110 research outputs found
Abklärung von Aborten und anderen tiergesundheitlichen Problemen beim Rind im Zusammenhang mit der Blauzungenvirus-Impfung 2009
No full textZusammenfassung
Durch die Verteilung eines Meldebogens unter allen
schweizerischen Nutztierärzten konnten Aborte und
tiergesundheitliche Störungen im Zusammenhang
mit der Impfung gegen die Blauzungenkrankheit
2009 abgeklärt werden. Der Meldebogen diente dazu,
Plausibilität und den zeitlichen Zusammenhang der
Ereignisse zu gewährleisten. Insgesamt konnten 58
Rinderaborte sowie verschiedene tiergesundheitliche
Störungen auf Bestandesebene abgeklärt werden. Da
sich eine Impfung als Abortursache nicht direkt nachweisen
lässt, wurden nachgewiesene Abortursachen
vor und nach der BT-Impfung mittels klinikinternen
Daten miteinander verglichen. Da Abortursachen und
Aufklärungsrate vor und nach den BT-Impfungen
keine abweichenden Ergebnisse zeigten, kann die BTImpfung
selber nicht dafür verantwortlich gemacht
werden. Bestandesdiagnostische Abklärungen verschiedener
Krankheitsbilder liessen erkennen, dass die
BT-Impfung nicht dafür verantwortlich war oder auf
dem Betrieb schon vor den BT-Impfungen Probleme
vorhanden waren. Bestandesprobleme sind ein multifaktorielles
Geschehen, wobei es nicht in jedem Fall
einfach war, den Einfl uss der BT-Impfung auf das beklagte
tiergesundheitliche Problem einzuschätzen.
Schlüsselwörter: BT-Impfung, Aborte, Bestandesprobleme,
Abklärungen
Investigation of abortions and other animal
health problems in relation to vaccination
against Bluetongue virus in 2009
By the distribution of a questionnaire between all
Swiss cattle practitioners it was possible to investigate
abortions and other animal health problems related
to Bluetongue vaccination 2009. The questionnaire
helped to obtain plausibility and timely relation of the
reported disorders. 58 abortions in cattle and different
herd health problems could be examined. Because
there is no possibility to show that a vaccination itself
leads to an abortion the results of proven causes
of abortions prior and after Bluetongue vaccination
were compared regarding their diagnosis. Due to the
fact that diagnosis and solving rate of abortions did
not differ before and after vaccination, the vaccination
itself cannot be responsible for the abortions. Evaluation
of different herd health problems showed that
Bluetongue vaccination was not responsible for these
disorders which often existed already prior to vaccination.
Herd health problems generally have multifactorial
causes what makes it diffi cult to asses the effect of
Bluetongue vaccination in some cases.
Keywords: Bluetongue vaccination, abortions, herd
health problems, investigation
Einfluss der Temperatur auf die Gas-Feststoff-Strömung in Riser-Reaktoren
No full textCatalytic gas-solids reactions play an important role in the field of the chemical and petrochemical industry. Beside fixed bed processes, moving bed technologies like heterogeneous catalytic reactions in Riser reactors, with its excellent heat and mass transfer characteristics, are applied to a greater extend. Riser reactors can be assigned to the circulating fluidized bed technology. In contrary to conventional circulating fluidized bed processes how applied in the combustion area, Riser reactors can be characterized by the replacement of the downflow section with a regeneration step of the catalyst. Due to the separation of reactor and regenerator, higher conversion and selectivity rates are expected compared to conventional fluidized bed processes. This Riser-reactor-regenerator concept is already applied to the catalytic cracking of heavy hydrocarbons. At the moment, intensive research is done to transfer this concept to the production of maleic anhydride. This step requires an extensive knowledge of the fluiddynamical behaviour of Riser reactors. Beside the fact that the majority of applications of Riser reactors operate at elevated temperatures most of the investigation of the flow pattern are done at ambient conditions. The objective of this work is to describe the influence of the temperature on the flow pattern of Riser reactors. In order to characterize the temperature influence, a high temperature circulating fluidized bed with the focus on the Riser was designed for temperatures up to 450°C. The measurements were carried out with two different solids over a broad range of superficial gas velocities (UG = 3 m/s to 19 m/s), solids mass flows (GS = 70 kg/(m2s) to 650 kg/(m2s)) and temperatures (T = 20°C to 400°C). For the investigations of flow pattern axial and local measuring methods were used. The consideration of axial pressure profiles allowed studying the temperature influence on the axial development of the flow pattern. In addition to that local measuring techniques like capacitance probes and an X-ray-computer-tomography system were used. Due to the fluctuating nature of the local flow pattern, an invasive capacitance probe system, providing high time resolute information, was chosen. Supplementary, a non-invasive X-ray-computer-tomography system with a high spatial resolution was applied. Based on the results of the X-ray tomography measurements, the design of the bottom section was optimized in respect to a symmetrical distribution of solids in the inlet area. It proofed, that the usage of a hybrid L-valve with a direct gas feeding improved the uniformity of the solids distribution. In the industrial application of heterogeneous catalytic reactions educts are frequently fed in a liquid phase into the hot gas-solids flow of the riser. The distribution of the three phases has a considerable influence on the efficiency of the total process. To investigate the distribution of the separate phases a dual-energy technique combined with the X-ray-tomography system was applied at the high temperature riser unit. The results of the dual-energy X-ray-tomography proofed the possibility to describe experimentally the liquid feed injection in gas-solids flows at elevated temperatures. The characterization of the temperature influence on the flow pattern differentiated between axial and radial effects. The gas-solids flow of a Riser reactor can be subdivided into three axial sections, a lower steady-state section, a transition zone and an upper steady-state section. The influence of the temperature is mainly effective in the high concentrated lower steady-state section and in the transition zone of the riser. In general, in these two zones the acceleration of the solids occurs. With an increasing temperature an improved fluidization combined with an increased solids circulation rates was observed. At temperatures up to 200°C the local solids mass flow profiles show the characteristics of a core-annular-flow structure. At higher temperatures a redistribution of the solids was observed, with the highest upwards orientated mass fluxes in the wall region. Beside this, the influence of the temperature on the flow pattern of the upper section was negligible. A comparison of the experimental conditions with different models led to the conclusion that the flow structure in the upper steady-state section can be described as a homogeneous gas-solids system, while in the transition zone and lower steady-state section the flow structure is dominated by the development of strands and clusters. Based on the development of clusters and strands and intensified axial backmixing of solids was found. The results were used to describe the axial backmixing of solids, which can be seen as qualitative measure of residence time behaviour, as a function of the process parameters. Based on the experimental data a state diagram was developed allowing estimate the internal backmixing behaviour of the reactor. Conclusively, this work provides experimental data and models to describe the influence of the temperature on the flow pattern of the gas-solids flow of a Riser reactor. The results built an important basis to precalculate the conversion- and selectivity rates as the consequence of a chemical reaction in a Riser reactor.Obwohl die meisten Anwendungen von Riser-Reaktoren im Hochtemperaturbereich stattfinden, erfolgten die bisherigen Charakterisierungen des Strömungszustands bei Umgebungsbedingungen. Das Ziel dieser Arbeit ist es, den Einfluss der Temperatur auf den Strömungszustand in einem Riser-Reaktor zu untersuchen. Zur Untersuchung des Temperatureinflusses auf den Strömungszustand entstand eine Riser-Versuchsanlage im Technikumsmaßstab für den Temperaturbereich von Umgebungsbedingungen bis zu 450°C. Unter Verwendung von zwei verschiedenen Feststoffen wurden Untersuchungen in einem breiten Intervall von Leerrohrgasgeschwindigkeiten (UG = 3 m/s bis 19 m/s), Querschnittsbelastungen (GS = 70 kg/(m2s) bis 650 kg/(m2s)) und Temperaturen (T = 20°C bis 400°C) durchgeführt. Bei der Untersuchung des Strömungsverhaltens wurden im Rahmen dieser Arbeit axial und lokal messende Verfahren eingesetzt. Die Betrachtung von axialen Druckprofilen erlaubte es, die Auswirkungen der Temperatur auf die axiale Entwicklung des Strömungszustands näher zu betrachten. Zusätzlich dazu wurden aber auch lokal messende Techniken, wie ein kapazitives Sondenmesssystem und die Röntgen-Computer-Tomographie, eingesetzt. Bei der kapazitiven Sondenmesstechnik handelt es sich um ein invasives Verfahren mit einer sehr hohen zeitlichen Signalauflösung. Als Ergänzung dazu kam die Röntgen-Computer-Tomographie zu Einsatz, als berührungsloses, örtlich sehr hochauflösendes Messprinzip. Anhand der tomographischen Ergebnisse erfolgte auch die Optimierung der konstruktiven Gestaltung des Einlaufbereichs der Riserströmung hinsichtlich der Gas- und Feststoff-Verteilung. Es hat sich gezeigt, dass die Verwendung eines hybriden L-Valves mit direkter Gaseinspeisung zur gleichmäßigsten Gas- und Feststoffverteilung führt. In der Praxis werden bei heterogen-katalysierten Reaktionen die Edukte häufig in flüssiger Form dem Riser-Reaktor zugeführt. Die Verteilung der drei Phasen hat maßgeblichen Einfluss auf die Effizienz des Gesamtprozesses. Zur phasenaufgetrennten Untersuchung wurde ein erweitertes Tomographieverfahren an der Technikumsanlage bei Hochtemperaturbedingungen eingesetzt. Die Ergebnisse der Doppel-Energie Röntgen-Computer-Tomographie zeigten, dass es möglich ist, Vorgänge der Flüssig-Edukt-Einspeisung in heiße Gas-Feststoff-Systeme experimentell zu erfassen. Bei der Untersuchung der Auswirkungen der Temperatur auf den Strömungszustand erfolgte die Betrachtung aufgeteilt in axiale und radiale Effekte. Der Riser-Reaktor lässt sich in drei axiale Bereiche, nämlich einer unteren Beharrungsstrecke, Übergangszone und einer oberen Beharrungsstrecke, unterteilen. Der Einfluss der Temperatur wirkt sich dabei hauptsächlich auf den Strömungszustand im Einflussbereich der unteren, hochkonzentrierten Beharrungsstrecke und in der Übergangszone des Risers aus. Mit steigender Systemtemperatur war eine verbesserte Fluidisation einhergehend mit größeren Massenströmen zu beobachten, zusätzlich dazu finden sich die charakteristischen Merkmale des Strömungszustands der unteren Beharrungsstrecke in größeren Anlagenhöhen wieder. Der Strömungszustand der unteren Beharrungsstrecke beeinflusst mit steigender Systemtemperatur größere Bereiche des Riser-Reaktors. Im Rahmen der Betrachtung des lokalen Strömungszustands hat sich gezeigt, dass das Strömungsverhalten im unteren Bereich der Anlage durch Beschleunigungseffekte gekennzeichnet ist. Auch die lokalen Feststoffmassenströme verdeutlichen die ausgeprägten Auswirkungen der Temperatur auf den unteren Strömungszustand. Bis zu einer Temperatur von 200°C zeigten die lokalen Massenstromprofile die Merkmale einer Kern-Ring-Strömung. Bei höheren Temperaturen erfolgte teilweise eine Umlagerung der Strukturen mit den höchsten aufwärts gerichteten Feststoffmassenströmen in Rohrwandnähe. Der Einfluss der Temperatur auf den oberen Strömungszustand war im Allgemeinen zu vernachlässigen. Vergleiche der Strömungszustände im Riser mit verschiedenen Modellen führten zu dem Schluss, dass die Gas-Feststoff-Strömung im Bereich der oberen Beharrungsstrecke zufrieden stellend als homogene Verteilung von Einzelpartikeln angesehen werden kann. In der Übergangszone und im Bereich der unteren Beharrungsstrecke wird das Verhalten der Strömung eher durch die Ausbildung von Strähnen und Clustern geprägt. Dort kommt es durch die Ausbildung der Aggregationen verstärkt zu einer axialen Rückvermischungsneigung des Feststoffs. Die gewonnenen Ergebnisse konnten dazu verwendet werden, die axiale Rückvermischung, als qualitatives Maß des Verweilzeitverhaltens, in Abhängigkeit der Betriebparameter zu beschreiben. Es wurde ein Zustandsdiagramm erstellt, welches es erlaubt, die reaktorinterne Rückvermischung abzuschätzen. Die Berechnung des Rückvermischungsverhaltens erfolgte anhand einfacher Korrelationen
Mastitis-Management in Schweizer Milchviehbetrieben mit Eutergesundheitsproblemen
No full textThe objective of this study was to describe the udder health management in Swiss dairy herds with udder health problems. One hundred dairy herds with a yield-corrected somatic cell count of 200'000 to 300'000 cells/ml during 2010 were selected. Data concerning farm structure, housing system, milking technique, milking procedures, dry-cow and mastitis management were collected during farm visits between September and December 2011. In addition, quarter milk samples were collected for bacteriological culturing from cows with a composite somatic cell count ≥ 150'000 cells/ml. The highest quarter level prevalence was 12.3 % for C. bovis. Eighty-two percent of the pipeline milking machines in tie-stalls and 88 % of the milking parlours fulfilled the criteria for the vacuum drop, and only 74 % of the pipeline milking machines met the criteria of the 10-l-water test. Eighty-five percent of the farms changed their milk liners too late. The correct order of teat preparation before cluster attachment was carried out by 37 % of the farmers only. With these results, Swiss dairy farmers and herd health veterinarians can be directed to common mistakes in mastitis management. The data will be used for future information campaigns to improve udder health in Swiss dairy farms.L. Kretzschmar et al., Band 155, Heft 8, August 2013, 453 – 462
DOI
10.1024/0036-7281/
a
000491
Schweizer Archiv für Tierheilkunde
© 2013 Verlag Hans Huber, Hogrefe AG, Bern
453
Mastitis-Management in Schweizer Milchviehbetrieben
Zusammenfassung
Ziel dieser Studie war das Eutergesundheits-Manage-
ment in Sc
hweizer Milchviehbetrieben mit Euterge-
sundheitsproblemen zu beschreiben. Dazu wurden
100 Milchviehbetriebe mit einer theoretischen Tank-
zellzahl im Jahr 2010 von 200'000 bis 300'000 Zellen/
ml selektiert. Daten zu Betriebsstruktur, Haltung,
Melktechnik, Melkarbeit, Trockensteh- und Mastitis-
Management wurden während eines Betriebsbesuches
im Zeitraum von September bis Dezember 2011 erho-
ben. Zusätzlich wurden Milchproben von Kühen mit
≥
150'000 Zellen/ml bakteriologisch analysiert. Die
höchste Erregerprävalenz auf Viertelniveau lag mit
12.3 % bei
C. bovis
. Zweiundachtzig Prozent der Rohr-
melkanlagen im Anbindestall und 88 % der Melkstän-
de lagen beim Melkmaschinentest «Vakuumabfall» im
Normbereich und nur 74 % erfüllten den «10-l-Was-
sertest». Der Wechsel der Zitzengummis erfolgte in
85 % der Betriebe zu spät. Nur 37 % der Betriebsleiter
hielten bei der Eutervorbereitung eine korrekte Rei-
henfolge der Arbeitsschritte ein. Mit den vorliegenden
Resultaten sollen Milchproduzenten und Bestandes-
tierärzte auf häufi
ge Managementfehler aufmerksam
gemacht werden. Die Daten dienen als Grundlage für
zukünftige Informationskampagnen, mit dem Ziel die
Eutergesundheit in Schweizer Milchviehbetrieben zu
verbessern
[Herd problem: udder health. Retrospective study of farms assessed by the Swiss Bovine Health Service (BHS) from 1999 to 2004]
No full textData from 59 farms with complaints of udder health problems and insufficient quality of delivered milk that had been assessed by the Swiss Bovine Health Service (BHS) between 1999 and 2004 were retrospectively analysed. Data evaluated included farm characteristics such as farm size, herd size, average milk yield, milking system and housing system, deficits of the milking equipment and the milking practices, and bacteriological results of milk samples from all cows in lactation. The average size of the farms assessed by the BHS was larger than the size of the were evaluated, 42 showed obvious failures which the farm managers could have noticed. Only 5 of the 57 milkers carried out their work according to the generally valid guidelines of the National Mastitis Council. More than 2 basic mistakes were observed in the milking practices of 36 milkers. In 51 farms, mixed infections with several problem bacteria (those present in at least 20 % of the tested cows on a farm) were found. Staphylococcus aureus proved to be the most common problem germ. As the bacteria responsible for the herd problem (the sole problem bacteria detectable on a particular farm) Staphylococcus aureus was detected in 4 farms. The current study revealed that education in the area of milking techniques and milking practices of farmers should be improved in order to reduce the incidence of udder health problems on herd level. Staphylococcus aureus is the most important problem bacteria involved in herds with udder health problems in Switzerland. Staphylococcus aureus might be used in practice as the indicator germ for early recognition of management problems in dairy farms
Immunoglobulin G absorption from pooled maternal colostrum, commercial powder and freeze-dried colostrum by newborn calves
No full textFor many reasons, a lot of newborn ruminants have no access to their mother's colostrum
and are therefore not protected against neonatal diseases. Many commercial
colostra-replacers are now available, but their ability to pass the intestinal
wall is not well established. Therefore, two experiments were carried out to test
the value of two maternal colostra, freeze-dried immunoglobulins extracted from the
colostra of Holstein cows, and a commercial dried colostrum powder, as colostrum
substitute. Fifty-seven Holstein calves were fed the same immunoglobulin concentration
exactly 1, 7 and 15 h after birth. They were divided into four groups A, B, C and D
with respectively 16, 16, 13 and 12 animals. Total immunoglobulin G concentrations
were the highest at 24 h in all groups but the freeze-dried colostrum was best absorbed.
The IgG of the whole and the freeze-dried colostra were well absorbed by the calves:
the second meal increased the IgG of the calves over 10 gL, usually considered as
the minimum level of protection of the newborn. The commercial dried colostrum
powder was not well absorbed and showed low immunoglobulin levels at 24 h postpartum.
It was concluded that even when colostra are given in the same concentrations to
calves, the absorption of immunoglobulins differ, because of the complexity and the
probable sensitivity and alteration of colostrum components during technological
treatments.Absorption des immunoglobines G chez le veau nouveau-né. Pour diverses raisons,
de nombreux ruminants nouveau-nés n'ont pas accès au colostrum de leur mère pour
se protéger contre les infections néonatales. Des substituts du colostrum sont
actuellement disponibles sur le marché mais leur absorption intestinale par le
nouveau-né n'est pas clairement établie. Deux expérimentations ont été conduites
dans le but de tester l'absorption de deux "colostra-maternels " , d'un colostrum
en poudre commercialisé et d'un extrait lyophilisé à partir du colostrum bovin.
Cinquante sept veaux Holstein au total ont été répartis en quatre lots A, B, C et D
comprenant respectivement 16, 16, 13 et 12 animaux. Chaque groupe a reçu trois
repas des différents régimes exactement 1, 7 et 15 h après la naissance.
Les quantités d'immunoglobulines G distribuées par kg de poids vif étaient
identiques pour les quatre régimes. Les immunoglobulines des "colostra-maternels "
et celles de l'extrait lyophilisé ont été bien absorbées par le veau : dès la 11e
heure, les immunoglobulines G plasmatiques des veaux dépassaient le taux de 10 gL,
habituellement considéré comme nécessaire pour assurer la protection immunitaire du
nouveau-né. Quant aux immunoglobulines G du colostrum commercial écrémé déshydraté,
elles ont été mal absorbées, leur taux n'atteignant les 10 gL qu'au bout
de 19-24 h après la naissance
Preliminary results of NA61/SHINE at the CERN SPS on pion production in p+C interactions at 31 GeV/c for T2K
No full textRisk factors for death and unwanted early slaughter in Swiss veal calves kept at a specific animal welfare standard
No full textCalf losses (CL, mortality and unwanted early slaughter) in veal production are of great economic importance and an indicator of welfare. The objective of the present study was to evaluate CL and the causes of death on farms with a specific animal welfare standard (SAW) which exceeds the Swiss statutory regulations. Risk factors for CL were identified based on information about management, housing, feeding, and medication. In total, 74 production cohorts (2783 calves) of 15 farms were investigated. CL was 3.6%, the main causes of death were digestive disorders (52%), followed by respiratory diseases (28%). Factors significantly associated with an increased risk for CL were a higher number of individual daily doses of antibiotics (DDA), insufficient wind deflection in winter, and male gender. For administration of antibiotics to all calves of the cohort, a DDA of 14-21 was associated with a decreased risk for CL compared to a DDA of 7-13 days
Determination of conjugated fatty acid in ovine milk, meat, fat and intestinal digesta
No full textPositional and geometric isomers of geometric isomers of linoleic acid (CLA) were separated from interfering species on commercially available two reversed-phase C18-columns (Nova Pak, Waters) in gradient systems composed of acetonitrile and water, utilizing photodiode array detection. The biological samples were hydrolyzed with 2 M NaOH for 35 min at 85°C. After cooling, the hydrolysates were acidified with 4 M HCl and the free fatty acids were extracted with dichloromethane. The CLA isomers were determined directly using UV detection at 234.5 nm or after pre -column derivatization with 2,4’-dibromoacetophenone in the presence of triethylamine and UV detection at 256 and 235 nm. HPLC system with pre-column derivatization enables more efficient fractionation of the CLA isomers than the direct HPLC system. On the other hand, elimination of derivatization procedure provides a less expensive, more specific and simpler analytical tool for determination of CLA than HPLC method with precolumn derivatization. The presented HPLC methods provide analytical tools for simple quantification of CLA in ovine meat, milk, fat and intestinal digesta samples
Comparative Phytochemical, Antioxidant, and Hemostatic Studies of Extract and Four Fractions from Paulownia Clone in Vitro 112 Leaves in Human Plasma
No full textBackground: The Paulownia Clone in Vitro 112, known as oxytree or oxygen tree, is a hybrid clone of the species Paulownia elongata and Paulownia fortunei (Paulowniaceae). The oxytree is a fast-growing hybrid cultivar that can adapt to wide variations in edaphic and climate conditions. In this work, Paulownia Clone in Vitro 112 leaves were separated into an extract and four fractions (A–D) differing in chemical content in order to investigate their chemical content using LC-MS analysis. The extract and fractions were also evaluated for their anticoagulant and antioxidant properties in a human plasma in vitro. Results: The Paulownia leaf extract contained mainly phenolic compounds (e.g., verbascoside), small amounts of iridoids (e.g., aucubin or 7-hydroxytometoside) and triterpenoids (e.g., maslinic acid) were also detected. Our results indicate that the extract and fractions have different effects on oxidative stress in human plasma treated with H2O2/Fe in vitro, which could be attributed to differences in their chemical content. For example, the extract and all the fractions, at the two highest concentrations of 10 and 50 µg/mL, significantly inhibited the plasma lipid peroxidation induced by H2O2/Fe. Fractions C and D, at all tested concentrations (1–50 µg/mL) were also found to protect plasma proteins against H2O2/Fe-induced carbonylation. The positive effects of fraction C and D were dependent on the dose. Conclusions: The extract and all four fractions, but particularly fractions C and D, which are rich in phenolic compounds, are novel sources of antioxidants, with an inhibitory effect on oxidative stress in human plasma in vitro. Additionally, the antioxidant potential of fraction D may be associated with triterpenoids
Comparison of analyses of the QTLMAS XIV common dataset. I: genomic selection
No full textBackground - For the XIV QTLMAS workshop, a dataset for traits with complex genetic architecture has been simulated and released for analyses by participants. One of the tasks was to estimate direct genomic values for individuals without phenotypes. The aim of this paper was to compare results of different approaches used by the participants to calculate direct genomic values for quantitative trait (QT) and binary trait (BT). Results - Participants applied 26 approaches for QT and 15 approaches for BT. Accuracy for QT was between 0.26 and 0.89 for males and between 0.31 and 0.89 for females, and for BT ranged from 0.27 to 0.85. For QT, percentage of lost response to selection varied from 8% to 83%, whereas for BT the loss was between 15% and 71%. Conclusions - Bayesian model averaging methods predicted breeding values slightly better than GBLUP in a simulated data set. The methods utilizing genomic information performed better than traditional pedigree based BLUP analyses. Bivariate analyses was slightly advantageous over single trait for the same method. None of the methods estimated the non-additivity of QTL affecting the QT, which may be one of the constrains in accuracy observed in real data. -------------------------------------------------------------------------------
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