27 research outputs found
Longitudinal studies of intramammary infection in suckler ewes
Four longitudinal studies were conducted. The first study investigated the
longitudinal pattern of udder half somatic cell count (HSCC) and intramammary
infection (IMI) in 48 UK suckler ewes over the first 10 weeks of lactation. This was
the first study to demonstrate that HSCC of suckler ewes followed a quadratic and
cubic relationship with days in lactation over the first 10 weeks of lactation. Udder
half somatic cell count was also explained by presence of bacteria. Ewes older than 6
years of age had significantly higher HSCC than younger ewes.
The second study investigated the relationships between udder conformation, SCC
and lamb weight. Whilst accounting for lamb age and birth weight, significantly
lower lamb weight was associated with a ewe SCC of >400,000 cells/ml (-1.7 kg), a
traumatic teat lesion (bite, tear or chapping) 2 weeks previously (-1.1 kg), and a ewe
body condition score (BCS) of <2.5 before lambing (-1.3kg). Higher HSCCs were
observed in ewes with a lower suspended udder, and older ewes in poorer body
condition. The findings from this study make an important contribution to the
knowledge of the impact of udder health of suckler ewes by demonstrating that udder
conformation is associated with IMI and that IMI and teat damage are negatively
associated with lamb weight.
The third study investigated the effect of dry cow therapy (DCT) on subclinical
mastitis in a lowland flock with a low incidence of clinical mastitis by recording
HSCC and lamb weights in the following lactation. To the author’s knowledge, there
are no published reports of the effect of broad spectrum DCT on subclinical mastitis
in suckler ewes in the literature. No significant effect was found between the use of
DCT and HSCC or lamb weight in the subsequent lactation.
The fourth study was a randomised controlled trial to assess the effect of DCT on
clinical mastitis in a suckler flock with a high level of clinical mastitis. Dry cow
treatment significantly reduced the incidence of clinical mastitis over one year, with
a 70% reduction of clinical mastitis in ewes that received treatment from 6.2% to
1.8%. This was the first field trial to investigate and demonstrate the clinical benefit
of the use of a broad spectrum DCT in suckler ewes.
These studies have enhanced our knowledge of longitudinal patterns of infection and
demonstrated the importance of udder health for optimising production of suckler
ewes. Factors to control for when using SCC as a tool to measure intramammary
infection were described
Analysing the opinions of UK veterinarians on practice-based research using corpus linguistic and mathematical methods
The use of corpus linguistic techniques and other related mathematical analyses have rarely, if ever, been applied to qualitative data collected from the veterinary field. The aim of this study was to explore the use of a combination of corpus linguistic analyses and mathematical methods to investigate a free-text questionnaire dataset collected from 3796 UK veterinarians on evidence-based veterinary medicine, specifically, attitudes towards practice-based research (PBR) and improving the veterinary knowledge base.
The corpus methods of key word, concordance and collocate analyses were used to identify patterns of meanings within the free text responses. Key words were determined by comparing the questionnaire data with a wordlist from the British National Corpus (representing general English text) using cross-tabs and log-likelihood comparisons to identify words that occur significantly more frequently in the questionnaire data. Concordance and collocation analyses were used to account for the contextual patterns in which such key words occurred, involving qualitative analysis and Mutual Information Analysis (MI3). Additionally, a mathematical topic modelling approach was used as a comparative analysis; words within the free text responses were grouped into topics based on their weight or importance within each response to find starting points for analysis of textual patterns.
Results generated from using both qualitative and quantitative techniques identified that the perceived advantages of taking part in PBR centred on the themes of improving knowledge of both individuals and of the veterinary profession as a whole (illustrated by patterns around the words learning, improving, contributing). Time constraints (lack of time, time issues, time commitments) were the main concern of respondents in relation to taking part in PBR. Opinions of what vets could do to improve the veterinary knowledge base focussed on the collecting and sharing of information (record, report), particularly recording and discussing clinical cases (interesting cases), and undertaking relevant continuing professional development activities. The approach employed here demonstrated how corpus linguistics and mathematical methods can help to both identify and contextualise relevant linguistic patterns in the questionnaire responses. The results of the study inform those seeking to coordinate PBR initiatives about the motivators of veterinarians to participate in such initiatives and what concerns need to be addressed. The approach used in this study demonstrates a novel way of analysing textual data in veterinary research
International evidence-based medicine survey of the veterinary profession: information sources used by veterinarians
Veterinarians are encouraged to use evidence to inform their practice, but it is unknown what resources (e.g. journals, electronic sources) are accessed by them globally. Understanding the key places veterinarians seek information can inform where new clinically relevant evidence should most effectively be placed. An international survey was conducted to gain understanding of how veterinary information is accessed by veterinarians worldwide. There were 2137 useable responses to the questionnaire from veterinarians in 78 countries. The majority of respondents (n = 1835/2137, 85.9%) undertook clinical work and worked in a high income country (n = 1576/1762, 89.4%). Respondents heard about the survey via national veterinary organisations or regulatory bodies (31.5%), online veterinary forums and websites (22.7%), regional, discipline-based or international veterinary organisations (22.7%) or by direct invitation from the researchers or via friends, colleagues or social media (7.6%). Clinicians and non-clinicians reportedly used journals most commonly (65.8%, n = 1207/1835; 75.6%, n = 216/286) followed by electronic resources (58.7%, n = 1077/1835; 55.9%, n = 160/286), respectively. Respondents listed a total of 518 journals and 567 electronic sources that they read. Differences in veterinarian preference for resources in developed, and developing countries, were found. The nominated journals most read were the Journal of the American Veterinary Medical Association (12.7% of nominations) for clinicians and the Veterinary Record (5.7%) for non-clinicians. The most accessed electronic resource reported was the Veterinary Information Network (25.6%) for clinicians and PubMed (7.4%) for non-clinicians. In conclusion, a wide array of journals and electronic resources appear to be accessed by veterinarians worldwide. Veterinary organisations appear to play an important role in global communication and outreach to veterinarians and consideration should be given to how these channels could be best utilised for effective dissemination of key research findings
A longitudinal study of risk factors for teat lesions in 67 suckler ewes in a single flock in England
A longitudinal study of 67 suckler ewes on a commercial sheep farm near Wolverhampton, England was carried out from March to July 2010. Data on ewe teat lesions and udder and teat conformation were collected together with data on lamb health and weight at lambing and at 14-day intervals until lambs were 8–10 weeks old. Each ewe was examined on 4–5 occasions. Teat lesions were categorised as traumatic or non-traumatic based on appearance. Risk factors for the development of each type of teat lesion were investigated using mixed effect binomial regression models. The incidence of traumatic teat lesions was greatest 3–4 weeks after lambing with 27.9% new cases by udder half. There was an increased risk of traumatic teat lesions in 2 year old ewes (OR 3.5, CI 1.2, 10.5) compared with 6 year old ewes and in ewes with abnormal compared with normal teat placement, a wide or narrow udder width compared with a normal udder width, a heavy total litter weight, body condition score (BCS) < 2.5, compared with BCS of 2.5 14-days previously, and in ewes with abnormal udder skin (waxy, dry or chapped) compared with normal udder skin. The incidence of non-traumatic teat lesions was greatest 7–10 weeks after lambing with 21.4% new cases. Non-traumatic lesions were more likely to occur in ewes with BCS = 3 compared with BCS of 2.5. The risk factors for traumatic and non-traumatic teat lesions differ. Traumatic lesions are associated with teat and udder morphology, ewe age and BCS, and lamb growth rate, whereas non-traumatic lesions are associated with ewe BCS
Ein- und mehrstufige totaldehnungs- und spannungskontrollierte Wechselverformungsexperimente an einem Stahl vom Typ 42 CrMo 4 unter Eigen- und Mittelbeanspruchungsvariation Abschlussbericht
Work under this research project covered tests with the quenched and tempered steel 42 CrMo 4 to which one- and two-stage tension-compression fatigue stresses were applied with varying mean loads, under conditions of nominal stress and total strain control. Shot peening was used to induce various microstructural conditions in the material at the surface and near below. Softening in the material was observed to be a continuous process, and the steel showed no stabilised, cyclic deformation behaviour. The cyclic stress-strain curve measured with equal stress amplitudes and total strain control applied shows higher plastic strain amplitudes than that measured with nominal stresses. The fatigue behaviour under two-stage loading depends on the chosen sequence of loads applied, the testing periods, and the overall testing procedure, so that there is no way of deriving data for two-stage testing procedures from single-stage test results. (orig.)Im Rahmen des Forschungsvorhabens wurden an dem Verguetungsstahl 42 CrMo 4 ein-und zweistufige nennspannungs- und totaldehnungskontrollierte Zug-Druck-Wechselverformungsexperimente mit unterschiedlichen Mittelbeanspruchungen durchgefuehrt. Durch Kugelstrahlbehandlungen wurde der Zustand oberflaechennaher Werkstoffbereiche gezielt beeinflusst. Der untersuchte Verguetungszustand des 42 CrMo 4 entfestigt stetig und weist kein stabilisiertes zyklisches Verformungsverhalten auf. Die zyklische Spannungs-Dehnungs-Kurve zeigt bei gleichen Spannungsamplituden unter Totaldehnungskontrolle groessere plastische Dehnungsamplituden als unter Nennspannungskontrolle. Das Wechselverformungsverhalten bei zweistufiger Beanspruchung ist von der Beanspruchungsreihenfolge, den Blocklaengen sowie der Versuchsfuehrung abhaengig und kann deshalb nicht direkt aus Einstufenversuchen abgeleitet werden. (orig.)SIGLEAvailable from TIB Hannover: RA 2383(191) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekStifterverband fuer die Deutsche Wissenschaft e.V., Essen (Germany). Stiftung StahlanwendungsforschungDEGerman
Table of the top ten electronic resources most accessed as nominated as by respondents working in developing and developed countries.
<p>Respondents could nominate up to 10 electronic resources.</p
Respondents place of work, according to the UN classification of continent and country.
<p>Developed countries were those considered high income in IMF classification (n = 1576), and developing countries were those belonging to the remaining 4 IMF classification categories (n = 186). Only data from clinician respondents were collected.</p
Table of the top ten journals most read as nominated by respondents working in developing and developed countries.
<p>Respondents could nominate up to 10 different journals.</p
Top 10 journals nominated by respondents as most useful (n = 1159).
<p>Top 10 journals nominated by respondents as most useful (n = 1159).</p
Sections of peer–reviewed paper read by clinicians and non-clinicians.
<p>Sections of peer–reviewed paper read by clinicians and non-clinicians.</p