Toxoplasma gondii infection in slaughter pigs in Serbia: seroprevalence and demonstration of parasites in blood

ABSTRACT: A seroepizootiological study of Toxoplasma gondii infection involving a total of 488 slaughter pigs (468 market-weight pigs and 20 sows) in the Belgrade area, also included examination of the presence of T. gondii in the blood. Blood sampled at the slaughter line was examined for specific antibodies by modified direct agglutination, and blood clots of those seropositive at titres of 1:50-1:12800 were bioassayed in mice. The overall seroprevalence was 9.2%, significantly higher (p = 0.0063) in sows (30.0%) than in market-weight pigs (8.3%). Amongst the 22 bioassays performed, a total of 16 (72.7%) were positive, by observation of T. gondii cysts (12), seropositivity (7, including 3 in which cysts were not detected), and/or detection of T. gondii DNA by real-time PCR (12, including one otherwise negative). The positive bioassays originated from the blood of 12 market-weight pigs and 4 sows. Despite a general increase in the rate of demonstration of T. gondii with the increase in the specific antibody level, the association was not significant (p = 0.101). The risk of infection was 41-fold increased in sows vs market-weight pigs, and 15-fold in pigs from smallholders' finishing type farms vs those from large farrow-to-finish farms. The presence of viable T. gondii in a proportion of the samples indicates that some of the pigs had an active parasitaemia at the time of slaughter, which, along with the seroprevalence established, points to a potential source of human infection in Serbia. This is the first report on parasitaemia in naturally infected swine.     

The electric stunning of pigs for slaughter

Electrical stunning is the most common stunning method in the FRG. Beside manual stunning with tongs (70-250 V) there are also automatic high-voltage stunning devices (400-1000 V) in use. In the FRG the maximally allowed stunning voltage is 250 V for manual working apparatus. Electrical stunning is acceptable from the animal point of view, if a minimal current of 1.2 ampere is reached, immediately after the beginning of the stunning operation. This current provokes an epileptic insult combined with unconsciousness. Immobilisation combined with stiffness can be reached with lower currents. The current, flowing during stunning operation, depends on both stunning voltage and resistance between electrodes and surface of the animal. Current curves were recorded during manual stunning operations with different kinds of tong and different voltages. It was found, that a stunning voltage lower than 250 V under practise conditions is not acceptable from the animal point of view, because 1.2 ampere were not reached within 1 second. Electrical stunning with 250 V is acceptable, when an exact positioning of the tongs is possible because of a short fixation of the pig. The following demands can be formulated for an effective electrical stunning of pigs: 1. pigs should be wet prior to stunning. 2. positioning of the tongs must be done in such a way that the brain lies on the shortest line between the two electrodes. 3. between electrodes and pig surface should be an intensive contact. 4. stunning voltage should be at least 250 V, better higher. 5. bleeding should be done not later than 20 seconds after the end of the stunning, the time between bleeding and scalding being at least 3 minutes.     

Ochratoxin A in blood of slaughter pigs

The global ochratoxin A contamination of Swedish feed cereals was studied by analysis of pig blood samples from 122 different herds. The samples were collected at seven Swedish slaughterhouses. The ochratoxin A analysis showed 21% of the samples to contain greater than or equal to 2 ng ochratoxin A per ml. Samples from Visby showed a significantly higher frequency of contamination compared with the rest of the country.     

Osteochondrosis in six breeds of slaughter pigs

Summary

The severity and extent of osteochondral lesions have been examined, macroscopically, radiographically as well as histopathologically, in six different breeds of pigs (Belgian Landrace (B), Duroc (D), Dutch Landrace (N), Dutch Yorkshire (G), Hampshire (H) and Piétrain (P)). In these pigs three different levels of feeding were used.

Duroc pigs had significantly more severe lesions in the fore limbs than Dutch Landrace (N), Dutch Yorkshire (G), Hampshire (H) and Piétrain (P) pigs, while Belgian Landrace pigs (B) had significant more severe lesions than Dutch Yorkshire (G) pigs. The differences between breeds related more to the degree of severity of the lesions in the articular surfaces of the distal humerus and proximal radius‐ulna and in the distal ulnar growth plate than to the presence of the lesions per se. In the hind limbs Belgian Landrace pigs (B) had significantly more severe osteochondral lesions than all other breeds, while Dutch Landrace pigs (N) had significantly more severe lesions than Duroc (D), Dutch Yorkshire (G), Hampshire (H) and Piétran (P) pigs.

Pigs with the highest growth rate showed sginificantly more severe osteochondral lesions in the distal ulnar growth plate and in the medial fe,moral condyle than pigs with a more restricted growth rate.     

Osteochondrosis in six breeds of slaughter pigs

Summary The severity and extent of osteochondral lesions have been examined, macroscopically, radiographically as well as histopathologically, in six different breeds of pigs (Belgian Landrace (B), Duroc (D), Dutch Landrace (N), Dutch Yorkshire (G), Hampshire (H) and Piétrain (P)). In these pigs three different levels of feeding were used. Duroc pigs had significantly more severe lesions in the fore limbs than Dutch Landrace (N), Dutch Yorkshire (G), Hampshire (H) and Piétrain (P) pigs, while Belgian Landrace pigs (B) had significant more severe lesions than Dutch Yorkshire (G) pigs. The differences between breeds related more to the degree of severity of the lesions in the articular surfaces of the distal humerus and proximal radius-ulna and in the distal ulnar growth plate than to the presence of the lesions per se. In the hind limbs Belgian Landrace pigs (B) had significantly more severe osteochondral lesions than all other breeds, while Dutch Landrace pigs (N) had significantly more severe lesions than Duroc (D), Dutch Yorkshire (G), Hampshire (H) and Piétran (P) pigs. Pigs with the highest growth rate showed sginificantly more severe osteochondral lesions in the distal ulnar growth plate and in the medial fe,moral condyle than pigs with a more restricted growth rate.     

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.     

A survey of gastrointestinal parasites in pigs of the Plateau and Rivers States, Nigeria

Faecal samples were collected from a total of 1,000 pigs from the Port Harcourt and Jos areas of the Rivers and Plateau States, respectively, between January 1987 and March 1988. In the Jos area the parasite incidence was: Ascaris suum 53.1%, Trichuris suis 8.5%, Hyostrongylus rubidus 13.1%, Metastrongylus salmi 3.7%, Strongyloides ransomi 87.7%, Oesophagostomum dentatum 35.1% and Eimeria spp. 2.4% while in Port Harcourt the incidence rate was Ascaris suum 10.4%, Trichuris suis 47.2%, Oesophagostomum dentatum 50%, Hyostrongylus rubidus 2%, Ancylostoma duodenale 83.2% and Eimeria spp. 3.6%. The high rate of parasitic infections was due to poor management practices as shown by poor sanitary conditions. Access to human faeces, poor feeding and lack of deworming were also very evident. The different rates in the incidence of parasites in Jos and Port Harcourt areas were due to the varying moisture conditions in these states.     

猪的体内寄生虫

猪的生产性能受到体内寄生虫的影响,大多数寄生虫主要生存在幼龄、生长期的猪。体内寄生虫能导致猪死亡,但是,食欲不振、日增重下降、饲料转化效率差和容易感染其它病原体是寄生虫病引发的较常见症状。生产性能影响大多因所在地理区域、猪舍类型、管理方式、营养水平、     

Survey on Salmonella prevalence in slaughter pigs from Saskatchewan

A study on slaughter pigs from Saskatchewan detected Salmonella organisms in 12.5% and 5.2% of cecal content and ileocaecal lymph node samples, respectively. Cecal content prevalence was associated with larger farms and longer lairage periods. Antimicrobial resistance was detected in 41.5% of the isolates. Salmonella Enteritidis was the second most prevalent serotype.     

The prevalence of anti-yersinia outer protein antibodies in Bavarian slaughter pigs

The aim of the present study was to provide current data on the prevalence of anti-Yersinia-antibodies in Bavarian slaughtering pigs. The recomBlot Westernblot assay based on five recombinantly produced Yersinia Outer Proteins (YopD, YopE, YopH, YopM, V-antigen) is well evaluated for the use in the diagnosis of human yersiniosis and proved to be also a valuable tool for the detection of porcine antibodies. 965 out of 1002 meat juice samples collected in 53 Bavarian pig farms contained anti-Yop/V-Ag-antibodies. Only blots with three or more detectable signals were considered as positive. On the basis of these results a possible previous history of Yersinia infection was detected in 45.4% of the pigs and all of the pig farms. The high prevalence of anti-Yersinia-antibodies found in this investigation demonstrates the need for further epidemiological surveillance and animal studies to assess consumers' endangering.     

Residues of azaperone and azaperol in slaughter pigs

An investigation was carried out to determine the residues of azaperone in slaughter pigs and pig meat products. The butyrophenone tranquillizer azaperone is frequently administered to pigs by intramuscular injection in order to reduce mortality and loss of meat quality resulting from transportation from the farm to the slaughter house. In the pig, following administration of azaperone as recommended by the manufacturer (0.4 mg/kg i.m.) residue concentrations of about 0.05 μg/g azaperone, and 0.20 μg/g azaperol (the main biotransformation product in the pig) were found in the kidneys; the kidneys proving to be the sampling organs of choice. Pasteurization and other technological procedures did not influence residues measurably. Toxicological evaluation suggests that the residues found do not per se constitute a danger to public health. None the less, the presence of any drug residue in meat or meat products is undesirable, and alternative, non-pharmacological approaches to the problems arising from transportation prior to slaughter should be considered.     

人道屠宰对猪肉品质的影响

<正>人道屠宰广义上讲就是在动物的运输、装卸、停留待宰以及宰杀过程中,采取合乎动物行为的方式,以尽量减少动物的紧张和恐惧,也就是要善待动物,     

Comparison of serologic testing and slaughter evaluation for assessing the effects of subclinical infection on growth in pigs

OBJECTIVE: To compare serologic testing with slaughter evaluation in assessing effects of subclinical infection on average daily weight gain (ADG) in pigs. DESIGN: Cohort study. ANIMALS: 18 cohorts (30 to 35 pigs/cohort) of pigs on/farms. PROCEDURE: Blood samples were collected, and pigs were weighed at 8, 16, and 24 weeks of age. Sera were tested for antibodies to porcine reproductive and respiratory syndrome virus (PRRSV), swine influenza virus (SIV), transmissible gastroenteritis virus (TGEV), pseudorabies virus, Mycoplasma hyopneumoniae, and Actinobacillus pleuropneumoniae. At slaughter, skin, nasal turbinates, lungs, and liver were examined. Associations between ADG and results of serologic testing and slaughter evaluation were examined by use of multiple linear regression. RESULTS: Pathogens that had a significant effect on any given farm during any given year and the magnitude of that effect varied. However, at 16 and 24 weeks of age, a higher antibody titer was consistently associated with a lower ADG. Mean differences in ADG between seropositive and seronegative pigs were 18 g/d (0.04 lb/d) for SIV, 40 g/d (0.09 lb/d) for PRRSV, 38 g/d (0.08 lb/d) for M hyopneumoniae, and 116 g/d (0.26 lb/d) for TGEV. Of the evaluations performed at slaughter, only detection of lung lesions was consistently associated with a decrease in ADG. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that subclinical infection with any of a variety of pathogens commonly found in swine herds was associated with a decrease in ADG. Serologic testing was more effective than slaughter evaluation in assessing the impact of subclinical infection on ADG in these pigs.     

The prevalence of salmonella infection in sheep at slaughter

The prevalence of subclinical Salmonella infection in sheep at slaughter was monitored at two slaughter-houses in the southern part of the North Island over a 17-month period during 1975 and 1976. The crude prevalence rate was 4.7% (96/2027). Prevalence rates were greatest in the 2 and 4-tooth age group, with maximum monthly rates of 30%and 32% during 1975 and 1976 respectively. The seasonal distribution of infections was similar in each age group, prevalence rates being greatest in March, April and May, and least in October, November and December.

Salmonella typhimurium was found in 78% of the infected sheep, and phage-type 1 caused 72% of these infections. Other serotypes isolated were S. bovis-morbificans, S. derby, S. newingion, S. saintpaul, S. anatutn and S. enieritidis. The organisms were all fully sensitive to nine antibiotics. On the grounds that 87% of the infected sheep had salmonellae in their intestinal lymph nodes, it was deemed likely that most of the infected sheep harboured their infections while still on the farms of origin.