Browsing by Subject "Schwein"
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Publication Adaption and assessment of a UHF-RFID system for livestock management(2018) Adrion, Felix; Gallmann, EvaA prerequisite for the implementation of concepts of precision livestock farming is data acquisition on the level of the individual animal, which is only possible on a large scale by applying electronic animal identification. Radio-frequency identification (RFID) systems in the ultra-high frequency range (UHF, 860 – 960 MHz) offer the possibility of simultaneous detection of transponders and a variably adjustable read range of more than 3 m. Until now, these systems were, however, only insufficiently adapted to the operating conditions in livestock farming. In collaboration with industry partners, passive UHF-RFID transponders for integration into ear tags for cattle and pigs and readers have been developed and tested. The objective of this thesis was the adaption and assessment of this UHF-RFID system for livestock farming. In particular, 1) the construction and test of a static test bench for UHF-RFID ear tags, 2) the development of a method of measuring the influence of ear tissue on the performance of UHF-RFID ear tags, and 3) the application and validation of the UHF-RFID system for monitoring of trough visits of growing-finishing pigs should be carried out. The experiments supported the selection and further development of UHF transponder ear tags and reader antennas for application in livestock farming. A suitable test method for UHF-RFID technology in the fields of research covered was established and applied for the first time. It repeatedly became clear during the experiments that the greatest challenge for the application of UHF transponders in ear tags is the reduction of the sensitivity against ear tissue. In addition to the monitoring of animal health with UHF-RFID, further research could be carried out regarding the positioning of animals for measurement of motion activity, the combination of transponders with sensors, for example, to measure body temperature, and the utilisation of the technology for implementation of the Internet of Things in food supply chains.Publication Analyse komplexer Merkmale beim Schwein mittels SNP-Chip Genotypen, Darmmikrobiota- und Genexpressionsdaten(2017) Maushammer, Maria; Bennewitz, JörnIn the present scientific research, SNP chip genotypes, gut microbiota and gene expression data were used for analysing complex traits in a Piétrain population. These data were collected from around 200 performance tested sows and were used for genetic and microbial analyses of complex trait as well as for structural and functional meat quality traits. The gut microbiome plays a major role in the immune system development, state of health and energy supply of the host. Quantitative-genetic methods were applied to analyse the interrelationship between pig gut microbiota compositions, complex traits (daily gain, feed conversion and feed intake) and pig genomes. The specific aims were to characterize the gut microbiota of the pigs, to analyse the effects of host genetics on gut microbial composition, and to investigate the role of gut microbial composition on the host’s complex traits. The pigs were genotyped with a standard 60K SNP chip. Microbial composition was characterized by 16S rRNA gene amplicon sequencing technology. Ten out of 51 investigated bacterial genera showed a significant host heritability, ranging from 0.32 to 0.57. Conducting genome wide association analysis showed associations of 22 SNPs and six bacterial genera. The potential candidate genes identified are involved in the immune system, mucosa structure and secretion of digestive juice. These results show, that parts of the gut microbiota are heritable and that the gut microbiome can be seen as quantitative trait. Microbial mixed linear models were applied to estimate the microbiota variance for each of the investigated traits. The fraction of phenotypic variance explained by the microbial variance was 0.28, 0.21, and 0.16 for daily gain, feed conversion, and feed intake, respectively. The SNP data and the microbiota data were used to predict the phenotypes of the traits using both, genomic best linear unbiased prediction (G-BLUP) and microbial best linear unbiased prediction (M-BLUP) methods. The prediction accuracies of G-BLUP were 0.35, 0.23, and 0.20 for daily gain, feed conversion, and feed intake, respectively. The corresponding prediction accuracies of M-BLUP were 0.41, 0.33, and 0.33. Thus, the gut microbiota can be seen as an explaining variable for complex traits like daily gain, feed conversion and feed intake. In addition, in combination with meat quality traits, transcript levels of muscle tissue were analysed at time of slaughtering. This study should give an insight into the biological processes involved in meat quality characteristics. The aims were to functionally characterise differentially expressed genes, to link the functional information with structural information obtained from GWAS, and to identify potential candidate genes based on these results. An important meat quality trait is the intramuscular fat content, since it affects the juiciness, the taste and the tenderness of the meat. Another important trait is drip loss which causes not only a loss of weight but also a loss of important proteins. Both traits have an impact on the consumer acceptance of fresh meat products. For each of the two traits, eight discordant sibling pairs were selected out of the Piétrain sample and were used for genome-wide gene expression analyses. Thirty five and 114 genes were identified as differentially expressed and trait correlated genes for intramuscular fat content and drip loss, respectively. On the basis of functional annotation, gene groups belonging to the energy metabolism of the mitochondria, the immune response and the metabolism of fat, were associated with intramuscular fat content. Gene groups associated with protein ubiquitination, mitochondrial metabolism, and muscle structural proteins were associated with drip loss. Furthermore, genome-wide association analyses were carried out for these traits and their results were linked to the genome-wide expression analysis by functional annotation. In this context, intramuscular fat was related to muscle contraction, transmembrane transport and nucleotide binding. Drip loss was characterized by the endomembrane system, the energy generation of cells, and phosphorus metabolic processes. Three and four potential candidate genes were identified for intramuscular fat content and drip loss, respectively.Publication Bewertung praxisüblicher Mastschweinehaltungen in Nordrhein-Westfalen hinsichtlich der Tiergerechtheit(2002) Zaludik, Katrina; Valle Zárate, AnneThe aim of this study was to assess animal welfare in conventional fattening pig systems. Development of means to improve animal welfare shall put the producer in a position to structure the production more in line with consumer requirements. To carry out this assessment the data of 100 fattening pig farms in North-Rhine Westphalia have been analysed. The study comprises of two parts, firstly the collection of operational data and data of housingsystems, and secondly behaviour investigations. In the analysis of the farm data it was found that, particularly in farms with slatted systems important points of the SVHO (1995) were not followed. Deficits were found in space allowance, dimensions of the slatted floors, drinking systems and objects for occupation. Problems apparent in all housing systems were mainly caused by climatic conditions and lighting. In the observational data the most frequent observation was the lying behaviour. This was significantly lower in deep litter systems. The values for the lying behaviour were in line with the figures quoted in the literature for intensively kept pigs. Animals on farms with straw systems, were significantly more active than animals on farms with fully slatted floors, due to the incentives given by the availability of straw. In slatted floor systems the manipulation of penmate and occupational objects were much higher represented in the total behaviour than in straw systems. Abnormal behaviour was found in all housing systems, however only in small amounts. At the end of this study suggestions for ways of improvement were made specific to the relevant husbandry systems, which included housing as well as management factors.Publication Development of high quality niche products from local chicken and pig genetic resources(2016) Muth, Philipp; Valle Zárate, AnneThis thesis indicates that the application of non-conventional and/or slow-growing pig and chicken genotypes alone does not guarantee a superior and/or distinctive meat color and quality of the products. It appears that the valorization of monogastric meat products through niche marketing is critically dependent on matching the respective genotype with appropriate production methods, thus, for instance, highlighting the need for producers to be discerning in regard to the choice of slaughter age and feeding strategy. In the case that these premises are implemented, a distinguished positioning of meat products derived from local pig and chicken genetic resources can be realized, and, expanded by standards that also take the social and economic dimensions of food value chains into account, translated into a common pool resource as a basis for an alternative food network. Efforts should then be directed toward the elaboration of stable distribution channels and effective governance structures in the respective food network.Publication Diurnal and photoperiodic effects on the immune system and glucocorticoid signaling in domestic pigs(2019) Engert, Larissa; Stefanski, VolkerPhysiology and behavior of humans and animals display pronounced diurnal and seasonal rhythmic variations. Diurnal rhythms are controlled by daylight and seasonal rhythms are adjusted by the photoperiod, i.e., the relative span of light per day. Modern human life and housing conditions of livestock are often directed against natural daylight conditions and thus, may entail circadian disruption causing misalignment between the central circadian pacemaker and peripheral tissues. Thereby, glucocorticoids are regarded as a main link between these compartments. Circadian disruption might be detrimental for health, in particular affecting immune function, which was mainly investigated in humans and nocturnal rodents but underlying mechanisms are not clearly defined yet. Therefore, the main objective of the present thesis was to investigate diurnal and photoperiodic effects on the immune system and glucocorticoid signaling as well as potential underlying endocrine, behavioral, and molecular mechanisms of these effects in domestic pigs. Adult male castrated pigs, held under specific lighting schedules, were surgically catheterized to enable blood collection without disturbance of the animals. Initially, domestic pigs were held under standard 12L:12D-lighting conditions and blood samples were taken every 2 hours over periods of up to 50 hours. Cosinor analyses revealed pronounced diurnal rhythmicity in peripheral leukocyte numbers of various immune cell populations. These rhythms were mainly comparable to results in humans and nocturnal rodents in relation to their respective rest-activity cycles, with the exception of porcine neutrophils differing from both species. Moreover, the investigated diurnal rhythms in activity behavior and plasma cortisol concentration confirmed that domestic pigs under the applied experimental conditions are diurnally active like humans. Linear mixed model analyses revealed associations of immune cell counts with plasma cortisol concentration, which also resembles results from humans and rodents. Subsequently, photoperiodic effects on diurnal rhythms in peripheral immune cell numbers were investigated for the first time in any species. Domestic pigs were held either under long day conditions (LD) or under short day conditions (SD) and were sampled every 2 hours over periods of 50 hours. Distinct photoperiodic differences in relative amplitudes and peak times of cell counts in various porcine leukocyte types were found, whereas mesor values did not differ. Moreover, photoperiodic effects on diurnal rhythms in plasma cortisol concentrations and activity behavior were found, which is in agreement with human and primate studies. Generalized linear mixed model analyses again revealed associations of leukocyte counts with plasma cortisol concentration and with activity behavior as well. In summary, the results imply stronger rhythmicity of peripheral immune cell numbers in general under SD than under LD. Common intrinsic mechanisms seem to regulate diurnal rhythms in peripheral leukocyte numbers in most immune cell types in domestic pigs, except for neutrophils again. Finally, to investigate potential molecular differences in diurnal regulation between different immune cell types, glucocorticoid receptor (GR) number and affinity were examined in peripheral blood mononuclear cells (PBMC) and granulocytes of domestic pigs. Thereby, a greater number of GR sites per cell and a higher GR binding affinity in PBMC compared to granulocytes were found, pointing to differences in the molecular mechanisms of glucocorticoid signaling between leukocyte populations. The results of the present thesis project are subsequently discussed in regard to specific implications for immune function and health as well as animal husbandry and welfare. Moreover, a methodological assessment of the approaches used within the thesis project was carried out and finally, suggestions for future research directions were given. In conclusion, the present thesis revealed for the first time diurnal and photoperiodic effects on the immune system as well as glucocorticoid signaling in domestic pigs and uncovered potential underlying mechanisms of these effects. Hence, an additional diurnally active model species in chronoimmunology research was established. Moreover, conducting chronoimmunology research in the porcine species represents an innovative approach in agricultural science and provides entirely new opportunities to improve animal health and welfare. Thereby, future studies might investigate diurnal differences in immune function, clarify the role of different zeitgebers on immune rhythms, and assess potential consequences of stressor exposure at different times of the day.Publication Efficiency and productivity in pig nutrition(2011) Mosenthin, RainerThe efficient use of feed ingredients in diets for pigs is an important determinant of the productivity in modern pig production systems. Thus, there is a need to accurately estimate the feeding value of various feed ingredients. Several factors have to be considered for the adequate nutritional evaluation of feedstuffs. These include information (i) on the content of energy yielding nutrients (e.g. starch, sugars, lipids, protein), (ii) the digestibility and post absorptive utilization of nutrients, in particular indispensable amino acids, (iii) the physico-chemical characteristics (e.g. solubility, viscosity) of feedstuffs, but also (iv) potential effects of feed ingredients on pigs? voluntary feed intake and (v) effects of specific feed ingredients on animal product quality (e.g. fatty acid composition) need to be identified. Moreover, so called anti-nutritional factors (ANF?s) have been recognized as important factors that may negatively affect efficiency and productivity in pig nutrition. Some of the most important ANF?s present in feedstuffs which are frequently used in pig nutrition will be addressed in greater detail in the following. The EU-wide ban on the use of protein from animal sources in 2001 contributed to an increased demand for plant protein sources in the feeding of livestock. However, most protein-rich feedstuffs of plant origin contain various kinds of ANF?s that interfere with the utilization of nutrients, thus limiting their use particularly in the nutrition of non-ruminant animals such as pigs and poultry. As a result, depressions in growth performance and animal health due to a variety of mechanisms including reducing protein digestibility, binding to various nutrients or damaging the intestinal wall, thereby lowering digestive efficiency, were observed. Major ANF?s that interfere with nutrient digestion and absorption in non-ruminants include protease inhibitors, lectins, tannins, alkaloids, pyrimidine glycosides, α-galactosides, glucosinolates, and sinapins. The type and content of these ANFs may vary considerably among different feedstuffs, moreover, many feedstuffs contain several ANFs, and the amount of ANFs may vary both between and within varieties, due to differences in plant?s growing conditions and genetics. Protease inhibitors and lectins are most significant for legume seeds (soybeans, peas, faba beans, lupins), tannins are present in rapeseed, faba beans and peas, whereas glucosinolates and sinapins dominate in rapeseed. Finally, alkaloids and α-galactosides are important in lupins, and pyrimidine glycosides can generally be found in faba beans. However, due to significant progress in plant breeding, grain legume and oilseed cultivars with negligible low contents of ANF?s are commercially available. Moreover, the application of refined processing technologies designed to reduce the content of ANF?s in feedstuffs has proven to be an efficient tool. In particular, the use of hydrothermal treatment procedures during feed processing substantially reduces the activity of several heat-labile ANFs such as lectins and protease inhibitors but contents of tannins and glucosinolates are diminished as well.Publication Epidemiological and clinical description of Candidatus Mycoplasma haemosuis, an emerging pathogen in pigs(2023) Ade, Julia; Hölzle, LudwigCandidatus Mycoplasma haemosuis is an emerging pathogen infecting pigs. It belongs to the group of uncultivable hemotrophic mycoplasmas. This group includes other long-known porcine representatives, i. e. Mycoplasma parvum und Mycoplasma suis. M. suis is the causative agent of infectious porcine anemia (IAP), a disease of great economic importance to the pig industry. Previously, Ca. M. haemosuis was only described in China, South Korea and Thailand, with no knowledge of its occurrence outside Asia or of its general clinical and economic importance in general. The present work investigates the occurrence of the novel hemotrophic bacterium and its clinical importance in Germany for the first time. For this, a quantitative real-time PCR was first successfully developed for the detection of Ca. M. haemosuis in pigs. The SYBR® Green-based PCR amplifies a 177-bp fragment of the Ca. M. haemosuis gap, which encodes the NAD-dependent glyceraldehyde 3-phosphate dehydrogenase (GAPDH). Using this PCR, Ca. M. haemosuis was detected in a total of seven pigs during an acute clinical disease in May 2017. This represents the first detailed description of a disease induced by Ca. M. haemosuis and the first detection of this novel HM species outside of Asia. In a further study, the newly established PCR was used to comprehensively investigate the occurrence of Ca. M. haemosuis in clinically healthy animals of different age groups in Southern Germany. Ca. M. haemosuis was prevalent in 6.25% of the sows (n=208), in 4.50% of the piglets (n=622), in 17.50% of the pigs (n=200), and in 0.00% of the breeding boars (n=183). By sampling the piglets immediately after birth and prior to the first colostrum uptake, the possibility of a vertical transmission of Ca. M. haemosuis was also determined within this thesis. Since 76.92% of the Ca. M. haemosuis positive sows gave birth to at least one Ca. M. haemosuis positive piglet, a vertical transmission is regarded as very likely. HMs are known to be transmitted blood-dependent and thus, transmitted iatrogenic or via wounds from animal to animal. The detection of M. suis in blood-free excretions such as saliva, urine, nasal, and vaginal secretions from experimentally infected animals has initiated the discussion of additional, blood-independent transmission routes. Saliva (n=148) and urine samples (n=47) were also collected from the sows examined by blood sampling, semen samples (n=183) were also obtained from the examined boars and applied to Ca. M. haemosuis qPCR. The pathogen was not detected in any of the saliva, urine, or semen samples. On the one hand, this demonstrates the lack of suitability of blood-free sample materials for diagnostics; on the other hand, it highlights the blood-dependent transmission pathways known to date and thus strengthens the potential to limit infections through strict hygiene measures during veterinary procedures and through the control of bloodsucking arthropods. In conclusion, based on the newly established qPCR assay for the sensitive and specific detection of Ca. M. haemosuis, the present work provides the first clinical and epidemiological description of the emerging hemotrophic pathogen in pigs. Further, the qPCR assay will be the basis for future studies regarding the epidemiology as well as the clinical relevance and pathogenesis of Ca. M. haemosuis -infections in pigs.Publication Erhöhung der Butyratbildung durch Fütterung von Resistenter Stärke beim Schwein: Konsequenzen für die Mitose und Apoptoseregulation der Colonmucosa(2004) Mentschel, Joachim; Claus, RolfEffects of nutrition on health status were examined in numerous studies for human as well as animal species. The interest is mainly focused on those components which are known to exert a beneficial effect on health. Specifically prae- and probiotic substances are discussed to decrease the use of antibiotics in animal nutrition. Moreover epidemiological studies suggest that a higher fiber content reduces the risk for carcinogenesis. The effects seem to be mediated by short chain fatty acids (SCFA). SCFA are major products of microbial fermentation of fiber in the hindgut and are essential for normal colonic function. Butyrate has been shown to have the most significant effects on colonic epithelium. For example colonic recovery after mucosal atrophy is improved due to butyrate supply. To examine the principles of the butyrate dependent effects, in numerous studies the effects of butyrate on mitosis, cell differentiation, and apoptosis of epithelial cells were determined. It has been shown that butyrate increases proliferation of normal cells both in vitro and in vivo, but decreases proliferation in neoplastic cells in vitro. In addition the incubation of adenoma and tumour cell lines with butyrate induced apoptosis whereas the absence of butyrate from the incubation medium triggered apoptosis in guinea pig colonic mucosa. This antiapoptotic function of butyrate has been confirmed in the bovine ruminal epithelium. The reasons for these contradicting results and the regulation of butyrate mediated apoptosis have not been examined so far. In the present study, therefore, the effects of butyrate on colonic epithelium were investigated by feeding resistant potato starch. Effects were verified by determining immunocytochemical parameters. The experiments were performed with 18 castrated male pigs (German Landrace x Pietrain). They were divided into the control group, the resistant starch group (RS), and the realimentation group (RE). At the end of the feeding period the pigs were killed and tissue samples for immunocytochemical studies were obtained. The controls were fed during the whole treatment period (19d) with a ration containing pregelatinized starch with a high ileal digestibility (14,13 MJME and 173,5g XP / kg DM). The RS group received the same diet for 10 days. Thereafter a ration with a lower ileal digestibility containing raw potato starch (11,28 MJME and 138,5g XP/ kg DM) was fed for 5 days in the adaptation period and for 19 d in the treatment period. The pigs of the RE group were fed identically, however after the control diet a starvation period of 3 days was included. Due to the lower energy content of resistant starch compared to pregelatinized starch the average energy and protein content differed between the two rations. To ensure an equal energy and protein supply the RS and RE group received a higher amount of the resistant starch ration. For later analytical determination of pH and SCFA, representative amounts of fresh faeces were collected every morning. They were stored deep frozen (-20°C). At the end of the experimental period pigs were killed and colonic tissue samples were taken for histological and immunocytochemical analysis. Feeding of resistant starch led to a 2.2-fold increase of butyrate in faeces. The morphological results revealed a significant increase of crypt depth (20%) in the resistant starch groups. This difference, however, can not be explained by a different mitotic rate which was nearly identical in both groups. Thus the morphological difference has to be attributed to the differences in the apoptotic activity which was significantly lower (40%) in the groups fed with resistant starch. This decrease of apoptosis was paralleled by an increase of the mucus area of goblet cells which were shown to contain EGF (epidermal growth factor). The difference was about 50%. The results indicate a link between apoptosis and EGF in the colonic epithelium. A reduction of apoptosis by 40% and no change of mitotic rate should lead to higher differences in epithelial development. The low increase of crypt depth can be explained by the shift of apoptosis along the crypt axis. In the group with high butyrate levels 39% of the apoptotic cells were located in the basal compartment of the crypts, in the control-group, however, only 17%. This higher incidence of apoptosis in the stem-cell compartment led to an decrease of average lifespan of colonocytes and consequently to the relative low increase of epithelium. The compartmental distribution of apoptosis is regulated by pro- and antiapoptotic members of the bcl-2 family. Compared to the control group the higher apoptotic rate in the basal compartment of the butyrate group was paralleled by the higher expression (3,5- fold) of the proapoptotic protein Bak. In addition the expression of the antiapoptotic protein Bcl-2 was increased in the luminal compartment by 55%. The results of the RS and RE group did not differ significantly. Due to the treatment-period of 19 days and the high turnover-rate in the colon the effects of starvation seem to be compensated. In conclusion the results demonstrate that under in vivo conditions in the pig butyrate is an inhibitor of apoptosis, but additional mechanisms ensure that the resulting proliferation is limited.Publication Exogenous influences on skatole formation in the pig(2015) Wesoly, Raffael; Weiler, UlrikeCastration of male piglets without anesthesia and analgesia has been an ancient and traditional practice in several European countries to prevent problems with boar taint. The commencement of the National Protection of Animals Act on 13th July 2013 intends to end castration without anesthesia in Germany by 2019. In Europe, the goal is to end castration of piglets by raising entire male pigs only from 2018 onwards. This, however, is a challenge for the entire supply chain of the pig production industry, since sufficient consumer protection from tainted boar meat cannot be guaranteed so far. Off-odors in boar meat are caused by the testicular steroid androstenone and the tryptophane metabolite skatole. Exogenous and endogenous factors which favor the formation of both boar taint substances, but especially of skatole, have so far been only partially identified. Thus the aim of the present thesis was to determine exogenous influences on skatole formation and deduce measures to reduce the amount of tainted carcasses. In the first part of the thesis (Chapter 3), the current state of research on the impact of feeding strategies on skatole physiology was summarized. The mechanisms of different feeding strategies and feed additives were described in their effect on formation, metabolism and fat deposition of skatole. Based on a deduced formation cascade of skatole, different feeding strategies aiming to reduce skatole can be evaluated in a simplified manner. It could be shown that promising feeding strategies to reduce skatole have to be effective on more than one level of the formation cascade at the same time. In the second part of this thesis (Chapter 4), the reasons for varying androstenone and skatole concentrations found at slaughter plants in animals from the same origin were investigated. In order to identify the reasons leading to said differences, a study with 169 boars from three different farms was conducted. Each farm delivered animals, split into two groups, to two different slaughter plants with a time interval of one day. The duration of transport as well as the duration of pre-unloading and the time spent on the vehicle before unloading were recorded. During the slaughter process, samples of blood, feces and urine were collected for hormone analysis. Carcasses were scored visually for lesions in cold storage after slaughter, and adipose tissue was removed for boar taint analysis. Even in animals of the same origin, the same genotype as well as the same feeding regimen, significant differences in androstenone and skatole concentrations in fat could be measured, which could be traced back to the different transport and pre-unloading times. In contrast to androstenone, skatole in the fat of the animals was influenced predominately by the pre-unloading time and increased by more than 20 ng/g with every hour of pre-unloading time. In addition, animals with higher lesion scores had higher skatole concentrations in fat. Transport time, on the other hand, had an effect on androstenone concentrations in fat, which increased by about 0.1 µg/g per hour transport. Skatole concentrations, however, were only slightly affected by transport time. Positive correlations could be found between cortisol and testosterone in various substrates with deposition of boar taint substances in fat. However, further research is required to clarify the mechanisms of these effects in detail. Minimizing transport and pre-unloading times before the slaughter process, however, seems mandatory to reduce the amount of tainted carcasses. The third part of this thesis (Chapter 5) investigated the impact of management factors on variability of skatole concentrations in blood and fat. Modern breeding companies take fat biopsy samples to estimate the breeding value for the trait boar taint in AI boars. However, it is not yet known to which extent repeated biopsies or different sampling locations may themselves affect skatole levels. Furthermore, the influence skin contamination of animals and of transdermal skatole diffusion have been matters of heated discussion for decades. The published results, however, are in part contradictory and it is not clear to which extent skatole can diffuse through the skin and to which degree this source may contribute to the concentrations in the carcass. As a consequence, the clarification of these complex relationships was the subject of the third study. The results show that skatole concentrations reveal a low variability in samples from the dorsal part of the carcass, although 20% higher concentrations were measured in the ventral area. The transdermal diffusion of skatole was confirmed in this study, but it was also shown that this diffusion is local and that skatole levels of the carcass in general were not increased. Repeated biopsies under total anesthesia temporarily increased skatole levels in blood and were accompanied by a similar course of cortisol concentrations in blood. Punch biopsies in conscious animals had no effect on the course of skatole or cortisol in blood. The present thesis illustrates that, besides nutrition, stress is an important factor for off-odors in boar carcasses. The results from the experimental studies suggest that an improvement of animal welfare can reduce the risk of off-odor in entire male pig production and thus contribute to consumer protection. However, the results also show that any success of the farmer in the reduction of boar taint can be partially undone on the way to slaughter.Publication Genomische und mikrobielle Analysen von Effizienzmerkmalen beim Schwein(2022) Weishaar, Ramona Ribanna; Bennewitz, JörnMost traits in animal breeding, including efficiency traits in pigs, are influenced by many genes with small effect and have moderate heritabilities between 0.1 and 0.5, which enables efficient selection. These so-called quantitative traits are influenced by genetic factors and environmental factors. The use of next-generation sequencing methods, such as 16S rRNA sequencing to analyse the gut microbiome of livestock, allows identification and analysis of the gut microbiota. It has been shown that the composition of the microbiota in the gastrointestinal tract is heritable and has an influence on efficiency traits. Thus, the animal genome influences the phenotype not only directly by altering metabolic pathways, but also indirectly by changing the composition of the microbiota. This increases the interest in implementing gut microbiota into existing breeding strategies as an explanatory variable. The potential of an efficient utilization and absorption of nutrients varies between individuals. Differences in nutrient absorption depend on feed intake, digestion of dietary components in the stomach and intestine, and intake of digested nutrients from the gastrointestinal tract into blood and lymphatic vessels. Undigested nitrogen is excreted as urea and can be detected by blood urea nitrogen (BUN). The BUN is correlated with efficiency traits and there exist differences between pig breeds. Thus, therefore the BUN would be conceivable as an easier recordable trait for nitrogen utilisation efficiency in pig breeding. In the first chapter of this study, an existing data set of the Department for Animal Genetics and Breeding of the University of Hohenheim was used. This is a data set with 207 phenotyped and genotyped Piétrain sows. The relationship between gut microbial composition, efficiency traits and the porcine genome is investigated using quantitative genetic methods. The heritabilities of the traits FVW, RFI, TZ, and FI ranged from 0.11 to 0.47. The microbiabilities of the traits were significant and ranged from 0.16 to 0.45. In a further step, the previously generated microbial animal effects were used as observation vector for a genomic mixed model. Subsequently, heritabilities for the microbial animal effect were estimated, ranging from 0.20 to 0.61. The similarity of the heritabilities and microbiabilities suggests that the traits are influenced to a similar extent by both genetics and gut microbiota and that the microbial animal effect is determined by the host. These results are underlined by the identification of genera and phyla with significant effects on efficiency traits. The microbial architecture of the traits demonstrated a poly-microbial nature, there are many OTUs with small effects involved in the variation of the observed traits. Genomic Best Linear Unbiased Predictions (G-BLUP) and Microbial Best Linear Unbiased Predictions (M-BLUP) were performed to predict complex traits. The accuracies of M-BLUP and G-BLUP were all in a similar range between 0.14-0.41. This shows that gut microbiota could be used to predict performance traits or be included as a variable in the existing models of breeding value estimation to realize an increase in accuracies. The second part of the paper analysed a dataset from a research project called "ProtiPig". The data set included 475 sows and castrates of crossbreds of German Landrace x Piétrain and was analysed for protein utilization efficiency and nitrogen(N)-utilization efficiency. N-utilization efficiency is a trait that is difficult to record. Because conventional metabolic cage methods are a very complex procedure and difficult to integrate in the standard recording, it was tested whether the BUN is suitable as a proxy trait. Moderate to medium heritabilities could be estimated for all traits and ranged from 0.13 to 0.49. The genome-wide association studies showed that the traits were polygenic. For the BUN, SNPs could be detected that were above the genome-wide significance level. Significant genetic and phenotypic correlations were found between some traits. In particular, the heritabilities of BUNs and the significant genetic correlation between BUN and N-utilization efficiency indicate an opportunity to use the BUN to select for improved N-utilization efficiency. Before the research results generated here can be implemented in breeding practice, further questions must be clarified. In addition, a larger number of animals is needed to validate the results. The results presented here demonstrate the potential of microbial-assisted breeding value estimation and the use of BUN to identify selection candidates for breeding for increased efficiency.Publication Geschlechtsspezifische Unterschiede in der Fötalentwicklung beim Schwein(2007) Häußler, Susanne; Claus, RolfBasic mechanisms of sexual differentiation in higher mammals are well established. The development of the testes is controlled by genetic mechanisms and initiated by the Y-chromosome. Further differentiation of the ?Anlagen? is performed by the presence of testicular androgens but requires no specific signal in females (basic femaleness). Speculation exists during the fetal development of pigs, because androgens are also measurable in female fetuses. In addition, the male gonad is able to synthesize remarkably high levels of estrogens. The aim of the present study was to follow up concentrations of steroids in peripheral plasma throughout fetal development, starting with week 6, and in particular to analyze changes in testicular cell populations (spermatogonia, Leydig cells) and to correlate them with testicular androgens, estrogens, 19-nortestosterone and cortisol. The expression of steroid converting enzymes such as 11beta-HSD 2 and aromatase as well as receptors were determined by immunocytochemistry and quantitative PCR. Altogether each of the stages of gestation (weeks 6, 10, 13, and 15 of pregnancy) was represented by 4 sows, so that a total of 158 fetuses were collected. Testicular steroid synthesis (testosterone, estradiol) could be demonstrated as early as week 6, but was independant of gonadotropine. 19-nortestosterone, which is formed during estrogen synthesis, was detected in amniotic fluid using a new established enzymeimmunoassay in this study. Aromatase activity clearly correlated with a wave-like pattern of cell development. Therefore the activity was elevated both during an alternating rise of Leydig cells or spermatogonia mitosis. During the rise of spermatogonia development Leydig cells remained quiescent and during the Leydig cell mitosis spermatogonia remained inactive. An increased aromatase activity was observed both during the rise of spermatogonia and Leydig cell mitosis, and in consequence an elevated concentration of estradiol was found. But during an increased Leydig cell formation aromatase expression and thus estradiol synthesis was taken over by spermatogonia. It is therefore reasonable to resume that estrogens are important mitogenic signals as it was also found earlier in mature boars. The expression of glucocorticoid receptors by spermatogonia could be demonstrated for the first time in fetal pig testes. As also shown for other tissues, its likely role in testes is the differentiation of new cells. This important role also explains the expression of the enzyme 11beta-HSD 2 both by Leydig cells and spermatogonia. This enzyme is a well known fine-tuning mechanism which indicates cortisol and thus the ligand for the glucocorticoid receptor. Its expression in parallel to the rise of estrogens suggests a dependancy on estrogens. Investigating this was, however, not the topic of the present study. The demonstration of androgens both in blood plasma and amniotic fluid in female fetuses seems to contradict the principle of basic femaleness. It was shown however, that concentrations of testosterone in males increase up to 2.01 ng/ml plasma during the main period of sexual differentiation whereas female levels remain at 0.2 ng/ml so that it is simply the concentration which decides where the male differentiation does occur. It can not be ruled out, however, that low concentrations in female fetuses may have an effect on follicular differentiation, as was also demonstrated in mature sows. At the same time androgens could have a mitotic effect caused by insulin-like growth factors (IGF I + II). Thus the present investigation was able to clarify of several new mechanisms and basic data of fetal pig development. Further confirmation of the mechanisms suspected in this study may be served by an aromatase inhibitor.Publication Der Glucocorticoidrezeptor des Schweins: Herstellung und Charakterisierung eines polyklonalen Antiserums, sowie Studien zur Verteilung des GCR im Intestinaltrakt von Ebern und Kastraten(2002) Gutscher, Monika; Claus, RolfGlucocorticoids are well known to be essential for many physiological and developmental processes. Such functions include their effects on carbohydrate and protein metabolism and their regulatory influences on the immune system. In cell regulation they play a dose-dependent key role for differentiation and apoptosis. In rapidly renewing tissues the stringent control of these mechanisms is central to the maintenance of tissue homeostasis. ln the gastrointestinal tract both the adaption to changing nutrients and the presentation with a vast array of different types of antigens, including potential pathogens and harmless dietary antigens requires a granular regulation of cell proliferation, differentiation and cell death. In the pig, the differences in the turn-over rate for instance between skeletal muscle and the gut tissue could be attributed to different GCR concentrations respectively. This explains the tissue specific sensitivty on circulating corticoids. Thus studies on GCR distribution contributes to the clarification of the role of glucocorticoids in the regulation of these mechanisms in the intestinal tract. In the pig, so far receptor detection has been performed by radio ligand binding assays, which only measures steroid unoccupied non-activated receptors in the cytoplasm. Selective GCR antibodies react with both occupied and unoccupied GCR. In addition, antibodies enable celltype specific detection of the GCR in complex tissues by immunocytochemistry. The aim of this investigation was the production of porcine GCR-specific polyclonal antibodies by detailed analysis of the cDNA sequence of the GCR and the recombinant expression of a suitable antigen fragment. A fragment with 2.1 kb of the GCR cDNA (gcr2.1) was sequenced. Based on Blast sequence analysis a GCR antigen fragment for recombinant expression was selected from the modulatory region (GCRmr) and cloned in a T7-expression system as a His-tag fusion protein. After affinity chromatographic und preparative purification The anti-pGCR-antibodies bind the pGCRmr antigen with high affinity, as well as the denatured receptor in western blot analysis. In additon, immunoprecipitation assays demonstrated that cytosolic GCR is recognized regardless of whether it is unoccuppied or occuppied with dexamethasone. Thus, the antiserum is able to bind the native GCR both in its inactivated form as a multiprotein complex in association with HSP90 and in its activated form with shed HSP 90. Our investigations with immunoprecipitation assays support the applicability of the anti-pGCR antiserum in immunohistochemistry. The characterized antibodies were implemented in immunohistochemy for studies of distribution and localization of the GCR in the small bowl and colon of boars and barrows. The intracellular distribution of the GCR was examined by western blot assays. Immunohistochemical studies showed an increased number of immunostained GCR in the colon compared with the small intestine, as has been shown earlier with ligand-binding assays. 32,9 % and 14,5 % of the cells of the lamina propria were GCR immunoreactive in the small intestine of barrows and boars. In the colon 49,3 % and 43,3 % showed immunostaining. Epithelial cells showed a reversed pattern compared to the lamina propria in both groups. The number of GCR immunoreactive cells in barrows and boars decreased from 9,6 % and 9 % in the small intestine to 5,4 and 5,6 % in the colon, respectively. Comparison of both groups ? barrows and boars - revealed significant differences in the number of GCR immunoreactive cells in the lamina propria of the small bowl. Boars showed a decreased GCR expression of 10 % in the duodenum and 30 % in the jejunum. The number of GCR immuostained colonic cells amounts to 36,9 % in the colon ascendens and 49,2% in the colon descendens of boars and 47,5 % and 51 % in barrows. Studies of the subcellular localization by western blot analysis of cytosolplasmic and nuclear proteins demonstrated that in both groups in the ileum a higher amount of GCR was translocated into the nucleus. In the colon the number of cytoplasmic GCR was higher. The different subcellular GCR distribution in the two segments of the intestine can be explained by the increased expression of 11â-hydroxysteroid dehydrogenase 2 in the colon. 11â-HSD 2 inactivates cortisol and thus inhibits receptor activation and thereby translocation to the nucleus.Publication Impact of dietary phosphorus and fermentable substrates on the immune system and the intestinal microbiota of the pig(2016) Heyer, Charlotte Maria Elisabeth; Stefanski, VolkerPhosphorus (P) represents a crucial input for agriculture and food industries as a mineral present in ingredients used for livestock feeding as well as in mineral fertilisers. In the current systems, P is primarily derived from the finite mined phosphate rock resource. Thus, a critical challenge of global P scarcity is directly linked to future food security and sustainable resource management, especially in the European Union which is dependent on raw P from outside Europe. Apart from other future activities in animal nutrition, new dietary formulations of livestock diets emerged as a potential approach to increase the digestibility of plant P, phytate (myo inositol 1,2,3,4,5,6 hexakisphosphate, InsP6), and to reduce the supplementation with mineral phosphate. In non-ruminant animals, such as the pig, InsP6 hydrolysis is incomplete, as the small intestine lacks sufficient enzymes such as endogenous mucosal phytase and phosphatase. As a consequence, there is rising scientific interest to improve the understanding of InsP6 degradation in the digestive tract as well as the effects on nutritional factors and finally animal performance and health. The aim of the present thesis was to investigate the impact of dietary P, InsP6 and InsP6 hydrolysis products in combination with different fermentable substances (protein, carbohydrate) on the porcine immune system, the intestinal microbiota and animal health. First, a comprehensive literature overview describes the impact of P on the immune system and the microbiota along the gastrointestinal tract (GIT), including potential effects on host health with special focus on the pig. Secondly, an in vivo study with growing pigs was conducted to examine the effects of diets with varying mineral calcium-phosphorus (CaP) levels as well as different fermentable substrates on intestinal CaP concentration, InsP6 hydrolysis, the intestinal microbial ecosystem, and the peripheral and gut-associated immune system. In 2 consecutive experiments, 31 growing pigs (55 ± 4 kg) were allotted to a 2 × 2 factorial arrangement with 4 treatment groups, fed either a corn-soybean meal or a corn-pea based diet, each with 2 different CaP levels (low, 66% of the CaP requirement; high, 120% of the CaP requirement) supplemented with monocalcium phosphate and calcium carbonate. After 3 weeks of adaptation to the diets, all pigs were immunized twice with keyhole limpet hemocyanin (KLH). Blood and faeces samples were taken. After slaughtering, immunological tissue (jejunal, ileal mesenteric lymph nodes, spleen) as well as jejunal, ileal, caecal and colonic digesta were taken. Faecal and digesta samples were examined for P, Ca, inositol phosphate (InsP) isomers and for the marker titanium dioxide. The number of different leukocyte subpopulations analysed by flow cytometry, mitogen-induced lymphocytes proliferation in vitro were assessed. In addition, concentrations of plasma anti KLH IgM and plasma anti-KLH IgG analysed by ELISA and haematological parameters analysed by an automated hematology system have been measured in blood and tissue samples. In digesta samples, bacterial 16S rRNA gene copy numbers were determined by quantitative real-time PCR. The concentration of short chain fatty acids (SCFA) and ammonia was assessed. In addition, the use of terminal restriction fragment length polymorphism has been proven to characterize the structure of porcine gut microbiota. Results of the current study demonstrated that CaP and fermentable substrates had a distinct effect on the peripheral and gut-associated immune system, as well as on microbial composition and activity in growing pigs. High dietary CaP concentrations and the corn-pea diets increased P net absorption. Almost no InsP6 degradation could be observed in the GIT, and mainly myo inositol pentakisphosphate (InsP5) isomers were measured in jejunal, caecal digesta and faecal samples. In particular, the high CaP diets showed higher InsP6 and InsP5 concentrations, indicating a reduction of the initial steps of P release from InsP6 and a further breakdown of InsP5 isomers. The low CaP content might cause an impaired first line of defence and activation of the cellular and humoral adaptive immune response. As an example, the high CaP content affected the outcome of the adaptive immune response including a higher number of antigen experienced T-helper cells in the blood as well as higher plasma anti-KLH IgG concentrations. The reactivity of blood and mesenteric lymph node lymphocytes to Concanavalin A in these pigs was impaired, indicating modulating effects of other origin such as migration patterns or activity of antigen-presenting cells. Since results of the present study suggest contradictory effects of CaP level on immune cell numbers and lymphocyte reactivity in vitro and in vivo, further studies are needed to determine effects on cell signalling such as cytokine production profiles. Moreover, the high CaP content and the soybean meal diets increased the number of butyrate-producing bacteria, such as Eubacterium rectale and Roseburia spp. and increased the concentration of various SCFA in the small and large intestine, thereby contributing to improve gut health. Potentially harmful bacteria, such as Enterobacteriaceae and Bacteroides Prevotella Porphyromonas, were increased by the low CaP level and pea diets, indicating a less healthy microbiota. Results demonstrated that both, CaP supply and the amount of fermentable substrates, may beneficially affect gut health due to modulations of the composition and activity of the intestinal microbiota. Further studies should evaluate the impact of CaP on specific pathogenic bacteria known to produce toxic products creating a direct link to the immune system and animal health. Although most parameters of the present study indicate a positive effect of the high CaP diet, not all values showed a consistent effect on animal health, such as immune cell numbers and lymphocyte proliferation in vitro. In conclusion, variations in P availability and the formation of individual InsPs have to be considered when formulating diets in support of a stable intestinal microbial ecosystem and immune functions of the host.Publication Influence of frequent regrouping and social status on behavioral, endocrine and immune responses of group housed pregnant sows(2020) Schalk, Christiane; Stefanski, VolkerIn modern animal husbandry, dynamic group-housing of pregnant sows is a common practice. Every regrouping of animals or every change of group composition is associated with the establishment or the adjustment of a new dominance hierarchy, which provokes aggressive behavior, fights and injuries. This process is known to result in social stress by an activation of different stress systems. The subsequent release of neuroendocrine signals like glucocorticoids (e.g. cortisol) has the potential to alter several immune functions and immune cell numbers in the blood which may be directly associated with animals’ health, reproduction, embryonic development and economic losses. The effects of frequent regrouping or mixing on pregnant sows’ behavior, stress hormones and especially the distribution of blood leukocyte subpopulations represent a major research gap in the field of stress assessment of dynamic group-housing conditions in pig production. The aim of the present doctoral thesis was to evaluate whether frequent regrouping acts as a chronic social stressor influencing behavior as well as the endocrine and immune system of group-housed pregnant sows. Special emphasis was put on the question whether frequent changes of the group composition affect blood leukocyte subpopulations. A study with 40 pregnant sows was designed to investigate the influence of frequent changes of group composition on numbers of blood leukocyte subpopulations in combination with analyses of agonistic behavior and the endocrine status. Pregnant multiparous sows were housed in groups of five animals. Sows were either assigned to a repeated social mixing treatment with a mutual exchange of two randomly selected sows of two specific groups (2x2) twice a week over a period of eight weeks, or remained undisturbed in their original group. Blood samples of all sows were collected during pregnancy at five time points before, during, and after the mixing period to evaluate the number of blood leukocyte subpopulations and plasma cortisol concentrations. Blood immune cell numbers were analyzed during all trimesters of gestation and the impact of social status on these modifications was assessed. Behavioral data of pregnant sows of this experiment were used to compare various recommended dominance indices to rank individuals based on different methodical aspects to investigate whether these indices are comparable and equally applicable for determination of dominance relationships. Results of the current study demonstrated that pregnancy-associated alterations in the immune system generally exist in sows. The numbers of T cells, natural killer cells, B cells, cytotoxic T cells, and CD8+ γδ- T cells decreased during the last trimester of pregnancy, while neutrophils and plasma cortisol concentrations increased during pregnancy. Those pregnancy-associated alterations in the immune system were affected especially in middle-ranking sows, which had higher numbers of B cells and monocytes than sows with lower ranking positions. Plasma cortisol concentrations also tended to be higher in middle-ranking sows compared to low-ranking sows indicating that social rank can influence the immune system and endocrine status in sows during pregnancy. These findings showed the necessity to choose the appropriate measurement for calculation of dominance relationships. Repeated social mixing by frequent changes of group composition not only resulted in an increase of aggressive behavior during the entire mixing period, but also in altered immune cell numbers. The immunological profile in blood of mixed sows was characterized by lower numbers of antigen-experienced T helper cells, cytotoxic T cells and natural killer cells. This work demonstrated that frequent changes of group composition affect both cell numbers of the innate and the adaptive part of the immune system, which may weaken immunological memory functioning and reduce the resistance against certain infections in pregnant sows. For most of these immune cells a certain period of instable housing conditions was required to induce a change, but once manifested, these immunological alterations persisted even after the end of the mixing period. Although the findings of the present work on blood immune cell numbers resemble in many aspects a picture of stress-induced immunomodulation previously reported in context with social stress, no clear differences in measured plasma stress hormone concentrations between treatment groups or rank-positions were found. Whether other factors have influenced cortisol concentrations needs to be further evaluated. The overall picture emerging from the current doctoral thesis indicates that frequent changes of group composition and social status have the potential to induce stress-related immunological changes in pregnant sows which might adversely affect sows’ health.Publication Joint QTL analysis of three connected F2-crosses in pigs(2012) Rückert, Christine; Bennewitz, JörnMapping Quantitative Trait Loci (QTL) has received considerable attention in livestock genetic research over the last two decades. Knowledge of the location, the mode of inheritance and the size of effects of QTL contribute to a deeper understanding of the genetic architecture of quantitative or complex traits. Furthermore, mapped QTL were envisaged for use in so-called marker assisted selection programs. Before the era of genomics started, microsatellites were usually used as genetic markers for QTL mapping. In pigs, F2-crosses were frequently established from divergently selected founder breeds. Usually, the sizes of these F2-experiments are in the range of 300 individuals, which is too small to obtain sufficient statistical power to map QTL precisely. One large F2-experiment was set up in the 90th of the last century at the University of Hohenheim. Three F2-crosses from three genetically different founder breeds (Meishan, Pietrain and European Wild Boar) with almost 1000 individuals were genotyped and phenotyped for around 50 quantitative traits. In further studies, each of the crosses were analysed separately and more complex modes of inheritance were ignored. However, several researchers showed that a combined analysis with several QTL experiments can boost statistical power. Additionally, the mode of inheritance is sometimes not restricted to additive and dominant gene action. The overall aim of this thesis was the joint analysis of these three F2-crosses with more appropriate statistical models and to draw more precise conclusions about the QTL segregating within these experimental designs.Publication Microbiological and proteome analysis to gain insights into the pathogenesis of the highly adapted not-cultivated hemotrophic Mycoplasma suis(2016) Dietz, Stefanie; Hölzle, LudwigThe aims of this work were to establish a chronic pig infection model and to clarify unrecognized transmission pathways of M. suis. In addition, proteomics-based investigations of M. suis should be performed to improve the knowledge on the host pathogen interactions and host adaptation in IAP. Based on the succeeded and frequently applied splenectomized M. suis pig model (acute infection model) it was possible to establish a novel non-splenectomized M. suis pig model. This infection model enables the experimental investigation of the chronic M. suis infection. To this end, the piglets were infected intramuscularly with a highly virulent M. suis strain. Infected animals exhibited clinical signs (e.g. Morbus maculosus) including the typical cyclic course of chronic IAP. In the next step, potential transmission pathways of M. suis were analyzed during acute and chronic M. suis infection based on these two pig infection models. Feces, urine, air and dust as well as nasal, vaginal and saliva excretions were collected during the course of infection and examined for M. suis DNA by Rt-PCR. For the first time it was possible to detect M. suis in urine with and without erythrocytes as well as in nasal, vaginal and saliva excretions during acute and chronic infections. These results indicate blood-independent M. suis transmission via vaginal discharge, nasal excretions, saliva, and urine. The non-culturability limited the improvement of proteomic-based investigations of M. suis-related host-pathogen interactions. Therefore, we used modern and sophisticated proteome analysis to solve this problem. Blood samples from experimentally infected pigs at different time points of infection were investigated. For this, novel enrichment methods for M. suis proteins (especially membrane proteins) were established. These methods enabled an improved resolution of the protein expression profile of M. suis and thereby deeper insights into the pathogenesis of this microorganism. Despite of the missing cultivation system it was possible to identify more than 50% of the predicted M. suis proteins during acute infection. This identification ratio is similar to the one found in cultivable bacteria. Furthermore, the results of the proteome analysis indicate that nutrients such as glucose, hexose-6-phosphate, spermidine, putrescine, phosphate, amino acids, magnesium, potassium, sodium and iron are taken up by M. suis from the host leading to the high degree of host adaptation. Therefore, gained information on expressed M. suis proteins involved in transport are helpful in the establishment of an in vitro cultivation system in future. Particularly the supplementation of individual nutrients can play key functions in the media to support growth. Besides the M. suis proteome the acquired dataset firstly enables also the quantitative identification of Sus scrofa proteins differentially expressed during M. suis infection. This information can be used to unravel infection-relevant processes in the host in further studies.Publication Optimising breeding programmes with local pig breeds in North Vietnam considering functions of pigs for smallholders and logistic determinants(2009) Rößler, Regina; Valle Zárate, AnneDue to an increasing national demand for pig meat products in Vietnam, national development incentives focus on the intensification of the pig production. Still, the majority of the national pig herd is kept on smallholder farms. For a successful integration of smallholders into a market-oriented pig production, numerous constraints have to be overcome. One possibility is the development of village breeding programmes. This study uses an innovative approach, combining an institutional analysis of the pig breeding organisation and deterministic modelling to evaluate the technical appropriateness as well as organisational feasibility of alternative smallholder breeding schemes with the aim to identify an appropriate design of village breeding programmes for different smallholder pig production systems in Northwest Vietnam. In concluding, heterogeneous breed and trait preferences for local pig breeds of smallholders in different pig production systems have to be considered for the successful implementation of village breeding programmes. In addition, measures have to be adopted to improve factors that increase the genetic gain and to decrease high breeding costs. For the latter, a simplification of the currently complex and research-oriented performance testing scheme is recommended. The integration of smallholder pig breeding into regional and national structures is necessary to ensure the sustainability of village breeding programmes. Stratified crossbreeding schemes linking villages in different production systems together with the establishment of breeding cooperatives at village level and short food supply chains could help strengthen the currently weak links of smallholders to other breeding institutions and integrate several villages into a producer cooperative. Thus, small pig breeding populations could be enlarged and smallholders, particularly those in remote villages with poorly developed infrastructure, could be integrated into existing regional value chains for local pig meat products. Yet, limited financial and technical capacities of smallholders require the support from the government, particularly in the implementation phase. Implemented breeding programmes should be as simple as possible in order to reduce the risk for smallholders.Publication Die Regulation der Futteraufnahme beim Schwein - Untersuchung der Wirkungen eines Serotonin Noradrenalin Wiederaufnahmehemmers (Sibutramin) und eines MCH-R1 Antagonisten (Compound B4)(2007) Sommer, Torsten; Claus, RolfThe regulation of food- and feed intake is a highly topical investigative area in animal husbandry as well as in human medicine. Here the focus of medicine is primarily on the reduction of food intake and at the same time change of the metabolism to increased energy expenditure in order to counteract the rising number of adiposity and metabolic syndrome. Therefore, substances from pharmacological research are known which act in different nuclei of the hypothalamus and control food intake and energy expenditure. In the present study two of these new substances were examined with regards to their impact on pigs. The results lead to a more detailed understanding of the corresponding mechanisms in pigs, one of the most important animals used in agriculture. In addition, the pig is also a suitable model for human pharmacological research, as it equals the human physiological regulation more than the rat, which is the most common animal model. Study work flow: Two different regulative substances were examined, on the one hand a serotonin noradrenalin reuptake inhibitor (Sibutramine) and on the other hand, a melanin concentrating hormone receptor antagonist (MCH-R1 antagonist; Compound B4). For the evaluation of the effectiveness the following factors were measured; feed intake, water consumption, weight gain, feed conversion rate and the development of body fat content. The changes caused in the regulation of the metabolism were evaluated by anabolic (Growth hormone and IGF-I) and catabolic (cortisol and aldosterone) hormones. In addition, thyroid hormones and urea in the blood plasma were measured as a parameter of protein turnover. The study was divided in three trials, each of them taking six weeks. During the first trial sibutramine was given per os to three animals and three animals were kept as control. During the second trial sibutramine was given intravenously to two animals and two animals were kept as control. During the third trial the MCH-R1 antagonist, Compound B4, was given per os to six animals. The results are described in the following sections. Results of the sibutramine application: The pharmacological effectiveness of sibutramine is mainly explained through its metabolites (desmethyl sibutramine and didesmethyl sibutramine). It was found that for the per os intake of 20 mg/kg LW sibutramine, as well as sibutramine as the first metabolite desmethyl-sibutramine, a lower concentration in the blood plasma existed compared to the intravenous application. Whereas concentration of the second metabolite didesmethyl-sibutramine was higher for per os application than for intravenous application. Since the effectiveness of sibutramine is mainly based on its second metabolite didesmethyl-sibutramine, the way of application was crucial for its effectiveness. This means that the intravenous application was ineffective. After per os application feed intake was significantly reduced, also dependent on the dose applied, but did not lead to a reduced weight gain of the animals. Further, no impact was found on the feed conversion ratio. In contrast, the treatment with sibutramine per os led to significantly increased water consumption. The application of sibutramine had no impact on the growth hormone secretion. However, IGF-1 concentration was increased while feed intake was decreased. The cortisol concentration in blood plasma was not impacted by any treatment. Results of the application of the MCH-R1 antagonist (Compound B4): The application of the antagonist led to a significant reduction of feed intake, dependent on the dose applied. The means derived for daily weight gain show considerable individual differences per animal, hence the reduction of daily weight gain overall was not significant. Further, changes in water consumption were also detected in this trial. However, it could not be clarified if this was caused by the application of the antagonist or the reduced feed intake. Generally, the application of Compound B4 tends to result in energy saving mechanisms, which have an impact on metabolic active hormones. IGF-1 for example, was slightly lower in the control phase. Neither sibutramine nor the MCH-R1 antagonist Compound B4 had any impact on the concentration of thyroid hormones or cortisol. Conclusions: The studies have shown that the MCH-R1 antagonist leads to a significant reduction of feed intake in pigs, whereas the metabolic active hormones, and therefore the energy expenditure, do not seem to be impacted at all. In addition, it was proven that the pig is a useful animal model for such human pharmacological investigations. However, the large amount of substances required can be seen as disadvantageous and as a limiting factor in the investigation of new agents with an initially small amount of substance synthesis.Publication Simultanerfassung von Mastschweinen mit RFID-Technologie(2015) Stekeler, Tobias; Jungbluth, ThomasThe aim of the research project was to develop and evaluate technologies and methods which enable a simultaneous identification of fattening pigs marked with RFID technology instead of identifying them individually. Two approaches were pursued for doing so. A multiple reading device was developed operating at RFID low frequency. This reading device was comprised of several small synchronized single readers in order to realize a space division multiple access (SDMA) operation mode. Examinations using a newly developed test bench showed that several transponders could be identified simultaneously. Identification rates of nine transponders moving simultaneously through the reading area of the multiple reading device averaged 88.0 %, six transponders averaged 96.3 % and three transponders averaged 99.8 %. However, a different picture emerged in regards to the number of activated single readers: increasing numbers of activated single readers led to increased average identification rates. An average identification rate of 85.1 % was observed using four single readers, whereas six single readers averaged an identification rate of 99.2 % and eight single readers led to an average identification rate of 99.7 %. With the activation of eight single readers, even nine transponders could be identified simultaneously at an average identification rate of more than 98.0 %. The multiple reading device’s reading distance of less than 10 cm is however not sufficient for practical applications in pig farming. RFID systems operating at ultra-high frequency (UHF) are currently not used in livestock farming though they are well suited for simultaneous identification. The suitability of these systems for animal identification was investigated. In particular, the impact of water on the readability of UHF systems was observed since water acts as a disturbance value and has thus hindered the use of UHF systems for animal identification so far. One standard transponder type (N), two advanced transponder types (A and B) and two reading devices (I and II) were examined. With transponders A and B, reading distances of more than 1 m could be achieved even when impacted by water. A transponder’s actual reading distance achieved varied case by case depending on which reading device was used as well as the transponder’s orientation towards the reading device during the reading process. The examined transponder types A and B were used to build electronic ear tags to tag customary housed pigs. The suitability for electronic tagging and simultaneous identification of pigs were tested through regular identification trials with reading devices I and II over the span of one fattening period. Identification rates of 0 % to 100 % were observed. The average identification rates were 44.9 % for transponder type A and 56.8 % for transponder type B. An interaction between the different transponder types and reading devices was observable. Transponder type A achieved significantly higher identification rates in combination with reading device I, in comparison to reading device II (A.I: 60,5 %; A.II: 29,2 %). Transponder type B showed lower identification rates in combination with reading device I, in comparison to reading device II (B.I: 50,2 %; B.II: 63,5 %). Further interaction between transponder type and the array of the reading devices was observed. The ultra-high frequency trials showed the potential and the current limitations regarding the application of ultra-high frequency in electronic animal identification. UHF systems are capable of achieving reading distances comparable to those of low frequency systems even when impacted by the disturbance value of water. Electronic animal tagging and simultaneous identification are feasible under conditions of practice, the observed identification rates are however not sufficient enough for a reliable identification of tagged animals. Sufficient identification accuracy could not be achieved. In summary, the examined ultra-high and low frequency RFID-systems can be considered to be unsuitable for simultaneous identification of animals. Starting points for further development of the systems resulting in a reliable simultaneous identification under conditions of practice are, however, present. Further research and development is required regarding tagging capabilities, transponder and reading device features and the interaction of system components of RFID systems.Publication Stress hormone-induced immunomodulation and interplay between immune cells and bacteria in response to stress hormones in domestic pigs(2020) Reiske, Lena; Stefanski, VolkerThe two main endocrine systems involved in the regulation of stress reactions are the HPA axis, leading to the synthesis of glucocorticoids like cortisol or corticosterone, and the SAM axis, whose activation is associated with the release of the catecholamines adrenaline and noradrenaline. These stress hormones modulate the function of the immune system. Although pigs in modern husbandry systems face many stressors, the consequences of elevated plasma stress hormone levels on porcine immune cell numbers and functionality are insufficiently resolved. While some research on glucocorticoid effects has been conducted, data on many parameters are missing and catecholamines have not been studied systematically in the pig, yet. It is known that stress can negatively affect pigs’ resistance to infections like salmonellosis, but the underlying mechanisms are still subject to intense research efforts, with new perspectives arising since the discovery of interkingdom-signalling and microbial catecholamine perception. The aim of this thesis was to determine the effects of cortisol, adrenaline and noradrenaline on porcine immune cell functionality and the blood numbers of different leukocyte subsets. Furthermore, the interplay of immune cells and Salmonella Typhimurium under the influence of catecholamines was investigated. Adult male castrated pigs were surgically equipped with indwelling catheters to enable stress-free blood collection and intravenous application of hormones. In an initial experiment, the effects of in vitro stress hormone treatment on lymphocyte proliferation and the production of the proinflammatory cytokine TNFa were described. Cortisol reduced both proliferation and number of TNFa producers. Both catecholamines caused an increased lymphocyte proliferation at low concentrations whereas noradrenaline drastically decreased proliferation at high concentrations. While noradrenaline had no impact on TNFa producers, they were reduced in gd T cells and monocytes upon adrenaline addition. Overall, the effects were comparable to humans in terms of direction and dose but there were some disparities regarding adrenaline. In the second part of the project, the impact of in vivo stress hormone administration on immune cell numbers and functionality was examined by infusion for 48h. Cortisol and noradrenaline led to a decreased lymphocyte proliferation but to a variable extent and all three hormones promoted phagocytic function of innate immune cells. Cortisol caused a marked increase of neutrophil numbers while almost all other cell types declined strongly. For most cell types, noradrenaline exerted similar effects but solely after 2h whereas cortisol-induced alterations lasted the whole treatment period. Adrenaline effects were mostly reduced to CD8- T cells, which were reduced at first but increased after 24h. A sharp peak in NK cell numbers after 2h adrenaline infusion is particularly noteworthy and resembles findings from rodent and human studies. Overall, both hormone groups led to a shift from adaptive to innate immunity, underpinning the picture of a promotion of fast and unspecific defence systems to respond to threats in stressful situations. In a third study, S. Typhimurium was grown in the presence of catecholamines to determine the effects of supernatants from these cultures on porcine immune cell function. Both lymphocyte proliferation and TNFα production were hampered substantially, as opposed to the findings on catecholamine effects in the first experiment. It was demonstrated that these effects were not caused by catecholamines or their oxidation products and the formation of a so-far unknown immunosuppressive substance by catecholamine-primed bacteria was assumed. The results contribute to a better understanding of the increased susceptibility to infection in stressed animals and reveal a new dimension of cross-species communication. Finally, the results of the present thesis were discussed regarding their comparability to studies in humans and rodents and previous stress experiments in pigs. Furthermore, the effects of acute and chronic stress as well as different coping styles that are characterised by a SAM or HPA predominance on animal welfare and pig health were discussed, based on the endocrine mechanisms investigated in the present thesis. Possible implications of enhanced glucocorticoid and catecholamine levels for practical pig husbandry were given. Lastly, suggestions for future research to further elucidate the impact of stress hormones on the porcine immune system and the interplay with pathogenic bacteria were made.