Analysis of porcine body size variation using re-sequencing data of miniature and large pigs.

BACKGROUND: Domestication has led to substantial phenotypic and genetic variation in domestic animals. In pigs, the size of so called minipigs differs by one order of magnitude compared to breeds of large body size. We used biallelic SNPs identified from re-sequencing data to compare various publicly available wild and domestic populations against two minipig breeds to gain better understanding of the genetic background of the extensive body size variation. We combined two complementary measures, expected heterozygosity and the composite likelihood ratio test implemented in "SweepFinder", to identify signatures of selection in Minipigs. We intersected these sweep regions with a measure of differentiation, namely FST, to remove regions of low variation across pigs. An extraordinary large sweep between 52 and 61 Mb on chromosome X was separately analyzed based on SNP-array data of F2 individuals from a cross of Goettingen Minipigs and large pigs. RESULTS: Selective sweep analysis identified putative sweep regions for growth and subsequent gene annotation provided a comprehensive set of putative candidate genes. A long swept haplotype on chromosome X, descending from the Goettingen Minipig founders was associated with a reduction of adult body length by 3% in F2 cross-breds. CONCLUSION: The resulting set of genes in putative sweep regions implies that the genetic background of body size variation in pigs is polygenic rather than mono- or oligogenic. Identified genes suggest alterations in metabolic functions and a possible insulin resistance to contribute to miniaturization. A size QTL located within the sweep on chromosome X, with an estimated effect of 3% on body length, is comparable to the largest known in pigs or other species. The androgen receptor AR, previously known to influence pig performance and carcass traits, is the most obvious potential candidate gene within this region.

[Computed tomography of the pig lung. An innovative approach to the definition of the pulmonary health status]. / Computertomographie der Lunge des Schweines. Ein innovativer Ansatz zur Definition des Lungengesundheitsstatus.

OBJECTIVE: In veterinary medicine computed tomography (CT) imaging has gained importance in recent years, especially for diagnostics in pets, but also during the course of experimental studies in animal models for human medicine. In this study the applicability of CT as an imaging method for the depiction of the porcine thorax and in particular of the pig lung was evaluated. MATERIAL AND METHODS: CT examinations were performed with 11 healthy pigs of two age groups. For evaluation, CT findings were related to clinical, radiological, macroscopical, microscopical, and microbiological findings. RESULTS: Clinically relevant anatomical structures were determined and recorded using transverse slices. In ventral recumbency, lung parenchyma density measurements at the levels of the second, fourth and seventh thoracic vertebrae resulted in significantly higher densities of the ventral in comparison to those of the dorsal lung quadrants. CONCLUSION AND CLINICAL RELEVANCE: Computed tomography is a valuable tool for the high-contrast depiction of the porcine lung without superposition. In future studies this CT reference base for unaltered pig lungs may facilitate the identification of anatomical structures within the porcine lung as well as the assessment of pathological lung alterations.

Spider silk nerve graft promotes axonal regeneration on long distance nerve defect in a sheep model.

Peripheral nerve injuries with substantial tissue loss require autologous nerve transplantation or alternatively reconstruction with nerve conduits. Axonal elongation after nerve transection is about 1 mm/day. The precise time course of axonal regeneration on an ultrastructural level in nerve gap repair using either autologous or artificial implants has not been described. As peripheral nerve regeneration is a highly time critical process due to deterioration of the neuromuscular junction, this in vivo examination in a large animal model was performed in order to investigate axonal elongation rates and spider silk material degradation in a narrowly delimited time series (20, 30, 40, 50, 90, 120, 150 and 180 days) by using a novel spider silk based artificial nerve graft as a critical prerequisite for clinical translation. Autologous nerves or artificial nerve conduits based on spider silk of the spider species Trichonephila edulis were transplanted in a 6.0 cm nerve defect model in the black headed mutton. At each of the post-implant time point, electrophysiology recordings were performed to assess functional reinnervation of axonal fibers into the implants. Samples were analyzed by histology and immunofluorescence in order to verify the timeline of axonal regeneration including axonal regeneration rates of the spider silk implant and the autologous transplant groups. Spider silk was degraded within 3 month by a light immune response mainly mediated by Langhans Giant cells. In conjunction with behavioral analysis and electrophysiological measurements, the results indicate that the spider silk nerve implant supported an axonal regeneration comparable to an autologous nerve graft which is the current gold standard in nerve repair surgery. These findings indicate that a biomaterial based spider silk nerve conduit is as effective as autologous nerve implants and may be an important approach for long nerve defects.

Characterization of the porcine transferrin gene (TF) and its association with disease severity following an experimental Actinobacillus pleuropneumoniae infection.

Transferrin (TF)-mediated provision of iron is essential for a productive infection by many bacterial pathogens, and iron-depletion of TF is a first line defence against bacterial infections. Therefore, the transferrin (TF) gene can be considered a candidate gene for disease resistance. We obtained the complete DNA sequence of the porcine TF gene, which spans 40 kb and contains 17 exons. We identified polymorphisms on a panel of 10 different pig breeds. Comparative intra- and interbreed sequence analysis revealed 62 polymorphisms in the TF gene including one microsatellite. Ten polymorphisms were located in the coding sequence of the TF gene. Four SNPs (c.902A>T, c.980G>A, c.1417A>G, c.1810A>C) were predicted to cause amino acid exchanges (p.Lys301Ile, p.Arg327Lys, p.Lys473Glu, p.Asn604His). We performed association analyses using six selected TF markers and 116 pigs experimentally infected with Actinobacillus pleuropneumoniae serotype 7. The analysis showed breed-specific TF allele frequencies. In German Landrace, we found evidence for a possible association of the severity of A. pleuropneumoniae infection with TF genotypes.

Prevalence of pathogenic Yersinia enterocolitica strains on liver surfaces of pigs and their antimicrobial susceptibility.

A study to determine the occurrence of pathogenic Yersinia enterocolitica on surfaces of slaughtered pig livers and the antimicrobial resistant pattern of the isolates was carried out in a slaughterhouse in Lower Saxony, Germany. During the slaughtering process, 1,500 surfaces of pig livers from 50 fattening herds were swabbed in order to isolate and characterize Y. enterocolitica isolates by serotyping, detecting the virulence plasmid coding the yopT gene, and resistance testing. Of the livers tested, 4.7% were positive for Y. enterocolitica O:3, which was the only identified serotype. The virulence gene yopT was found in 90.0% of these isolates. Antimicrobial susceptibility was tested by the broth dilution method, and the MICs were determined for 13 antimicrobials. All isolates were resistant to ampicillin and sulfamethoxazole but were susceptible to ciprofloxacin, nalidixic acid, gentamicin, ceftiofur, tetracycline, kanamycin, cefotaxime, and chlorphenicol. Up to now, resistance to florfenicol has always been described in combination with resistance to chloramphenicol. In the present study, 15.3% of the isolates were resistant to florfenicol, while no chloramphenicol-resistant strains could be identified. Multiresistance to three or more antimicrobials was detected in 22 strains (27.3%). Nevertheless, third-generation cephalosporines or fluoroquinolones, which were recommended for extraintestinal Y. enterocolitica infection in humans, were not affected.

Detection of PR-39, a porcine host defence peptide, in different cell sub-linages in pigs infected with Actinobacillus pleuropneumoniae.

Innate immunity is critically important for the outcome of infection in many diseases. It was previously shown that cathelicidin PR-39, an important porcine multifunctional host defence peptide, is elevated in bronchoalveolar lavage fluid and respiratory tract tissue after experimental infection with Actinobacillus pleuropneumoniae (A.pp.). To date, neutrophil polymorphonuclear leukocytes (PMNs) are thought to be the only source of PR-39. The aim of this study was to further characterize PR-39⁺ cells and selected immune cell populations in lung tissue during the peracute (7-10 hours), acute (2 days), reconvalescent (7 days) and chronic (21 days) stages of experimental infection with A.pp. serotype 2. In total, six mock-infected control pigs and 12 infected pigs were examined. Using immunofluorescence double-labeling, antibodies against PR-39 were combined with antibodies against CD3 (T-cells), CD79 (B-cells), Iba1 (activated macrophages), TTF-1 (lung epithelial cells expressing surfactant proteins), macrophage/L1 protein and myeloperoxidase (MPO, cells of the myeloid linage). In the peracute and acute phases of infection, total PR-39⁺ cells and myeloid linage cells increased, whereas CD3⁺ cells and TTF-1⁺ cells decreased. Double labeling revealed that most Macrophage/L1 protein+ cells and to a lesser extent MPO⁺ cells co-expressed PR-39. In addition, few bronchial epithelial cells and type 2 alveolar epithelial cells (both identified with TTF-1) produced PR-39. Occasionally, CD3⁺ T cells expressing PR-39 were seen in infected animals. Taken together, this study identifies cell types, other than PMNs, in lungs of A.pp.-infected pigs that are capable of producing PR-39. In addition, these findings provide further insights into the dynamics of different immune cell populations during A.pp.-infection.

[Uterine neoplasia in two geriatric miniature pet pigs - diagnostics and therapy. Two case reports]. / Uterustumore bei älteren Miniaturschweinen - Diagnostik und Therapie. Zwei Fallberichte.

Miniature pet pigs are becoming ever more common among the patients of small animal practices. Due to an advanced age attained in these animals in comparison with conventional pigs in pork production, miniature pet pigs develop age-related diseases that are infrequently observed in farm pigs, including neoplastic alterations of the uterus. We describe two cases of a uterine adenocarcinoma and a leiomyoma, respectively, in two miniature pet pig sows. Options and limits of diagnostic measures (unspecific clinical symptoms, x-ray, sonography and computed tomography) and therapy within the legal limits as well as the risk of an incorrect diagnosis based upon the more common differential diagnoses in swine medicine, including obstipation, cystitis and endometritis, are discussed.

[Clinical and laboratory diagnostic findings in chronic pleuropneumonia of swine]. / Klinische und labordiagnostische Befunde bei der chronischen Pleuropneumonie des Schweines.

In the course of an experimental study 12 pigs were infected intrabronchially with the pathogen of infectious porcine pleuropneumonia, Actinobacillus pleuropneumoniae. All animals survived the acute stage of infection due to the application of subtherapeutic doses of antibiotics. After infection all of the animals showed clinical signs of acute pneumonia with an elevation of body temperature to about 41 degrees C. Bronchoalveolar lavage fluid (BALF) was taken every week endoscopically. An increase of neutrophil granulocytes could be observed at day 7 and 14 after infection. In parallel, a clear granulocytosis and a shift to the left of the nuclei was observed at day 7. Comparing the methods for detection of Actinobacillus pleuropneumoniae serological assays like the complement-fixation assay (CFA) and enzyme-linked immunosorbent assay (ELISA) as well as immunofluorescence in lung tissue and BALF were more sensitive than cultural isolation from lung tissue, tonsils and BALF.

[Causes of pre- and perinatal piglet loss]. / Ursachen prä- und perinataler Ferkelverluste.

The main part of the extensive embryonic losses in swine is usually attributed to endogenous regulatory processes. Beyond that a lot of endogenous and exogenous noxae can induce embryonic and fetal death. 60-80% of the preweaning mortality occur during the perinatal period, i.e. the time direct before farrowing until the third day of life. Aetiology, which generally is due to noninfectious causes, and clinical symptoms of perinatal mortality are described.

[Housing- and management-specific effects on the health of swine]. / Haltungs- und managementspezifische Einflüsse auf die Gesundheit von Schweinen.

Important diseases with regard to inadequate housing and management conditions in pig production are given. Typical examples like claw lesions, cannibalism and infectious factorial diseases are described. Beside negative factors of pig housing and management which are of particular pathogenic importance some aspects of disease control and herd health are listed finally.

[Progression and control of leptospirosis in a sow herd]. / Verlauf und Bekämpfung der Leptospirose in einem Sauenbestand.

After a short review about etiology, epidemiology, clinical symptoms, diagnosis and therapy of leptospirosis the course and therapy of an acute leptospirosis outbreak in a breeding herd with nearly 240 sows is described. The microscopic agglutination test (MAT) served for diagnosis and was most reliable for estimation the actually stage of infection when used twice with an interval of several weeks. As causative agent serovar L. pomona was identified, whereby cross-reactions were seen to serovars L. grippotyphosa, L. bratislava and L. copenhageni. Therapy of all animals with Terramycin/LA (Pfizer) at three times with intervals of five days and doses of 20 mg oxytetracycline/kg b.w. distinctly reduced the incidence of abortion and stillborn or mummified pigs. Local irritations, relative to the intramuscular administration of oxytetracycline, mostly were low-graded and temporary. For the next months acute infections could not be registered. Probably due to infections from leptospires-reservoirs, maintained by numerous existing mice and puddles on the pasture-ground, leptospirosis occurred again six months later. Only another antibiotic therapy of the whole herd and simultaneous eradication of rodents as well as closing the pasture led to a long-termed control of leptospirosis in this herd.

[Outlook for control of current zoonoses in swine--an issue on consumer health protection]. / Ausblick zur Bekämpfung aktueller Zoonosen des Schweines--ein Beitrag zum Verbraucherschutz.

With the development of a uniform European strategy for the control of zoonoses the European Commission has placed the main emphasis on the protection of consumer health. This direction is clearly marked by the White Paper on Food Safety and the attached proposals for directives and regulations. The present article considers the peculiarities of the epidemiological situation of the agents Campylobacter spp. and Yersinia enterocolitica in pork production. The situation of zoonoses in Europe is used as an opportunity to present the distinctive characteristics of these agents, results of epidemiological studies available, and the risk to consumer health in light of the literature. For the approaching transfer of the responsibility for food safety to the primary producers, i.e. the farmers, the most interesting data concern the prevalence, distribution and risk factors. But as there is a strong need for clarification of further questions about the main ways of entry of these agents on farms and into the production chain before a successful preventive strategy can be developed on pig farms, these issues are considered in more detail here.

[Keeping sows outdoors during the winter season]. / Freilandhaltung von Sauen während des Winterhalbjahres.

During the last decade the number of outdoor breeding pig units increased in Northern Europe. With comparable results in reproduction and up to 70 per cent lower capital outlays in relation to the conventional indoor systems the interest of farmers in outdoor breeding grew also in Germany. There are a number of issues that are specific to outdoor systems that need to be considered during winter season.

[Investigations on Brachyspira--diagnostic and therapeutic strategies in swine dysentery]. / Untersuchungen zur Brachyspira--Diagnostik und Behandlungsstrategie bei der Schweinedysenterie.

The infectious agent of swine dysentery, Brachyspira (Br.) hyodysenteriae, seems to be widespread in German pig herds. Due to different reasons the eradication is increasingly difficult. Not only the success of therapeutic procedures but also the possibilities of diagnostics are unsatisfactory. Although only the bacteriological investigation of faeces or intestinal probes by culture techniques allows the typing of Brachyspira strains and the testing of drug resistance, however, the rate of false negative results is relatively high. In comparison with the cultural method an easy, prompt and cheap immunofluorescent test (IFT) resulted in a good sensitivity (90%). The higher rate of negative results by culture techniques can not be attributed to a lower specificity of the IFT, but to an insufficient transport of samples to the laboratory. The IFT therefore has to be considered as a valuable supplement to the cultural diagnostic of Br. hyodysenteriae. It is absolutely necessary to establish strategies in eradication of swine dysentery which result in pig breeding herds free of Br. hyodysenteriae. Only weaner pigs which are reliable free of this germ guarantee a fattening period sufficiently free of swine dysentery. The principles of different measures in effective eradication are described.

Studies on the effect of specific egg antibodies against Escherichia coli infections in piglets.

The effect of chicken egg powder enriched with immunoglobulins specific for rotavirus antigen and fimbrial adhesions F4, F5, F6 of enterotoxigenic Escherichia coli (ETEC) (Globigen 66 S, Lohmann Animal Health, Cuxhaven, Germany) was studied in 465 sucking piglets on a commercial farm. Half of those piglets were given Globigen 66 S as an additive to milk replacer from day 2 until day 12 of life in addition to sows' milk. These piglets showed a higher intake of milk replacer and a lower prevalence of diarrhoea on days 2 and 3 of life. Statistical evaluation showed, that the effect of sows' milk on the duration of diarrhoea and on piglet weight gains was more pronounced than the effect of Globigen 66 S. Anti-ETEC F4-antibody-activities were measured using an indirect ELISA (enzyme-linked immunosorbent assay). There was an inverse relationship between the intensity of diarrhoea and colostral antibody-activity (r = -0.2). Comparison of binding affinities of avian and porcine antibodies for F4 showed only a limited common spectrum of epitopes, so, in all probability, they might complement each other in the intestine.

[The effect of bacterial interference phenomena in experimental Staphylococcus hyicus infections of gnotobiotic piglets]. / Untersuchungen über die Wirkung bakterieller Interferenzphänomene bei der experimentellen Staphylococcus-hyicus-Infektion gnotobiotischer Ferkel.

The prevention of exudative epidermitis could be confirmed in experimental investigations with gnotobiotic piglets when the skin first was colonized with avirulent strains of Staphylococcus (Staph.) hyicus and subsequently exposed to virulent strains of Staph. hyicus. However, locally restricted cutaneous lesions in the area of application corresponding to exudative epidermitis were seen in five of nine piglets. Using the strain Staph. sciuri the spread of virulent Staph. hyicus could not be suppressed. Such infected two piglets developed generalized exudative epidermitis. In another experiment with four piglets it could be shown, that the relative protective mechanism correlating to bacterial interference on the one hand can be influenced by the virulence of causative organisms. On the other hand it even can be abolished when skin lesions are involved. For that reason probably the utilization of bacterial interference in prevention of exudative epidermitis under field conditions is considerably limited.

[Investigations on clinical diagnosis and pathogenesis of otitis media et interna in swine]. / Untersuchungen zur Diagnostik und Pathogenese der Otitis media et interna beim Schwein.

A total of 25 pigs with a head tilt as clinical sign of otitis media et interna were examined. The majority were weaner-pigs with respiratory tract disorders. In lateral and ventrodorsal radiographic views of the bulla tympanica, there was an increased opacity, often accompanied by marginal destruction or thickening of the bulla wall. The findings confirmed the clinical diagnosis in each affected pig. In the case of leptomeningitis an examination of the cerebrospinal fluid revealed a drastic increase in the cell count. In 20 of 23 microbiologically examined empyemic bullae a polyinfection was seen. The results indicate that the route of infection of the middle ear is by the auditory tube. Mange on the other hand plays only a minor role in the pathogenesis of otitis media.

[CO2-stunning of slaughter pigs: effects on EEG, catecholamines and clinical reflexes]. / CO2-Betäubung von Schlachtschweinen: Einfluss auf EEG, Katecholaminausschüttung und klinische Reflexe.

Investigations were carried out on the response of slaughter pigs to CO2 stunning with two different gas concentrations (80 vol%, 90 vol%, 73 s) under practical conditions in a one gondola-dip-lift system. EEG measurements were performed and blood constituents such as catecholamines (adrenaline, nor-adrenaline) and lactate as well as clinical reactions (nasal septum and corneal reflex, heart beats) investigated. Special EEG-electrodes were adapted for the measurement on pigs and a mobile data logger was prepared for the use in the lairage of the slaughter house and in the stunning unit. The CO2 concentrations were measured continuously close to the head of the pigs when transported up and down in the stunning gondola. The results show that the technique is suited to monitor the effects of different CO2 gas concentrations on the EEG of the pigs under practical conditions. There is strong evidence that CO2 concentrations of 80 vol% applied over 70 s as required by law are not sufficient to stun pigs properly. A large part of the animals still showed typical reflexes when leaving the stunning pit. When an atmosphere of 90 vol% CO2 is applied, most animals are already dead before bleeding commences. This may create problems in respect to meat hygiene. The blood analysis revealed very high concentrations of catecholamines after stunning. The values for adrenaline and nor-adrenaline in the sticking blood rose by a factor of about 1000 as compared to the concentrations in blood samples taken in the lairage before stunning. It seems necessary to revise the current legislation on gas stunning and to look in greater detail in the effects of CO2 stunning on the welfare of slaughter pigs.

[Septicaemia in piglets associated with a positive finding of a methicillin-resistant S. aureus strain]. / Septikämisches Krankheitsbild bei Saugferkeln mit MRSA-Nachweis.

Staphylococcus (S.) aureus has been associated with septicaemia, mastitis, vaginitis, metritis, osteomyelitis, and endocarditis. This case report demonstrates S. aureus-induced septicaemia in suckling pig- lets. Three days after birth, littermates displayed severe ecchymosis and cyanosis, with a 50% mortality rate. The surviving littermates were cross-fostered, but died 1 day later. Other piglets, which were allowed to suck at the sow, developed similar clinical signs. Haematological findings were anaemia, thrombocytopenia, and leukopenia; therefore, neither isohaemolytic anaemia nor septicaemia could be excluded as differential diagnoses. At necropsy, petechial bleeding on inner organ surfaces and free blood in body cavities were found. Bacteriological examination of the sow's milk and of the spleen of one piglet detected a methicillin-resistent S. aureus strain (MRSA CC398), which was in all likelihood the cause of the disease. Potential differential diagnoses are discussed.

Antibiotic susceptibility of Salmonella, Campylobacter coli, and Campylobacter jejuni isolated from Northern German fattening pigs.

This study was conducted to assess the antimicrobial susceptibility rate of Salmonella and Campylobacter spp. isolated from Northern German fattening pigs. From 540 lymph node samples, 16 Salmonella Typhimurium, 1 Salmonella Brandenburg, 37 Campylobacter coli, and 11 Campylobacter jejuni strains were isolated. Antibiotic susceptibility testing was carried out by the broth dilution method. The 14 tested antibiotics for Salmonella were ampicillin, cefotaxime, ceftazidime, chloramphenicol, ciprofloxacin, colistin, florfenicol, gentamicin, kanamycin, nalidixic acid, streptomycin, sulfamethoxazole, tetracycline, and trimethoprim. The eight tested antibiotics for Campylobacter spp. were ampicillin, ampicillin-sulbactam (2:1), ciprofloxacin, erythromycin, gentamicin, nalidixic acid, sulfamethoxazole-trimethoprim (1:19), and tetracycline. In total, 93.7% (n = 16) of Salmonella Typhimurium, 75.7% (n = 37) of C. coli, and 54.5% (n = 11) of C. jejuni isolates were resistant to at least one of the tested antibiotics. Multiresistance to three antibiotics was observed in 75% of Salmonella Typhimurium, 16.2% of C. coli, and 0% of C. jejuni isolates. Pansusceptibility was detected in 6.3% of Salmonella Typhimurium, 24.3% of C. coli, and 45.5% of C. jejuni isolates. Multiresistance is defined as resistance to three or more antibiotics, and pansusceptibility is defined as not having resistance to any antibiotic. Regarding drugs of last resort--cefotaxime, ciprofloxacin, and nalidixic acid--resistance was not common among Salmonella (6.3%). The resistance rate of Campylobacter spp. to last-resort drugs--erythromycin, ciprofloxacin, and nalidixic acid--varied between species. The observed trend was not statistically significant. No C. coli isolates and few C. jejuni isolates (9.1%) were resistant to erythromycin. In contrast to C. jejuni, the C. coli isolates were more likely to be resistant to ciprofloxacin (9.1 and 18.9%, respectively) and nalidixic acid (0 and 13.5%, respectively). The same phenomenon was detected for tetracycline (27.3 and 62.2%, respectively), sulfamethoxazole (9.1 and 43.2%, respectively), and ampicillin (9.1 and 21.6%, respectively).