5 results on '"Opsal T"'
Search Results
2. Comparison of diagnostic methods for assessment of Ostertagia ostertagi exposure in Norwegian dairy herds.
- Author
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Opsal T, Toftaker I, Robertson L, Woolsey I, and Hektoen L
- Subjects
- Female, Animals, Cattle, Ostertagia, Cross-Sectional Studies, Milk, Norway epidemiology, Enzyme-Linked Immunosorbent Assay veterinary, Cattle Diseases epidemiology, Ostertagiasis diagnosis, Ostertagiasis veterinary
- Abstract
Background: The gastrointestinal nematode (GIN) Ostertagia ostertagi can cause severe disease in first season grazers (FSG) and impaired performance due to subclinical infections in adult cows. Diagnostic methods to assess exposure include faecal egg count and detection of specific antibodies using antibody-ELISAs resulting in an optical density ratio (ODR). Using the ELISA test on bulk tank milk (BTM) allows for a herd level diagnosis. Appropriate use of diagnostic methods for evaluation of O. ostertagi exposure is required to optimize herd parasite surveillance and aid in a sustainable control regime. The aim of this study was to describe the relationship between different diagnostic tests used to assess GIN exposure in Norwegian production systems. A cross-sectional field study was carried out in twenty herds in Norway in the fall of 2020. Serum and faecal samples were taken from 380 individuals, of which 181 were FSG and 199 were cows. In addition, milk was collected from every cow and one BTM sample was taken from each herd. Faecal egg counts were performed. The distribution of ODR values in individual samples within and between herds and the associations between BTM ODR and individual ODR values were described. The data were analysed using visual assessment of scatter plots, Pearson correlation coefficients and linear regression., Results: A high variability of the within-herd individual ODR values in serum and milk in every herd was detected. The ODR in BTM explained a low degree of the variation in the individual serum and milk samples. When plotting the ODR results in milk or serum according to four BTM categories, the distribution of ODR values were notably different in the highest and lowest BTM categories. The correlation between individual milk and serum samples was moderate (r = 0.68), while the highest correlation (r = 0.81) was between the BTM ODR and the group average individual milk samples., Conclusions: A poor predictive ability for BTM ODR to assess individual ODR values in both FSG and cows was demonstrated. However, the study indicates that the evaluation by ELISA test on BTM to assess exposure to GIN could be useful in herds with a very high or low BTM ODR., (© 2023. The Author(s).)
- Published
- 2023
- Full Text
- View/download PDF
3. Gastrointestinal nematodes and Fasciola hepatica in Norwegian cattle herds: a questionnaire to investigate farmers' perceptions and control strategies.
- Author
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Opsal T, Toftaker I, Nødtvedt A, Robertson LJ, Tysnes KR, Woolsey I, and Hektoen L
- Subjects
- Animals, Cattle, Farmers, Female, Gastrointestinal Tract, Humans, Surveys and Questionnaires, Fasciola hepatica, Nematoda
- Abstract
Background: Pasture management influences the prevalence and impact of the pasture parasites (PP) in cattle herds, which cause production-limiting disease worldwide. Evaluating farmer management strategies is vital when considering sustainable PP control practices. The aim of this questionnaire-based study was to describe the pasture management and control strategies regarding PP in Norwegian beef cattle (BC) and dairy cattle (DC) production systems with a focus on gastrointestinal nematodes (GIN) and Fasciola hepatica., Results: A total of 745 responses from BC (return rate 20.5%) and 1347 responses from DC farmers (30.7%) were included. The mean total pasture time for DC was 4.2 months for first-season grazers and 4.3 months for second-season grazers and cows, while the corresponding finding in BC was 5.4 months. Home pasture was used for most of the pasture period, particularly for first-season grazer dairy heifers (81%), which were also commonly grazed on the same pasture every year (79%). For most farmers it was necessary for grazing areas to be used for cattle for more than one season (77% of BC farmers and 89% of DC farmers). However, changing the pasture during the season was common in both DC (67%) and BC (70%) herds. The majority of DC farmers (60%) stated that they did not consider that they had a problem with PP. Of the remaining 40%, few respondents could specify whether their herds had a problem due to infection by GIN (11%) or liver flukes (12%). Treatment for GIN was performed by 52% of DC and 34% of BC farmers. Diagnostic faecal samples were collected upon suspicion of parasitic disease by 5% of DC and 16% of BC farmers. Veterinarians were stated as a central source of information about parasite management and treatment., Conclusions: Potential risks for exposure to PP were identified, such as use of the same pasture every year for first-season grazers and frequent use of home pasture. The perception of problems related to PP appeared low. Regular anthelmintic treatment without concurrent use of diagnostic faecal samples seems to be common practice., (© 2021. The Author(s).)
- Published
- 2021
- Full Text
- View/download PDF
4. The Promises and Pitfalls of Engaging Male Juvenile Offenders in Gender Violence Prevention and Bystander Education.
- Author
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Opsal T, Aguilar J, and Briggs S
- Subjects
- Adolescent, Health Promotion organization & administration, Humans, Male, Risk Assessment, Violence prevention & control, Criminals psychology, Gender-Based Violence psychology, Juvenile Delinquency psychology
- Abstract
Drawing on interviews with and observations of boys enrolled in a bystander violence prevention program at a juvenile detention center, this article provides a sociological case study on how the boys' biographies and violent lived experiences shaped their engagement with the program. Previous research on bystander prevention programs has typically focused on men enrolled in college who do not have the same kinds of violent histories as the boys in this study do. This article builds upon prior research on prevention programs by demonstrating how at-risk youth participants understand and access the program. We offer suggestions for tailoring bystander prevention programs to more adequately address the specific needs of these populations.
- Published
- 2019
- Full Text
- View/download PDF
5. "There Are No Known Benefits . . .": Considering the Risk/Benefit Ratio of Qualitative Research.
- Author
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Opsal T, Wolgemuth J, Cross J, Kaanta T, Dickmann E, Colomer S, and Erdil-Moody Z
- Subjects
- Humans, Research Personnel, Ethics Committees, Research, Qualitative Research, Risk Assessment
- Abstract
Institutional review boards (IRBs) are responsible for weighing the risks and benefits of research participation. Qualitative researchers note numerous instances where IRB ethical frameworks fail to align with the ethics of their research projects and point out that IRB understandings of the benefits and risks of research often differ from those of the participants they seek to protect. This qualitative cross-case research investigates participants' interview experiences in six qualitative studies that differed in their methods, subject of focus, and populations. Our findings indicate that contemporary IRBs' use of population "vulnerability" and topic "sensitivity" to assess project risk does not adequately determine the benefits, risks, or ethicality of research. We recommend that IRBs treat as real the evidence for benefits in qualitative research, recognize that sensitivity and vulnerability do not predict risk, and encourage researchers to attend to relationships in their projects., (© The Author(s) 2015.)
- Published
- 2016
- Full Text
- View/download PDF
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