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Respiratory diseases, mostly multifactorial, cause problems in pig farms worldwide. Next to infectious agents, such as Porcine Circovirus Type 2 (PCV2) andIn the first phase, it was shown that the group vaccinated against PCV2 (Group B: SuvaxynVaccination against PCV2 leads to improved animal health and higher daily weight gains.The combined vaccine studied here provides farmers and veterinarians with an additional option for the improvement of animal health in pig production.Atemwegserkrankungen, meist multifaktoriell bedingt, führen weltweit zu Problemen in Schweinepopulationen. Infektiöse Ursachen, wie das Porzine Circovirus Typ 2 (PCV2) undIn einem zweiphasigen Versuch wurden 524 (Phase 1) bzw. 521 (Phase 2) klinisch gesunde Ferkel in der ersten Lebenswoche eingeschlossen. In der ersten Phase wurden Leistungsparameter bei Tieren verglichen, die nur gegenIn der ersten Phase zeigte sich, dass die Gruppe, die die PCV2-Impfung erhalten hatte (Gruppe B: SuvaxynDie Einführung einer Impfung gegen PCV2 führte zu einer verbesserten Tiergesundheit und zu höheren täglichen Zunahmen.Mit dem hier untersuchten Kombinationsimpfstoff steht Landwirten und Tierärzten eine weitere Möglichkeit zur Verbesserung der Tiergesundheit in der Schweinehaltung zur Verfügung.

In breeding farms with a high health status, pigs are frequently sampled using invasive methods (i. e. blood sampling). The aim of the present study was to evaluate less invasive methods concerning their suitability for an early detection of the infection with the porcine reproductive and respiratory syndrome virus (PRRSV).Blood and saliva swabs, chewing rope derived oral fluids and serum samples were used for PRRSV-1 and PRRSV-2 detection via PCR. 19 gilts were repeatedly sampled following intramuscular or intranasal vaccination with live-attenuated vaccines containing PRRSV-1 or -2. Swabs were either moistened with saliva from the mouth mucosa or with blood from the ear veins following superficial needle puncture. Serum samples were taken via puncture of the V. jugularis externa. Chewing ropes served for a means of oral fluid sampling and were kept hanging in the barn at the pigs' head height for 30 minutes.All animals were negative for PRRSV at the time of vaccination (sampling point 0). In serum samples, the first virus detection was achieved 12 hours following vaccination (p. vacc.). From day 4 p. vacc. on all animals were viremic and from day 10 p. vacc. on the percentage of positive animals decreased. The first detection of PRRSV in GenoTubeThis study demonstrates that serum samples taken from the V. jugularis externa may be considered as the gold standard for diagnostic of PRRSV viremia. Detection rates in serum were higher than in the alternative sample types. However, since sample collection procedures and processing of the alternative sample materials offer clear advantages with regard to welfare, practical handling and logistics, further attempts are warranted in order to improve these methods. Based on the presented results, the described method using eSwabIn Zuchtbetrieben mit hohem Gesundheitsniveau werden Schweine häufig mit invasiven Methoden (Blutprobenentnahme) beprobt. Ziel der Untersuchung war die Evaluierung von weniger invasiven Verfahren auf ihre Eignung zur Früherkennung einer Infektion mit dem Virus des Porzinen Reproduktiven und Respiratorischen Syndroms (PRRSV).Blut- und Speicheltupfer sowie Kaustrick- und Serumproben wurden von 19 Jungsauen zu unterschiedlichen Zeitpunkten nach intramuskulärer bzw. intranasaler Impfung mit PRRSV-1 oder -2 mittels PCR untersucht. Die Tupfer wurden mit Speichel von der Maulschleimhaut bzw. nach einem oberflächlichen Nadelstich mit Ohrvenenblut benetzt. Zur Serumgewinnung erfolgte eine Punktion der V. jugularis externa. Die Kaustricke wurden auf Kopfhöhe der Jungsauen für 30 Minuten in die Bucht gehängt.Alle Tiere waren zum Zeitpunkt der Impfung (Beprobungszeitpunkt 0) PRRSV-negativ. Die ersten Virusnachweise gelangen 12 Stunden p. vacc. im Serum. Ab Tag 4 p. vacc. waren alle Tiere virämisch und ab Tag 10 p. vacc. nahm der Anteil der positiven Tiere ab. Die ersten Nachweise im GenoTubeDie Studie zeigt, dass Serumproben aus der V. jugularis externa weiterhin als Goldstandard angesehen werden können, da die Nachweisraten höher liegen als in alternativen Probenmedien. Da Entnahme und Verarbeitung der alternativen Probenmaterialien allerdings deutliche Vorteile bieten, sollte versucht werden, diese Verfahren weiter zu verbessern. Die verwendete Methode mit eSwab

Summary A 2-day-old female piglet was submitted with multiple congenital, nodular skin masses located on the head, neck, trunk and legs. Histopathological examination revealed the presence of nodular, cutaneous tumours with a biphasic growth pattern and comprising a population of undifferentiated, oval or slightly polygonal, frequently perivascularly located cells and a population of spindle-shaped, fibroblast-like cells arranged in bundles. Multifocally, tumour cells infiltrated subcutaneous adipose and muscular tissue. Immunohistochemically, the undifferentiated tumour cells expressed vimentin and calponin, whereas the spindle-shaped tumour cells were positive for vimentin, α-smooth muscle actin and calponin. Based on these findings, the diagnosis was myofibroblastic tumours closely resembling the multicentric form of human infantile myofibromatosis.

Background Porcine Reproductive and Respiratory Syndrome virus (PRRSV) stability, besides meeting production targets, is also a requirement for several control options of PRRS in pig breeding farms. This study aimed to investigate the frequency of, and risk factors associated with, PRRSV instability in pig breeding farms in northern Germany. In 120 sow herds, a questionnaire on production and management parameters was filled, and blood samples from 30 suckling pigs from 10 different litters were taken and examined using real-time polymerase chain reaction (PCR). Results PRRSV was detected in 32 herds (27%), thus classified as PRRSV-unstable. According to multivariable logistic regression analysis, a suckling period ≤ 21 days, a low distance between the cadaver collection site and the actual sow barn, ≥ 2 pig herds in a 1000 m radius, presence of external employees, a time interval between purchase of gilts of ≤ 9 weeks and a 1- or 2-weekly farrowing rhythm were associated with a higher risk of PRRSV instability. Conclusions External and internal biosecurity as well as management factors were associated with PRRSV instability, which could be targeted by farmers and veterinarians to help them to achieve PRRSV PCR-negative status and in the control of PRRS.

Respiratory disorders in fattening pigs are of major concern worldwide. Particularly Enzootic Pneumonia remains a problem for the pig industry. This chronic respiratory disease is primarily caused by Mycoplasma hyopneumoniae (M. hyopneumoniae). However, more recently it was hypothesised that M. hyorhinis can also cause similar lung lesions. To investigate the relevance of M. hyorhinis as a cause of pneumonia in fattening pigs 10 farms in Switzerland (considered free of Enzootic Pneumonia) and 20 farms in Germany (regarded as endemic for Enzootic Pneumonia) with a history of chronic and/or recurrent respiratory diseases were included in the study. During a one-time farm visit the coughing index was determined in the batch of oldest fattening pigs in each farm before submission to slaughter. In total, 1375 lungs from these pigs were collected at the abattoir and individually scored for lesions. Furthermore, 600 lungs with, if present, indicative lesions for Enzootic Pneumonia (purple to grey areas of tissue consolidation in the cranio-ventral lung lobes) were tested for mycoplasma species by culture and by real-time PCR for the presence of M. hyorhinis and M. hyopneumoniae. In total, 15.7% of the selected lungs were tested positive for M. hyorhinis by real-time PCR. The prevalence of M. hyorhinis was 10% in Switzerland and 18.5% in Germany and differed significantly between these two countries (p=0.007). M. hyorhinis was detected significantly more often in pneumonic lungs (p=0.004) but no significant association was found between M. hyorhinis and the coughing index or the M. hyopneumoniae status of the pig. M. hyopneumoniae was detected in 0% and 78.5% of the selected lungs in Switzerland and Germany, respectively. We found no evidence that M. hyorhinis alone can lead to similar lung lesions as seen by an infection with M. hyopneumoniae in fattening pigs. In addition, a simultaneous infection with both M. hyorhinis and M. hyopneumoniae did not aggravate the observed lung lesions. Moreover, the presence of M. hyorhinis showed no clinical effect in terms of coughing at least at the end of the fattening phase. However, different levels of virulence of M. hyorhinis isolates as well as interactions with viral pathogens like porcine reproductive and respiratory syndrome virus (PRRSV) or porcine circovirus type 2 (PCV2) were reported in the literature and need to be further investigated.

International audience; Pig farmers are strongly encouraged to reduce their antimicrobial usage because of the rising threat from antimicrobial resistance. However, such efforts should not compromise the herd health status and performance. This study aimed to describe the profile of so-called ‘top-farms’ that managed to combine both high technical performance and low antimicrobial usage. A cross-sectional study was conducted among 227 farrow-to-finish farms in Belgium, France, Germany and Sweden. Among them, 44 farms were allocated to the top-farms group and were compared with the ’regular’ farms group in terms of farm characteristics, biosecurity and health status. Top-farms had fewer gastrointestinal symptoms in suckling pigs and fewer respiratory symptoms in fatteners, which could partly explain their reduced need for antimicrobials and higher performance. They also had higher biosecurity and were located in sparsely populated pig areas. However, 14 farms of the top-farms group were located in densely populated pig areas, but still managed to have low usage and high technical performance; they had higher internal biosecurity and more extensive vaccination against respiratory pathogens. These results illustrate that it is possible to control infectious diseases using other approaches than high antimicrobial usage, even in farms with challenging environmental and health conditions.

Vaccinia virus (VACV) spreads across cell monolayers 4-fold faster than predicted from its replication kinetics. Early after infection, infected cells repulse some superinfecting extracellular enveloped virus (EEV) particles by the formation of actin tails from the cell surface, thereby causing accelerated spread to uninfected cells. This strategy requires the expression of two viral proteins, A33 and A36, on the surface of infected cells and upon contact with EEV this complex induces actin polymerisation. Here we have studied this phenomenon further and investigated whether A33 and A36 expression in cells lines causes an increase in VACV plaque size, if these proteins are able to block superinfection by EEV, and which protein(s) on the EEV surface are required to initiate the formation of actin tails from infected cells. Data presented show that VACV plaque size was not increased by expression of A33 and A36, and these proteins did not block entry of the majority of EEV binding to these cells. In contrast, expression of proteins A56 and K2 inhibited entry of both EEV and IMV. Lastly, VACV protein B5 was required on EEV to induce the formation of actin tails at the surface of cells expressing A33 and A36, and B5 short consensus repeat 4 is critical for this induction.

A natural reassortant influenza A virus consisting of seven genome segments from pandemic (H1N1) 2009 virus and a neuraminidase segment from a Eurasian porcine H1N1 influenza A virus was detected in a pig herd in Germany. The obvious reassortment compatibility between the pandemic (H1N1) 2009 and H1N1 viruses of porcine origin raises concern as to whether swine may become a reservoir for further reassortants of pandemic (H1N1) 2009 viruses with unknown implications for human health and swine production.

The Porcine reproductive and respiratory syndrome virus (PRRSV) can persist for several weeks in infected pigs, and readily spreads from viraemic pigs to other pigs as well as to other herds. In regions with dense pig populations such as the North-Western part of Germany the virus is endemic. The aim of this study was to analyse the genetic diversity of PRRSV found in 18 herds in this region, which had pigs with respiratory or reproductive failures, and where PRRSV had been demonstrated by RT-PCR. Phylogenetic trees were calculated using the complete nucleotide sequences of the ORF5. Of the 65 samples sequenced, five PRRSV from four herds were of the North American (NA; Type 2) genotype, and 60 of the European (EU; Type 1) genotype. To ascertain if the field PRRSV varied with time and to monitor the health condition of the herds they were revisited 2 years later. Although only two herds still reported clinical signs, PRRSV was found by RT-PCR in 10 of the 18 herds. Phylogenetic analysis showed that of the 23 PRRSV sequenced, 15 were of the European (EU) genotype. The EU genotype isolates from both samplings could be assigned to one of 12 clusters. There was no indication for the existence of herd specific clusters. ORF5 sequence identities between PRRSV from one herd in one cluster were either 100%, or had single base exchanges. These data indicate that the mutation rates for the European field isolates are similar to that found for the NA genotype vaccine strain used in Germany.

The frequency of PRRSV corresponding to live vaccines and wild-type was determined in 902 pigs from North-Western Germany submitted for post-mortem examination. Overall, 18.5% of the samples were positive for the EU wild-type virus. EU genotype vaccine virus was detected in 1.3% and the NA genotype vaccine virus in 8.9% of all samples. The detection of the EU vaccine was significantly higher in pigs vaccinated with the corresponding vaccine (OR = 9.4). Pigs vaccinated with NA genotype had significantly higher detection chances for the corresponding vaccine virus when compared to non-vaccinated animals (OR = 3.34) animals, however, NA vaccine was also frequently detected in non-vaccinated pigs. Concluding, the dynamics of NA genotype vaccine and EU wild-type virus corresponds with studies on PRRSV spread in endemically infected herds. The potential of spontaneous spread of the NA genotype vaccine should be considered in the planning of eradication programs.

Risk factors for the spread of Mycoplasma hyopneumoniae in sows have not been studied although vertical transmission from sows to their offspring is considered a significant risk factor in the development of enzootic pneumonia in growers and finishers. Seropositivity for M. hyopneumoniae in sows, as assessed by commercial ELISA, is a possible indicator of infection pressure among sows. The objective of this study was to estimate seroprevalence and associated risk factors of a sow being seropositive for M. hyopneumoniae. A cross-sectional study was carried out in 2578 sows from 67 herds in north-west Germany. Data concerning general herd characteristics, acclimatisation practices, indoor and outside contacts, as well as data describing the immediate local environment were collected during a herd visit via questionnaire. Blood samples were seropositive in 65% of the 2578 sows, and all herds had >/=14% seropositive sows. Data analysis was performed in two steps. First, univariate analysis of predictor variables for the risk of a sow being seropositive for M. hyopneumoniae was performed using chi-square test. Secondly, all variables associated with the risk of a sow being seropositive (P

BACKGROUND In recent years, the occurrence and the relevance of Mycoplasma hyopneumoniae infections in suckling pigs has been examined in several studies. Whereas most of these studies were focused on sole prevalence estimation within different age groups, follow-up of infected piglets or assessment of pathological findings, none of the studies included a detailed analysis of individual and environmental risk factors. Therefore, the aim of the present study was to investigate the frequency of M. hyopneumoniae infections in suckling pigs of endemically infected herds and to identify individual risk factors potentially influencing the infection status of suckling pigs at the age of weaning. RESULTS The animal level prevalence of M. hyopneumoniae infections in suckling pigs examined in three conventional pig breeding herds was 3.6% (41/1127) at the time of weaning. A prevalence of 1.2% was found in the same pigs at the end of their nursery period. In a multivariable Poisson regression model it was found that incidence rate ratios (IRR) for suckling pigs are significantly lower than 1 when teeth grinding was conducted (IRR: 0.10). Moreover, high temperatures in the piglet nest during the first two weeks of life (occasionally >40°C) were associated with a decrease of the probability of an infection (IRR: 0.23-0.40). Contrary, the application of PCV2 vaccines to piglets was associated with an increased infection risk (IRR: 9.72). CONCLUSIONS Since single infected piglets are supposed to act as initiators for the transmission of this pathogen in nursery and fattening pigs, the elimination of the risk factors described in this study should help to reduce the incidence rate of M. hyopneumoniae infections and thereby might contribute to a reduced probability of high prevalences in older pigs.

In industrial countries, Hepatitis E virus (HEV) transmission to humans is predominantly assumed to be a zoonotic infection. Recently, it has been demonstrated that about 50% of domestic pigs in Germany carry HEV-specific antibodies. However, further investigations concerning the distribution of HEV in different age groups of German domestic pigs, phylogenetic analyses and the viral load in the porcine liver are still pending. Liver samples of all age groups from herds in a pig-dense region in north-western Germany were investigated for the presence and quantity of HEV RNA and subsequently genotyped. Out of 251 liver samples, 34 contained ORF2-specific RNA, whereas 19 samples were positive using ORF1-specific primers, resulting in an overall detection rate of 13.5% and 7.6%, respectively. Especially nursery pigs and growers were tested positive for viral RNA. Furthermore, determination of the HEV copy numbers revealed high replication levels. Up to 10(9) genome copies per g of liver tissue could be detected suggesting a likely high degree of viral spread to the environment. In the HEV-positive liver samples we found no hints for pathohistological changes reflecting the HEV status.The HEV sequences showed marked diversity but could be assigned to HEV genotype 3 without exception. However, by comparing two different genomic fragments, we found indications for infections with two different HEV variants in domestic pigs. Apart from this, the current study confirms the outcome of our recent serological HEV survey and for the first time gives direct proof of HEV infections in the German domestic pig population.

The objective of this study was to determine the effect of using a gonadotrophin releasing factor (GnRF) vaccine on growth performance of male pigs. Vaccinated pigs were compared with surgically castrated pigs and entire males under conventionally managed farm conditions. Male pigs were randomly assigned to three treatment groups: pigs surgically castrated during the first week of life (group "C", n=274), pigs immunised twice during the fattening period with a GnRF vaccine, the first when 13-14 weeks of age and the second when 20-21 weeks of age (group "V" n=280) and entire males (group "E", n=56). Average daily weight gain (ADG) was measured during the study. Additionally, feed conversion ratio (FCR) as defined by feed intake/weight gain and feed consumption was assessed during the fattening period. No difference in the ADG during the fattening period could be determined between "C" and "V". From the start of the study until slaughter at study day 160/173 the ADG in group "E" was lower (625 g/day; P) than in group "C" (681 g/day; P0.001) and group "V" (675 g/day; P0.01). The FCR during the fattening period until study day 160, three days before the first batch of pigs were slaughtered at 24-25 weeks of age, was higher in group"C" (2.72 kg feed intake/kg weight gain) compared with group "V" (2.44 kg feed intake/kg weight gain; P0.001) and group "E" (2.44 kg feed intake/kg weight gain; P0.01). Pigs in group "V" performed similarly to those in group "E" until the second vaccination (day 135) after which time they showed a substantial increase in feed intake and ADG, while retaining an FCR advantage over group C.

The diagnosis of enzootic pneumonia at the herd level should be based on a combination of different methods. Currently, clinical examination is usually considered to be a low value method, particularly compared to the direct detection of Mycoplasma hyopneumoniae in lung lesions by PCR. The present study compared the value of accurate clinical examination (including the quantitation of coughing), PCR on bronchoalveolar lavage fluid, and serological testing of blood samples for the purpose of diagnosing enzootic pneumonia. The coughing index (average % of pigs coughing per minute of observation) was determined in fattening pigs from 59 herds, and ranged from 0% to 6.7% with a median of 2.4%. Five hundred and ninety bronchiolar lavage samples and 1179 serum samples were taken from pigs in those 59 herds and tested for M. hyopneumoniae specific DNA and antibodies, respectively. In herds where ≥ 50% of lavage fluids were PCR positive, the likelihood of a higher coughing index was increased by 76% (OR: 1.76; 95% CI: 1.14-2.72) compared to herds with50% of positive samples. For antibodies (determined by ELISA) a seroprevalence of ≥ 50% increased the likelihood of a high coughing index by 50% (OR: 1.50; 95% CI: 1.03-2.20). In 78.1% of all herds with a seroprevalence of ≥ 50% against M. hyopneumoniae, the PCR-prevalence and the coughing index were above the median (50% and 2.4%, respectively). It was concluded that in fattening pigs a quantitative assessment of the onset of coughing - typically dry and non-productive - improves the diagnosis of enzootic pneumonia and can occasionally substitute for the detection of M. hyopneumoniae by PCR.

Since differences in the virulence of Mycoplasma (M.) hyopneumoniae strains have been described, the isolation of field strains followed by genotypic and phenotypic characterisation has become a major goal in epidemiological studies. The aim of this study was to compare various M. hyopneumoniae isolates from different pig herds and numerous pigs within the same herd. Therefore, pigs of 109 herds located in North-Western Germany were sampled either on-farm or during necropsies. Overall, 52 isolates of M. hyopneumoniae were recovered from 45 pigs originating from 21 herds. The identity of cultures was confirmed by PCR targeting the 16S–23S intergenic spacer region. Typing of isolates was achieved by random amplified polymorphic DNA (RAPD) analysis and multi-locus analysis of variable number of tandem repeats (VNTR) and demonstrated a high degree of heterogeneity of M. hyopneumoniae isolates. Differences among isolates recovered from animals of the same herd or even from the same pig revealed a grouping into different genotypic clusters. This outcome was observed with both methods. It was concluded that more than one strain of M. hyopneumoniae might be present in a pig herd and even in a single pig, suggesting high genetic heterogeneity between isolates of the same epidemiological source. These factors should be considered when applying nucleic amplification techniques for characterising M. hyopneumoniae strains to specify the epidemiology of infection and to evaluate virulence factors triggering the corresponding disease.

Diagnosis of infection with Lawsonia (L.) intracellularis, the causative agent of porcine proliferative enteropathy, is routinely based on the detection of L. intracellularis in faeces and/or tissue samples by PCR. Furthermore, infection can be determined by the detection of antibodies in serum samples. The aim of this comparative study was to examine whether results from molecular biology and serological testing are influenced by applying live bacteria vaccine Enterisol Ileitis or antimicrobial treatment to pigs naturally exposed to L. intracellularis. Decreased shedding was detected in tylosin treated pigs only. Thus, the distribution of 345 pigs into groups of 0-, 1- oror = 2-times positive by PCR was significantly influenced by the treatment (P0.0001). A global effect of positive PCR results on average daily weight gain was also highly significant (P0.0001). The serological reaction was detected by a blocking ELISA after infection but not after vaccination independent of treatment. The results indicate no influence of vaccination on applied diagnostic tests.

The aim of this study was to determine the prevalence of Campylobacter spp. and Yersinia spp. in a total of 1,040 faecal samples taken from animals at different ages from four farrowing and twelve fattening herds. In the farrowing unit, faeces were collected from 68 sows (faecal samples) and 256 suckling piglets (rectal swab samples). Further samples were collected from 362 growing and 354 finishing pigs (rectal swab samples). Additionally, 56 feed and environmental samples were collected. During the slaughtering process, 122 pigs and their carcasses respectively, were sampled three times. Finally, 86 meat and minced meat samples were taken from 34 retail stores. Campylobacter spp. were isolated in sows (33.8 %), piglets (80.9 %), growing (89.2 %) and finishing (64.7 %) pigs. Yersinia spp. were detected in growing (15.2 %) and finishing (13.3 %) pigs only. After twelve hours of chilling neither Campylobacter spp. nor Yersinia spp. were detected. In raw meat samples, Campylobacter spp. were isolated from one liver sample and Yersinia enterocolitica from two meat samples. Common slaughter techniques and hygiene procedures may be effective tools to reduce the risk of contamination and recontamination of meat products since Campylobacter spp. and Yersinia spp. were found only sporadically in raw meat samples.

The aim of this study in breeding gilt rearing herds was to identify production-specific risk factors for an increased Salmonella seroprevalence. The statistical analysis for determining risk factors based on 10,429 animals from 40 herds. Blood samples were taken regularly between 2001 and 2003 from gilts five and six months of age. Only those herds from which at least 60 samples per year and 10 per quarter were available were included in the statistical analysis of risk factors. For this, the results of the serological examinations were combined with data obtained from a questionnaire and subsequent visual examination of the herds and their environment. Different kinds of categories were validated using sensitivity analysis. Finally, all herds with a Salmonella seroprevalence0.15 were classified as "Salmonella low risk", and those with a Salmonella seroprevalenceor = 0.15 were classified as "Salmonella high risk". Four of the sixteen variables could be ascertained as risk factors for enhanced Salmonella seroprevalences: the use of pelleted or granulated feed, the use of purchased feed, partially or not slatted floors in the pens, a floor space of 0.85m2/pig and the freedom of PRRSV-infection in a herd. Some of these variables were identified as risk factors in earlier studies, too. The identification of these risk factors in pig herds of a breeding company with a low Salmonella seroprevalence, emphasises the importance of these factors for controlling Salmonella infections in pig herds.

The problem of successfully controling PRRS with traditional methods has led to a growing interest in eradication. This review summarizes the current literature on topics of PRRS-eradication, including the relevant routine diagnostic procedures, routes of virus transmission between pig herds (as i.e. pig movement, semen, aerosols, insects, fomites, transport vehicles) and eradication by closerollover and testremoval, respectively. On the basis of this knowledge and experiences it can be concluded that PRRS eradication in Germany with its intensive pig production and remarkably high pig density in several regions may only be possible through a national eradication program. The lack of potent marker vaccines that reduce the virus spread significantly, combined with the lack of differentiating diagnostic tests for routine laboratory use leads to the recommendation not to launch a national eradication program under the given circumstances. For the future it should be taken into account that the situation after reintroduction of PRRSV in a free region could only be managed by stamping-out which is generally poorly accepted by the majority of pig producers.

The study was performed with the aim to characterize seasonal variations on the Salmonella seroprevalence in gilts. Serological results from a total of 13,511 gilts were available for the analysis. The samples were taken from 11 nucleus herds, 19 suppliers and 46 breeding gilt rearing herds. In principle, it was planned to take 10 blood samples at monthly intervals from gilts five to six months of age. The overall seroprevalences of Salmonella were low in the herds of this study. The analysis of seasonal variation showed a statistically significantly lower seroprevalence during the summer quarter (July through September). In comparison to other studies in Germany it must be pointed out that the herds belonged to a single breeding company, which has a strong commitment to enhanced biosecurity. The marked seasonal variation in Salmonella seroprevalences should be taken into consideration in the classification of herds within the scope of monitoring programmes. Scoring of herds is meaningful only after regular sampling for at least one year. Further investigations considering management, housing and hygienic conditions are necessary to determine the factors leading to higher Salmonella seroprevalence in the winter.

The objective of this study was to compare the detection rate of bacterial agents in bronchoalveolar lavage fluid (BALF), taken without visual control, to that in affected lung tissue obtained from the same pig at necropsy. BALF and affected lung tissue were examined for Mycoplasma hyopneumoniae using PCR, and standard cultural methods were used for Actinobacillus pleuropneumoniae, Bordetella bronchiseptica, Haemophilus parasuis, Pasteurella multocida and Streptococcus suis. All pigs with a history of respiratory symptoms were submitted as live animals for routine diagnostic examination. In each animal the site of lavage, marked by injecting methylene blue, differed from the site of pneumonic lesions. M. hyopneumoniae was detected more frequently in lung tissue than in BALF in cases with moderate or severe lung lesions. The detection rates of M. hyopneumoniae were higher in the BALF of pigs with mild lesions. Cultural examination of BALF was at least as satisfactory as affected lung tissue for detecting B. bronchiseptica, H. parasuis and P. multocida.

Background Mycoplasma hyopneumoniae is the etiologic agent of enzootic pneumonia mainly occurring in fattening pigs. It is assumed that horizontal transmission of the pathogen during nursery and growing phase starts with few suckling pigs vertically infected by the sow. The aim of the present study was the exploration of the herd prevalence of M. hyopneumoniae infections in suckling pigs followed by an investigation of various herd specific factors for their potential of influencing the occurrence of this pathogen at the age of weaning. Results In this cross-sectional study, 125 breeding herds were examined by taking nasal swabs from 20 suckling pigs in each herd. In total, 3.9% (98/2500) of all nasal swabs were tested positive for M. hyopneumoniae by real-time PCR. Piglets tested positive originated from 46 different herds resulting in an overall herd prevalence of 36.8% (46/125) for M. hyopneumoniae infection in pigs at the age of weaning. While the herds were epidemiologically characterized, the risk for demonstration of M. hyopneumoniae was significantly increased, when the number of purchased gilts per year was more than 120 (OR: 5.8), and when the number of farrowing pens per compartment was higher than 16 (OR: 3.3). In herds with a planned and segregated production, where groups of sows entered previously emptied farrowing units, the risk for demonstration of M. hyopneumoniae in piglets was higher in herds with two or four weeks between batches than in herds with one or three weeks between batches (OR: 2.7). Conclusions In this cross-sectional study, several risk factors could be identified enhancing the probability of breeding herds to raise suckling pigs already infected with M. hyopneumoniae at the time of weaning. Interestingly, some factors (farrowing rhythm, gilt acclimatisation issues) were overlapping with those also influencing the seroprevalences among sows or the transmission of the pathogen between older age groups. Taking the multifactorial character of enzootic pneumonia into account, the results of this study substantiate that a comprehensive herd specific prevention programme is a prerequisite to reduce transmission of and disease caused by M. hyopneumoniae.