Relationship between food deprivation before transport and aggression in pigs held in lairage before slaughter

Pigs from three farms were deprived of food for up to one hour, 12 hours or 18 hours before being sent for slaughter. In lairage, the animals' behaviour was monitored, and at slaughter a blood sample was collected and analysed for cortisol, lactate and creatine phosphokinase, potential indicators of stress and physical activity. The carcases were assessed for skin damage as an index of fighting, and rigor in the hind leg as an indicator of stress and/or fatigue. Measurements were also made of cold carcase weight, backfat thickness and liver glycogen concentration. General activity was very high on entry to the lairage pen. Drinking and mounting occurred almost immediately. Fighting developed after an exploratory period, and could last up to 60 minutes. There were large differences in the behaviour of pigs from the three farms. Pigs from farm A fought frequently but showed little mounting activity, whereas pigs from farm C were involved in mounting but little fighting. The period of food deprivation had no effect on average skin damage or rigor score, but the frequency of carcases with the highest scores was different The pigs deprived of food for up to an hour had the lowest incidence of severe skin damage and high rigor scores. Boars had a higher incidence of severe skin damage but a lower incidence of carcases with a high rigor score than gilts. Liver glycogen was almost completely depleted in the pigs deprived of food for 12 and 18 hours and was lower in the pigs deprived for up to an hour than in animals fed immediately before slaughter. The period of food deprivation had no effect on the levels of cortisol, creatine phosphokinase or lactate in the blood.     

Relationship between early post-mortem muscle pH and shortening-induced toughness in the Pectoralis major muscle of processed broilers air-chilled at 0 degrees C and -12 degrees C

1. An experiment was conducted to investigate the development of shortening-induced toughness in the Pectoralis major (PM) muscles of commercially processed broilers, air-chilled at 0 degrees C and -12 degrees C, as a function of muscle pH early post-mortem. Electrical stimulation was used immediately after stunning and neck cutting to provide carcases with pH values 15 min post-mortem (pH15 min) ranging between 6.79 and 5.85. 2. The deep PM muscle temperatures of carcases chilled at -12 degrees C were lower (cooler) after primary chilling and at 215 min post-mortem than those chilled at 0 degrees C, although chilling regimen had no major effect on pH values over the 24 h post-mortem period. However, carcases chilled at -12 degrees C had longer sarcomeres, lower cooking losses and lower shear force values than those chilled at 0 degrees C. 3. Correlation analysis of the results for both chilling regimens clearly demonstrated that over the pH15min range 6.79 to 5.85, carcases with the lowest pH15min values had the shortest sarcomeres, the highest cooking losses and the toughest meat. In addition, there was no evidence to support the occurrence of cold shortening within this population. This suggests that an early onset of rigor at higher temperatures in broiler carcases, as well as inducing rigor shortening and toughness, might also induce greater protein denaturation and subsequent loss of water holding capacity as manifested in increased cooking losses. 4. Quadratic regression curves showed that over the pH15min range 6.80 to 6.30, only the fast chilling regimen at -12 degrees C could inhibit rigor shortening and minimise changes in cooking loss and shear force values. However, neither chilling regimen was effective in preventing severe rigor shortening, increased cooking losses and adverse toughness in carcases with pH15min values below 6.30. 5. The benefits of fast chilling carcases with pH15min values above 6.3 can also be quantified in terms of carcases exceeding a 4.00 kg/cm2 toughness threshold. Only 1.9% of these carcases chilled at -12 degrees C exceeded this limit (maximum shear force value of 4.72 kg/cm2) compared to 34.9% of the carcases chilled at 0 degrees C (maximum shear force value of 8.46 kg/cm2), further emphasising the considerable reduction in textural variability and improvement in tenderness gained by fast air-chilling at -12 degrees C.     

The isolation of salmonella from kangaroos and feral pigs processed for human consumption

A total of 154 feral pig carcases and 81 kangaroo carcases were examined for the presence of Salmonella, coliforms and total aerobic counts. Approximately 34% of pig carcases yielded one or more serotypes of Salmonella, while about 11% of kangaroo carcases were contaminated with salmonella. The results differed widely between sampling occasions. A total of 13 serotypes were isolated from feral pigs with S. anatum (31 isolates) and S. typhimurium (9 isolates) being the predominant serotypes. Coliforms were isolated from approximately 90% of carcases. The mean log10 coliform count on feral pigs was 4.39 +/- 1.45/g and the mean log10 total count was 6.15 +/- 1.15/g. About 21% of carcases were contaminated with more than 100,000 coliforms/g. A total 3 serotypes were isolated from kangaroos (S. bahrenfeld, S. binza, and S. onderstepoort). The mean log10 coliform count on kangaroos was 3.54 +/- 1.04. More than 50% of kangaroo carcases were contaminated with less than 100 coliforms/g. About 15% of carcases were contaminated with more than 10,000 coliforms/g. The mean log10 total count was 5.2 +/- 1.01/g.     

Infection of pigs with transmissible gastroenteritis virus from contaminated carcases

Sixteen 6-month-old pigs were exposed to transmissible gastroenteritis (TGE) virus by placing them in close contact with piglets infected at 1 week of age. Fourteen of the older pigs were slaughtered between 1 and 5 d after exposure to infection and their carcases dressed in simulated abattoir conditions. Samples of muscle, bone marrow and carcase lymph nodes were stored at -25 degrees C for at least 30 d and then homogenised and fed to groups of 1-week-old and 3-week-old pigs. Four of 12 one-week-old pigs died and TGE virus was isolated from intestinal contents of one of these. All pigs of both age groups developed neutralising antibody to TGE virus over the ensuing 4 w. The results indicate that carcases from pigs infected with TGE virus can represent a source of infection for susceptible pigs given access to them.     

Abattoir condemnation of pigs and its economic implications in Singapore

Losses due to mortality and rejection of carcases and viscera in a population of 2,959,607 pigs admitted for slaughter in Singapore abattoirs between 1984 and 1986 were studied. Mortality losses were 2822 pigs (9.5 per 10,000 admissions) while 3039 whole carcases (10.3 per 10,000 admissions) were condemned at post-mortem examination. The main reason for rejection of carcases was pyaemia (30.3%). Kidneys and livers were the two main organs of economic value rejected. Rejection of kidneys was primarily due to nephritis (54.8%) while liver condemnation was mainly due to cirrhosis (38.6%). The financial loss from abattoir rejection was S$5.27 millions or S$1.78 per pig admitted. The value of abattoir condemnation data as a tool in preventive medicine is discussed.     

Slaughterfloor decontamination of pork carcases with hot water or acidified sodium chlorite - a comparison in two Australian abattoirs

A decontamination trial on the effectiveness of hot water or acidified sodium chlorite (SANOVA) treatment on Salmonella spp., Escherichia coli and Total Viable Count (TVC) was undertaken on pork carcases prior to primary chilling in two large pork abattoirs in Australia using belly-strip excision sampling. A total of 123 samples from Abattoir A and 400 samples from Abattoir B were cultured and analysed. Test pigs were selected from herds with a known high level of on-farm Salmonella infection. At Abattoir A, Salmonella spp. were not isolated from carcases. The prevalence of E. coli on control carcases was 92.9% compared with 9.8% for hot water and 12.5% for SANOVA treated carcases. The mean log(10) E. coli concentration for control carcases was 0.89 cfu/gram, compared with -0.83 cfu/gram from hot water and -0.75 cfu/gram from SANOVA treated carcases. The mean log(10) TVC for control carcases was 4.06 compared with 1.81 cfu/gram for hot water and 2.76 cfu/gram for SANOVA treated carcases. At Abattoir B, the prevalence of Salmonella on control carcases was 16% compared with 2.7% for hot water and 7.0% for SANOVA treated carcases. The prevalence of E. coli on control carcases was 69.3% compared with 22% for hot water and 30% for SANOVA treated carcases. The mean log(10) E. coli concentration for control carcases was 0.45 cfu/gram, compared with -0.65 cfu/gram from hot water and -0.60 cfu/gram from SANOVA treated carcases. The mean log(10) TVC for control carcases was 3.00 cfu/gram compared with 2.10 cfu/gram for hot water and 2.53 cfu/gram for SANOVA treated carcases. The reductions in prevalence and mean log(10) concentrations in the present trial were all found to be statistically significant and indicate that carcases decontamination with either hot water or SANOVA are effective risk management options immediately available to the pork industry.     

Relationships between tail biting in pigs and disease lesions and condemnations at slaughter

Two matched case-control studies were performed at an abattoir with a capacity of 780 pigs per hour, each study using the approximately 7000 pigs slaughtered on one day. In the first study, the severity of tail biting and pneumonia were recorded in pigs with bitten or intact tails. In the second study, the tail score, sex, and the presence of pleuritis, externally visible abscesses and trimming were recorded in pigs with bitten or intact tails. In study 1, there was no significant association between the tail score and the percentage of lung tissue affected by lesions typical of enzootic pneumonia, but there was a significant association between the severity of tail biting and the prevalence of lungs with abscesses and/or pleuritic lesions (P<0.0001). In study 2, there were significant associations between the severity of tail biting, and the prevalence of external carcase abscesses and carcase trimming; the carcases of castrated males had evidence of tail biting more frequently than the carcases of females (P<0.05).     

Oral transmission of transmissible gastroenteritis virus by muscle and lymph node from slaughtered pigs

A study was conducted in the USA to determine whether transmissible gastroenteritis (TGE) virus could be transmitted from carcases of slaughtered pigs. Transmissible gastroenteritis virus was transmitted to 6-day-old piglets by dosing with homogenates of muscle and lymph node collected from 500 clinically normal pigs at the time of slaughter. All piglets in 2 separately housed litters showed clinical signs of TGE with 5 piglets dying within 10 d of oral dosing with homogenates. Transmissible gastroenteritis virus was isolated from 2 of these piglets and all piglets developed TGE antibody. Transmissible gastroenteritis virus was not isolated in tissue culture from muscle and lymph node homogenates, but was isolated from 4 (0.8%) of 500 tonsil samples collected from the same pigs. A survey of 250 serum samples provided an estimate of the prevalence of slaughtered pigs with TGE antibody of 34.8% in the sample population. The results indicate that carcases of some pigs from TGE endemic areas contain viable TGE virus, and that there would be a substantial risk of introducing TGE virus into Australia by the importation of uncooked pig meat from these areas.     

Assessment of producer conducted antemortem inspection of market pigs in Australia

OBJECTIVE: A field trial was conducted to evaluate the effectiveness of on-farm antemortem inspection performed by Australian pig producers in terms of proficiency in detecting unhealthy animals (suspects), the impact on food safety and animal welfare outcomes. ANIMALS: A total of 64 trial groups of market pigs (n= 10,703) were dispatched from 20 herds to three abattoirs in three states. PROCEDURE: All producers and abattoir antemortem inspectors were trained in antemortem inspection prior to the trial using a standardised set of antemortem criteria. Study 1 consisted of three comparisons: on-farm versus abattoir antemortem inspections on the same pigs, transport effects in suspect and normal pigs, and meat rejection and carcase disposition in suspect and normal pigs. Study 2 compared Salmonella spp status of suspect and normal pigs. Studies 3 and 4 were conducted to assist the interpretation of the results of on-farm versus abattoir inspection. Antemortem inspection results of three producers and one abattoir antemortem inspector were compared with those of a reference inspector (Gold Standard). RESULTS: Of the pigs examined, 2.12% (95% CI: 1.84%, 2.42%) were classified as suspect at on-farm antemortem inspection compared to only 0.14% at abattoir antemortem inspection. Forty one percent of pigs classified as suspect on-farm had locomotor problems (arthritis, lameness and foot abscess). Compared to normal pigs, suspect pigs had a relative risk of 67.7 (P < 0.0001) of suffering transport injuries. Meat rejection amounted to the equivalent of 9.68% of suspect carcases, compared to the equivalent of 0.35% of normal carcases. The isolation of Salmonella species from caecal content from 20.9% of 67 suspect pigs and 18.8% of 133 control pigs (two matched healthy pigs from the same batch for each suspect pig) were not significantly different. When compared with the reference inspector on-farm, three producers classified abnormalities in 2,495 pigs with high specificity (0.98), acceptable sensitivity (0.82) and kappa (0.57). CONCLUSIONS: With training, producer sensitivity in antemortem inspection may be high and more proficient than abattoir antemortem inspection. Use of producer inspections may have benefits for animal welfare and chain efficiency, but not food safety.     

Effects of bolus injection of epinephrine and norepinephrine on systolic time intervals in stress-resistant and stress-susceptible pigs

Systolic time intervals were measured in 15 stress-susceptible (SS) pigs to derive regression equations to determine to what extent their ventricular functions differed from those of stress-resistant (SR) pigs. Regression analysis revealed that the RR interval was the variable that was significantly (P less than 0.01) related to electromechanical systole and left ventricular ejection time. The preejection period (PEP) was independent of the RR interval. A normal increase of all systolic time intervals with age, independent of the RR interval, was also observed in SR and SS pigs. The 55-kg SS pigs had a higher noradrenergic tone than did 15-kg and 90-kg SS pigs, because their mean arterial blood pressure was higher and because their index values for electromechanical systole and their PEP were shorter than those of SR pigs of the same body weights. The cardiovascular responses to biogenic amines were also different according to the degree of development and stress susceptibility. Changes in mean arterial pressure and PEP were not as pronounced after injections of epinephrine and norepinephrine (10(-8) mol/kg of body weight) were given. Subsequently, a decrease in cardiovascular responses to epinephrine and norepinephrine injections in 90-kg SS pigs were recorded. These results indicate that 55-kg SS pigs have a higher level of circulating catecholamines and that the myocardium becomes less sensitive to epinephrine and norepinephrine after it is chronically exposed to these amines.     

Production of dark firm dry meat in slaughtered pigs with so-called liver degeneration characterized by yellowish discoloration and high lipid contents

The livers which are discolored yellowish and have a large amount of lipids (liver degeneration) are frequently observed in slaughtered pigs. Dark firm dry (DFD) meat and liver degeneration have a common etiological agent of exhaustion in pigs before slaughter. The correlation between them was examined. In 65 cases of 77 slaughtered pigs with the degenerative liver, which contained more than 6.6% total lipids of liver wet weight, the carcasses showed early rigor mortis and the higher final pH above 6.0. R values of the muscles, which indicated the decrease of ATP, were higher. The meat had a DFD appearance and the muscle fibers had no tendency to shrink. These data showed that the pigs with liver degeneration produced DFD meat at a high rate. In 4 cases of 5 pigs exhausted experimentally by 53 hr fasting and hard exercise before slaughter, both liver degeneration and DFD meat were produced simultaneously. The livers of them were discolored and contained about 8.0% or more total lipids. The carcasses of them showed early rigor mortis and the higher final pH above 6.0. From these data, it was suggested that the exhaustion in pigs before slaughter caused both liver degeneration and DFD meat.     

Assessment of producer conducted antemortem inspection of market pigs in Australia

OBJECTIVE: A field trial was conducted to evaluate the effectiveness of on-farm antemortem inspection performed by Australian pig producers in terms of proficiency in detecting unhealthy animals (suspects), the impact on food safety and animal welfare outcomes. ANIMALS: A total of 64 trial groups of market pigs (n = 10,703) were dispatched from 20 herds to three abattoirs in three states. PROCEDURE: All producers and abattoir antemortem inspectors were trained in antemortem inspection prior to the trial, using a standardised set of antemortem criteria. Study 1 consisted of three comparisons: on-farm versus abattoir antemortem inspections on the same pigs, transport effects in suspect and normal pigs, and meat rejection and carcase disposition in suspect and normal pigs. Study 2 compared Salmonella spp. status of suspect and normal pigs. Studies 3 and 4 were conducted to assist the interpretation of the results of on-farm versus abattoir inspection. Antemortem inspection results of three producers and one abattoir antemortem inspector were compared with those of a reference inspector (Gold Standard). RESULTS: Of the pigs examined, 2.12% (95% CI: [1.84%, 2.42%]) were classified as suspect at on-farm antemortem inspection compared to only 0.14% at abattoir antemortem inspection. Forty one percent of pigs classified as suspect on-farm had locomotor problems (arthritis, lameness and foot abscess). Compared to normal pigs, suspect pigs had a relative risk of 67.7 (P < 0.0001) of suffering transport injuries. Meat rejection amounted to the equivalent of 9.68% of suspect carcases, compared to the equivalent of 0.35% of normal carcases. The isolation of Salmonella species from caecal content from 20.9% of 67 suspect pigs and 18.8% of 133 control pigs (two matched healthy pigs from the same batch for each suspect pig) were not significantly different. When compared with the reference inspector on-farm, three producers classified abnormalities in 2495 pigs with high specificity (0.98), acceptable sensitivity (0.82) and kappa (0.57). CONCLUSIONS: With training, producer sensitivity in antemortem inspection may be high and more proficient than abattoir antemortem inspection. Use of producer inspections may have benefits for animal welfare and chain efficiency, but not food safety.     

An assessment of carbon dioxide stunning in pigs

The vocalisation patterns of pigs subjected to stunning in 86 per cent carbon dioxide in a commercial abattoir suggested that narcosis began 30 to 39 seconds after the start of the immersion procedure. The spontaneous and reflex physical behaviour of the pigs after immersion indicated that they were effectively stunned, but the majority of the animals were not considered to be brain-stem dead. None of the carcases showed pale soft exudative meat.     

Cross-sectional studies of ultimate pH in lambs

The ultimate pH of the longissimus muscle was measured in 1536 lambs routinely slaughtered at a meat export works in the southern part of the North Island during the 1981/82 season. The mean ultimate pH of all samples was 5.60, and 7.2 percent of the carcases had values equal to, or above, 6.00 whereas 85.3 percent of carcases had values below 5.80 which is considered to be optimal. The ultimate pH values of samples from lambs slaughtered during the summer period was significantly higher than those obtained during three other seasonal sampling periods and Perendale lambs had significantly higher ultimate pH values as compared to lambs of other breeds. There was no statistical association between distance travelled before slaughter and the ultimate pH of carcases but there was a highly significant direct correlation between holding periods of lambs in the stockyards and ultimate pH of their meat. There was also a highly significant inverse correlation between fleece weight and ultimate pH and it is suggested that both this effect and the seasonal pattern of ultimate pH values indirectly reflect the major role that nutrition may play in the development of high ultimate pH meat in lambs. It is further suggested that washing of animals prior to slaughter and the length of subsequent resting periods are important factors in relation to the development of undesirably high ultimate pH values.     

A further survey of neoplasms in abattoir sheep

The ultimate pH of the longissimus muscle was measured in 1536 lambs routinely slaughtered at a meat export works in the southern part of the North Island during the 1981/82 season. The mean ultimate pH of ail samples was 5.60, and 7.2 percent of the carcases had values equal to, or above, 6.00 whereas 85.3 percent of carcases had values below 5.80 which is considered to be optimal. The ultimate pH values of samples from lambs slaughtered during the summer period was significantly higher than those obtained during three other seasonal sampling periods and Perendale lambs had significantly higher ultimate pH values as compared to Iambs of other breeds. There was no statistical association between distance travelled before slaughter and the ultimate pH of carcases but there was a highly significant direct correlation between holding periods of lambs in the stockyards and ultimate pH of their meat. There was also a highly significant inverse correlation between fleece weight and ultimate pH and it is suggested that both this effect and the seasonal pattern of ultimate pH values indirectly reflect the major role that nutrition may play in the development of high ultimate pH meat in lambs. It is further suggested that washing of animals prior to slaughter and the length of subsequent resting periods are important factors in relation to the development of undesirably high ultimate pH values.     

Observations on Cysticercus bovis in slaughter cattle in the Matabeleland province of Zimbabwe

Cysticercus bovis was detected at meat inspection in 2.16 per cent of 102,087 carcases of cattle from Matabeleland Province, slaughtered in Bulawayo during a period of 11 months. Lightly infested (detained) carcases accounted for 95 per cent of those with cysticercosis. The head was the only site affected in 58.4 per cent of the detained carcases, the shoulder in 20.1 per cent and the heart in 7.9 per cent. In more heavily infested (condemned) carcases 81.1 per cent had at least three sites affected. The incidence of cysts was highest in older male animals but in younger animals it was highest in cows. In the detained carcases an average of 1.5 cysts were found, of which 76 per cent were live and 24 per cent dead. Condemned carcases had more than 58 cysts on average, of which 98 per cent were live and 2 per cent dead. Live cysts were more common in older cattle and dead cysts were more common in younger animals. The incidence of C bovis in carcases of cattle originating from communal areas was 3.2 per cent compared with 1.6 per cent in those originating from commercial farms.     

Experimental Pathological Study of Acute African Swine Fever

To study the clinicopathology and histopathology of African swine fever (ASF), and to explore the internal relationship between pathological changes and disease occurrence and development and its pathological mechanism, 13 Landrace pigs with bodyweight about 20 kg were intramuscular injected with African swine fever virus (ASFV), strain Pig/HLJ/18 at a dose of 10²HAD₅₀·mL^-1. During the experiment, all the dead pigs were systematically dissected and sampled, paraffin sections were produced, and haematoxylin-eosin staining was performed. Clinicopathological evaluation standards for acute ASF were established, then pathological lesions (classification variables) were expressed by counting frequency and percentage, and the lesion degree (continuous variables) was graded and scored according to different pathological changes of various tissues and organs. The results showed that all infected pigs were in line with the clinical characteristics of ASF, including acute, febrile and highly infectious, with a 100% incidence rate and 100% mortality. The dead pigs showed typical characteristics of septicemia, cadavers prone to corruption, blood clotting adverse or hemolysis, rigor mortis incomplete. The main pathological lesions were hemorrhagic necrotizing lymphadenitis, acute inflammatory splenomegaly (septic spleen), cerebral edema, pulmonary edema and lung consolidation et al. The spleen and lymphonodus are the target organs attacked by ASFV, with the most significant lesions, the earliest occurrence time, the longest duration and the highest frequency. The most prominent pathological changes are blood circulation disorders, including multiple pathological manifestations such as edema, hyperemia, congestion, hemorrhage, infarction, disseminated intravascular coagulation (DIC), and the most important characteristics are hemorrhagic lesions. The inflammatory reaction of lymphocytic exudation caused by ASFV runs through the whole process, especially in the middle and later stages of the course. The results suggest that the main pathological process of acute African swine fever is a typical immune/inflammatory cascade reaction and severe systemic blood circulation disorder, which resulted in the high incidence rate and high mortality rate of acute ASF.     

急性非洲猪瘟的实验病理学研究

旨在通过对非洲猪瘟临床病理学和组织病理学的研究,探讨病理学变化与疾病发生发展的内在关系及其病理机制。选用体重20 kg左右的长白猪13头,肌内注射非洲猪瘟病毒毒株Pig/HLJ/18,剂量10²HAD₅₀·mL^-1。试验期间的死亡猪,全部进行系统剖检和取材,制备石蜡切片,苏木素伊红染色。建立病理学评价标准,病变（无序分类变量）用频率和百分比表示,病变程度（有序分类变量）按各组织器官的不同病变进行分级和评分。结果表明,发病猪符合非洲猪瘟急性、热性、高传染性等临床特征,发病率100%,病死率100%。病死猪表现败血症典型特征,尸体易腐败,血凝不良或溶血,尸僵不全。主要病理损伤为出血性坏死性淋巴结炎、急性炎性脾肿（败血脾）、脑水肿、肺水肿和肺实变等。脾和淋巴结是非洲猪瘟病毒攻击的靶器官,病变最为显著,出现时间最早,持续时间最长,发生频率最高。病理变化以血液循环障碍尤为突出,包括水肿、充血、淤血、出血、梗死和弥散性血管内凝血等多种病理表现,出血性病变为其最主要的特征。非洲猪瘟病毒引发的以淋巴细胞渗出为主的炎症反应贯穿始终,在病程的中后期表现更为明显。结果提示,急性非洲猪瘟的主要病理过程为典型的免疫/炎症级联反应和严重的全身血液循环障碍,共同导致急性非洲猪瘟的高发病率和高死亡率。     

Prevalence of pleurisy in pigs at slaughter

The mean (+/- sd) batch prevalence of pleura stripping of finished pigs going for slaughter in four abattoirs in eastern England was 0.15 +/- 0.04, and the average batch proportion of lungs totally condemned was 0.23 +/- 0.05. There was a significant positive correlation between the number of carcases requiring total lung condemnation and the number of carcases requiring pleura stripping. There was no significant differences between the type of producer, the herd size or the mean batch live weight and the prevalence of pleurisy, either within individual abattoirs or combining the data from the four abattoirs. There was considerable variation in the batch prevalence of pleurisy from the same producer, indicating the need to monitor a number of batches in order to determine the prevalence of pleurisy on a farm.     

Detection of high serological prevalence and comparison of different tests for Salmonella in pigs in Northern Ireland

Thirty-one farrow-to-finish pig units with a Zoonoses National Control Programme (ZNCP) for Salmonella above the UK target of 10 per cent during the previous 12 months were selected for the study. Pooled faecal samples were collected from different groups of pigs. Furthermore, mice, rat and bird faeces and carcases were collected, if found on the unit. In total, 937 samples were collected on-farm and analysed for Salmonella. The four carcases selected monthly per producer by the slaughterhouse for the British Pig Executive ZNCP Salmonella Programme were tested for antibodies to groups B and C with a mix-ELISA test. The same four carcases were swabbed externally and internally, mesenteric lymph nodes (MLNs) were collected and colonic contents were swabbed. A wide variety of Salmonella serovars was isolated from the samples. Most of the isolates were detected in the rearing herd (on-farm) and in the MLNs (slaughterhouse). There was no correlation between ELISA results from the meat juice and bacteriological isolations using Spearman correlation analyses. Furthermore, no significant association was found between positive results of ELISA and positive results from the bacteriological samples taken.