Influenza surveillance in pigs: balancing act between broad diagnostic coverage and specific virus characterization

BACKGROUND

Monitoring of infectious diseases on swine farms requires a high diagnostic sensitivity and specificity of the test system. Moreover, particularly in cases of swine influenza A virus (swIAV) it is desirable to include characterization of the virus as precisely as possible. This is indispensable for strategies concerning prophylaxis of swIAV and furthermore, to meet the requirements of a purposeful monitoring of newly emerging swIAV strains in terms of vaccine design and public health. Within the present cross-sectional study, we compared the diagnostic value of group samples (wipes of surfaces with direct contact to mouth/nose, dust wipes, udder skin wipes, oral fluids) to individual samples (nasal swabs, tracheobronchial swabs) for both swIAV identification and characterization. Sampling included different stages of pig production on 25 sow farms with attached nursery considered as enzootically infected with swIAV. Firstly, samples were analyzed for IAV genome and subsequently samples with Ct-values < 32 were subtyped by multiplex RT-qPCR.

RESULTS

Nasal swabs of suckling piglets and nursery pigs resulted in a higher odds to detect swIAV (p < 0.001) and to identify swIAV subtypes by RT-qPCR (p < 0.05) compared to nasal swabs of sows. In suckling piglets, significant higher rates of swIAV detection could be observed for nasal swabs (p = 0.007) and sow udder skin wipes (p = 0.036) compared to contact wipes. In the nursery, group sampling specimens were significantly more often swIAV positive compared to individual samples (p < 0.01), with exception of the comparison between contact wipes and nasal swabs (p = 0.181). However, in general nasal swabs were more likely to have Ct-value < 32 and thus, to be suitable for subtyping by RT-qPCR compared to dust wipes, contact wipes, udder skin wipes and tracheobronchial swabs (p < 0.05). Interestingly, different subtypes were found in different age groups as well as in different specimens in the same holding.

CONCLUSION

Although population-based specimens are highly effective for swIAV monitoring, nasal swabs are still the preferable sampling material for the surveillance of on-farm circulating strains due to significantly higher virus loads. Remarkably, sampling strategies should incorporate suckling piglets and different age groups within the nursery to cover as many as possible of the on-farm circulating strains.

Antimicrobial Susceptibility from a One Health Perspective Regarding Porcine Escherichia coli from Bavaria, Germany

Antimicrobial resistance is one of the most crucial One Health topics worldwide. Consequently, various national and international surveillance programs collect data and report trends regularly. Ceftiofur, colistin and enrofloxacin belong to the most important and critical class of anti-infective medications in both human and veterinary medicine. In the present study, antimicrobial resistance was analyzed using the epidemiological cut-off (ECOFF) value on 6569 Escherichia coli isolated from pigs in Bavaria, Germany, during five years, from 2016 to 2020. The statistically relevant results regarding antimicrobial resistance revealed a decrease for colistin, an increase for enrofloxacin, and a constant level for ceftiofur. In Germany, the usage of all three antimicrobial substances in livestock has fallen by 43.6% for polypeptides, 59.0% for fluoroquinolones and 57.8% for the 3rd + 4th generation cephalosporines during this time. Despite the decline in antimicrobial usage, a reduction regarding antimicrobial resistance was solely observed for colistin. This finding illustrates that in addition to the restriction of pharmaceutical consumption, further measures should be considered. Improved biosecurity concepts, a reduction in crowding, and controlled animal movements on farms may play a key role in finally containing the resistance mechanisms of bacteria in farm animals.

Application of a topical anesthetic reduces pain-associated parameters during spermatic cord transection in piglet castration using a minimal anesthesia model

OBJECTIVE

This study assessed the use of a topical anesthetic as a feasible approach to reduce pain during piglet castration using a minimal anesthesia protocol.

ANIMALS

18 male piglets, aged 3-6 days, were included in this study.

METHODS

A minimal anesthetic state was induced with isoflurane administered by facemask, with anesthetic depth individually adjusted based on responses to interdigital pinch. To desensitize the scrotal skin, a vapocoolant was applied 3 times. Scrotal incisions were made subsequently and Tri-Solfen (TS) or Placebo (P) was administered in both incisional gaps. After 30 seconds, the spermatic cords were severed followed by a further application of TS/P to both incision edges. Nociception-related variables, such as mean arterial blood pressure (MAP), heart rate (HR), and nocifensive movements, were assessed.

RESULTS

Significant differences in MAP changes were assessed between the TS (14 ± 4 mmHg) and the P group (36 ± 8 mmHg) for cutting the spermatic cords. Furthermore, significantly fewer nocifensive movement score points appeared in the TS than in the P group (0; IQR = 0 vs 5; IQR = 6).

CLINICAL RELEVANCE

In this anesthesia model, the application of TS after skin incision significantly reduced MAP responses and nocifensive movements with spermatic cord transection compared with the application of P. However, the waiting period between TS-application and spermatic cord transection might limit the benefit of the method in conscious piglets, as pain during castration is reduced but additional stress is caused by the prolonged handling. Furthermore, using a vapocoolant did not provide anesthesia for skin incisions.

Examination on the Occurrence of Coinfections in Diagnostic Transmittals in Cases of Stillbirth, Mummification, Embryonic Death, and Infertility (SMEDI) Syndrome in Germany

The stillbirth, mummification, embryonic death, and infertility (SMEDI) syndrome is most commonly associated with porcine parvovirus 1 (PPV1) infections. Little is known about the occurrence of coinfections with SMEDI-associated pathogens and the associations among these pathogens. In our study, we included 40 SMEDI-affected litters from 18 different farms. In total, 158 out of 358 available fetuses from diagnostic transmittals were selected by systematic random sampling and examined for PCV2, PCV3, PPV1, and Leptospira spp. by q-PCR. Results from diagnostic materials showed the following results: in eleven farms, PCV2 was present; in nine farms, PPV1 was present; in five farms, PCV3 was present; and in two farms, Leptospira spp. was present. The detection of Leptospira spp. was significantly associated with a PCV2 coinfection (OR: 26.3; p < 0.001). PCV3 positivity resulted in a reduced probability of detecting PCV2 in the corresponding fetus (OR: 0.078; p = 0.008). Fetal maceration was associated with Leptospira spp. detection (OR: 8.6; p = 0.003), whereas mummification (p = 0.047), reduced crown-rump length (p < 0.001), and bodyweight (p = 0.001) of fetuses were significantly associated with PPV1 and PCV2 coinfection and thus, presumably, a shorter time to death after infection, indicating an enhanced negative effect on the development of fetuses with PCV2 + PPV1 coinfection.

Field trial: disinfection of contaminated anesthetic masks for piglets

This paper aimed to assess the success of cleaning and disinfection on microbiological contamination of anesthetic masks, which were used for automated isoflurane anesthesia for surgical castration of male piglets. Data collection took place on 11 farms in Southern Germany between September 2020 and June 2022. Each farm was visited three times (one farm having two different anesthesia devices was visited six times), and microbiological assessments took place at four sample points (SP): after unpacking the masks (SP0), after disinfection before anesthesia (SP1), after anesthesia of all piglets to be castrated in this run (SP2), and after disinfection after anesthesia (SP3). The microbiological assessment included the determination of total bacteria count, total count of hemolytic and non-hemolytic mesophilic aerotolerant bacteria and a qualitative detection of indicator bacteria Escherichia (E.) coli, extended-spectrum beta-lactamase-producing E. coli (ESBL) and methicillin-resistant Staphylococcus aureus (MRSA). For analysis, a generalized linear mixed model was applied using farms and farm visits as random effects and sampling points nested in farm visits as fixed effect. The fixed effect was highly significant for all three variables (total bacteria count, total count of hemolytic and non-hemolytic mesophilic aerotolerant bacteria) (p < 0.001). The bacterial counts at SP0 were about the same as at SP3. Concerning indicator bacteria, their presence was highest at SP2 and lowest at SP3. No indicator bacteria were present at SP1. It can be concluded that disinfection of anesthetic masks, especially before performing anesthesia, may effectively protect piglets of the following batch against unwanted transmission of pathogens. These findings will help farmers plan cleaning and disinfection activities.

Viral and Bacterial Profiles in Endemic Influenza A Virus Infected Swine Herds Using Nanopore Metagenomic Sequencing on Tracheobronchial Swabs

Swine influenza A virus (swIAV) plays an important role in porcine respiratory infections. In addition to its ability to cause severe disease by itself, it is important in the multietiological porcine respiratory disease complex. Still, to date, no comprehensive diagnostics with which to study polymicrobial infections in detail have been offered. Hence, veterinary practitioners rely on monospecific and costly diagnostics, such as Reverse Transcription quantitative PCR (RT-qPCR), antigen detection, and serology. This prevents the proper understanding of the entire disease context, thereby hampering effective preventive and therapeutic actions. A new, nanopore-based, metagenomic diagnostic platform was applied to study viral and bacterial profiles across 4 age groups on 25 endemic swIAV-infected German farms with respiratory distress in the nursery. Farms were screened for swIAV using RT-qPCR on nasal and tracheobronchial swabs (TBS). TBS samples were pooled per age, prior to metagenomic characterization. The resulting data showed a correlation between the swIAV loads and the normalized reads, supporting a (semi-)quantitative interpretation of the metagenomic data. Interestingly, an in-depth characterization using beta diversity and PERMANOVA analyses allowed for the observation of an age-dependent interplay of known microbial agents. Also, lesser-known microbes, such as porcine polyoma, parainfluenza, and hemagglutinating encephalomyelitis viruses, were observed. Analyses of swIAV incidence and clinical signs showed differing microbial communities, highlighting age-specific observations of various microbes in porcine respiratory disease. In conclusion, nanopore metagenomics were shown to enable a panoramic view on viral and bacterial profiles as well as putative pathogen dynamics in endemic swIAV-infected herds. The results also highlighted the need for better insights into lesser studied agents that are potentially associated with porcine respiratory disease. IMPORTANCE To date, no comprehensive diagnostics for the study of polymicrobial infections that are associated with porcine respiratory disease have been offered. This precludes the proper understanding of the entire disease landscape, thereby hampering effective preventive and therapeutic actions. Compared to the often-costly diagnostic procedures that are applied for the diagnostics of porcine respiratory disease nowadays, a third-generation nanopore sequencing diagnostics workflow presents a cost-efficient and informative tool. This approach offers a panoramic view of microbial agents and contributes to the in-depth observation and characterization of viral and bacterial profiles within the respiratory disease context. While these data allow for the study of age-associated, swIAV-associated, and clinical symptom-associated observations, it also suggests that more effort should be put toward the investigation of coinfections and lesser-known pathogens (e.g., PHEV and PPIV), along with their potential roles in porcine respiratory disease. Overall, this approach will allow veterinary practitioners to tailor treatment and/or management changes on farms in a quicker, more complete, and cost-efficient way.

Behavior of Piglets in an Observation Arena before and after Surgical Castration with Local Anesthesia

Surgical castration of piglets is generally recognized as a painful procedure, but there is currently no gold standard for the assessment of pain behavior in piglets. However, pain assessment is essential for evaluating the effectiveness of local anesthetics. In this study, we investigated the efficacy of four local anesthetics in terms of pain relief during and after surgical castration in three sequential study parts. To do so, we filmed 178 piglets before the applied procedures, after injection of the local anesthetic, and up to 24 h after castration (five observation times in total) in an observation arena and compared their behavior before and after castration and between treatments and control groups. The results showed significant differences in the behavior of the piglets before and after castration and between the sham-castrated control group and the control group castrated without anesthesia. The different local anesthesia treatment groups showed diverging differences to the control groups. The most frequently shown pain-associated behaviors of the piglets were changes in tail position and hunched back posture. We observed a reduction but no complete elimination of the expressed pain-associated behaviors after local anesthesia. Several behavioral changes-such as changes in tail position, hunched back posture or tail wagging-persisted until the day after castration. Owing to the limited duration of the effects of the local anesthetics, local anesthesia did not influence long-term pain.

Explorative Field Study on the Use of Oral Fluids for the Surveillance of Actinobacillus pleuropneumoniae Infections in Fattening Farms by an Apx-Real-Time PCR

Simple Summary

Oral fluid sampling (OFS) is an animal friendly and easy way for surveillance purposes in domestic swine populations, especially concerning respiratory diseases. In case of Actinobacillus (A.) pleuropneumoniae surveillance, measures are usually combined with burdensome sampling for animals and humans. In the present study, we evaluated the suitability of oral fluids (OFs) for surveillance purposes of A. pleuropneumoniae infections in fattening pigs using an Apx-toxin real-time PCR. We were able to demonstrate that the examination of OFs by an Apx-toxin real-time PCR is suitable for A. pleuropneumoniae surveillance in the field in an animal friendly and easy way. These results might contribute to an increased compliance of laboratory diagnostic measures on pig farms and thereby to increased animal welfare due to less burdensome sampling and improved animal health.

Abstract

Oral fluids (OFs) represent a cost effective and reliable tool for surveillance purposes, mostly regarding viruses. In the present study, we evaluated the suitability of OFs for surveillance purposes concerning Actinobacillus (A.) pleuropneumoniae infections in fattening pigs under field conditions. OFs were examined with an Apx-toxin real-time PCR that detects the genes encoding for Apx I-, Apx III-, and Apx IV-toxin. For this purpose, we conducted a pen-wise collection of OFs over one fattening period from fattening pigs of two farms (farm A and B) with a known history of A. pleuropneumoniae infection. Lung lesions were determined at slaughter to estimate the extend of pulmonary lesions and pleural affection. Apx III- and Apx IV-toxin DNA were present in the OFs of both farms whereas Apx I-toxin DNA was present on farm A only. We were able to detect Apx I-, Apx III-, and Apx IV-toxin DNA in different patterns directly after introduction of the new pigs in the farms and over the entire study period. In summary, or results indicate the suitability of OFS for the early detection and surveillance of A. pleuropneumoniae in fattening farms.

Implementation of piglet castration under inhalation anaesthesia on farrowing farms

BACKGROUND

Since 01.01.2021, suckling piglets may no longer be castrated without anaesthesia in Germany. Previous studies showed castration using isoflurane anaesthesia in combination with a suitable analgesic, meet the requirements of the German Animal Welfare Act. It can be carried out independently by farmers and other qualified persons with an automated and certified isoflurane device. Therefore, the aim of the present field study was to implement the use of three different anaesthetic devices for surgical castration of male piglets under automated isoflurane anaesthesia on 15 conventional pig farms in southern Germany. In addition, the depth of anaesthesia based on defensive movements, the labour time required in contrast to anaesthetic-free castration, castration-related anaesthetic incidents and the piglet mortality rate as well as occupational safety were investigated. For this purpose, farrowing batches of 11,574 piglets castrated under isoflurane anaesthesia (IA) were compared with the results of the 1568 piglets of anaesthetic-free farrowing batches (AF).

RESULTS

In total, 80.1% of the castrated piglets showed sufficient depth of anaesthesia, although this varied significantly between devices. 1.7% of the piglets suffered an anaesthetic incident, of which 0.1% died during or within 24 h after anaesthesia. The required time for the complete working process differed significantly between AF (1.7 ± 0.8 min/piglet) and IA batches (2.2 ± 0.8 min/piglet) but not for castration itself. The mean isoflurane consumption was 0.57 ± 0.27 ml/piglet and differed significantly between the devices (p < 0.001). The isoflurane concentration in the ambient air of the person-related workplace safety measurements was below the internationally lowest value of 15 mg/m³ from Ontario and Israel.

CONCLUSION

In conclusion, 2 of the 3 types of devices used, a sufficient depth of anaesthesia during castration under isoflurane was achieved in 85% of castrated piglets. Anaesthetic incidents occurred in 1.7% of the animals, of which 0.1% died. Castration under isoflurane is more time-consuming than anaesthetic-free castration, but the castration time itself did not differ significantly. The occupational exposure limits were below the internationally lowest limit value of 15 mg/m³ for the persons involved. Even though castration under isoflurane is more time consuming than anaesthetic-free castration, it is a well-establishable method for practice and a dear improvement for animal welfare.

[Hind limb paralysis in fattening pigs due to a new strain of porcine Teschovirus A11]

In a fattening farm in southern Germany, paralysis of the hind limbs was observed in 2 age groups (50 kg as well as 60 kg) during a 4 week period. Despite a low morbidity of 3.3 % the majority of the affected animals needed to be euthanized in consequence to the progression of their hind limb paralysis. During pathomorphological examinations of 2 affected fattening pigs severe lymphohistiocytic meningoencephalomyelitis and vasculitis were detected. Immunhistochemistry revealed the presence of Porcine Teschovirus antigen in all parts of the central nervous system as well as in several cell types (neurons, glia cells, endothelial cells, mononuclear cells). Porcine Teschovirus was detected by PCR in spinal cord samples. The subsequently performed phylogenetic analysis PCR revealed a close relation (88 % full genome sequence) to porcine Teschovirus A11 strain "Dresden". Other swine relevant pathogens were excluded by PCR, bacteriologic examination and sequencing. Following a period of 4 weeks no additional cases of hind limb paralysis were observed in the fattening farm.

Occurrence of 'Candidatus Mycoplasma haemosuis' in fattening pigs, sows and piglets in Germany using a novel gap-based quantitative real-time PCR assay

Background

The appearance of the novel porcine haemotrophic mycoplasma (HM) species ‘Candidatus Mycoplasma haemosuis’ was reported in apparently healthy but also in clinically sick animals in China, Korea and in a case report from Germany. Outside of Asia, however, nothing further is known about the frequency of ‘Ca. M. haemosuis’ in pigs to date. To investigate the distribution of this novel HM species in Germany, fattening pigs, sows and pre-suckling piglets were examined using a herein developed quantitative real-time PCR assay (qPCR). Because the piglets were sampled before the first colostrum uptake, additional information on a possible vertical transmission from dams to their offspring was obtained.

Results

Our novel qPCR assay successfully detected ‘Ca. M. haemosuis’ in all blood samples from the ‘Ca. M. haemosuis’-infected pigs. No cross-reactivity was detected when DNA from non-target Mycoplasma spp. and other bacterial species representing 10⁵ bacteria/reaction were used as a template. The lower limit of detection of the qPCR was thus 10 gap gene copies per reaction and 2.5 x 10³ genome equivalents (GE) per mL blood.

‘Candidatus M. haemosuis’ was detected by this qPCR in blood samples from a total out of 6.25% sows (13/208), 4.50% pre-suckling piglets (28/622) and 17.50% fattening pigs (35/200). On farm level, 3 out of 21 piglet producing farms (14.28%) and 9 out of 20 fattening farms (45.00%) were positive for ‘Ca. M. haemosuis’. Co-infections with M. suis were evident in all age groups.

Conclusion

‘Candidatus M. haemosuis’ infection is present in German pig farms and the detection of the novel porcine HM species in piglets immediately after birth before colostrum intake indicates vertical transmission. The novel qPCR assay specific for ‘Ca. M. haemosuis’ described herein will be a prerequisite for future studies on the prevalence, epidemiology as well as the clinical and economic impact of ‘Ca. M. haemosuis’ infections.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-022-03147-1.

Cross-sectional study on the in-herd prevalence of Mycoplasma hyopneumoniae at different stages of pig production

BACKGROUND

A cross-sectional study was carried out to assess the prevalence of Mycoplasma hyopneumoniae infections before vaccination in 3-week-old piglets and to gain information about infection dynamics.

METHODS

In 13 German and three Austrian farms with a known history of enzootic pneumonia, 790 piglets and 158 sows were sampled (blood samples, tracheobronchial swabs [TBS] [piglets], laryngeal swabs [LS] [sows]), and 525 pen-based oral fluids (OFs) were collected in growing and fattening pigs. Laboratory diagnostics included enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (PCR) analyses.

RESULTS

Antibodies to M. hyopneumoniae were present in 87.5 per cent of all herds. Seroprevalence ranged from 0.0 to 100.0 per cent and 0.0 to 88.0 per cent in sows and piglets, respectively. M. hyopneumoniae-deoxyribonucleic acid (DNA) was present in 3.8 and 0.4 per cent of LS and TBS, respectively. Gilts had a 10.9 times higher chance being M. hyopneumoniae PCR-positive than older sows. In 75.0 per cent of all farms, M. hyopneumoniae-DNA was present in OFs. Detection rate was significantly higher in OFs of 20-week-old than in younger pigs (p < 0.001).

CONCLUSION

Results indicate that M. hyopneumoniae infections of the lower respiratory tract in piglets are rare but highlight the role of gilts in maintaining infection in the herd. Collecting OFs seems promising for surveillance, if coughing occurs simultaneously.

Detection of porcine circovirus type 3 DNA in serum and semen samples of boars from a German boar stud

Porcine circovirus type 3 (PCV3) is regularly reported in association with various clinical presentations, including porcine dermatitis and nephropathy syndrome (PDNS)-like lesions, respiratory signs, congenital tremor, and reproductive disorders. To investigate the epidemiology of PCV3 in a boar stud, we analysed fresh boar semen and matching sera from 181 boars from a German stud supplying semen for artificial insemination (AI) to approximately 740 breeder farms for PCV3 DNA. PCV3 DNA was detected in 1.7% semen samples and 24.3% sera. Spearman rho correlation demonstrated a significant positive correlation between boar age and quantitative DNA (by PCR quantification cycles [Cq] values) in serum samples (r = 0.636; P < 0.001). Sera from boars up to 12 months of age had higher viral loads (P < 0.001) and were PCV3-positive significantly more often (P < 0.01) than older boars. Detection of PCV3 DNA was not associated with breed (P> 0.05). PCV3 DNA was detected sporadically in fresh boar semen. Based on the assumption that processing fresh semen reduces viral load in semen used for AI, it is likely that the risk of sexual transmission of PCV3 during AI in is low. However, young boars may contribute to the maintenance of PCV3 infection in boar studs.

Update on shedding and transmission routes of porcine haemotrophic mycoplasmas in naturally and experimentally infected pigs

Horizontal transmission of Mycoplasma suis via parenteral exposure during standard practices or through bites during fightings have been identified as key epidemiological routes. However, as knowledge gaps on other potential shedding and transmission routes exist, the present study combines both laboratory experiments and field surveys to gain new insights into the epidemiology of porcine haemotrophic mycoplasmas. Splenectomised pigs were orally inoculated with a M. suis field strain and investigated for clinical signs related to infectious anaemia of pigs (IAP) and the presence of M. suis in blood, urine and saliva samples by qPCR. All blood samples were negative for M. suis and animals did not show obvious clinical signs of IAP throughout the entire study period. Additionally, urine, nasal and saliva samples from sows of conventional piglet producing farms and semen samples from a boar stud revealed no detection of M. suis and ‘Candidatus Mycoplasma haemosuis’ by qPCR. Thus, the results indicate that blood-independent transmission routes might be of minor relevance under field conditions.

[Investigations on suckling piglets castrated under automated isoflurane anesthesia]

OBJECTIVE

Investigation of defensive reactions, piglet losses, post-bleeding and recovery time of suckling piglets castrated under automated isoflurane anesthesia as well as measurements of isoflurane concentrations in ambient air and estimation of the cleaning and disinfection success of anesthesia masks.

MATERIAL AND METHODS

A total of 955 suckling piglets (age: 4.0 ± 1.2 days; weight: 2.0 ± 0.5 kg) were castrated under automated isoflurane anesthesia (PorcAnest 3000^®) after the administration of a non-steroidal anti-inflammatory drug. Reactions during the procedure were assessed before castration using the interdigital claw reflex and during castration by defensive movements and vocal response. The piglets' recovery time was evaluated in the stable corridor (pass 1) and the farrowing pen (passes 4-5). In 73 animals, the spermatic cord was cut with a scalpel and the post-operative bleeding visually evaluated. In addition, exposure measurements of isoflurane were performed and anesthetic masks were examined for total bacterial contamination and indicator bacteria before and after the anesthetic procedure and following their disinfection.

RESULTS

Following insufflation of isoflurane for 90 seconds 94.3 % of the piglets and after prior testing of the interdigital claw reflex and possible extension of the anesthetic supply 95.3 % of the piglets showed no or minimal defensive movements during castration. An anesthetic incident occurred in 0.9 % of the piglets, but no animal died. The recovery time lasted 7.3 ± 4.7 minutes (pass 1) and 6.2 ± 3.3 minutes (passes 4-5). Cutting the spermatic cord with a scalpel led to a higher post-bleeding score (p < 0.001) compared to use of the emasculator. Isoflurane concentrations in ambient air ranged between 4.5 und 28.1 mg/m³. Masks disinfection reduced the total germ count by 99.8 %. Contaminations with Escherichia coli and MRSA were no longer detectable in 4 of 6 cases after disinfection.

CONCLUSION

Isoflurane anesthesia led in over 94 % of the piglets to no or minimal defensive reactions during castration. Anesthetic incidents occurred rarely and no piglet losses were recorded. Therefore, automated isoflurane anesthesia is associated with a low risk for suckling piglets. Measurements of isoflurane concentrations on persons involved were below the internationally lowest limit value. Disinfection of the anesthesia masks may prevent germ transmission between animal groups via this potential vector.

Clinical, haematological and pathomorphological findings in Mycoplasma suis infected pigs

BACKGROUND

Mycoplasma suis (M. suis) belongs to the group of haemotrophic mycoplasmas and is known as the causative agent of infectious anaemia in pigs. In the last few years valuable insights into the mechanism of adhesion and invasion, shedding patterns and cell tropism of M. suis were gained by the use of new molecular techniques. However, details on M. suis induced lesions as well as the distribution of M. suis in different organs are still lacking. Therefore, seven splenectomised pigs were experimentally infected and clinical and laboratory investigations as well as a detailed histopathological examination were performed. Detection and quantification of M. suis DNA in blood and various tissue samples was done using a quantitative real-time PCR.

RESULTS

During the course of experimental infection, periodically occurring signs of infectious anaemia of pigs including severe icteroanaemia, fever, apathy and anorexia were observed. In addition, dermatological manifestations such as haemorrhagic diathesis presenting as petechiae occurred. The most important haematological alterations were normochromic, normocytic anaemia, hypoglycaemia as well as increased bilirubin and urea concentrations. Necropsy revealed predominant evidence of haemolysis with consecutive anaemia, as well as disseminated intravascular coagulation. M. suis was found in all investigated tissues with the highest copy numbers found in the kidneys. In Giemsa stained sections M. suis was only detected red blood cell (RBC)-associated.

CONCLUSION

In the present study, no RBC independent sequestration of M. suis was detected in organs of experimentally infected pigs. Pathological findings are most likely resulting from haemolysis, consecutive anaemia as well as from disseminated intravascular coagulation and subsequent organ impairments.

Exposure of wild boar to Influenza A viruses in Bavaria: Analysis of seroprevalences and antibody subtype specificity before and after the panzootic of highly pathogenic avian influenza viruses A (H5N8)

Swine influenza A viruses (S-IAV) circulate in wild boar populations worldwide. Subtypes primarily reflect those actually present within the respective pig industry. Accordingly, infections with swine H1N1, H1N2 and H3N2 have been reported for several regions of Germany. As pigs are susceptible not only to S-IAV but also to avian and human influenza A viruses, it is necessary to consider the possibility that new reassortant viruses with pandemic potential may arise in these new hosts. Therefore, in this study the impact of recent IAV epidemics on antibody prevalences in Bavarian wild boar was assessed. Important events considered were the H1N1pdm09 pandemic, which affected humans and swine, and the highly pathogenic avian influenza (HPAI) H5N8 panzootic in 2016 and 2017, affecting wild and domestic birds. IAV seroprevalences were determined analysing 1,396 samples from before and after the H5N8 panzootic, from various regions in Bavaria, a large administrative region in the South of Germany. Taken together, seroprevalences varied markedly from 1.44% to 12.59%, relative to region and time. However, no discrete correlation was found to population density either in wild boar or in pigs. Antibodies against H1N1 were the most prevalent. In addition, antibodies were detected reacting against H1N2 and against H1pdmNx reassortant viruses, already known to circulate in domestic pigs in Bavaria and notably also against the avian influenza A virus H5N8; the latter in samples taken in 2017. These results confirm the exposure of wild boar to IAV of diverse origin and the increasing variability of S-IAV present in the field. The necessity for continuous IAV surveillance not only of domestic swine but also of wildlife is emphasized.

Discriminating the eight genotypes of the porcine circovirus type 2 with TaqMan-based real-time PCR

Background

The porcine circovirus type 2 (PCV2) is divided into eight genotypes including the previously described genotypes PCV2a to PCV2f and the two new genotypes PCV2g and PCV2h. PCV2 genotyping has become an important task in molecular epidemiology and to advance research on the prophylaxis and pathogenesis of PCV2 associated diseases. Standard genotyping of PCV2 is based on the sequencing of the viral genome or at least of the open reading frame 2. Although, the circovirus genome is small, classical sequencing is time consuming, expensive, less sensitive and less compatible with mass testing compared with modern real-time PCR assays. Here we report about a new PCV2 genotyping method using qPCR.

Methods

Based on the analysis of several hundred PCV2 full genome sequences, we identified PCV2 genotype specific sequences or single-nucleotide polymorphisms. We designed six TaqMan PCR assays that are specific for single genotypes PCV2a to PCV2f and two qPCRs targeting two genotypes simultaneously (PCV2g/PCV2d and PCV2h/PCV2c). To improve specific binding of oligonucleotide primers and TaqMan probes, we used locked nucleic acid technology. We evaluated amplification efficiency, diagnostic sensitivity and tested assay specificity for the respective genotypes.

Results

All eight PCV2 genotype specific qPCRs demonstrated appropriate amplification efficiencies between 91 and 97%. Testing samples from an epidemiological field study demonstrated a diagnostic sensitivity of the respective genotype specific qPCR that was comparable to a highly sensitive pan-PCV2 qPCR system. Genotype specificity of most qPCRs was excellent. Limited unspecific signals were obtained when a high viral load of PCV2b was tested with qPCRs targeting PCV2d or PCV2g. The same was true for the PCV2a specific qPCR when high copy numbers of PCV2d were tested. The qPCR targeting PCV2h/PCV2c showed some minor cross-reaction with PCV2d, PCV2f and PCV2g.

Conclusion

Genotyping of PCV2 is important for routine diagnosis as well as for epidemiological studies. The introduced genotyping qPCR system is ideal for mass testing and should be a valuable complement to PCV2 sequencing, especially in the case of simultaneous infections with multiple PCV2 genotypes, subclinically infected animals or research studies that require large sample numbers.

[The porcine respiratory disease complex (PRDC) - a clinical review]

The porcine respiratory disease complex describes a clinical condition that often manifests as treatment-resistant respiratory disease of growing to finishing pigs. Its multifactorial etiology includes infectious and non-infectious factors. Besides management and hygiene conditions, particularly viral and bacterial pathogens contribute to the development and course of PRDC. The porcine reproductive and respiratory syndrome virus (PRRSV), porcine circovirus type 2 (PCV2), influenza A virus (IAV) and Mycoplasma (M.) hyopneunoniae are considered as the major pathogens involved in PRDC. The clinical outcome and necropsy findings may differ depending on the involvement of the different pathogens. The complex nature of the PRDC impedes the diagnostic and preventive measures on affected farms. The present review provides insight into the pathomorphology, pathogenesis and inter-pathogen-interactions and aims to support practitioners in implementing purposeful diagnostic and preventive measures.

Application of an economic calculator to determine the cost of porcine reproductive and respiratory syndrome at farm-level in 21 pig herds in Germany

BACKGROUND

Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) continues to be a major economic issue for the swine industry worldwide, not only due to acute outbreaks but also endemic infections. PRRS disease severity and consequently financial losses can vary greatly between endemically infected farms and estimation of damage is challenging. This study aimed to assess the economic effect of PRRS in a systematic way at individual farm-level for endemically infected herds, using a PRRS cost simulation tool. In total 21 German sow herds with endemic PRRSV infection were investigated. Data on health and production performance, farm management and environment to be fed into the calculator was collected on each farm, and blood samples taken to confirm the PRRSV status.

RESULTS

All study farms experienced a significant loss attributable to PRRS. The median farm budget across all farms was - 31 € per sow and year, compared to a median simulated farm budget of 248 € if these farms had been PRRSV negative. The median total loss attributable to PRRS was 74,181 € per farm per year, corresponding to a median total loss per sow and year of 255 €. The impact of PRRS on farm profits was - 19.1% on average and - 41% in the worst case.

CONCLUSIONS

The calculated losses give a good hint of the economic damage due to PRRS for the pig industry. Even in endemically infected farms, farmers face a non-negligible damage and profit from a concerted PRRS control. The calculator has proven itself in the field to render a valid estimation of losses due to PRRS in endemically infected farms.

Local anesthesia in piglets undergoing castration-A comparative study to investigate the analgesic effects of four local anesthetics on the basis of acute physiological responses and limb movements

Surgical castration of male piglets without analgesia is a painful procedure. This prospective, randomized and double-blinded study aimed to evaluate the analgesic effects of four different local anesthetics for piglet castration during the first week of life. In total, 54 piglets aged 3 to 7 days were distributed into 6 treatment groups: handling (H); castration without pain relief (sodium chloride, NaCl); and castration with a local anesthetic: 4% procaine (P), 2% lidocaine (L), 0.5% bupivacaine (B) or 20 mg/ml mepivacaine (M). By excluding stress and fear as disruptive factors via a minimum anesthesia model, all piglets received individual minimum alveolar concentration (MAC) isoflurane anesthesia. Twenty minutes before castration, all treatment groups except group H received one injection per testis. Then, 0.5 ml of a local anesthetic or NaCl was injected intratesticularly (i.t.), and 0.5 ml was administered subscrotally. Acute physiological responses to noxious stimuli at injection and castration were evaluated by measuring blood pressure (BP), heart rate (HR), cortisol, epinephrine, norepinephrine and chromogranin A (CgA); limb movements were quantified. The results confirm that castration without analgesia is highly painful. Surgical castration without pain relief revealed significant changes in mean arterial blood pressure (MAP) and HR. Local anesthetic administration significantly reduced changes in BP and HR associated with castration. Piglets receiving a preoperative local anesthetic exhibited the fewest limb movements during castration, while the NaCl group exhibited the most. Injection itself was not associated with significant changes in MAP or HR. However, many piglets exhibited limb movements during injection, indicating that the injection itself causes nociceptive pain. No significant differences were found between groups regarding parameters of plasma cortisol, catecholamines and CgA. In conclusion, all four local anesthetics administered are highly effective at reducing signs of nociception during castration under light isoflurane anesthesia. However, injection of a local anesthetic seems to be painful.

Detection of a novel haemoplasma species in fattening pigs with skin alterations, fever and anaemia

BACKGROUND

In a fattening farm in Southern Germany, skin alterations (urticaria, haemorrhagic diathesis) and high fever were observed in 30% of the pigs 2 weeks after arrival. Feed intake was severely compromised in affected pigs.

METHODS

After detailed clinical observation, blood samples from affected pigs were collected for haematological, PCR and serological investigations. In addition, pathological investigations were performed on one pig.

RESULTS AND CONCLUSION

Analysis of blood parameters revealed a normocytic, normochromic anaemia. A novel porcine haemoplasma species was detected in blood samples of affected pigs and spleen sample of the necropsied pig by PCR. Phylogenetic analyses based on the 16S rDNA showed 99% identity to a novel porcine haemoplasma ('Candidatus (Ca.) M. haemosuis') species which has recently been described in China. Interestingly, this is the first report of 'Ca. M. haemosuis' in pigs with clinical signs resembling those of Mycoplasma (M) suis and the first description of this novel haemoplasma species outside Asia. On-farm affected pigs were treated with oxytetracycline and non-steroidal anti-inflammatory drugs. Clinical signs improved after implementation of treatment and optimisation of management procedures. This case might indicate that other porcine haemoplasma species than M suis can induce fever and skin alterations and may have an economic impact on affected farms.

Influences of Immunocastration on Endocrine Parameters, Growth Performance and Carcass Quality, as Well as on Boar Taint and Penile Injuries

Simple Summary

Surgical castration of male pigs is associated with pain. Improvac^®, a GnRH vaccine induces an endogenous immune reaction that leads transiently to a decrease in testicular steroid synthesis after second vaccination. Investigating consequences of different vaccination schemes revealed that GnRH vaccination reliably prevents boar taint, if the manufacturers’ recommendations are applied. It had beneficial effects on animal welfare as it reduced penile injuries. Animals showed improved feed efficiency, leaner carcasses, and lower PUFA (polyunsaturated fatty acids) percentages than surgically castrated animals. Thus, immunocastration offers a reliable and animal friendly alternative to surgical castration.

Abstract

Castration of male pigs without anesthesia is a significant welfare issue. Improvac^®, a GnRH vaccine induces an endogenous immune response leading to a decrease in testicular steroids. Consequences of different vaccination schemes on testicular function and carcass quality were evaluated in immunocastrated boars (IC), surgical castrates (SC), and entire males (EM). Therefore, 128 male piglets were assigned to five treatment-groups and a long term follow-up group. IC groups received two vaccinations (V1, V2) with Improvac^® at 8 and 12, 12 and 16, or 12 and 18 weeks. Testosterone-concentrations decreased significantly two weeks after V2 in feces and dropped in serum from V2 to slaughter (S) except IC-8/12 without differing significantly. GnRH-binding results indicated the highest values for IC-12/18 animals. While IC-12/16 and IC-12/18 animals showed boar taint compounds below the threshold levels, two IC-8/12 animals had concentrations above the threshold level. Feed-efficiency was higher in EM than in SC with IC in between. In IC compared to EM, a decreasing amount of polyunsaturated-fatty-acids was obvious and GnRH-vaccination reduced penile injuries. The examined vaccination protocols reduce penile injuries, improve feed efficiency and carcass quality, and reliably prevents boar taint, if manufacturer’s recommendations concerning vaccination schedules are applied. Therefore immunocastration offers a reliable, animal friendly alternative to surgical castration.

Reproductive performance of pandemic influenza A virus infected sow herds before and after implementation of a vaccine against the influenza A (H1N1)pdm09 virus

Background

Reproductive failure in sow herds due to infection with influenza A viruses has been described in the literature, but only a few studies have focused on the pathogenesis and the clinical signs of the infection. Case reports indicate an association between infections with influenza A viruses and reduced reproductive performance, although it has been difficult to experimentally reproduce the clinical outcome of poor reproductive performance. The aim of the present longitudinal field study was to compare the reproductive performance parameters before and after the implementation of vaccination against the influenza A (H1N1)pdm09 virus in sow herds infected with pandemic influenza A virus. Therefore, farm-specific data of 137 sow herds in Germany, including 60,153 sows, as well as the clinical presentation of the infection were surveyed via questionnaire. Furthermore, average performance parameters (return to oestrus rate, abortion rate, stillbirth rate, number of piglets born alive per litter, preweaning mortality rate and number of piglets weaned per sow per year) were recorded for 6 months before vaccination and 6 months after completion of primary vaccination.

Results

In 79.8% of the farms, the clinical presentation of the infection was characterised by a reduced reproductive performance. These findings were confirmed by analysis of the performance parameters, which revealed a significant decline in the return to oestrus rate (p < 0.001), abortion rate (p < 0.001) and preweaning mortality rate (p = 0.023) and a significant increase of the number in piglets born alive (p = 0.001) and piglets weaned per sow per year (p < 0.001) after immunisation. The stillbirth rate did not change significantly.

Conclusion

The present study represents the first attempt to demonstrate the association of influenza A virus infection, vaccination and the alteration in reproductive performance parameters, investigating a large number of cases. The results show that by vaccinating against the influenza A (H1N1)pdm09 virus, an improvement in reproductive performance can be achieved in sow herds infected with pandemic influenza A virus. Additionally, the large number of herds that were affected by poor reproductive performance after infection with the aforementioned virus confirms the assumption of an association between pandemic influenza A virus and reproductive losses.

Mild maternal hyperglycemia in INS C93S transgenic pigs causes impaired glucose tolerance and metabolic alterations in neonatal offspring

Alongside the obesity epidemic, the prevalence of maternal diabetes is rising worldwide, and adverse effects on fetal development and metabolic disturbances in the offspring's later life have been described. To clarify whether metabolic programming effects are due to mild maternal hyperglycemia without confounding obesity, we investigated wild-type offspring of INS^C93S transgenic pigs, which are a novel genetically modified large-animal model expressing mutant insulin (INS) C93S in pancreatic β-cells. This mutation results in impaired glucose tolerance, mild fasting hyperglycemia and insulin resistance during late pregnancy. Compared with offspring from wild-type sows, piglets from hyperglycemic mothers showed impaired glucose tolerance and insulin resistance (homeostatic model assessment of insulin resistance: +3-fold in males; +4.4-fold in females) prior to colostrum uptake. Targeted metabolomics in the fasting and insulin-stimulated state revealed distinct alterations in the plasma metabolic profile of piglets from hyperglycemic mothers. They showed increased levels of acylcarnitines, gluconeogenic precursors such as alanine, phospholipids (in particular lyso-phosphatidylcholines) and α-aminoadipic acid, a potential biomarker for type 2 diabetes. These observations indicate that mild gestational hyperglycemia can cause impaired glucose tolerance, insulin resistance and associated metabolic alterations in neonatal offspring of a large-animal model born at a developmental maturation status comparable to human babies.

Editor's choice: Mild maternal hyperglycemia causes impaired glucose tolerance and metabolic alterations in wild-type neonatal offspring of INS^C93S transgenic pigs, a novel large animal model for mutant INS gene-induced diabetes of youth (MIDY).

Detection of Mycoplasma suis in pre-suckling piglets indicates a vertical transmission

Background

Transmission of Mycoplasma (M.) suis mainly occurs via iatrogenic or zootechnical manipulations or due to ranking fights. Other transmission routes including ingestion of secretes/excretes; blood-sucking arthropods and intra-uterine transmission have thought to play an epidemiological role without being experimentally proven. To investigate a vertical transmission of M. suis under field conditions blood samples from pre-suckling piglets and their corresponding dam were examined for M. suis by quantitative polymerase chain reaction (qPCR) in 21 farms in Southern Germany.

Results

A total of 14.35% of the 474 blood samples from pre-suckling piglets reacted qPCR positive. Additionally, M. suis was detected in 65 (31.25%) of the 208 sows at farrowing. On farm level, 16 (76.2%) of the 21 farms had at least one M. suis positive animal. M. suis positive farms had an average of 0.41 more stillborn piglets per litter than M. suis negative farms (p = 0.007).

Conclusion

The present study provides further insights into M. suis infection dynamics as it is the first detection of M. suis in piglets immediately after birth prior to colostrum intake and the first large scale investigation of M. suis in sows at farrowing.

[Pain and distress response of suckling piglets to injection and castration under local anaesthesia with procaine and licocaine - Part 2: Defence behaviour, catecholamines, coordination of movements]

OBJECTIVE

Comparison of the effectiveness of local anaesthesia (LA) in piglet castration with the combination of scrotal and inguinal application of procaine 2 % and lidocaine 5 % to the intratesticular application of lidocaine 1 % using following parameters: adrenaline (A), noradrenaline (NA), defensive movements and coordinated movement patterns.

MATERIAL AND METHODS

In 2 substudies 232 male suckling piglets (3-6 days of age) were randomly allocated to study groups. In groups L5 and group P2 lidocaine 5 % and procaine 2 % was applied inguinally and scrotally, respectively, while piglets of groups H (handling) and K (castration without local anaesthesia) were only fixated as for an injection. In group L1 lidocaine 1 % was injected intratesticularly. After 30 min piglets were were castrated, whereas animals of group H were again only fixated. In substudy 1 (n = 112) blood samples were taken to determine the concentration of catecholamines after castration. During injection and castration defensive movements were judged. In substudy 2 (n = 120) piglets completed a chute to document the individual stress level.

RESULTS

Groups H and L1 demonstrated significantly less defensive movements during fixation for injection/injection compared to the other study groups (p ≤ 0.05). After the injection piglets of group P2 had significantly more difficulties in the chute and needed > 50 % more time to complete the course. In all study groups defensive movements during castration were the highest at the moment of severing the spermal cord. Group K obtained the highest possible rating of 8 and differed significantly from the other groups as well as when cutting the skin (p ≤ 0.05). Both the concentration of A and NA significantly rose in all groups. The increase in A and NA was significantly higher in group 2, as well as the increase in NA in group K, both in comparison to the other study groups (p ≤ 0.05).

CONCLUSION

None of the applied techniques for local anaesthesia achieved a complete elimination of pain during castration of suckling piglets. The behaviour analysis indicated an altogether higher distress for P2. After castration, this injection led to a neuroendocrine pain reaction that was comparable to or higher than that of group K. In both lidocaine groups (L1, L5) the pain reaction after castration tended to be lower. These results provide approaches to apply longer acting LA with a higher analgesic potency in an appropriate dosage and with an appropriate method of application.

[Pain and distress responses of suckling piglets to injection and castration under local anaesthesia with procaine and lidocaine - Part 1: Cortisol, chromogranin A, wound healing, weights, losses]

OBJECTIVE

Comparison of the effectiveness of local anaesthesia (LA) in piglet castration by procaine 2 % and lidocaine 5 % both through combined inguinal and scrotal application as well as by intratesticular application of lidocaine 1 %. The parameters used were serum cortisol and chromogranin A (CgA) concentrations as well as wound healing, body weight and animal losses.

MATERIAL AND METHODS

In 2 substudies, a total of 232 male piglets aged 3-6 days were included. Substudy 1 (112 piglets): Group H: fixation of piglets as for an injection; group L5: inguinal and scrotal injection of lidocaine 5 %; group P2: inguinal and scrotal injection of procaine 2 %; group L1: intratesticular injection of lidocaine 1 %. In all the groups, blood samples were taken 45 minutes before and 30 minutes post-injection (p. i.). Substudy 2 (120 piglets): Group H: handling only as for an injection and castration; group K: handling as for an injection and castration without LA after 30 minutes. Groups L5, P2 and L1: management as in substudy 1 and castration after 30 minutes. Blood samples were taken 75 minutes before as well as 30, 60 and 240 minutes post-castration (p. c.). The evaluated parameters were serum cortisol and CgA concentrations, wound healing, body weight and piglet losses.

RESULTS

Substudy 1: The elevation of the cortisol and CgA concentrations in group P2 p. i. were significantly higher than in the other groups. The mean total cortisol concentration of group P2 p. i. was significantly higher than those of the other groups. Substudy 2: At 30 minutes p. c., all the groups displayed a significant increase in the cortisol concentration compared to group H. In group P2, the highest total cortisol concentration was measured 60 minutes p. c. and the elevation of the cortisol level was significantly higher than in the other groups. In group L1, a significantly greater increase in the CgA level was observed at 60 minutes p. c. when compared to the other groups. Regarding wound healing, body weight and losses, there were no significant differences between the groups.

CONCLUSION

The combined inguinal and scrotal injection of procaine 2 % induced a greater neuroendocrine stress response than the inguinal and scrotal injection of lidocaine 5 % and the intratesticular injection of lidocaine 1 %. LA using procaine 2 %, lidocaine 5 % or lidocaine 1 % did not completely eliminate pain during castration. Castration under LA with procaine 2 % induced a greater pain reaction than castration without LA. Both groups castrated with LA using lidocaine (L1, L5) tended to display lower pain responses after castration than group K. On the basis of the findings of this study, other local anaesthetics that have a stronger effect could be further investigated according to their pain-killing effects in an appropriate application route.

[Technopathies of the limbs in finishing pigs: risk factors, origin and impact on animal welfare. - Study phase 2]

OBJECTIVE

Determination of possible risk factors of adventitious bursae (AB) in finishing pigs depending on different types of flooring and evaluation of their impact on animal welfare.

MATERIAL AND METHODS

The prevalence of adventitious bursae in 1702 finishing pigs from nine conventional fattening farms with different types of flooring (fully slatted, PigPort = partially slatted floor, slanted floor = solid concrete floor, deep straw-bedded) was investigated at entry into fattening farm and shortly before slaughter. Existing bursae were recorded and graded and the skin of the affected locations was evaluated. Additionally, the weight of each individual pig was recorded on both dates.

RESULTS

On fully slatted floors 94.0 % of the pigs showed at least one bursa shortly before slaughter, in PigPort-farms 87.6 %, in slanted floor-farms 82.9 % and on deep straw-bedded floor 50.3 %. When comparing both assessment dates the pigs on fully slatted floors had the highest increase in prevalence of bursae, followed by the pigs in PigPorts, on slanted floors and on straw. Furthermore, the pigs fattened on fully slatted floors showed a significantly (p < 0.001) higher number of bursae per animal at the end of the fattening period than the pigs fattened on other types of flooring as well as a significantly (p < 0.001) higher proportion of more severe bursae.

CONCLUSION AND CLINICAL RELEVANCE

The high prevalence of bursae assessed in this study represents, irrespective of the presence of pain, a deficit regarding animal husbandry in terms of technopathy and therefore a serious issue regarding animal welfare. That requires changes in terms of animal welfare standards. By reducing the amount of slots in the pens of fattening farms, as it is the case in PigPort- and even more in slanted floor-farms, the prevalence and number of bursae per pig and the severity of bursae can be reduced. An additional supply of a soft, flexible lying area, e.g. with straw as litter, is another positive measure that should be implemented if possible.

Influence of age, group size and the presence of porcine reproductive and respiratory syndrome virus on the collection of oral fluids

Pen-based oral fluid (OF) samples have been approved for detecting porcine reproductive and respiratory syndrome virus (PRRSV) RNA and antibodies. The aim of the study was to investigate the influence of age, group size and the presence of PRRSV infection on sampling using pen-based OF collected by presenting pigs with a rope to chew. Samples were collected from pigs of 4/5 weeks of age, 7/8 weeks of age and 12/14 weeks of age. Subsequent PRRSV-PCR and ELISA analyses of OF and serum samples were performed. In this study, 76.5-81.9% of pigs chewed the rope. The group size had significant impact on the pig-rope-interaction (P=0.047). OF and serum had an almost perfect and significant agreement for the detection of antibodies (κ=0.829, P<0.001) and a fair and not significant agreement (κ=0.347, P=0.75) for the detection PRRSV-genome.

Cross-sectional study on viraemia and shedding of porcine circovirus type 2 in a subclinically infected multiplier sow herd

Vertical and horizontal transmission of porcine circovirus type 2 (PCV2) plays an important role for the spread of PCV2 within piglet-producing farms and following production steps. Further information is crucial to learn about the principles of PCV2 circulation among sows in piglet-producing farms to improve preventive healthcare concerning porcine circovirus diseases (PCVD) in downstream production steps. The present study was conducted as a cross-sectional study in a 400 sow multiplier herd in Germany with no PCV2 vaccination. Blood, faeces and saliva of the sows in all stages of production were tested for PCV2-DNA by real-time PCR. Results were analysed under respect of the parity and stage of production of the sows. PCV2-DNA in faeces or saliva was observed especially in young sows. Highest rates of viraemia in productive sows were found in the early stages of pregnancy. The results revealed that particularly gilts from the quarantine and rearing area and sows up to the second parity play a major role for the spread of PCV2 and thus for the maintenance of PCV2 infection in sow herds. Furthermore, the stage of production had a significant influence on the detection rate of PCV2-DNA in serum, saliva or faeces of the sows.

[Technopathies of the limbs in finishing pigs: risk factors, origin and impact on animal welfare - Study phase 1]

OBJECTIVE

The aim of the first part of the present study was to specify risk factors for the development of adventitious bursae on the limbs of weaning and finishing pigs.

MATERIAL AND METHODS

In total, 192 pigs were examined weekly, recording the following parameters: general condition, number, size and localization of adventitious bursae on the limbs and sternum, gait and claws.

RESULTS

Adventitious bursae can occur at 13 positions on the limbs or sternum. These adventitious bursae were already evident when pigs were moved to the nursery. The prevalence of adventitious bursae increased constantly from weaning to slaughter. At the age of 24 weeks, 97.8 % of all investigated pigs displayed adventitious bursae (aged 4 weeks: 25.5 %; aged 12 weeks: 67.6 %). Heavier pigs had significantly more and larger adventitious bursae than lighter pigs of the same age. Furthermore, heavier pigs retrieved feed from the automatic feeder less frequently but ate larger amounts each time. In addition, pigs with poorer gait displayed significantly more adventitious bursae. In 95.6 % of all investigated pigs, claw lesions were evident at slaughter. The general condition was unaffected by adventitious bursae.

CONCLUSION AND CLINICAL RELEVANCE

Referring to the results of the present study and the general function of bursae protecting underlying structure against pressure, there is no indication that adventitious bursae affect the animal welfare in terms of the sensation of pain. Influenced by various factors, adventitious bursae develop with high prevalence and number per animal over the course of the life of pigs and can be described as a technopathy. Because of the exposure of adventitious bursae, there is a risk to become an ulcerated bursa of degree three in relation to injuries.

Metabolic syndrome and extensive adipose tissue inflammation in morbidly obese Göttingen minipigs

OBJECTIVE

The worldwide prevalence of obesity has increased to 10% in men and 15% in women and is associated with severe comorbidities such as diabetes, cancer, and cardiovascular disease. Animal models of obesity are central to experimental studies of disease mechanisms and therapeutic strategies. Diet-induced obesity (DIO) models in rodents have provided important insights into the pathophysiology of obesity and, in most instances, are the first in line for exploratory pharmacology studies. To deepen the relevance towards translation to human patients, we established a corresponding DIO model in Göttingen minipigs (GM).

METHODS

Young adult female ovariectomized GM were fed a high-fat/high-energy diet for a period of 70 weeks. The ration was calculated to meet the requirements and maintain body weight (BW) of lean adult minipigs (L-GM group) or increased stepwise to achieve an obese state (DIO-GM group). Body composition, blood parameters and intravenous glucose tolerance were determined at regular intervals. A pilot chronic treatment trial with a GLP1 receptor agonist was conducted in DIO-GM. At the end of the study, the animals were necropsied and a biobank of selected tissues was established.

RESULTS

DIO-GM developed severe subcutaneous and visceral adiposity (body fat >50% of body mass vs. 22% in L-GM), increased plasma cholesterol, triglyceride, and free fatty acid levels, insulin resistance (HOMA-IR >5 vs. 2 in L-GM), impaired glucose tolerance and increased heart rate when resting and active. However, fasting glucose concentrations stayed within normal range throughout the study. Treatment with a long-acting GLP1 receptor agonist revealed substantial reduction of food intake and body weight within four weeks, with increased drug sensitivity relative to observations in other DIO animal models. Extensive adipose tissue inflammation and adipocyte necrosis was observed in visceral, but not subcutaneous, adipose tissue of DIO-GM.

CONCLUSIONS

The Munich DIO-GM model resembles hallmarks of the human metabolic syndrome with extensive adipose tissue inflammation and adipocyte necrosis reported for the first time. DIO-GM may be used for evaluating novel treatments of obesity and associated comorbidities. They may help to identify triggers and mechanisms of fat tissue inflammation and mechanisms preventing complete metabolic decompensation despite morbid obesity.

Safety and immune responses after intradermal application of Porcilis PRRS in either the neck or the perianal region

The objective of the present study was to assess safety and immune responses in gilts after intradermal application of Porcilis® PRRS in two different application sites under field conditions. Forty-four gilts were allocated to one of three groups: Gilts of group 1 (n = 10) served as non-vaccinated controls, gilts of group 2 (n = 17) were vaccinated intradermally in the neck and gilts of group 3 (n = 17) received an intradermal vaccination in the perianal region. Clinical observations, local injection site reactions and histopathologic examination of the injection site were used for safety assessments. Frequency and degree of clinical signs were not significantly different between all three groups. Minor local reactions for both vaccination groups were observed; however, at 6, 7, 8, 9 and 15 days post-vaccination (dpv), the mean injection site reaction score was significantly lower in pigs vaccinated in the perianal region. In histopathologic examination, an extended inflammatory dimension was observed more frequently in pigs vaccinated in the neck. Blood samples were analyzed to quantify the post-vaccination humoral (ELISA and virus neutralization test) and cellular (IFN-γ ELISPOT) immune responses. PRRSV-specific antibodies were present in the serum of all vaccinated animals from 14 dpv onwards, whereas all control pigs remained negative throughout the study. Neutralizing antibody titers were significantly higher in pigs vaccinated in the perianal region at 28 dpv. At 14, 21 and 28 dpv, PRRSV-specific IFN-γ secreting cells were significantly increased in both vaccination groups compared to non-vaccinated gilts. Analysis of mean numbers of PRRSV-specific IFN-γ secreting cells did not result in statistically significant differences between both vaccination groups. The results of this study indicate that the perianal region is a safe alternative application site for intradermal vaccination of gilts with Porcilis PRRS. Furthermore, the intradermal application of Porcilis PRRS induced humoral and cellular immune responses independent of the administration site.

Full genome characterization of porcine circovirus type 3 isolates reveals the existence of two distinct groups of virus strains

BACKGROUND

The occurrence of the novel porcine circovirus type 3 (PCV3) was reported from the Americas, Asia and Europe. Although this virus was detected in association with various clinical syndromes in pigs, its role as possible swine pathogen remains unclear. PCV3 was detected with high prevalence in Polish farms, but to date no genome sequences were available from European PCV3 strains.

METHODS

We collected 1060 serum samples from piglets at the age of 20-24 weeks from 53 farms distributed all over Germany. PCV3 DNA was detected using a real-time PCR and subsequently complete PCV3 genome sequences were obtained after multiply primed rolling circle amplification and sequencing of overlapping PCR products. Phylogenetic analysis was performed by neighbor-joining method and maximum likelihood method.

RESULTS

We obtained 15 complete PCV3 genome sequences as well as nine partial sequences including the putative ORFs 1, 2 and 3 from PCV3 viremic animals in German pig farms. Phylogenetic analysis of these German as well as 30 full genome sequences received from GenBank divided the PCV3 strains into two main groups and several subclusters. Furthermore, we were able to define group specific amino acid patterns in open reading frame 1 and 2.

CONCLUSION

PCV3 is distributed with high prevalence in German pig industry. Phylogenetic analysis revealed two clearly separated groups of PCV3 strains, which might be considered as PCV3 genotypes. Specific nucleotide and amino acid marker positions may serve for easy and fast intraspecies classification and genotyping of PCV3 strains. No correlation between PCV3 variants with their geographical origin was evident. We found the same diversity of PCV3 strains in Germany as in other countries. We hypothesize that PCV3 is not a newly emerging virus in the German pig population. Future studies will have to show, if PCV3 genotype specific biological properties are evident.

Einfluss einer GnRH-Vakzine (Improvac®) auf Gewichtszunahmen und Schlachtkörperqualität von Ebern

Gegenstand und Ziel: Vergleich von Wirkung und Einfluss der GnRH-Vakzine Improvac® (Pfizer GmbH, Berlin) mit der chirurgischen Kastration bei männlichen Mastschweinen. Material und Methoden: Tiere der Gruppe K (n = 205) wurden in der 1. Lebenswoche (LW) chirurgisch kastriert, Schweine der Gruppe V (n = 191) in der 12. und 18. LW mit Improvac® vakziniert (2 ml subkutan). In der 1., 4., 12., 18. und 22. LW wurden alle Tiere gewogen. Bei 171 Schweinen der Gruppe V erfolgte in der 18. und 20. LW eine Messung der Hodengröße. Nach der Schlachtung wurden Schlachtkörpergewicht und weitere Schlachtparameter erhoben und mit Halsmuskelstücken aller Tiere Koch- und Bratproben durchgeführt. Ergebnisse: In der 22. LW differierte das Durchschnittsgewicht der Schweine beider Versuchsgruppen nicht signifikant (K = 89,4 kg; V = 88,6 kg), doch ergaben sich in Gruppe V im Mittel niedrigere Schlachtkörpergewichte sowie Muskel- und Speckdicken. Die mittleren Tageszunahmen (TGZ) in Gruppe V waren ab der 18. LW im Vergleich zur Gruppe K signifikant höher (V = 1121 g; K = 1007 g; p < 0,001), nicht jedoch im Zeitraum zwischen 12. und 18. LW (K = 740 g; V = 668 g; p < 0,001). Die Hoden der vakzinierten Tiere verkleinerten sich nach der zweiten Injektion signifikant. Koch- und Bratprobe von Muskelstücken aller Tiere waren negativ. Schlussfolgerung: Gegen Ebergeruch geimpfte Schweine zeigten vor der zweiten Impfung niedrigere TGZ als die chirurgisch kastrierten, glichen den Gewichtsunterschied jedoch nach der zweiten Impfung aus. Die Verkleinerung der Hoden nach der Vakzination kann als Impferfolg gewertet werden. Nach Applikation von Improvac® wurde an den Schlachtkörpern keine Geruchsabweichung festgestellt. Klinische Relevanz: Die Vakzination verhindert ebenso wie die chirurgische Kastration das Auftreten von Ebergeruch zuverlässig. Der nach der zweiten Impfung beobachtete Anstieg der TGZ lässt sich bei entsprechendem Management nutzen.

Vitamin-D-Intoxikation bei Sauen

Gegenstand und Ziel: Beschreibung und Diskussion einerHypervitaminose D3 beim Schwein unter Berücksichtigung der Differenzialdiagnosen. Material und Methoden: Fallbericht eines Ferkelerzeugerbetriebes mit 190 Sauen. Ergebnisse: Nach der Lieferung einer neuen Futtercharge abortierten innerhalb von zwei Wochen 28% der tragenden Sauen in unterschiedlichen Stadien der Trächtigkeit. Gleichzeitig traten Symptome wie Inappetenz, Apathie, Untertemperatur und Erbrechen auf. Vier Sauen wurden klinisch und pathologisch-anatomisch untersucht. Eine der beiden Sauen, die nicht abortierten, gebar zum physiologischen Zeitpunkt 13 Mumien bzw. tote Ferkel. Bei der pathologischen Untersuchung konnten umfangreiche Verkalkungen unterschiedlichen Schweregrades festgestellt werden. Die Untersuchung einer Futterprobe ergab einen Vitamin-D-Gehaltvon 2.350.000 IE/kg. Dies entspricht einer 200fachen überdosierung dieses Futterzusatzstoffes. Schlussfolgerungen: Die aufgetretenen klinischen Symptome und die pathologischen Befunde entsprechen denen einer Vitamin-D-Intoxikation. In der Literatur finden sich keine Quellen, die solche Fruchtbarkeitsstörungen im Zusammenhang mit einer Vitamin-D-Intoxikation beim Schwein beschreiben. In Verdachtsfällen einer Futtermittelintoxikation ist eine gezielte Probenentnahme durch einen vereidigten Probennehmer von großer Bedeutung. Futterproben sollten asserviert werden, um im Fall einer forensischen Untersuchung weiterführende Analysen durchführen zu können. Klinische Relevanz: Intoxikationen kommt beim Schwein eine große Bedeutung zu, da meist ganze Bestände oder eine große Anzahl von Tieren betroffen sind.

Histopathologic lesions in conventional pigs experimentally infected with Haemophilus parasuis serovar 5

Objective: In the present study various tissues of pigs were investigated for the presence of histopathologic lesions after an experimental infection with Haemophilus (H.) parasuis serovar 5. Material and methods: Conventional pigs (n = 36) were divided into a control group B (n = 9) and a challenge group A (n = 27), which was infected intratracheally. Pigs that did not die prior to study termination were euthanized on day 14 post inoculation. Postmortem samples of the lung, heart, liver, kidney, spleen, left tarsal joint capsule and brain were collected. Results: All but one pig with detectable histopathologic lesions (n = 11) showed typical macroscopic changes. Histopatho logic examination of all tissue samples identified pyelitis (n = 10), synovitis (n = 7) and meningitis (n = 7) and all those animals were euthanized prior to study termination. No histopathologic lesions were found in pigs of the control group. The correlations between pyelitis and meningitis, pyelitis and synovitis and synovitis and meningitis were significant (p < 0.001). No significant correlation could be observed between the histopathologic and the clinical examination of the joints. The investigation of samples from the joints by PCR was not significantly correlated with the observed synovitis. The clinical observation of neurologic signs was significantly correlated with meningitis (p = 0.03). A significant correlation (p < 0.001) could be detected between meningitis and the detection of H. parasuis by PCR in brain samples. Conclusions: H. parasuis constantly causes clinical signs and pathologic lesions as soon as it infects the brain while it can infect the joints without causing histopathologic lesions. Pigs with histopathologic lesions do not always show typical clinical signs. Only few studies described the finding of kidney lesions in pigs with Glässer’s disease and this is the first study to describe a pyelitis in pigs experimentally infected with H. parasuis. The observed pyelitis mainly occurred in acute cases.

Einsatz einer Lokalanästhesie bei der Kastration von Ferkeln

Gegenstand und Ziel: Die Kastration von männlichen Ferkeln ist ein tierschutzrechtlich und emotional kontrovers diskutiertes Thema. Die vorliegende Arbeit untersuchte bei Saugferkeln den Einfluss einer Lokalanästhesie auf den Serum-Kortisolgehalt bei der Kastration. Material und Methoden: Insgesamt 30 Saugferkel erhielten 15 Minuten vor der Kastration eine intratestikuläre Injektion von Procainhydrochlorid. Blutproben wurden vor der Kastration sowie eine, vier und 28 Stunden nach dem Eingriff entnommen und auf den Kortisolgehalt untersucht. Als Kontrolltiere dienten Ferkel, bei denen eine Kastration ohne Medikation vorgenommen wurde (n = 48), sowie Ferkel, die nur einer Fixation ohne Operation unterlagen (n = 46). Ergebnisse: Eine und vier Stunden nach der Kastration bestanden keine signifikanten Unterschiede der Kortisolwerte zwischen Ferkeln, die mit Lokalanästhesie (Procainhydrochlorid) operiert wurden, und Ferkeln, bei denen der Eingriff ohne Medikation erfolgte. Schlussfolgerung und klinische Relevanz: Die Kastration unter Lokalanästhesie mit Procainhydrochlorid scheint für die Ferkel eine zum Eingriff ohne Verwendung des Lokalanästhetikumsvergleichbare Belastung darzustellen. Die Forderung nach einer Verringerung der Schmerzen bei der Kastration von Saugferkeln wird durch die intratestikuläre Lokalanästhesie nicht erfüllt, da zwischen anästhesierten und nichtanästhesierten kastrierten Tieren anhand der Kortisol-konzentration kein Unterschied hinsichtlich der endogenen kastrationsbedingten Schmerzreaktion nachzuweisen ist.

Wirksamkeitsbeurteilung einer Kombinationstherapie aus Antibiose und NSAID nach experimenteller Haemophilus-parasuis-Infektion bei Absetzferkeln

Gegenstand: Untersuchung der Wirksamkeit einer Kombinationstherapie aus Antibiose (Enrofloxacin-Arginin-Formulierung, Baytril® RSi) und einem nichtsteroidalen Antiphlogistikum (Ketoprofen, Dinalgen® 60 mg/ml) nach experimenteller Infektion mit Haemophilus parasuis (HPS) bei Absetzferkeln. Material und Methoden: 48 Ferkel im Alter von 3 Wochen wurden vier Versuchsgruppen zugeteilt (Gr. 1: Negativkontrolle; Gr. 2: HPS-Infektion; Gr. 3: HPS-Infektion/Baytril® RSi; Gr. 4: HPS-Infektion/Baytril® RSi/Dinalgen®). Nach 10-tägiger Eingewöhnung im Infektionsstall erfolgte die intratracheale Infektion der Gruppen 2–4 mit 1 x 107 koloniebildenden Einheiten (KBE) HPS Serovar 5. Die Ferkel der Gruppe 1 erhielten physiologische Kochsalzlösung. An-hand eines Punktesystems wurden aus den Befunden der klinischen Untersuchung pro Tier und Tag ein klinischer und ein Gelenkscore ermittelt. Sieben Tage nach der Infektion wurden die Tiere euthanasiert. Die zusammengefassten Sektionsbefunde (Befunde der serösen Häute) ergaben den Serositisscore, der Schweregrad und Ausdehnung der Läsionen berücksichtigte. Ergebnisse: Hinsichtlich klinischer Symptome und pathologischer Veränderungen hatten die Tiere der Gruppe 1 die niedrigsten Score-Werte, gefolgt von den Tieren der Gruppen 4, 3 und 2. Beim Verlauf der inneren Körpertemperatur zeigten die Ferkel der Gruppe 4 nach der Infektion signifikant niedrigere Werte als die Tiere der anderen drei Gruppen. Die Tageszunahmen der Ferkel differierten zwischen den Gruppen nicht signifikant, doch ergab sich in Gruppe 4 mit 340,5 g/Tag eine tendenziell höhere mittlere Zunahme als in Gruppe 1 (323,8 g/Tag), 3 (278,0 g/Tag) und 2 (247,0 g/Tag). Die Tiere der Gruppe 2 wiesen die höchsten Werte im klinischen Score, im Gelenkscore sowie im Serositisscore auf. Schlussfolgerung: Die Therapie mit Ketoprofen und einer Enrofloxacin-Arginin-Formulierung (Baytril® RSi) zeigte nach experimenteller Infektion mit HPS eine bessere Wirksamkeit als eine alleinige Baytril® RSi-Gabe.

Feldstudie zur simultanen Vakzination gegen das porzine Circovirus Typ 2 und Mycoplasma hyopneumoniae

Ziel war zu prüfen, ob die an einer oder zwei Injektionsstellen durchgeführte simultane Applikation zweier Vakzinen gegen das porzine Circovirus Typ 2 (PCV2) bzw. Mycoplasma hyopneumoniae (M. hyo.) bei Saugferkeln ebenso wirksam ist wie die Verabreichung der einzelnen Impfstoffe. Material und Methoden: 598 Ferkel bildeten bei gemischter Aufstallung fünf Versuchsgruppen. Das Plazebo Porcilis® Diluvac forte sowie die Vakzinen Porcilis® M HYO („M HYO“) und Porcilis® PCV („PCV“) wurden jeweils in der 1. und 3. Lebenswoche (LW) wie folgt appliziert: Gruppe A: Plazebo/PCV, Gruppe B: M HYO/M HYO, Gruppe C: Plazebo/Plazebo, Gruppe D: M HYO/M HYO + PCV (kombinierte Einzeldosis), Gruppe E: Plazebo/M HYO + PCV (getrennte Injektionsstellen). Die Wirkung der simultanen Impfung wurde anhand von Tageszunahmen, pathomorphologischer Lungenveränderungen, Morbidität, Mortaliät und der Immunantwort gegen die verwendeten Antigene bestimmt. Die Verträglichkeit der simultanen Vakzination wurde anhand lokaler und systemischer Impfreaktionen bewertet. Ergebnisse: Die phasenweise schlechte Bestandsgesundheit, bedingt durch Saugferkeldurchfälle (n = 111) in der 1.–3. LW, ließ sich nicht eindeutig mit PCV2 in Zusammenhang bringen. Dennoch zeigten alle geimpften Tiere tendenziell höhere Tageszunahmen als die Kontrolltiere. Unterschiede zwischen den Gruppen hinsichtlich Lungenveränderungen, Morbidität und Mortalität waren nicht signifikant. M.-hyo.- und PCV2-spezifische Antikörpertiter lagen bei geimpften Tieren signifikant höher als bei nicht geimpften. Bei je einem Ferkel der Gruppen A (PCV2) und C (Plazebo) kam es zu lokalen Impfreaktionen. Schlussfolgerung und klinische Relevanz: In Betrieben mit suboptimaler Bestandsgesundheit lässt sich ein positiver Effekt beider Impfungen nachweisen. Die simultane Impfung gegen PCV2 und M. hyo. hatte keine negativen Auswirkungen. In Bezug auf die Steigerung der durchschnittlichen Tageszunahmen war der Effekt der simultanen Impfungen dem der Einzelimpfungen gleichwertig. Der Einsatz der Simultanimpfung gegen M. hyo. und PCV2, der Vorteile hinsichtlich Arbeitsaufwand und Tierschutz bringt, kann daher in der Praxis befürwortet werden.

Anwendbarkeit und Dosisfindung des Anästhetikums Thiopental für die Narkose des Schweins nach vorhergehender Neuroleptanalgesie

Gegenstand und Ziel: Ziel der Arbeit war, die Anwendbarkeit von Thiopental (Trapanal®) für die Anästhesie beim Schwein zu prüfen und eine Dosierung für Tiere verschiedener Gewichtsklassen und Nutzungsrichtungen nach vorhergehender Neuroleptanalgesie zu ermitteln. Material und Methoden: Die Untersuchung erfolgte unter klinischen Bedingungen an insgesamt 90 Schweinen mit Körpermassen zwischen 7,5 und 350 kg. Alle Tiere erhielten eine intramuskuläre Injektion von Ketamin (Ursotamin®, 15 mg/kg KM), Azaperon (Stresnil®, 2 mg/kg KM) und Atropin (0,02 mg/kg KM). Anschließend wurde Thiopental (Trapanal®) schrittweise bis zum Erreichen der chirurgischen Toleranz intravenös verabreicht. Der Narkoseverlauf wurde anhand der Parameter Atem- und Herzfrequenz, Körpertemperatur, periphere Sauerstoffsättigung, Reflexaktivität, Bulbusrotation und Hautsensibilität dokumentiert. Ergebnisse: Die Absatzferkel erreichten das Stadium der chirurgischen Toleranz mit einer durchschnittlichen Thiopentaldosierung von 8,20 ± 2,74 mg/kg KM, die Vormasttiere mit 8,20 ± 2,14 mg/kg KM, die Masttiere mit 7,33 ± 1,10 mg/kg KM, die Zuchttiere mit 3,20 ± 1,41 mg/kg KM und die Minipigs mit 2,79 ± 1,87 mg/kg KM. Klinische Relevanz: Die ermittelten Dosierungen sollen dem Praktiker als Anhaltspunkte dienen, wobei eine Dosierung nach Wirkung unter ständiger Reflexkontrolle unerlässlich bleibt.

Investigation of three outbreaks of Porcine Epidemic Diarrhea in Germany in 2016 demonstrates age dependent differences in the development of humoral immune response

Porcine epidemic diarrhea (PED) has reemerged in Europe since 2014. Characterized by a rapid onset of diarrhea in pigs of all ages, morbidity can reach up to 100% whereas mortality is variable. The virus strains involved in the recent European outbreaks all cluster together with US strains (S INDEL) that lead to less severe clinical signs. In this study, fattening pigs and suckling piglets (n = 105) on farms with no prior PED history were monitored after an acute outbreak of the disease, caused by an S INDEL strain of PED virus (PEDV). For diagnostic investigations in the affected farms, real time RT-PCR was performed to detect PEDV RNA in individually taken fecal samples, and two commercial ELISA kits, both based on the N protein of PEDV, were used to detect IgG in serum samples of pigs experiencing acute signs of the disease. PEDV RNA could be detected in fecal samples up to 14 days after initial sampling. Comparing both ELISAs by Cohens Kappa showed substantial agreement (κ = 0,771). Antibodies were detectable in all fattening pigs (100%) within 10 days after the occurrence of first clinical signs and remained detectable for about two months at least in 20.6% (farm 1) and 45.7% (farm 2) of the animals, respectively. In contrast, only 18 of 34 (52.9%) suckling piglets seroconverted. Although, PEDV RNA was found in fecal samples of all piglets, 13 piglets did not demonstrate antibodies at any sampling day. PCR to detect PEDV RNA in fecal samples seems to be a reliable diagnostic tool during and after the acute outbreak. In the present study, IgG ELISA kits proved to be a feasible diagnostic tool, but age dependent differences in detection rate and persistence of antibodies need to be considered.

Field study on the safety and efficacy of intradermal versus intramuscular vaccination against Mycoplasma hyopneumoniae

The present study compares the safety and efficacy of a needle-free, intradermal Mycoplasma hyopneumoniae vaccine to an intramuscular one. 420 piglets (21+3 days of age) were randomly assigned to two vaccination groups (intradermal vaccination V1 (n=138), intramuscular vaccination V2 (n=144)) and one unvaccinated control group (CG, n=138). As safety parameters clinical observations, local injection site reactions (ISR) and rectal temperatures were assessed. Average daily weight gain (ADWG) and pneumonic lung lesions (LL) were measured as efficacy parameters. ISRs were minor in V1. After both vaccinations, no adverse impact on appetite was observed and mean rectal temperatures remained within physiological range. ADWG during the fattening period was significantly higher in vaccinated groups (V1: 913.4 g, V2: 924.5 g) compared with CG (875.6 g). No differences in ADWG were observed between V1 and V2. Vaccinated pigs had a significantly reduced mean extent of LL compared with CG. V1 was superior in reducing the extent and prevalence of LL compared with V2. These results reveal that a needle-free intradermal vaccination is safe and efficacious in reducing both the prevalence and extent of lung lesions, as well as in improving performance parameters, in a farrow-to-finish farm with a late onset of M hyopneumoniae infection.

The Munich MIDY Pig Biobank - A unique resource for studying organ crosstalk in diabetes

OBJECTIVE

The prevalence of diabetes mellitus and associated complications is steadily increasing. As a resource for studying systemic consequences of chronic insulin insufficiency and hyperglycemia, we established a comprehensive biobank of long-term diabetic INSC94Y transgenic pigs, a model of mutant INS gene-induced diabetes of youth (MIDY), and of wild-type (WT) littermates.

METHODS

Female MIDY pigs (n = 4) were maintained with suboptimal insulin treatment for 2 years, together with female WT littermates (n = 5). Plasma insulin, C-peptide and glucagon levels were regularly determined using specific immunoassays. In addition, clinical chemical, targeted metabolomics, and lipidomics analyses were performed. At age 2 years, all pigs were euthanized, necropsied, and a broad spectrum of tissues was taken by systematic uniform random sampling procedures. Total beta cell volume was determined by stereological methods. A pilot proteome analysis of pancreas, liver, and kidney cortex was performed by label free proteomics.

RESULTS

MIDY pigs had elevated fasting plasma glucose and fructosamine concentrations, C-peptide levels that decreased with age and were undetectable at 2 years, and an 82% reduced total beta cell volume compared to WT. Plasma glucagon and beta hydroxybutyrate levels of MIDY pigs were chronically elevated, reflecting hallmarks of poorly controlled diabetes in humans. In total, ∼1900 samples of different body fluids (blood, serum, plasma, urine, cerebrospinal fluid, and synovial fluid) as well as ∼17,000 samples from ∼50 different tissues and organs were preserved to facilitate a plethora of morphological and molecular analyses. Principal component analyses of plasma targeted metabolomics and lipidomics data and of proteome profiles from pancreas, liver, and kidney cortex clearly separated MIDY and WT samples.

CONCLUSIONS

The broad spectrum of well-defined biosamples in the Munich MIDY Pig Biobank that will be available to the scientific community provides a unique resource for systematic studies of organ crosstalk in diabetes in a multi-organ, multi-omics dimension.

Porcine Epidemic Diarrhea in Europe: In-Detail Analyses of Disease Dynamics and Molecular Epidemiology

Porcine epidemic diarrhea (PED) is an acute and highly contagious enteric disease of swine caused by the eponymous virus (PEDV) which belongs to the genus Alphacoronavirus within the Coronaviridae virus family. Following the disastrous outbreaks in Asia and the United States, PEDV has been detected also in Europe. In order to better understand the overall situation, the molecular epidemiology, and factors that might influence the most variable disease impact; 40 samples from swine feces were collected from different PED outbreaks in Germany and other European countries and sequenced by shot-gun next-generation sequencing. A total of 38 new PEDV complete coding sequences were generated. When compared on a global scale, all investigated sequences from Central and South-Eastern Europe formed a rather homogeneous PEDV S INDEL cluster, suggesting a recent re-introduction. However, in-detail analyses revealed two new clusters and putative ancestor strains. Based on the available background data, correlations between clusters and location, farm type or clinical presentation could not be established. Additionally, the impact of secondary infections was explored using the metagenomic data sets. While several coinfections were observed, no correlation was found with disease courses. However, in addition to the PEDV genomes, ten complete viral coding sequences from nine different data sets were reconstructed each representing new virus strains. In detail, three pasivirus A strains, two astroviruses, a porcine sapelovirus, a kobuvirus, a porcine torovirus, a posavirus, and an enterobacteria phage were almost fully sequenced.

[Occurrence of genotypes of porcine circovirus (PCV2) in pig farms using different vaccination strategies against PCV2]

OBJECTIVE

Since 2004/2005 a worldwide shift of the detection rate of porcine circovirus (PCV) has been observed from PCV2a towards PCV2b. Currently commercially available vaccines are based on genotype PCV2a. The study was conducted as a pilot study to evaluate the occurrence of PCV2a and PCV2b in farms with different vaccination strategies against PCV2.

MATERIAL AND METHODS

For this purpose a total of 405 piglets originating from nine farms (three farms with sow vaccination [SI], piglet vaccination [FI] and no vaccination [NI] against PCV2, respectively) were enrolled and followed from day 3 of life until slaughter. Serum of the piglets was examined for PCV2-DNA by quantitative PCR, genotype differentiating duplex PCR, and after sequencing of the total genome, PCV2 isolates were phylogenetically assigned. The evaluation included the data from 383 animals.

RESULTS

In eight farms PCV2 could be detected (1x PCV2a; 6x PCV2b; 1x PCV2a and PCV2b). PCV2b was found in SI-, NI- and FI-farms, whereas PCV2a was only detected in SI- and NI-farms. A proportion of 55.4% was PCV2-positive at least once during the entire study period (FI: 7.8%, SI: 65.4%, NI: 93.7%). Of these samples 4.7% were PCV2a-, 92.2% PCV2b- and 2.4% PCV2a- and PCV2b-positive. The mean content of PCV2-DNA in the serum of PCV2b positive animals was significantly higher than from PCV2a positive animals. PCV2 isolates were identified as PCV2b-1A (5/9 farms), PCV2b-1B (1/9 farms) und PCV2a-2D (2/9 farms).

CONCLUSION AND CLINICAL RELEVANCE

The increased detection rate of PCV2b in comparison to PCV2a could be confirmed. The present study gives hint that the vaccination of piglets using PCV2a-based vaccines may lead to a further shift of the detection rate from PCV2a to PCV2b. To assess the clinical relevance of this observation, extensive comparative studies should be taken into account, which also evaluate the efficacy of PCV2a-based vaccines in PCV2a- and PCV2b-positive farms.

[Detection of Salmonella Choleraesuis var. Kunzendorf in a fattening pig with septicaemic salmonellosis. A case report]

The present case reports the detection of Salmonella (S.) Choleraesuis var. Kunzendorf and porcine circovirus type 2 in an organic fattening pig suffering from septicaemic salmonellosis and porcine dermatitis and nephropathy syndrome. Six weeks after pigs had been housed in an organic fattening farm, an increase in mortality, diarrhea and coughing was observed. In recent years, S. choleraesuis var. Kunzendorf has been frequently detected in wild boars in Germany, whereas the same serovar did not play an important role in the Western European domestic pig population. A direct transmission of this serovar from wild boars to domestic pigs in this case could not be proven. However, because wild boars are important reservoirs for the spread of epizootic diseases to the domestic pig population, this case emphasises the importance of taking epidemiological relationships under consideration and to comply with biosecurity measures according to German law (Schweinehaltungshygieneverordnung).