, and 75 carcasses were condemned for this lesion. Arthritis, whether localised or involving a number of joints, was the primary lesion in 32 carcasses. Focal interstitial nephritis was observed in the kidneys of 36 carcasses, while 23 carcasses were condemned for wounds and bruising. A number of other miscellaneous diseases and defects, including generalised peritonitis, jaundice, hepatic abscesses and fever, were observed at low rates in condemned carcasses. Resolution or localisation of lesions had occurred at the time of slaughter on average in 35% of the condemned carcasses and the judgment of total condemnation was difficult to justify on a scientific basis and would not have been applied to other classes of slaughtered livestock. In the case of wounds and bruising, 95.6% of the carcasses could have been trimmed. There was also considerable variation in the likely pathogenesis and systemic effects of the diseases and defects observed. A need for clear and specific judgment criteria to be applied to the carcasses of very young slaughter calves at post-mortem meat inspection was identified.     

猪链球菌扁桃体分离株的毒力因子分布特征与致病性

本研究设计并合成7对引物,用PCR方法对猪链球菌7种主要毒力因子,包括谷氨酸脱氢酶(gdh)、溶血素(sly)、胞外蛋白因子(ef)、溶茵酶释放蛋白(mrp)、纤连蛋白/血纤蛋白原结合蛋白(fpbs)、三磷酸甘油醛脱氢酶(gadph)和毒力相关序列orf2进行检测,分析了29株猪链球菌扁桃体分离株的毒力因子分布特征.在被检的25株2型菌株中,共检测出7个基因型.其中10株(40%)的基因型为cps2/gdh+/sly+/ef+/mrp+/fbps+/gadph+/orf2+,7株(28%)表现为cps2/gdh+/sly-/ef-/mrp+/fbps+/gadph+/orf2+,4株(16%)表现为eps2/gdh+/sly-/ef+/mrp+/fbps+/gadph+/orl2+,基因型表现为eps2/gdh+/sly+/ef+/mrp+/fbps+/gadph+/orf2-、cps2/gdh+/sly-/ef-/mrp+/fbps+/gadph+/orf2-、eps2/gdh+/sly-/ef-/mrp*/fbps+/gadph+/orf2+、eps2/gdh+/sly-/ef-/mrp-/fbps-/gadph+/orf2-各1株;1株猪链球菌7型(SS7)分离株,基因型表现为cps7/gdh+/sly+/ef-/mrp-/fbps+/gadph+/orf2+;3株猪链球茵9型(SS9)扁桃体分离株,均表现为cps9/gdh+/sly-/ef-/mrp-/fbps+/gadph+/orf2+.可见我国SS分离株的毒力基因分布较为复杂,而且SS2的优势流行菌株是同时具有多种毒力因子的高致病茵株.通过对不同毒力基因型毒株对西藏小型猪的感染试验发现:毒力基因型为cps2/gdh+/sly-/ef+/mrp+/fbps+/gadph+/orf2+的健康扁桃体分离株SH06-21D对西藏小型猪有较强的致病性,仅次于标准株HA9801,而基因型为sly-/ef-/mrp-/fbps-/gadph+/orf2-的健康扁桃体分离株GZ06-122B对西藏小型猪不表现明显的致病性.     

Serological and pathogenic characterization of Erysipelothrix rhusiopathiae isolates from tonsils of slaughter pigs in Indonesia

Erysipelothrix rhusiopathiae was isolated from tonsils of 245 (35.7%) of 687 apparently healthy slaughter pigs in Indonesia during the period of June 1987 to February 1988. A total of 150 of the 245 E. rhusiopathiae isolated could be serotyped within the 22 recognized serotypes. Serotype 2 was most prevalent with 23.7%, followed by Serotypes 11, 12, 1a, 5 and 6 representing 7.3, 5.3, 4.9, 4.9 and 4.1% of the isolates, respectively. The nine other serotypes (Serotypes 1b, 3, 4, 8, 9, 10, 13, 19 and 22) combined to make up 11.0% of the isolates. Antibiotic-resistant strains were not found. Of 86 selected isolates belonging to various serotypes, 76 (88.4%) were highly virulent for mice (LD50 less than 10(3.0) colony-forming units). In swine, 40 (51.2%) of 78 isolates induced local or generalized urticarial lesions after intradermal inoculation, and the remaining 38 isolates induced no clinical signs. Of 76 isolates used for challenge in the cross-protection study, 29 (38.2%) killed greater than 40% of mice immunized with an erysipelas bacterin marketed in Indonesia. A tendency to be refractory to the bacterin-induced immunity was observed in some isolates of various serotypes, but this characteristic was not consistent.     

Serotyping and pathogenicity of Erysipelothrix strains isolated from tonsils of slaughter pigs in Thailand.

Erysipelothrix strains were isolated from the tonsils of 46 (15.0%) of 307 apparently healthy slaughter pigs in Thailand during the period of August to September, 1997. A total of 27 of the 46 Erysipelothrix isolates could be classified into 5 serovars but the remaining 19 were untypable in this study. Of the 25 isolates serologically identified as Erysipelothrix rhusiopathiae, 20, 4, and 1 isolates belonged to serovars 2, 12, and 17, respectively. Only 2 isolates from the tonsils belonged to Erysipelothrix tonsillarum and represented either serovar 7 or 10. Although the periods and the districts of the survey were limited, the information obtained in the present investigation demonstrates the presence of a variety of serovars in pigs in Thailand. Of 29 selected isolates belonging to serovars 2, 7, 10, 12, 17, and untypable, only 5 (17.2%) were virulent for both mice and pigs. Five of these virulent isolates belonging to serovars 2 and 12 killed less than 30% of mice immunized with a swine erysipelas bacterin commercially available in Thailand, suggesting that the vaccine elicited a sufficient immunity to these field isolates.     

Pathological lesions in swine at slaughter. II. Culled sows

The same computerized recording system as described in Part I of this publication (Flesjå & Ulvesœter 1979) was applied to sows slaughtered at Sentralslakteriet, Forus, Stavanger.In the three-year period 1975–1977 a total of 10,051 apparently healthy sows were brought to the abattoir. About 17 % of the carcasses had one or more pathological lesions. Of the total number of lesions 89 % were confined to 18 of the available 57 disease codes. Pyaemia and abscess/-es occurred at a rate of 1.5 and 3.2 %, respectively. This comprised 21 % of all registered lesions. Scabies and numerous white liver spots came to another 21 %, occurring in 3.3 and 1.5 % of the animals, respectively. About 15 % were chest lesions, of which pleurisy was diagnosed in 1.4 % and pericarditis in 1.3 % of the slaughtered sows. Other lesions recorded in 1 % or more included perihepatitis and other non-parasitic liver lesions, arthritis and decubitus.Only code 31 — numerous white spots in the liver showed a convincing seasonal variation.Significantly higher frequencies of pyaemia and abscess/-es occurred in culled sows than in baconers, but no such difference could be found for peritonitis, polyarthritis and arthritis. For all other commonly observed lesions significantly lower frequencies were seen in sows compared to baconers.Various theories are suggested to explain the observed difference in the distribution of lesions between baconers and sows.     

Effect of separate transport, lairage, and slaughter on occurrence of Salmonella typhimurium on slaughter carcasses

The study aimed to reduce cross-contamination between finishers from Salmonella-positive and Salmonella-negative herds during transport, lairage, and slaughter, thereby reducing the prevalence of Salmonella Typhimurium on slaughter carcasses. In Phase 1 of the study, pigs from Salmonella-negative herds were kept in lairage for 2-4 hours either in clean pens (intervention group) or pens contaminated with Salmonella-infected faeces (control group). All pigs were slaughtered on the same slaughterline, and carcass swabs 24 hours after slaughter revealed a low degree of cross-contamination in the pens: there was no difference in Salmonella-positive carcasses between intervention (1.7%) and control groups (0.8%). In Phase 2, control pigs from Salmonella-negative herds were mixed with pigs from Salmonella-positive herds during lairage for 2-4 hours, while the intervention group still consisted of pigs from Salmonella-negative herds. All pigs were slaughtered on the same line: first intervention, then control. Carcass swabs taken 24 hours after slaughter failed to show a reduction in Salmonella-positive carcasses in the intervention group (4.5%) compared with the originally Salmonella-negative pigs in the control group (3.6%). In pigs from Salmonella-positive herds the occurrence of Salmonella was substantially higher at 10.4%. When the results were corrected for 6 carcass samples found positive with S. Heidelberg on the same day, which was attributed to a transient hygiene failure, only 2.2% of the carcasses in the intervention group were Salmonella-positive. We conclude that even though cross-contamination occurs in the abattoir pens, its importance on the slaughter line may be greater. However, the final results of this study should be awaited to conclude whether separate slaughter of pigs from Salmonella-positive and Salmonella-negative herds should be recommended.     

A HACCP-based approach to hygienic slaughter and dressing of lamb carcasses

AIMS: This paper compares changes in visible and microbiological contamination on lamb carcasses dressed using one system which includes process factors previously identified as potential critical control points for HACCP-based approaches to hygienic slaughter and dressing, and another system which excludes those factors. METHODS: Longitudinal changes in microbiological and visible contamination of lamb carcasses were quantified in two slaughterhouses, one utilising clean, shorn, unwashed lambs in an inverted dressing system, the other utilising dirty, woolly, washed lambs in a traditional dressing system. Excision samples (5 cm2 each) for microbiological analyses were taken from two sites on 25 carcasses per treatment group immediately after pelting, at the completion of dressing, after overnight chilling and after boning and packaging. Visible contamination on the surface of 300 carcasses per treatment group was assessed after pelting and after overnight chilling. RESULTS: Mean aerobic plate counts and Escherichia coli counts on the leg and loin in the inverted dressing system were low after pelting (log10/cm2 1.86 and 1.71; log10/cm2 0.13 and 0.05 respectively) but generally showed statistically significant increases through to final packaging. In the conventional dressing system, there were much higher counts on the leg and loin after pelting (log10/cm2 4.66 and 2.71; log10/cm2 2.21 and 0.24 respectively), but subsequent handling of the carcass by slaughter line workers had no measurable deleterious effects. The inverted dressing system resulted in final mean aerobic plate counts on meat at packaging that were 1.38% (leg) and 48.98% (loin) of those derived from the conventional dressing system. Mean E. coli counts from the inverted system were 21.37% (leg) and 67.61% (loin) of those from the conventional system. There was an inverse relationship between the prevalence of carcasses with visible faecal contamination and their microbiological status. CONCLUSION: Significant reductions in microbiological contamination of sheep carcasses can be brought about by HACCP-based systems. Possible critical control points are pre-slaughter presentation status (including avoidance of pre-slaughter washing), inverted dressing, handling by slaughter line workers and meat inspectors, and chilling. Use of levels of visual faecal contamination as an on-line monitoring parameter for slaughter hygiene can give erroneous results. Interactions between different process steps may alter the effectiveness of the HACCP plan, and successful design and application depends on a detailed knowledge of the specific process utilised in each slaughterhouse.     

CO2-stunning of swine for slaughter from the anesthesiological viewpoint

For investigations of CO2-stunning of feeder- and slaughter-pigs parameters of behaviour, blood-gas-analyses and electroencephalograms were chosen. The following results were obtained: 1. Blood-gas-analyses proved that the CO2-stunning does not produce unconsciousness due to a lack of oxygen. 2. The criterias of general anaesthesia: unconsciousness, muscle-relaxation and analgesia with total reversibility could be confirmed. 3. The violent convulsive symptoms were evaluated as reactions identical with the stage II of GUEDEL's scheme of anaesthesia. 4. Muscular agitation, which sometimes appeared a few seconds before the stage of excitation, was judged to belong either to the start of the excitation phase or to the end of Guedel's stage of analgesia, during which the sensitivity is decreased. Neither study of behavior nor objective measurements showed, during the first 10 to 20 seconds of exposure to the CO2, any sign of pain or suffering related to the Act for Prevention of Cruelty to Animals, and accordingly such suffering should not be ascribed to the CO2 stunning method.