Influence of porcine circovirus type 2 vaccination on the level of antimicrobial consumption on 65 Austrian pig farms.

The administration of antibiotics to farm animals is an important contemporary topic. Veterinarians, pig producers, politicians, retailers and consumers all have a vested interest in reducing antimicrobial use on farm, while ensuring adequate health and welfare of food-producing animals. Vaccination programmes may be used to reduce the overall level of clinical disease in a population, subsequently leading to a decline in antimicrobial use. In 2008, a vaccination programme against porcine circovirus type 2 (PCV-2) was initiated in Austria. In the retrospective observational study presented here, farm medication records (2008-2011) from 65 conventional pig farms were evaluated. As PCV-2 has been shown to lead to generalised immunosuppression, enabling secondary bacterial infections to occur, the authors hypothesised that PCV-2 vaccination would decrease antimicrobial consumption at farm level. Firstly, we focused on the annual antimicrobial consumption expressed as the number of administered animal daily doses per kg liveweight (nADDkg/kg/year). Secondly, a linear mixed effects model was applied to evaluate the influence of PCV-2 vaccination on the antimicrobial consumption at farm level. The interaction between farm type and PCV-2 vaccination was found to be a highly significant factor (P=0.0002) influencing antimicrobial use at farm level. The estimated impact of PCV-2 vaccination revealed a highly significant (P<0.001) decline in total antimicrobial drug use from 1.72 ADDkg/kg/year to 0.56 ADDkg/kg/year on finishing farms, whereas only a negligible decline was detectable on farrow-to-finish farms.

Economic comparison of the monitoring programmes for bluetongue vectors in Austria and Switzerland.

With the bluetongue virus serotype 8 (BTV-8) outbreak in 2006, vector monitoring programmes (according to EU regulation 1266/2007) were implemented by European countries to obtain information on the spatial distribution of vectors and the vector-free period. This study investigates the vector monitoring programmes in Austria and Switzerland by performing a retrospective cost analysis for the period 2006-2010. Two types of costs were distinguished: costs financed directly via the national bluetongue programmes and costs contributed in-kind by the responsible institutions and agricultural holdings. The total net costs of the monitoring programme in Austria amounted to €1,415,000, whereby in Switzerland the costs were valued at €94,000. Both countries followed the legislation complying with requirements, but differed in regard to sampling frequency, number of trap sites and sampling strategy. Furthermore, the surface area of Austria is twice the area of Switzerland although the number of ruminants is almost the same in both countries. Thus, for comparison, the costs were normalised with regard to the sampling frequency and the number of trap sites. Resulting costs per trap sample comprised €164 for Austria and €48 for Switzerland. In both countries, around 50 per cent of the total costs can be attributed to payments in-kind. The benefit of this study is twofold: first, veterinary authorities may use the results to improve the economic efficiency of future vector monitoring programmes. Second, the analysis of the payment in-kind contribution is of great importance to public authorities as it makes the available resources visible and demonstrates how they have been used.

[Correlation between antibodies against porcine reproductive and respiratory syndrome virus and pathological-anatomical organ findings in slaughter pigs at farm level]. / Zusammenhang zwischen dem Betriebsstatus für das Virus des Porzinen Reproduktiven und Respiratorischen Syndroms und Organbefunden an Schlachtkörpern.

OBJECTIVE: The porcine reproductive and respiratory syndrome (PRRS) worldwide causes important economic losses in pig production. Its causative agent, the PRRS virus (PRRSV), is one of the most frequently detected infectious agents in relation to respiratory diseases in pigs in Austria. We investigated the correlation between the PRRSV status of pig farms, determined by detection of PRRSV antibodies in the serum of slaughter pigs, and the prevalence of pathological-anatomical lung lesions in slaughter pigs of the respective farms. MATERIAL AND METHODS: Between December 1, 2011 and April 16, 2012, a total of 1056 serum samples of slaughter pigs from 66 pig farms were collected at an Austrian abattoir. The presence of PRRSV antibodies was tested by enzyme-linked immunosorbent assay in each sample and the PRRSV status of the respective farms was determined. No PRRSV vaccination was performed on any of the farms. In addition, the pathological-anatomical lung lesions of all slaughter pigs of the 66 farms that were slaughtered between September 1, 2011 and December 11, 2012 were recorded by authorized veterinarians at the abattoir. The prevalence of lung lesions and pleuritis in PRRSV-positive and unsuspected farms was compared and statistically interpreted. RESULTS: Slaughter pigs of PRRSV positive farms had a significantly higher prevalence of severe lung lesions and pleuritis visceralis and parietalis than slaughter pigs of PRRSV unsuspected farms. Pigs of combined farms (nursery and fattening unit at the same location) displayed a tendency for more moderate and severe lung lesions than pigs of exclusive fattening farms. CONCLUSIONS AND CLINICAL RELEVANCE: In the present study, the PRRSV status of pig farms displayed a significant influence on the prevalence of lung lesions in the slaughter pigs. Findings untypical for PRRS, including pleuritis, were also found significantly more often on those farms. This leads to the conclusion that other primary and/or secondary infections are involved, which can be exacerbated by the immunosuppressive effect of the PRRSV. There was a tendency for combined farms to be more severely affected than fattening farms.

Influence of porcine circovirus type 2 vaccination on the probability and severity of pneumonia detected postmortem.

To evaluate the influence of porcine circovirus type 2 vaccination (PCV-2) on the probability and severity of pneumonia, postmortem findings of 247,505 pigs slaughtered between 2008 and 2011 were analysed by applying a cumulative link mixed model. Three major effects could be observed: (1) PCV-2 vaccination significantly (P<0.01) reduced the odds (coefficient: -0.05) of postmortem findings of mild, moderate and severe pneumonia for vaccinated pigs. (2) Pigs from fattening farms were less likely (coefficient: -0.44; P<0.05) to exhibit signs of pneumonia at slaughter than pigs from farrow-to-finish farms. (3) When vaccinated, the odds of detecting postmortem signs showed an even more pronounced reduction (coefficient: -0.19; P<0.001) for pigs from fattening farms. Combining PCV-2 vaccination, farm type and interaction effects between these two factors, a pig vaccinated against PCV-2 from a fattening farm had only half the chance (OR 0.51) of pneumonia being detected at postmortem than a non-vaccinated pig from a farrow-to-finish farm. The study demonstrates the benefit of a vaccination programme against PCV-2 as an important tool to reduce the risk of postmortem pneumonia findings and the severity of pneumonia in pigs at slaughter.

Comparison of different commercial serological tests for the detection of Toxoplasma gondii antibodies in serum of naturally exposed pigs.

Toxoplasma gondii is the aetiological agent of the zoonotic disease toxoplasmosis and transmitted among other ways by chemically and physically untreated, that is, raw pork to humans. The detection of Toxoplasma gondii is impossible by currently practiced meat inspection, but serological tests can be used to detect Toxoplasma gondii antibodies in pig herds and can consequently be helpful to identify potentially contaminated pork. Therefore, appropriate serological tests are required. In this study, serum samples of 1368 naturally exposed slaughter pigs from 73 Austrian farms were collected. Serum samples of at least 16 slaughter pigs per farm were tested. The prevalence of Toxoplasma gondii antibodies in serum was measured by a commercial available modified agglutination test (MAT) and compared to three different commercial available enzyme-linked immunosorbent assays (ELISA). The MAT detected 6.5%, ELISA I 6.7%, ELISA II 4.8% and ELISA III 4.3% of the pigs as Toxoplasma gondii antibody positive. The agreement, according to the kappa coefficient (κ), was substantial between the MAT and ELISA I (κ = 0.62), II (κ = 0.64) and III (κ = 0.67). A better agreement was determined between ELISA I and II (κ = 0.715), ELISA I and III (κ = 0.747) and ELISA II and III (κ = 0.865). At least one pig per farm was detected Toxoplasma gondii antibody positive in 17 (23.3%) farms by the MAT, 26 (35.6%) farms by ELISA I, 16 (21.9%) farms by ELISA II and 11 (15.1%) farms by ELISA III. Pig farms with a high number of Toxoplasma gondii antibody-positive pigs or high antibody titres were identified by all of the four used serological tests. Concerning the occurrence of Toxoplasma gondii antibodies in Austrian pig farms, a monitoring and surveillance programme would be reasonable to find high-risk farms.

Antimicrobial drug use in Austrian pig farms: plausibility check of electronic on-farm records and estimation of consumption.

Electronic drug application records from farmers from 75 conventional pig farms were revised and checked for their plausibility. The registered drug amounts were verified by comparing the farmers' records with veterinarians' dispensary records. The antimicrobial consumption was evaluated from 2008 to 2011 and expressed in weight of active substance(s), number of used daily doses (nUDD), number of animal daily doses (nADD) and number of product-related daily doses (nPrDD). All results were referred to one year and animal bodyweight (kg biomass). The data plausibility proof revealed about 14 per cent of unrealistic drug amount entries in the farmers' records. The annual antimicrobial consumption was 33.9 mg/kg/year, 4.9 UDDkg/kg/year, 1.9 ADDkg/kg/year and 2.5 PrDDkg/kg/year (average). Most of the antimicrobials were applied orally (86 per cent) and at group-level. Main therapy indications were metaphylactic/prophylactic measures (farrow-to-finish and fattening farms) or digestive tract diseases (breeding farms). The proportion of the 'highest priority critically important antimicrobials' was low (12 per cent). After determination of a threshold value, farms with a high antimicrobial use could be detected. Statistical tests showed that the veterinarian had an influence on the dosage, the therapy indication and the active substance. Orally administered antimicrobials were mostly underdosed, parenterally administered antimicrobials rather correctly or overdosed.

Analysis of the variation in meat inspection of pigs using variance partitioning.

According to legal regulations, all slaughtered pigs in the European Union are subject to routine meat inspection at the slaughterhouses. The resulting post-mortem findings are valuable indicators that help improve slaughterhouse and farm management and can be used to establish a feedback system regarding animal health. A sufficiently high quality of meat inspection is therefore imperative, which implies that the results of the inspection must not depend on the person carrying out the examination. The objective of the study at hand is the estimation of the amount of variation in these post-mortem findings that can be attributed to the official meat inspectors. In order to reduce the influence of the heterogeneity in the health state of the pigs, the variation due to the farms of origin was considered in the statistical model as well. The analyzed meat inspection data were recorded by 12 official meat inspectors under real working conditions at an Austrian slaughterhouse. Logistic Multilevel Models with cross-classified random effects were applied to 20 post-mortem findings. On the basis of these models, variance partitioning coefficients (VPCs) were used to estimate the amount of variation in the probabilities of these findings due to meat inspector and farm levels. The estimated VPCs suggest that especially meat inspection of blood aspiration, scalding water lungs, skin lesions and hepatitis can be deemed as not sufficiently standardized. Hardly any variation in meat inspection could be identified for other post-mortem findings, such as pericarditis, peritonitis, arthritis and milkspots.

Rapid monitoring of Campylobacter in high-shedding flocks for targeted disease control.

Broilers excreting Campylobacter spp. at high levels (>7 log CFU/g of feces) were described in the Dutch Campylobacter Risk Management and Assessment project as an important source of carcass contamination. The researchers concluded that the risk of infection to humans could be economically and efficiently minimized by eliminating these flocks from fresh poultry meat chains. In the present study, we evaluated a simple and rapid gold-labeled immunosorbent assay (GLISA) for the identification of Campylobacter spp. in flocks shedding high levels of the pathogen. Results were obtained within 2 h. Pooled samples from 102 of the 114 Campylobacter-positive flocks produced positive results, resulting in a test sensitivity of 89.5% (95% confidence interval, 82.6 to 94.2%) and a test specificity of 94.5% (86.7 to 98.2%). Given a GLISA detection limit of 7.3 log CFU/g of feces, nearly all Campylobacter-positive flocks were identified as "high shedders." Therefore, reduction of the incidence of Campylobacter infections by elimination of high-shedding flocks from fresh meat production is an unrealistic approach. Under the constraints given, a reduction in the incidence of Campylobacter spp. in Austria will require either improved hygiene or an intensive carcass decontamination strategy in fresh meat production facilities.

Clostridium difficile in raw products of animal origin.

Prevalence of Clostridium difficile was examined in Austrian ground meat samples and bactofugates, following an evaluation of enrichment broths. Bactofugation is a centrifugation procedure used at sensitive dairies to lower the concentration of spores in raw milk before heat treatment. Among the five enrichment broths tested, C. difficile moxalactam norfloxacin boullion (CDMN) was the only one that allowed recovery of C. difficile from artificially spiked meat samples. Use of Tween 80 as a detergent in the enrichment of artificially contaminated bactofugates improved recovery of C. difficile. Following the enrichment procedures (meat without the use of TWEEN 80), one hundred ground meat samples and fifty bactofugates were enriched for 10-15days in CDMN and presumed positive colonies were isolated and identified by Gram staining, observation of colony fluorescence and ID 32 A ribotyping. Subsequently PCR ribotyping, PCR-based identification of toxin genes (tcdA, tcdB) and antimicrobial drug susceptibility testing to metronidazole, vancomycin, clindamycin and moxifloxacin were performed. C. difficile was isolated from three (3%) of the one hundred retail ground meat samples. Two C. difficile isolates of the same rare ribotype AI-57 were toxin gene-negative and sensitive to all antibiotics tested. One isolate was assignable to one of the most prevalent clinical ribotypes isolated in Austria and harboured the tcdA and tcdB genes. This isolate was also resistant to clindamycin and moxifloxacin. None of the fifty bactofugates tested were positive for C. difficile. The presence of an isolate of human origin could indicate contamination by human shedders during food processing rather than evidencing zoonotic potential. Bactofugates, although constituting concentrated spore suspensions, were not contaminated with C. difficile spores. This finding excludes raw milk as a major source of food contamination. In conclusion, C. difficile recovery rates found in our study were lower than expected from the literature. Sources other than zoonotic origin must be considered when studying the epidemiology of community acquired infections with this bacterium.

Easy-to-use rapid test for direct detection of Campylobacter spp. in chicken feces.

Human campylobacteriosis is the leading cause of acute bacterial gastroenteritis in developed countries. One important source of infection is poultry. Results from the Dutch Campylobacter Risk Management and Assessment project indicate that meat from broiler flocks shedding >or=7 log CFU Campylobacter per g of feces poses the greatest risk of transmitting campylobacteriosis. The objective of this study was to develop a simple and rapid test that would identify chicken flocks shedding high numbers of Campylobacter. We used lateral flow technology as the alternative test method, and selected the culture method according to International Organization for Standardization guidelines. To evaluate the test under field conditions, we sampled either chicken droppings at farms or cecal contents at the slaughterhouse. PCR was used to confirm presumptive Campylobacter spp. colonies. Under laboratory conditions, chicken feces containing >or=6.7 log CFU/g Campylobacter jejuni or >or=7.1 log CFU/g Campylobacter coli were identified by the lateral flow test. Overall, 3 (33%) of 10, and 29 (85%) of 34 C. jejuni- or C. coli-positive chicken flocks were identified at farms and slaughterhouses, respectively, by using the lateral flow test. Fecal samples containing >or=7.3 log of C. jejuni or C. coli CFU/g as determined by plating were always positive when using the lateral flow test. A single person testing seven flocks at a time could obtain test results within 2 h of sampling. This simple and rapid lateral flow test may contribute significantly to the identification of chicken flocks shedding high numbers of Campylobacter.

The Styrian Salmonella Monitoring Programme for pork production.

The Styrian Salmonella Monitoring Programme for pork production is based on a representative analysis of the current status, serological meat juice monitoring and bacteriological tests of carcass halves and parts and has been in operation since 1999. A total of 34 170 meat juice samples from 3417 finisher herds were tested using the meat juice SALMOTYPE-ELISA (Labor Diagnostik, Leipzig, Germany) in the period from 1999 to 2003. More than 95% of the samples investigated were below the negative cut-off of <20% based on the 5-year average. The mean extinction values for meat juice samples showed regional differences, which were visualized for epidemiological purposes using the VETGIS geographical information system (Department of Veterinary Administration, Graz, Austria). Salmonella spp. were detected in only 15 cases (0.13%) of a total of 11 330 bacteriologically tested wipe samples from meat-processing plants. The Salmonella isolates detected included four S. Typhimurium, two S. Enteritidis PT 4, five S. Infantis, one S. Bredeny, one S. Saintpaul, one S. Brenderup and one S. Livingstone isolates. The proportion of Salmonella-contaminated pork in the total population estimated from the annual sample showed a falling tendency. It decreased from 0.48% (CI: 0.23 < or = P < or = 0.85) in 1999 to 0.14% (CI: 0.07 < or = P < or = 0.24) in 2003. The contamination of Styrian pork with Salmonella is extremely low and thus poses a negligible risk of infection to consumers.

Campylobacter jejuni isolated from poultry and humans in Styria, Austria: epidemiology and ciprofloxacin resistance.

Sixty-six broiler flocks were sampled to determine the presence of Campylobacter spp. at slaughter in 1998. Thirty flocks (45%) tested positive and C. jejuni was identified in all isolates. Combined pulsed-field gel electrophoresis/amplified fragment length polymorphism (PFGE/AFLP) subtyping of 177 isolates from 24 positive flocks revealed 62 subtypes; 16 flocks harboured more than one subtype. When subtyping 101 clinical C. jejuni isolates collected in the same time period and area, 60 PFGE/AFLP types were identified. Comparison of subtypes from poultry and human isolates revealed three shared PFGE/AFLP types, which were present in 11 human isolates. Fifty per cent of all poultry isolates and 39% of all human isolates were resistant to ciprofloxacin. The present study confirms the increase in ciprofloxacin resistance in both human and poultry C. jejuni isolates in Austria, as observed in several countries worldwide. A small number of human isolates shared PFGE/AFLP types with poultry isolates, however, further studies should also focus on the identification of other sources of C. jejuni infection in humans.

[Influence of diagnostic tests for estimating prevalence during surveillance programs]. / Einfluss diagnostischer Tests auf die Ergebnisse von Prävalenzschätzungen im Rahmen von Surveillance-Programmen.

The influence of diagnostic tests on the estimation of the prevalence and the calculation of sample sizes with respect to different sampling schemes are presented in this paper. These sampling schemes are used for the implementation of surveillance programs. Assuming "perfect tests" (i.e. sensitivity = specificity = 100%) the calculated sample sizes, e.g. for an IBR/IPV-surveillance or a paratuberculosis survey, are half of the sample sizes considering sensitivity and specificity of the diagnostic tests. However the probability not to identify infected livestocks may be 4 times higher neglecting the test characteristics and assuming perfect tests.

[Fetal nucleated erythrocytes in the peripheral circulation of pregnant women as a noninvasive method of fetal sex determination]. / Fetální jaderné erytrocyty cirkulující v periferii gravidních zen jako neinvazivní zdroj detekce pohlaví fetu.

OBJECTIVE: Determination of the sex of the foetus from enriched nuclear red blood cells (NRBC) circulating in maternal blood during pregnancy. METHODS: NRBC were enriched from 13-28 ml peripheral blood of 32 pregnant women using double MACS procedure. NRBCs were enriched by magnetic activated cell sorting using anti-CD71 (transferrin receptor) monoclonal antibodies. Unwanted leukocytes were depleted using monoclonal antibodies against CD14 and CD45. The sex of the foetus was analysed by using dual-colour FISH with X and Y specific probes. The experimental results obtained from the noninvasive procedure were compared to karyotype obtained from amniocentesis or chorionic villus sampling. RESULTS: In 15 out of 17 male foetuses we could identify one X and one Y signal. In another 15 pregnant women carrying female foetuses two X signals were observed. CONCLUSION: NRBC circulating in blood of pregnant women can be used as an alternative source for determination of the sex of the foetus with a risk of false negative results (2/17, 12%). The problem of false negative results can be solved by using more sophisticated methods of enrichment and preparedness of the slides for FISH analysis.

[Levels of peripheral circulating nucleated erythrocytes in pregnant women for noninvasive prenatal diagnosis]. / Koncentrace fetálních jaderných erytrocytu cirkulujících v periferii gravidních zen pro úcely neinvazivní prenatální diagnostiky.

OBJECTIVE: Enrichment of nucleated red blood cells (NRBCs) from maternal blood for non-invasive prenatal diagnosis. DESIGN: Pilot study. SETTING: 2nd Clinic of Paediatrics, University Hospital Motol, Prague, Czech Republic. METHODS: Mononuclear cells were isolated from 13-28 ml of peripheral maternal blood between 13 and 37 weeks of gestation. Leukocytes from maternal peripheral blood were depleted from mononuclear cells by treatment with anti-CD14 and anti-CD45 microbeads and high-gradient magnetic cell separation (MACS) on VarioMACS. NRBCs were sorted from CD14-/CD45- fraction by positive selection using anti-CD71 microbeads on MiniMACS. All sorting steps were analysed by three-colour cytometric analysis with FACScan flow cytometer. RESULTS: In 68 out of 78 pregnant woman (87%) NRBCs were found in range 2 x 10(5) - 1.02 x 10(6). NRBC were enriched with an average enrichment rate of 138-fold ranging from 4-526 fold. In our cohort of pregnant woman the number of isolated NRBCs was individual. We identified NRBCs from the 13th week of gestation. CONCLUSION: The aim of the study is to establish and standardise the method of enrichment of NRBCs from maternal blood samples and verify the applicability of this alternative source for non-invasive prenatal diagnosis.

[Small game (foxes, brown hares, pheasants and ducks) as carriers of zoonoses]. / Niederwild (Fuchs, Feldhase, Fasan und Ente) als Träger von Zoonose-Erregern.

Small game involves numerous infection hazards in terms of contact zoonoses and foodborne diseases. Especially exposed are hunters, game dealers, veterinarians, housewives, farmers, forest workers, laboratory staff, and taxidermists, but also consumers of insufficiently cooked game. This paper gives a survey of the most significant zoonoses in small game in Europe, which are discussed in the light of the author's own research results in this field. Finally, measures concerning prophylaxis and food hygiene are suggested.

[Swine and wild pigs as carriers of zoonoses]. / Schwein und Wildschwein als Träger von Zoonosen.

This paper deals with zoonoses in European pig herds and wild boars in general and in particular with the risk of infection carried by veterinarians, farmers and workers handling pigs and pork in slaughterhouses and meat processing companies. Furthermore the risk of infection and intoxication as a result of pork consumption is discussed. Special reference is made to the responsibility of veterinarians for keeping production animals healthy and informing animal owners and consumers about zoonoses. It would appear that it will be necessary in future to intensify veterinarian herd care, perform regional monitoring and surveillance programmes, participate in establishing specific pathogen-free herds and to foster diagnosis and research into zoonoses together with human medicine.

BHV-1 infections in Styria (Austria) caused by intra-community trade.

The present paper describes the prevalence of BHV-1 (bovine herpes virus 1) infections in the Austrian province of Styria from 1990 to 1997 and the corresponding eradication programme. Based on the description of BHV-1 infections on seven holdings caused by intra-Community trade, the additional guarantees granted under Directive 64/432/EEC (CEC, 1964) are discussed and measures for improved protection of BHV-1-free regions suggested.

[Comparison of two castration methods in cattle: plasma cortisol levels, leukocyte count and behavioral changes]. / Vergleich zweier Kastrationsmethoden beim Rind: Plasmakortisolkonzentrationen, Leukozytenzahlen und Verhaltensänderungen.

Two methods of castration (surgical and Burdizzo method) of male calves were compared by measuring plasma cortisol concentrations. Increased plasma cortisol values were found only during the first three hours after castration. There were no significant differences in plasma cortisol values and changes of behaviour between groups of surgical and Burdizzo castrated calves. Plasma cortisol values did not decrease during the first days after castration. The results suggest, that surgical and Burdizzo-castration do not differ in regard to pain.

[The effect of husbandry, management and stall climate on lung changes in swine]. / Der Einfluss von Haltung, Management und Stallklima auf die Lungenveränderungen bei Schweinen.

21 swine fattening units (17 closed and 4 open swine herds), their pigs suffering from chronic respiratory disease since a long time were investigated concerning fattening period, morbidity, mortality, lung lesions by slaughtered swine, microorganisms involved, husbandry and management conditions, stall climate (indoor temperature, relative air humidity, contents of NH3, CO2, H2S, air microorganisms and dust). We estimated annual fattening periods of 137.4 +/- 6.8 days, morbidity of 49.1 +/- 12.2% and mortality of 6.8 +/- 3.7%. About 55-96% of lungs of slaughtered pigs showed pneumonic lesions in different degrees. Bacteriological examination of such lesions revealed up to 9 and not less than 3 different bacteria species per unit. Continuous producing systems were used by 19 units, only 2 units were managed by all in all out system. Pigs of 70 kg weight have air spaces of 1.7-3.1 m3, indoor temperature were between 21-26 C degrees and relative air humidity between 83.9 +/- 13.7%. Concentration of NH3 was found between 3-35 ppm, of CO2 between 500-3500 ppm, the numerical content of bacteria was within 900-1620 cfu (colony forming units) and of fungi between 2-80 cfu per litre air. There were also E. coli with and without haemolysis, Klebsiella pneumoniae, beta-haemolyzing streptococci and staphylococci in stall air. 2 swine houses gave 3-5, 15 houses 12-50 and 4 houses more than 50 cfu/cm2 blood agar plates exposed for 1 minute to the stable air (sedimentation method to judge stall dust). Animals of the later mentioned 4 houses showed the highest incidence of respiratory disorders (> 50% of pigs).(ABSTRACT TRUNCATED AT 250 WORDS)