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Background The aim of this study was to estimate the mortality risk within the first days of life for underweight or low-vital neonatal piglets. This risk estimation should start a discussion concerning the pre-conditions for the killing of compromised new-born piglets for the prevention of unnecessary pain and suffering. In a field study, various clinical and laboratory variables were examined in 529 piglets out of four farms. Body weight, crown-rump-length, rectal temperature, a 4-stage vitality score, an intrauterine-growth-retardation score, glucose, lactate, haemoglobin and immunocrit were assessed on the first day of life. Vitality was scored by three factors: movement, abdominal palpation and colour of the skin. Afterwards death or survival of the piglets was monitored up until the fifth day of age. Results Body weight, crown-rump-length, rectal temperature, vitality score, IUGR-score, glucose and immunocrit were significantly associated with the probability of death (univariate model, p =

The aim of the study was to investigate the influence of a higher content of soluble dietary fibre in the diet of growing pigs on tail biting. Pig groups were of equally distributed mixed gender and males were castrated during the first days of life. Two treatment groups were investigated over nine batches with on average 194.4 (SD 14.0) pigs per batch. One treatment group (n = 810) received a conventional diet (control) from 29 to 51 days of age. The other treatment group (n = 821) was fed with a commercially available dietary diet (fibre) wherein levels of soluble dietary fibre had been increased by 0.5 (Piglet-Growing-Food-I) respectively 1.6 (Piglet-Growing-Food-II) percentage points. Tail lesions and tail losses were scored once a week and weight was recorded at pen level during weaning, three weeks later and before the start of the fattening period. Tail biting was influenced by week after weaning (p

It was the aim of the study to investigate the effect of a prolonged suckling period and group housing before weaning on tail biting in undocked nursery pigs. To do this, experiments with three treatment groups were investigated. In the first group, pigs were conventionally housed in pens with farrowing crates for a four-week suckling period (SH-4). In the second group, suckling was prolonged to five weeks whereas housing was the same as in the first group (SH-5). The animals of the third group were kept in a group housing system for six sows and their piglets during a five-week suckling period (GH-5). At weaning, piglets were moved to conventional rearing pens in which two litters of the same treatment group were mixed together. Scoring of tail lesions and tail losses was carried out once a week from birth to end of rearing at the level of the individual animal. Significant effects on tail lesions were found for week after weaning (p

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.

The aim of this study was to investigate the effects on tail-biting during rearing of housing piglets of the same litter compared to piglets from different litters. The treatments “litter-wise” (LW, n =240) and “mixed litters” (ML, n =238) were housed in five identical units. Each tail was scored regarding tail lesions and tail losses once per week with a four-point score (0= no damage/original length to 3= severe damage/total loss). The effect of week after weaning had highly significant influences on tail lesions (p

The aim of this study was to reveal the effects of raw material provision on tail-biting outbreaks in long-tailed pigs. Two different substrates, dried corn silage (SG, n=245) and alfalfa hay (AG, n=245) were provided for the pigs twice per day from the second week of life until the end of rearing. The control of long-tailed pigs (CG, n=231) were kept without the provision of additional raw material. Each tail was scored regarding tail lesions/tail losses once per week with a four-point score (0=no damage/original length, 3=severe damage/total loss). Weight was collected at the beginning and at the end of rearing. The effect of week after weaning, the batch and the interaction between treatment group and batch had highly significant influences on tail lesions (p

Swine influenza A viruses (swIAVs) can play a crucial role in the generation of new human pandemic viruses. In this study, in-depth passive surveillance comprising nearly 2,500 European swine holdings and more than 18,000 individual samples identified a year-round presence of up to four major swIAV lineages on more than 50% of farms surveilled. Phylogenetic analyses show that intensive reassortment with human pandemic A(H1N1)/2009 (H1pdm) virus produced an expanding and novel repertoire of at least 31 distinct swIAV genotypes and 12 distinct hemagglutinin/neuraminidase combinations with largely unknown consequences for virulence and host tropism. Several viral isolates were resistant to the human antiviral MxA protein, a prerequisite for zoonotic transmission and stable introduction into human populations. A pronounced antigenic variation was noted in swIAV, and several H1pdm lineages antigenically distinct from current seasonal human H1pdm co-circulate in swine. Thus, European swine populations represent reservoirs for emerging IAV strains with zoonotic and, possibly, pre-pandemic potential.

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.

This study was conducted within the MulTiViS-project consortium on multivariate animal welfare assessment. The aim of this investigation was to perform a status quo analysis of the noise level in fattening pig farms (n = 214) and to evaluate the suitability of noise as an animal welfare indicator. In 755 conventional fattening compartments, noise measurements were carried out for one minute at animal height using the Acoustic Analyser XL2, including microphone M2210 (NTI Audio, Schaan, Liechtenstein). In addition, various animal health and environmental factors of 33,668 pigs were recorded in randomly selected pens (n = 1,668) of these compartments. The mean equivalent noise level was 70.2 ± 5.2 dB (min 52.5, max 92.4 dB). Noise levels in compartments housing older pigs were higher (72.0 ± 5.2 dB) than those in compartments housing younger pigs (68.5 ± 4.7 dB, ***P

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.

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.

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.

Background Straw is one of the most effective rooting materials to reduce tail biting in pigs. A so-called foraging-tower (FT) provides only small quantities of straw compatible with liquid manure systems. The focus of the present study was on the effect of providing straw by FT in order to prevent tail biting in tail docked pigs. Four consecutive batches of 160 pigs, randomly divided into a straw (SG) and a control group (CG) were followed up from weaning to slaughter. Results Tail wounds (Score ≥ 2) were detected in 104 out of 12,032 single observations (SG n = 48; CG n = 56) in 9 pens (SG n = 4/32; CG n = 5/32) mainly focused on the fattening period of batch 2 due to a failure in the ventilation system. No significant differences concerning the distribution of Score ≥ 2 in pens of the SG and CG could be identified. Bite marks (Score 1) were documented in 395 observations at animal level (SG n = 197, CG n = 198) in all batches. In the nursery period, the air velocity significantly increased the chance that at least one pig per pen and week showed a tail lesion score ≥1 (p = 0.024). In the fattening period ammonia concentration was positively associated with tail lesions (p = 0.007). The investigation of blood samples revealed infections with Mycoplasma hyopneumoniae in all batches and a circulation of Porcine Reproductive and Respiratory Syndrome Virus (NA-vaccine strain) and Porcine Circovirus Type 2 in two batches each. The average daily straw consumption was 3.5 g/pig (standard deviation (SD) = 1.1) during the rearing period and 31.9 g/pig (SD = 7.7) during the fattening period. Conclusion Due to the low prevalence of tail biting in all batches the effect of the FT tower could not be evaluated conclusively. The operation of the FT with an average daily straw consumption of 3.5 g/pig (SD = 1.1) during the rearing period and 31.9 g/pig (SD = 7.7) during the fattening period did not affect the weight gain. Exploratory behaviour seems to cause bite marks (score 1), which do not necessarily result in tail biting. The main outbreak of tail biting was probably triggered by a failure of the ventilation system, which resulted in a number of climatic and air quality changes including higher ammonia concentrations and sudden temperature changes. Electronic supplementary material The online version of this article (doi:10.1186/s40813-017-0052-7) contains supplementary material, which is available to authorized users.