Browsing by Subject "Pig"

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Analyse komplexer Merkmale beim Schwein mittels SNP-Chip Genotypen, Darmmikrobiota- und Genexpressionsdaten
(2017) Maushammer, Maria; Bennewitz, Jörn
In 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.
Bewertung praxisüblicher Mastschweinehaltungen in Nordrhein-Westfalen hinsichtlich der Tiergerechtheit
(2002) Zaludik, Katrina; Valle Zárate, Anne
The 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.
Development of high quality niche products from local chicken and pig genetic resources
(2016) Muth, Philipp; Valle Zárate, Anne
This 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.
Efficiency and productivity in pig nutrition
(2011) Mosenthin, Rainer
The 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.
Epidemiological and clinical description of Candidatus Mycoplasma haemosuis, an emerging pathogen in pigs
(2023) Ade, Julia; Hölzle, Ludwig
Candidatus 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.
Exogenous influences on skatole formation in the pig
(2015) Wesoly, Raffael; Weiler, Ulrike
Castration 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.
Geschlechtsspezifische Unterschiede in der Fötalentwicklung beim Schwein
(2007) Häußler, Susanne; Claus, Rolf
Basic 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.
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, Rolf
Glucocorticoids 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.
Impact of dietary phosphorus and fermentable substrates on the immune system and the intestinal microbiota of the pig
(2016) Heyer, Charlotte Maria Elisabeth; Stefanski, Volker
Phosphorus (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.
Influence of different plant extracts on CYP-mediated skatole and indole degradation in pigs
(2024) Marro, Philipp; Wesoly, Raffael; Stefanski, Volker
One of the primary substances responsible for the unpleasant odor in boar meat is skatole. Enzymes belonging to the cytochrome P450 (CYP) family play a pivotal role in the hepatic clearance of skatole. This study aimed to investigate the impact of oregano essential oil (OEO), Schisandra chinensis extract (SC), and garlic essential oil (GEO) on hepatic CYP2E1 and CYP2A activity in pigs. In three consecutive trials, cannulated castrated male pigs were provided with a diet containing 0.2–0.3% of one of these plant extracts. Following a 14-day feeding period, the animals were slaughtered, and liver and fat samples were collected. The findings indicate that the activities of CYP2E1 were unaffected by any treatment. However, GEO treatment demonstrated a significant reduction in CYP2A activity (p < 0.05). Pigs treated with GEO also exhibited a notable increase in skatole concentrations in both plasma and adipose tissue. In contrast, animals fed SC displayed elevated skatole concentrations in plasma but not in fat tissue. OEO did not influence skatole concentrations in either blood or fat. Furthermore, the study revealed that a supplementation of 6 g GEO per animal per day induced a significant increase in skatole concentrations in blood plasma within 24 h.
Influence of frequent regrouping and social status on behavioral, endocrine and immune responses of group housed pregnant sows
(2020) Schalk, Christiane; Stefanski, Volker
In 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.
Joint QTL analysis of three connected F2-crosses in pigs
(2012) Rückert, Christine; Bennewitz, Jörn
Mapping 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.
Microbiological and proteome analysis to gain insights into the pathogenesis of the highly adapted not-cultivated hemotrophic Mycoplasma suis
(2016) Dietz, Stefanie; Hölzle, Ludwig
The 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.
Optimising breeding programmes with local pig breeds in North Vietnam considering functions of pigs for smallholders and logistic determinants
(2009) Rößler, Regina; Valle Zárate, Anne
Due 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.
Simultanerfassung von Mastschweinen mit RFID-Technologie
(2015) Stekeler, Tobias; Jungbluth, Thomas
The 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.
Stress hormone-induced immunomodulation and interplay between immune cells and bacteria in response to stress hormones in domestic pigs
(2020) Reiske, Lena; Stefanski, Volker
The 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.
Studies of phytate degradation and associated mineral utilization in growing pigs
(2024) Klein, Nicolas; Rodehutscord, Markus
Phosphorus (P) is primarily stored in plant seeds as phytate, which is any salt of phytic acid (myo-inositol hexakisphosphate; InsP6). The enzymatic capacity of pigs and the microorganisms present in their digestive tract allows for only partial and incomplete prececal degradation of InsP6. To address this limitation, the addition of exogenous phytases to feed has been state-of-the-art for more than three decades. Phytases, found in various organisms like bacteria, fungi, plants, and animals, initiate the breakdown of InsP6 and inorganic phosphate, thereby making the liberated phosphate available for digestion. Substantial scientific research and practical field applications have shown that adding exogenous phytases to the diet of non-ruminants leads to an improvement in P digestibility and a reduction in P excretion. Over time, phytases with enhanced thermal profiles and higher activity at physiological pH milieus have been engineered. Additionally, advancements in plant breeding have increased intrinsic phytase activity in feed ingredients relevant to animal nutrition. Thus, this thesis aimed to deepen the understanding of inositol phosphate (InsP) degradation in ileal-cannulated pigs, focusing on how dietary variables can influence this process along the digestive tract. In the first study (Manuscript 1), diets based on wheat with variable intrinsic phytase activity and the addition of an exogenous phytase on InsP degradation in pigs were investigated. Although wheat intrinsic phytase contributed to increased InsP degradation and P digestibility in pigs, variation in intrinsic phytase activity by crossbreeding wheat, as achieved in this study, was not reflected in InsP degradation and P digestibility data. This discrepancy may be attributed to an inadequate proteolytic resistance of wheat phytase in the gastric compartment of the pig. A marked increase in prececal InsP degradation and P digestibility was achieved by adding a microbial phytase to the wheat-based feed. While exogenous phytase increases the digestibility of InsP-P, other dietary components may impair its hydrolytic activity. In the second study (Manuscript 2), the single and interactive effects of dietary Ca concentration and exogenous phytase in pigs were investigated. The study assessed the effects of dietary Ca and exogenous phytase on InsP degradation and nutrient digestibility in growing pigs. Additional dietary Ca decreased prececal InsP6 disappearance, but only with exogenous phytase. Concentrations of lower InsP isomers and myo-inositol in the ileal digesta and prececal P digestibility were greater with exogenous phytase, but not affected by dietary Ca concentration. In contrast, fecal InsP6 disappearance was lower and the concentration of InsP4-5 isomers in feces was greater with additional dietary Ca. The study revealed that dietary Ca concentration is relevant for InsP disappearance in the hindgut, but not in the ileum. However, when exogenous phytase is used, the dietary Ca concentration is important because prececal InsP degradation is affected by the Ca level in the diet. The third study (Manuscript 3) aimed to investigate the effects of dietary Ca sources, exogenous phytase, and formic acid on InsP degradation and nutrient digestibility in growing pigs. Replacing limestone with Ca formate reduced prececal InsP6 disappearance and prececal P digestibility. However, adding formic acid to a diet containing limestone and phytase enhanced prececal InsP6 disappearance and increased InsP2 and myo-inositol concentrations in the distal ileal digesta. Accordingly, prececal P digestibility was increased when formic acid was added to the diet containing limestone and exogenous phytase. This suggested that Ca formate is not a suitable alternative Ca source to limestone for optimizing prececal P release from InsP in growing pigs. The release of P from InsP by exogenous phytase in limestone diets can still be further increased by adding formic acid. In conclusion, the degradation of InsP in growing pigs is a complex process affected by dietary Ca concentration, dietary Ca source, and the presence of phytase. However, investigated dietary traits mainly affected InsP6, with lesser effects on lower InsP isomers, highlighting the importance of prececal hydrolytic breakdown of InsP6 to InsP5. This directly affected P digestibility of growing pigs. Intrinsic phytase activity in feed ingredients, such as wheat, can contribute to prececal InsP degradation but may be neglected when exogenous phytase is present in the feed. Exogenous phytase addition notably increased prececal InsP degradation and P digestibility in plant-based diets, and complete dephosphorylation of InsP in the prececal tract was implied by the increase of the final degradation product myo-inositol in the ileum content, urine, and blood. However, some P remained bound to InsP at the end of the ileum of growing pigs and was therefore not available for digestion. Nevertheless, some diets with exogenous phytase tested in this thesis met the recommended digestible P concentration. This suggests that diets formulated with adequate InsP-containing ingredients and exogenous phytase may obviate the need for mineral P addition, reducing the reliance on finite P sources in growing pig nutrition.
The exocrine pancreatic secretion in pigs and its hormonal regulation as influenced by carbohydrates and fats given per os or infused intraduodenally
(2000) Jakob, Stefan; Mosenthin, Rainer
In the present study the influence of carbohydrates in the form of potato fibre (NSP) and of different fats on the exocrine pancreatic secretion and on the regulative hormonal mechanisms was investigated. When feeding a diet supplemented with 2 potato fibre all measured parameters, e.g. volume of pancreatic secretion, protein output and total trypsin, lipase and alpha-amylase activities increased in pancreatic juice. Simultaneously there was a trend towards a decrease in plasma concentration of CCK. After the intraduodenal infusion of medium chain triglycerol (mct: glyceroltricaprylat), long chain triglycerol (lct: glyceroltristearat) or vegetable oils (olive oil or coconut oil) in all treatments a prandial peak was found as a direct reaction on feed intake for volume of secretion, total protein and colipase contents as well as the total activities of trypsin and lipase. After application of mct the secretion course occured in two phases. In phase 1 a parallel prandial increase in volume of secretion, total protein and colipse content as well as total activities of trypsin and lipase was found. For the same parameters in the second phase 60 min postprandially much lower values were observed compared to the preprandial values. The courses of the curves differed for total lipase activities. The diurnal course of plasma levels of CKK and PYY was not influenced. After coconut oil treatment the course of volume secretion was characterized by 2 phases. After a prandial peak in phase 1 the values decreased by 100 below the preprandial starting values. After the application of olive oil the specific lipase activity was elevated five times. In case of coconut oil there was only a prandial increase by 2.5. It is suggested that the exocrine pancreas responds differently in its secretion to different fat sources. Adaptation is probably regulated through a feedback-mechanism whereas CCK and PYY are of minor importance. Probably other hormones as e.g. secretin have a regulative
The porcine intestinal microbiota : studies on diversity and dietary impact
(2018) Burbach, Katharina; Seifert, Jana
The entirety of microbial communities within the gastrointestinal tract is referred to as intestinal microbiota and is predominantly composed of bacteria. Interactions between the microbiota, the host and the diet are essential for maintaining a healthy and functional intestinal ecosystem. The overarching aim of this thesis was the characterization of the porcine intestinal microbiota and further to enhance knowledge about the effects of varying diets. High-throughput sequencing of the 16S rRNA gene facilitates exploration of the taxonomic composition of the microbiota. However, the respective findings may be impaired by methodological variations. Thus, within this thesis, commercial DNA extraction kits are evaluated for their suitability in porcine microbiota analysis. The tested extractions yield into variations of quantity and quality of DNA. The DNA extracts are further used to elucidate the structure of the microbiota by a rapid fingerprinting (Terminal Restriction Fragment Length Polymorphism) and high-resolution sequencing (Illumina amplicon sequencing). While different variable regions of the 16S rRNA gene vary in the taxonomical resolution, sequencing analyses exhibit a good comparability of the two regions V1-V2 and the V5-V6. Furthermore, the microbiota profiles reveal a high consistency by the fingerprinting and sequencing approach but are distinguished by the different DNA extraction kits. Based on criteria of DNA extraction and the depicted microbiota composition, it is recommended to use the FastDNA SPIN Kit for Soil for further analysis of porcine intestinal microbiota. Subsequently, these methodological findings are applied to investigate the impact of varying diets. Illumina amplicon sequencing of the V1-V2 region of the 16S rRNA gene reveals different microbiota structures when diets are solely composed of rye or triticale. Besides the taxonomic analyses of ileal digesta and fecal samples, the concentrations of bacterial metabolites in feces are determined. In summary, rye promotes an increased abundance of saccharolytic bacteria like Lactobacillus, Bifidobacterium, and Prevotella and results in higher concentrations of bacterial metabolites in fecal samples. In contrast, a diet based on triticale is associated with an increased abundance of Clostridium sensu stricto, which may indicate an enhanced cellulolytic potential of the microbiota. When the crude protein content is increased (18%), compared to a lower content (14%), an increased abundance of Lactobacillus is demonstrated in microbiota of ileal digesta samples. However, the content of crude protein did not affect the overall microbiota significantly. In addition, dietary supplementation with probiotic Bacillus spp. shows no effect. In conclusion, these dietary effects on microbiota are considered together with results of a protein digestibility analysis. Moreover, an impact of dietary calcium and phosphorus in combination with different sources of dietary protein is analyzed by fingerprinting approach of digesta samples. Here, the content of calcium-phosphorus shows significant effects on the microbiota of caecal digesta and the putative identities of discriminative variables are determined by a cloning-sequencing approach. Similar, 16S rRNA gene sequencing reveals a significant impact of dietary calcium-phosphorus on the overall fecal microbiota without indicating specific discriminating variables. In combination with the results of a meta-proteomic approach, a gradual adaptation on dietary changes is indicated and consequently, a prolonged adaptation time of three to four weeks is recommended for diet-microbiota studies. This thesis includes a comprehensive analysis of the microbiota across and along the gastrointestinal tract of piglets and explores the dietary inclusion of four levels of insect larvae meal. Feeding insects represent an alternative source of dietary protein, whereby the increased content of chitin indicates a potential shift in microbiota composition compared to a control diet. However, in this case, the structural analysis demonstrates no effects on the overall microbiota’s structure. However, a pairwise comparison between diets reveals significant effects on the microbiota of digesta samples of the small intestine. Dietary inclusion of 5% insect meal increases the abundance of Lactobacillus, whereas the control treatment promotes Bifidobacterium. In conclusion, the results of the present thesis emphasize the importance of standardization within 16S rRNA gene based studies of the porcine intestinal microbiota. Furthermore, the necessity of studying various sampling sites combined with multidisciplinary approaches is demonstrated.
Transcriptomic analyses during infectious anemia in pigs
(2019) Mack, Sarah-Lena; Hölzle, Ludwig
Mycoplasma suis (M. suis) is a uncultivable hemotrophic bactreia parasiting red blood cells in pigs and a small range of other animals. It becomes more and more important because of leading to big economic losses in swine industry. M. suis causes anemia in pigs and is accompanied with other immunosuppressive diseases. A once infected animals is a life-long carrier and could infect other animals as well. To date, there is less information about the pathogenesis and reproduction of the bacteria and it is not possible to cultivate M. suis in vitro. One objective of the present study was to get more information about the transcriptomic changes in a pig during an infection course. Therefore, 3 splenectomized piglets were infected with the highly virulent strain KI_3806. After 2, 4 and 8 days post infection (p.i.) blood samples were taken and total RNA of blood was extracted. Microarray analyses were performed with a commercial Affymetrix array. Using microarrays more than 7000 DE genes from infected pigs could be detected. With M. suis in its host cells – the erythrocyte – we had a perfect model showing molecular interactions or signaling pathways in the M. suis infection process. With the help of the Ingenuity pathway analyses service many genes involved in immune and inflammatory response were found. Moreover typical genes involved in anemia, psoriasis and endothelial cell damage could be observed. The detection of these genes verified the depression and alteration of the immune system by M. suis resulting in evading the immune system and therefore in persisting among the organism. Another aim was to go deeper on the transcriptional level of M. suis and to get insights of the behavior of the bacteria at the time point of and after infection. RNA Sequencing was performed on a HiSeq 2000 Genome Analyzer from Illumina an resulting reads were mapped to reference sequences M. suis KI_3806 and Sus scrofa. Moreover, differential expression analysis was performed using the edgeR package. After mapping, it could be observed that on day 4 p.i. M. suis transcripts seem to be overlapped by porcine transcripts, whereas on day 8 p.i. most of the reads could be allocated to the M. suis genome resulting in almost all M. suis genes were found to be transcribed at the end of infection. When looking at the COG categories the group of proteins with “unknown function” (hypothetical proteins) represented the largest group on both days. Also a high number within the differentially expressed genes were hypothetical genes showing that these genes play an important role during infection. Further investigations are needed to confirm that the hypothetical genes also are involved in M. suis replication and recombination. In conclusion, our analysis revealed several thousand genes differentially expressed during acute IAP and numerous altered pathways and cellular processes throughout the course of host response to acute M. suis infections, thus contributing to a better understanding of the IAP pathogenesis. Moreover, this could lead to new approaches towards cultivation of M. suis as well as therapeutic treatments.