113 results on '"Doherty ML"'
Search Results
2. Outbreak of posthitis in grazing wethers in Scotland
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Doherty Ml
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Male ,Veterinary medicine ,Sheep ,General Veterinary ,business.industry ,Posthitis ,Outbreak ,Sheep Diseases ,General Medicine ,Biology ,Corynebacterium ,medicine.disease ,Poaceae ,Animal Feed ,Biotechnology ,Disease Outbreaks ,Scotland ,Species Specificity ,Grazing ,Balanitis ,medicine ,Animals ,Seasons ,business - Published
- 1985
3. Benthic and fish community composition on mesophotic reefs in Grand Cayman.
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Le Gall L, Johnson JV, Chequer A, Doherty ML, and Goodbody-Gringley G
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- Animals, Biodiversity, Biomass, Ecosystem, Porifera classification, Porifera physiology, Seaweed genetics, Seaweed physiology, Caribbean Region, Coral Reefs, Fishes
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Mesophotic Coral Ecosystems (MCEs) represent unique ecological habitats that range from 30 to 150 m deep, harbouring phylogenetically distinct species and offering refuge for many taxa during times of environmental stress. Yet owing to inaccessibility of ecosystems at these depths, most MCEs remain unexplored, with quantifications of ecological communities in these habitats lacking across many regions. Here, using open- and closed-circuit technical diving, we quantified benthic and fish community composition at four mesophotic reef sites (45 m depth) in Grand Cayman. We show significant differences in benthic community composition over a small spatial scale driven by disparate coverage of sponges, crustose coralline algae, and sand/rubble, yet consistent patterns of macroalgal dominance representing >50% coverage at each site and low hard coral cover at an average of 2.4%. Reef fish species richness, biomass, and density was consistent across sites, however the relative contribution of individual species to community composition differed significantly. Macrocarnivores were found to be the dominant contributors to biomass, with invertivores the most speciose, and omnivores and planktivores at the highest densities, consistent with previous descriptions of mesophotic fish assemblages in other regions. Similarly, the low hard coral cover and high macroalgae and sponge cover of the benthic communities also appear ecologically similar to several described mesophotic reefs yet is not uniform across the Caribbean. The ecological organisation of Grand Cayman's MCEs may result from a variety of factors such as isolation from other major land masses, geology, local geography, and anthropogenic activity at both the local and global scale and highlight the importance of continued exploration and documentation of MCE communities., Competing Interests: The authors declare that they have no competing interests., (© 2024 Le Gall et al.)
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- 2024
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4. Online, student-led, peer-to-peer teaching of clinical skills.
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Kelly RM, McCorry MZ, Rackard SM, Doherty ML, and Graham H
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- Animals, Humans, Students, Clinical Competence, Peer Group
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- 2022
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5. Advancing national animal health and welfare policy.
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Graham HA, Doherty ML, More SJ, Gordon SV, Gormley EP, Mooney CT, Hanlon AJ, Mullan SM, Leonard FC, and McAloon CG
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- Animals, Policy
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- 2022
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6. Using examination performance data and focus groups to inform teaching - a case study from final year students of veterinary medicine.
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McAloon CG, Kelly E, Rackard S, McAloon C, Beltman M, O'Grady L, Viora L, Crowe M, Doherty ML, and Ryan EG
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Background: Student feedback has played an important role in the maintenance of quality and standards in higher education. Perhaps the most commonly used method to capture feedback is a series of questions or statements where students indicate their degree of satisfaction or agreement. Focus groups offer an alternative means of capturing 'richer' qualitative data relating to students' thoughts on course structure. Aside from student evaluations, student examination performance has been used as a method to evaluate the efficacy of curriculum changes at programme level. However, this data is utilised less so at a 'finer detail' level to identify specific issues with the delivery of teaching., Case Presentation: The purpose of this report was to outline the approach taken using qualitative and quantitative data to identify problems with a specific area of teaching, inform a new teaching approach and to assess the impact of those changes. Following quantitative and qualitative analysis, a practical class on dairy herd fertility performance was highlighted as an area for improvement. After the introduction of the newly formatted practical class with a greater focus on self-directed learning, there was a significant increase in the average score ( p < 0.001) and a decrease in the proportion of students failing (p < 0.001) the question that assessed the analysis of dairy herd fertility data. In addition, the R-squared value between students' performance in the fertility question and their performance in the overall examination increased from 0.06 to 0.11., Conclusions: The combination of qualitative focus group data and quantitative analysis of examination performance data represent robust methods for identifying problems associated with specific aspects of veterinary teaching., Competing Interests: Competing interestsProf Michael Doherty is the Editor-in-Chief of Irish Veterinary Journal. Prof Michael Doherty has not been involved in the handling of the submission or in any way interacted with the review process or editorial decision making. A free waiver was granted by the journal for this manuscript., (© The Author(s). 2020.)
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- 2020
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7. Schmallenberg virus: a systematic international literature review (2011-2019) from an Irish perspective.
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Collins ÁB, Doherty ML, Barrett DJ, and Mee JF
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In Autumn 2011, nonspecific clinical signs of pyrexia, diarrhoea, and drop in milk yield were observed in dairy cattle near the German town of Schmallenberg at the Dutch/German border. Targeted veterinary diagnostic investigations for classical endemic and emerging viruses could not identify a causal agent. Blood samples were collected from animals with clinical signs and subjected to metagenomic analysis; a novel orthobunyavirus was identified and named Schmallenberg virus (SBV). In late 2011/early 2012, an epidemic of abortions and congenital malformations in calves, lambs and goat kids, characterised by arthrogryposis and hydranencephaly were reported in continental Europe. Subsequently, SBV RNA was confirmed in both aborted and congenitally malformed foetuses and also in Culicoides species biting midges. It soon became evident that SBV was an arthropod-borne teratogenic virus affecting domestic ruminants. SBV rapidly achieved a pan-European distribution with most countries confirming SBV infection within a year or two of the initial emergence. The first Irish case of SBV was confirmed in the south of the country in late 2012 in a bovine foetus. Since SBV was first identified in 2011, a considerable body of scientific research has been conducted internationally describing this novel emerging virus. The aim of this systematic review is to provide a comprehensive synopsis of the most up-to-date scientific literature regarding the origin of SBV and the spread of the Schmallenberg epidemic, in addition to describing the species affected, clinical signs, pathogenesis, transmission, risk factors, impact, diagnostics, surveillance methods and control measures. This review also highlights current knowledge gaps in the scientific literature regarding SBV, most notably the requirement for further research to determine if, and to what extent, SBV circulation occurred in Europe and internationally during 2017 and 2018. Moreover, recommendations are also made regarding future arbovirus surveillance in Europe, specifically the establishment of a European-wide sentinel herd surveillance program, which incorporates bovine serology and Culicoides entomology and virology studies, at national and international level to monitor for the emergence and re-emergence of arboviruses such as SBV, bluetongue virus and other novel Culicoides -borne arboviruses., Competing Interests: Competing interestsThe authors declare that they have no competing interests, (© The Author(s). 2019.)
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- 2019
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8. Routine Herd Health Data as Cow-Based Risk Factors Associated with Lameness in Pasture-Based, Spring Calving Irish Dairy Cows.
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Somers JR, Huxley JN, Doherty ML, and O'Grady LE
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Herd-level risk factors related to the cow's environment have been associated with lameness. Uncomfortable stall surface and inadequate depth of bedding as well as abrasive alley way surface are contributing factors to increased levels of lameness. Access to pasture has been found as having a beneficial effect on cows' locomotion. However, dairy cattle managed under grazing conditions are exposed to a different set of risk factors for lameness, mainly associated with cow tracks. Cow-based risk factors for lameness are not as clearly defined as the herd level risk factors. The objective of the present study was to use routine herd health monitoring data to identify cow-based risk factors for lameness and utilise this information to indicate cows at risk of developing lameness in the first 150 days of lactation. Lameness data were gathered from 10 pasture-based dairy herds. A total of 1715 cows were monitored, of which 1675 cows were available for analysis. Associations between lameness status and potential cow-level risk factors were determined using multivariable logistic regression. Parity 3 and 4 + cows showed odd ratios (OR's) for lameness of 3.92 and 8.60 respectively (95% confidence interval (CI) 2.46-6.24; 5.68-13.0). Maximum loss of Body condition score (BCS) after calving exhibits OR's for lameness of 1.49 (95% CI 1.08-2.04) if cows lost 0.5 in BCS after calving and 2.26 (95% CI 1.30-3.95) for cows losing more than 0.5 BCS. Animals calving in BCS 3.25 and ≥ 3.5 had correlating OR's of 0.54 (95% CI 0.34-0.87) and 0.33 (95% CI 0.16-0.65) for being lame compared to cows calving with BCS ≤ 2.75. Data gathered as part of herd health monitoring can be used in conjunction with lameness records to identify shortcomings in lameness management. Findings and recommendations on lameness management can be formulated from readily available information on cow-based risk factors for lameness., Competing Interests: The authors declare no conflict of interest.
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- 2019
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9. Genome-wide association study of endo-parasite phenotypes using imputed whole-genome sequence data in dairy and beef cattle.
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Twomey AJ, Berry DP, Evans RD, Doherty ML, Graham DA, and Purfield DC
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- Animals, Breeding, Fasciola hepatica pathogenicity, Fertility genetics, Genetic Variation genetics, Genome-Wide Association Study veterinary, Genotype, Parasites genetics, Parasites pathogenicity, Phenotype, Polymorphism, Single Nucleotide genetics, Quantitative Trait Loci genetics, Whole Genome Sequencing methods, Cattle genetics, Cattle Diseases genetics, Host-Parasite Interactions genetics
- Abstract
Background: Quantitative genetic studies suggest the existence of variation at the genome level that affects the ability of cattle to resist to parasitic diseases. The objective of the current study was to identify regions of the bovine genome that are associated with resistance to endo-parasites., Methods: Individual cattle records were available for Fasciola hepatica-damaged liver from 18 abattoirs. Deregressed estimated breeding values (EBV) for F. hepatica-damaged liver were generated for genotyped animals with a record for F. hepatica-damaged liver and for genotyped sires with a least one progeny record for F. hepatica-damaged liver; 3702 animals were available. In addition, individual cow records for antibody response to F. hepatica on 6388 genotyped dairy cows, antibody response to Ostertagia ostertagi on 8334 genotyped dairy cows and antibody response to Neospora caninum on 4597 genotyped dairy cows were adjusted for non-genetic effects. Genotypes were imputed to whole-sequence; after edits, 14,190,141 single nucleotide polymorphisms (SNPs) and 16,603,644 SNPs were available for cattle with deregressed EBV for F. hepatica-damaged liver and cows with an antibody response to a parasitic disease, respectively. Association analyses were undertaken using linear regression on one SNP at a time, in which a genomic relationship matrix accounted for the relationships between animals., Results: Genomic regions for F. hepatica-damaged liver were located on Bos taurus autosomes (BTA) 1, 8, 11, 16, 17 and 18; each region included at least one SNP with a p value lower than 10
-6 . Five SNPs were identified as significant (q value < 0.05) for antibody response to N. caninum and were located on BTA21 or 25. For antibody response to F. hepatica and O. ostertagi, six and nine quantitative trait loci (QTL) regions that included at least one SNP with a p value lower than 10-6 were identified, respectively. Gene set enrichment analysis revealed a significant association between functional annotations related to the olfactory system and QTL that were suggestively associated with endo-parasite phenotypes., Conclusions: A number of novel genomic regions were suggestively associated with endo-parasite phenotypes across the bovine genome and two genomic regions on BTA21 and 25 were associated with antibody response to N. caninum.- Published
- 2019
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10. A review of paratuberculosis in dairy herds - Part 2: On-farm control.
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McAloon CG, Roche S, Ritter C, Barkema HW, Whyte P, More SJ, O'Grady L, Green MJ, and Doherty ML
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- Animals, Cattle, Cattle Diseases microbiology, Mycobacterium avium subsp. paratuberculosis, Cattle Diseases prevention & control, Dairying, Paratuberculosis prevention & control
- Abstract
Bovine paratuberculosis is a chronic infectious disease of cattle, caused by Mycobacterium avium subspecies paratuberculosis (MAP). This is the second in a two-part review of the epidemiology and control of paratuberculosis in dairy herds. Several negative production effects associated with MAP infection have been described, but perhaps the most significant concern in relation to the importance of paratuberculosis as a disease of dairy cattle is the potential link with Crohn's disease in humans. Milk is considered a potential transmission route to humans and it is recognised that pasteurisation does not necessarily eliminate the bacterium. Therefore, control must also include reduction of the levels of MAP in bulk milk supplied from dairy farms. There is little field evidence in support of specific control measures, although several studies seem to show a decreased prevalence associated with the implementation of a combined management and test-and-cull programme. Improvements in vaccination efficacy and reduced tuberculosis (TB) test interference may increase uptake of vaccination as a control option. Farmer adoption of best practice recommendations at farm level for the control of endemic diseases can be challenging. Improved understanding of farmer behaviour and decision making will help in developing improved communication strategies which may be more efficacious in affecting behavioural change on farm., (Copyright © 2019 Elsevier Ltd. All rights reserved.)
- Published
- 2019
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11. A review of paratuberculosis in dairy herds - Part 1: Epidemiology.
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McAloon CG, Roche S, Ritter C, Barkema HW, Whyte P, More SJ, O'Grady L, Green MJ, and Doherty ML
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- Animals, Cattle, Dairying, Mycobacterium avium subsp. paratuberculosis, Cattle Diseases epidemiology, Paratuberculosis epidemiology
- Abstract
Bovine paratuberculosis is a chronic infectious disease of cattle caused by Mycobacterium avium subspecies paratuberculosis (MAP). This is the first in a two-part review of the epidemiology and control of paratuberculosis in dairy herds. Paratuberculosis was originally described in 1895 and is now considered endemic among farmed cattle worldwide. MAP has been isolated from a wide range of non-ruminant wildlife as well as humans and non-human primates. In dairy herds, MAP is assumed to be introduced predominantly through the purchase of infected stock with additional factors modulating the risk of persistence or fade-out once an infected animal is introduced. Faecal shedding may vary widely between individuals and recent modelling work has shed some light on the role of super-shedding animals in the transmission of MAP within herds. Recent experimental work has revisited many of the assumptions around age susceptibility, faecal shedding in calves and calf-to-calf transmission. Further efforts to elucidate the relative contributions of different transmission routes to the dissemination of infection in endemic herds will aid in the prioritisation of efforts for control on farm., (Copyright © 2019 Elsevier Ltd. All rights reserved.)
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- 2019
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12. Variance components for bovine tuberculosis infection and multi-breed genome-wide association analysis using imputed whole genome sequence data.
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Ring SC, Purfield DC, Good M, Breslin P, Ryan E, Blom A, Evans RD, Doherty ML, Bradley DG, and Berry DP
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- Analysis of Variance, Animals, Cattle, Genotype, Phenotype, Polymorphism, Single Nucleotide, Genome-Wide Association Study, Tuberculosis, Bovine genetics, Whole Genome Sequencing
- Abstract
Bovine tuberculosis (bTB) is an infectious disease of cattle generally caused by Mycobacterium bovis, a bacterium that can elicit disease humans. Since the 1950s, the objective of the national bTB eradication program in Republic of Ireland was the biological extinction of bTB; that purpose has yet to be achieved. Objectives of the present study were to develop the statistical methodology and variance components to undertake routine genetic evaluations for resistance to bTB; also of interest was the detection of regions of the bovine genome putatively associated with bTB infection in dairy and beef breeds. The novelty of the present study, in terms of research on bTB infection, was the use of beef breeds in the genome-wide association and the utilization of imputed whole genome sequence data. Phenotypic bTB data on 781,270 animals together with imputed whole genome sequence data on 7,346 of these animals' sires were available. Linear mixed models were used to quantify variance components for bTB and EBVs were validated. Within-breed and multi-breed genome-wide associations were undertaken using a single-SNP regression approach. The estimated genetic standard deviation (0.09), heritability (0.12), and repeatability (0.30) substantiate that genetic selection help to eradicate bTB. The multi-breed genome-wide association analysis identified 38 SNPs and 64 QTL regions associated with bTB infection; two QTL regions (both on BTA23) identified in the multi-breed analysis overlapped with the within-breed analyses of Charolais, Limousin, and Holstein-Friesian. Results from the association analysis, coupled with previous studies, suggest bTB is controlled by an infinitely large number of loci, each having a small effect. The methodology and results from the present study will be used to develop national genetic evaluations for bTB in the Republic of Ireland. In addition, results can also be used to help uncover the biological architecture underlying resistance to bTB infection in cattle., Competing Interests: The authors have declared that no competing interests exist.
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- 2019
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13. Genetic parameters for variability in the birth of persistently infected cattle following likely in utero exposure to bovine viral diarrhea virus.
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Ring SC, Graham DA, Kelleher MM, Doherty ML, and Berry DP
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- Animals, Bovine Virus Diarrhea-Mucosal Disease genetics, Bovine Virus Diarrhea-Mucosal Disease prevention & control, Bovine Virus Diarrhea-Mucosal Disease virology, Breeding, Cattle, Disease Eradication, Female, Ireland epidemiology, Linear Models, Male, Phenotype, Selection, Genetic, Bovine Virus Diarrhea-Mucosal Disease transmission, Diarrhea Viruses, Bovine Viral physiology, Genetic Variation, Infectious Disease Transmission, Vertical veterinary
- Abstract
Genetic selection is an inexpensive and complementary strategy to traditional methods of improving animal health and welfare. Nonetheless, endeavors to incorporate animal health and welfare traits in international breeding programs have been hampered by the availability of informative phenotypes. The recent eradication program for bovine viral diarrhea (BVD) in the Republic of Ireland has provided an opportunity to quantify the potential benefits that genetic selection could offer BVD eradication programs elsewhere, as well as inform possible eradication programs for other diseases in the Republic of Ireland. Using a dataset of 188,085 Irish calves, the estimated direct and maternal heritability estimates for the birth of persistently infected calves following likely in utero exposure to BVD virus ranged from not different from zero (linear model) to 0.29 (SE = 0.075; threshold model) and from essentially zero (linear model) to 0.04 (SE = 0.033; threshold model), respectively. The corresponding genetic SD for the direct and maternal effect of the binary trait (0, 1) ranged from 0.005 (linear model) to 0.56 (threshold model) units and ranged from 0.00008 (linear model) to 0.20 (threshold model) units, respectively. The coefficient of direct genetic variation based on the linear model was 2.56% indicating considerable genetic variation could be exploited. Based on results from the linear model in the present study, there is the potential to reduce the incidence of persistent infection in cattle by on average 0.11 percentage units per year which is cumulative and permanent. Therefore, genetic selection can contribute to reducing the incidence of persistent infection in cattle. Moreover, where populations are free from persistent infection, inclusion of the estimated genetic merit for BVD in national breeding indexes could contribute to a preservation of a BVD-free status. Results from the present study can be used to inform breeding programs of the potential genetic gains achievable. Moreover, the approaches used in the present study can be applied to other diseases when data become available.
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- 2019
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14. Low accuracy of Bayesian latent class analysis for estimation of herd-level true prevalence under certain disease characteristics-An analysis using simulated data.
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McAloon CG, Doherty ML, Whyte P, Verdugo C, Toft N, More SJ, O'Grady L, and Green MJ
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- Animal Diseases diagnosis, Animals, Bayes Theorem, Latent Class Analysis, Models, Statistical, Prevalence, Reproducibility of Results, Animal Diseases epidemiology
- Abstract
Estimation of the true prevalence of infected individuals involves the application of a diagnostic test to a population and adjusting according to test performance, sensitivity and specificity. Bayesian latent class analysis for the estimation of herd and animal-level true prevalence, has become increasingly used in veterinary epidemiology and is particularly useful in incorporating uncertainty and variability into analyses in a flexible framework. However, the approach has not yet been evaluated using simulated data where the true prevalence is known. Furthermore, using this approach, the within-herd true prevalence is often assumed to follow a beta distribution, the parameters of which may be modelled using hyperpriors to incorporate both uncertainty and variability associated with this parameter. Recently however, the authors of the current study highlighted a potential issue with this approach, in particular, with fitting the distributions and a tendency for the resulting distribution to invert and become clustered at zero. Therefore, the objective of the present study was to evaluate commonly specified models using simulated datasets where the herd-level true prevalence was known. The specific purpose was to compare findings from models using hyperpriors to those using a simple beta distribution to model within-herd prevalence. A second objective was to investigate sources of error by varying characteristics of the simulated dataset. Mycobacterium avium subspecies paratuberculosis infection was used as an example for the baseline dataset. Data were simulated for 1000 herds across a range of herd-level true prevalence scenarios, and models were fitted using priors from recently published studies. The results demonstrated poor performance of these latent class models for diseases characterised by poor diagnostic test sensitivity and low within-herd true prevalence. All variations of the model appeared to be sensitive to the prior and tended to overestimate herd-level true prevalence. Estimates were substantially improved in different infection scenarios by increasing test sensitivity and within-herd true prevalence. The results of this study raise questions about the accuracy of published estimates for the herd-level true prevalence of paratuberculosis based on serological testing, using latent class analysis. This study highlights the importance of conducting more rigorous sensitivity analyses than have been carried out in previous analyses published to date., (Copyright © 2018. Published by Elsevier B.V.)
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- 2019
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15. Genetic selection for hoof health traits and cow mobility scores can accelerate the rate of genetic gain in producer-scored lameness in dairy cows.
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Ring SC, Twomey AJ, Byrne N, Kelleher MM, Pabiou T, Doherty ML, and Berry DP
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- Animals, Breeding methods, Cattle Diseases genetics, Female, Gait, Phenotype, Cattle genetics, Cattle Diseases prevention & control, Hoof and Claw, Lameness, Animal genetics, Lameness, Animal prevention & control, Selection, Genetic
- Abstract
Cattle breeding programs that strive to reduce the animal-level incidence of lameness are often hindered by the availability of informative phenotypes. As a result, indicator traits of lameness (i.e., hoof health and morphological conformation scores) can be used to improve the accuracy of selection and subsequent genetic gain. Therefore, the objectives of the present study were to estimate the variance components for hoof health traits using various phenotypes collected from a representative sample of Irish dairy cows. Also of interest to the present study was the genetic relationship between both hoof health traits and conformation traits with producer-scored lameness. Producer-recorded lameness events and linear conformation scores from 307,657 and 117,859 Irish dairy cows, respectively, were used. Data on hoof health (i.e., overgrown sole, white line disease, and sole hemorrhage), mobility scores, and body condition scores were also available from a research study on up to 11,282 Irish commercial dairy cows. Linear mixed models were used to quantify variance components for each trait and to estimate genetic correlations among traits. The estimated genetic parameters for hoof health traits in the present study were greater (i.e., heritability range: 0.005 to 0.27) than previously reported in dairy cows. With the exception of analyses that considered hoof health traits in repeatability models, little difference in estimated variance components existed among the various hoof-health phenotypes. Results also suggest that producer-recorded lameness is correlated with both hoof health (i.e., genetic correlation up to 0.48) and cow mobility (i.e., genetic correlation = 0.64). Moreover, cows that genetically tend to have rear feet that appear more parallel when viewed from the rear are also genetically more predisposed to lameness (genetic correlation = 0.39); genetic correlations between lameness and other feet and leg type traits, as well as between lameness and frame type traits, were not different from zero. Results suggest that if the population breeding goal was to reduce lameness incidence, improve hoof health, or improve cow mobility, genetic selection for either of these traits should indirectly benefit the other traits. Results were used to quantify the genetic gains achievable for lameness when alternative phenotypes are available., (Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)
- Published
- 2018
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16. Culicoides species composition and abundance on Irish cattle farms: implications for arboviral disease transmission.
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Collins ÁB, Mee JF, Doherty ML, Barrett DJ, and England ME
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- Animals, Arbovirus Infections epidemiology, Arbovirus Infections transmission, Bluetongue prevention & control, Bluetongue transmission, Bluetongue virus isolation & purification, Cattle parasitology, Cattle Diseases epidemiology, Cattle Diseases virology, Ceratopogonidae classification, Disease Outbreaks prevention & control, Disease Outbreaks veterinary, Ecosystem, Farms, Ireland epidemiology, Livestock virology, Ultraviolet Rays, Arbovirus Infections veterinary, Cattle Diseases transmission, Ceratopogonidae virology, Epidemiological Monitoring veterinary, Insect Vectors virology, Livestock parasitology
- Abstract
Background: Following the emergence of Schmallenberg virus (SBV) in Ireland in 2012, a sentinel herd surveillance program was established in the south of Ireland with the primary aim of investigating the species composition and abundance of Culicoides on livestock farms in the region., Methods: Ultraviolet-light trapping for Culicoides was carried out on 10 sentinel farms. Each site was sampled fortnightly over 16 weeks (21st July to 5th November 2014). One Onderstepoort Veterinary Institute UV light trap was run overnight at each site and catches were transferred immediately into 70% ethanol. Culicoides were morphologically identified to species level. Collection site habitats were characterised using the Phase 1 habitat survey technique (Joint Nature Conservation Committee)., Results: A total of 23,929 individual Culicoides from 20 species was identified, including one species identified in Ireland for the first time, Culicoides cameroni. The most abundant species identified were Culicoides obsoletus/Culicoides scoticus (38%), Culicoides dewulfi (36%), Culicoides pulicaris (9%), Culicoides chiopterus (5%) and Culicoides punctatus (5%), comprising 93% of all Culicoides specimens identified. Collection site habitats were dominated by improved grassland and a combination of broadleaf woodland and native woodland species., Conclusions: The most abundant species of Culicoides identified were the putative vectors of bluetongue virus (BTV) and SBV in northern Europe. Their presence and abundance demonstrates the potential for future transmission of arboviruses among livestock in this region.
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- 2018
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17. Genetic variability in the humoral immune response to bovine herpesvirus-1 infection in dairy cattle and genetic correlations with performance traits.
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Ring SC, Graham DA, Sayers RG, Byrne N, Kelleher MM, Doherty ML, and Berry DP
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- Animals, Female, Fertility, Lactation, Milk, Pregnancy, Cattle, Genetic Variation, Herpesvirus 1, Bovine immunology, Immunity, Humoral genetics, Infectious Bovine Rhinotracheitis immunology
- Abstract
Bovine herpesvirus-1 (BoHV-1) is a viral pathogen of global significance that is known to instigate several diseases in cattle, the most notable of which include infectious bovine rhinotracheitis and bovine respiratory disease. The genetic variability in the humoral immune response to BoHV-1 has, to our knowledge, not ever been quantified. Therefore, the objectives of the present study were to estimate the genetic parameters for the humoral immune response to BoHV-1 in Irish female dairy cattle, as well as to investigate the genetic relationship between the humoral immune response to BoHV-1 with milk production performance, fertility performance, and animal mortality. Information on antibody response to BoHV-1 was available to the present study from 2 BoHV-1 sero-prevalence research studies conducted between the years 2010 to 2015, inclusive; after edits, BoHV-1 antibody test results were available on a total of 7,501 female cattle from 58 dairy herds. National records of milk production (i.e., 305-d milk yield, fat yield, protein yield, and somatic cell score; n = 1,211,905 milk-recorded cows), fertility performance (i.e., calving performance, pregnancy diagnosis, and insemination data; n = 2,365,657 cows) together with animal mortality data (i.e., birth, farm movement, death, slaughter, and export events; n = 12,853,257 animals) were also available. Animal linear mixed models were used to quantify variance components for BoHV-1 as well as to estimate genetic correlations among traits. The estimated genetic parameters for the humoral immune response to BoHV-1 in the present study (i.e., heritability range: 0.09 to 0.16) were similar to estimates previously reported for clinical signs of bovine respiratory disease in dairy and beef cattle (i.e., heritability range: 0.05 to 0.11). Results from the present study suggest that breeding for resistance to BoHV-1 infection could reduce the incidence of respiratory disease in cattle while having little or no effect on genetic selection for milk yield or milk constituents (i.e., genetic correlations ranged from -0.13 to 0.17). Moreover, even though standard errors were large, results also suggest that breeding for resistance to BoHV-1 infection may indirectly improve fertility performance while also reducing the incidence of mortality in older animals (i.e., animals >182 d of age). Results can be used to inform breeding programs of potential genetic gains achievable for resistance to BoHV-1 infection in cattle., (Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)
- Published
- 2018
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18. Little genetic variability in resilience among cattle exists for a range of performance traits across herds in Ireland differing in Fasciola hepatica prevalence.
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Twomey AJ, Graham DA, Doherty ML, Blom A, and Berry DP
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- Abattoirs, Animals, Breeding, Cattle physiology, Cattle Diseases parasitology, Dairying, Fasciola hepatica parasitology, Fascioliasis epidemiology, Fascioliasis parasitology, Female, Gene-Environment Interaction, Ireland epidemiology, Lactation genetics, Liver parasitology, Male, Phenotype, Prevalence, Cattle genetics, Cattle Diseases epidemiology, Fasciola hepatica isolation & purification, Fascioliasis veterinary, Fertility genetics, Genetic Variation, Milk metabolism
- Abstract
It is anticipated that in the future, livestock will be exposed to a greater risk of infection from parasitic diseases. Therefore, future breeding strategies for livestock, which are generally long-term strategies for change, should target animals adaptable to environments with a high parasitic load. Covariance components were estimated in the present study for a selection of dairy and beef performance traits over herd-years differing in Fasciola hepatica load using random regression sire models. Herd-year prevalence of F. hepatica was determined by using F. hepatica-damaged liver phenotypes which were recorded in abattoirs nationally. The data analyzed consisted up to 83,821 lactation records from dairy cows for a range of milk production and fertility traits, as well as 105,054 young animals with carcass-related information obtained at slaughter. Reaction norms for individual sires were derived from the random regression coefficients. The heritability and additive genetic standard deviations for all traits analyzed remained relatively constant as herd-year F. hepatica prevalence gradient increased up to a prevalence level of 0.7; although there was a large increase in heritability and additive genetic standard deviation for milk and fertility traits in the observed F. hepatica prevalence levels >0.7, only 5% of the data existed in herd-year prevalence levels >0.7. Very little rescaling, therefore, exists across differing herd-year F. hepatica prevalence levels. Within-trait genetic correlations among the performance traits across different herd-year F. hepatica prevalence levels were less than unity for all traits. Nevertheless, within-trait genetic correlations for milk production and carcass traits were all >0.8 for F. hepatica prevalence levels between 0.2 and 0.8. The lowest estimate of within-trait genetic correlations for the different fertility traits ranged from -0.03 (SE = 1.09) in age of first calving to 0.54 (SE = 0.22) for calving to first service interval. Therefore, there was reranking of sires for fertility traits across different F. hepatica prevalence levels. In conclusion, there was little or no genetic variability in sensitivity to F. hepatica prevalence levels among cattle for milk production and carcass traits. But, some genetic variability in sensitivity among dairy cows did exist for fertility traits measured across herds differing in F. hepatica prevalence.
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- 2018
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19. Genetic correlations between endo-parasite phenotypes and economically important traits in dairy and beef cattle.
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Twomey AJ, Carroll RI, Doherty ML, Byrne N, Graham DA, Sayers RG, Blom A, and Berry DP
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- Animals, Cattle, Cattle Diseases genetics, Fascioliasis parasitology, Female, Fertility, Genetic Predisposition to Disease, Parasitic Diseases, Animal parasitology, Cattle Diseases parasitology, Genetic Variation, Parasitic Diseases, Animal genetics
- Abstract
Parasitic diseases have economic consequences in cattle production systems. Although breeding for parasite resistance can complement current control practices to reduce the prevalence globally, there is little knowledge of the implications of such a strategy on other performance traits. Records on individual animal antibody responses to Fasciola hepatica, Ostertagia ostertagi, and Neospora caninum were available from cows in 68 dairy herds (study herds); national abattoir data on F. hepatica-damaged livers were also available from dairy and beef cattle. After data edits, 9,271 dairy cows remained in the study herd dataset, whereas 19,542 dairy cows and 68,048 young dairy and beef animals had a record for the presence or absence of F. hepatica-damaged liver in the national dataset. Milk, reproductive, and carcass phenotypes were also available for a proportion of these animals as well as their contemporaries. Linear mixed models were used to estimate variance components of antibody responses to the three parasites; covariance components were estimated between the parasite phenotypes and economically important traits. Heritability of antibody responses to the different parasites, when treated as a continuous trait, ranged from 0.07 (O. ostertagi) to 0.13 (F. hepatica), whereas the coefficient of genetic variation ranged from 4% (O. ostertagi) to 20% (F. hepatica). The antibody response to N. caninum was genetically correlated with the antibody response to both F. hepatica (-0.29) and O. ostertagi (-0.67); a moderately positive genetic correlation existed between the antibody response to F. hepatica and O. ostertagi (0.66). Genetic correlations between the parasite phenotypes and the milk production traits were all close to zero (-0.14 to 0.10), as were the genetic correlations between F. hepatica-damaged livers and the carcass traits of carcass weight, conformation, and fat score evaluated in cows and young animals (0.00 to 0.16). The genetic correlation between F. hepatica-damaged livers in cows and milk somatic cell score was 0.32 (SE = 0.20). Antibody responses to F. hepatica and O. ostertagi had favorable genetic correlations with fertility traits, but conversely, antibody response to N. caninum and F. hepatica-damaged livers were unfavorably genetically correlated with fertility. This study provides the necessary information to undertake national multitrait genetic evaluations for parasite phenotypes.
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- 2018
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20. Risk factors associated with animal mortality in pasture-based, seasonal-calving dairy and beef herds.
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Ring SC, McCarthy J, Kelleher MM, Doherty ML, and Berry DP
- Subjects
- Animals, Cattle, Dairying, Female, Logistic Models, Male, Odds Ratio, Parity, Parturition, Pregnancy, Risk Factors, Seasons, Cattle Diseases mortality
- Abstract
Animal mortality is indicative of animal health and welfare standards, which are of growing concern to the agricultural industry. The objective of the present study was to ascertain risk factors associated with mortality at multiple life stages in pasture-based, seasonal-calving dairy and beef herds. Males and females were stratified into seven life stages based on age (0 to 2 d, 3 to 7 d, 8 to 30 d, 31 to 182 d, 183 to 365 d, 366 to 730 d, and 731 to 1,095 d) whereas females with ≥1 calving event were further stratified into five life stages based on cow parity number (1, 2, 3, 4, and 5). Mortality was defined as whether an animal died during each life stage; only animals that either survived the entire duration or died during a life stage were considered. The data, following edits, consisted of 4,404,122 records from 1,358,712 animals. Multivariable logistic regression was used to estimate the logit of the probability of mortality in each life stage separately. The odds of a young animal (i.e., aged ≤ 1,095 d) dying was generally greater if veterinary assistance was required at their birth relative to no assistance (odds ratio [OR]: 3.10 to 31.85), if the animal was a twin relative to a singleton (OR: 1.46 to 2.31) or if the animal was male relative to female (OR: 1.14 to 6.15). Moreover, the odds of a cow (i.e., females with ≥1 calving event) dying were greater when she required veterinary assistance at calving (OR: 2.69 to 7.55) compared with a cow that did not require any assistance, if she produced twin relative to singleton progeny (OR: 1.59 to 2.03) or male relative to female progeny (OR: 1.09 to 1.20). Additionally, the odds of a first or second parity cow dying when she herself had received veterinary assistance at birth were only 0.63 to 0.66 times that of a cow that was provided no assistance at birth. For both young animals and cows, the odds of dying generally increased with herd size, whereas animals residing in expanding herds had lower odds of dying. Results from the present study indicate that the risk factors associated with mortality in pasture-based, seasonal-calving herds are similar to those reported in literature in confinement, nonseasonal-calving herds. Moreover, the present study identifies that these risk factors are similar in both dairy and beef herds, yet the magnitude of the association often differs and also changes with life stage.
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- 2018
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21. Eradicating BVD, reviewing Irish programme data and model predictions to support prospective decision making.
- Author
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Thulke HH, Lange M, Tratalos JA, Clegg TA, McGrath G, O'Grady L, O'Sullivan P, Doherty ML, Graham DA, and More SJ
- Subjects
- Animals, Bovine Virus Diarrhea-Mucosal Disease epidemiology, Bovine Virus Diarrhea-Mucosal Disease virology, Cattle, Female, Ireland epidemiology, Male, Models, Theoretical, Prevalence, Risk Factors, Bovine Virus Diarrhea-Mucosal Disease prevention & control, Decision Making, Diarrhea Viruses, Bovine Viral physiology, Disease Eradication
- Abstract
Bovine Viral Diarrhoea is an infectious production disease of major importance in many cattle sectors of the world. The infection is predominantly transmitted by animal contact. Postnatal infections are transient, leading to immunologically protected cattle. However, for a certain window of pregnancy, in utero infection of the foetus results in persistently infected (PI) calves being the major risk of BVD spread, but also an efficient target for controlling the infection. There are two acknowledged strategies to identify PI animals for removal: tissue tag testing (direct; also known as the Swiss model) and serological screening (indirect by interpreting the serological status of the herd; the Scandinavian model). Both strategies are effective in reducing PI prevalence and herd incidence. During the first four years of the Irish national BVD eradication programme (2013-16), it has been mandatory for all newborn calves to be tested using tissue tag testing. During this period, PI incidence has substantially declined. In recent times, there has been interest among stakeholders in a change to an indirect testing strategy, with potential benefit to the overall programme, particularly with respect to cost to farmers. Advice was sought on the usefulness of implementing the necessary changes. Here we review available data from the national eradication programme and strategy performance predictions from an expert system model to quantify expected benefits of the strategy change from strategic, budgetary and implementation points of view. Key findings from our work include (i) drawbacks associated with changes to programme implementation, in particular the loss of epidemiological information to allow real-time monitoring of eradication progress or to reliably predict time to eradication, (ii) the fact that only 25% of the herds in the Irish cattle sector (14% beef, 78% dairy herds) would benefit financially from a change to serosurveillance, with half of these participants benefiting by less than EUR 75 per annum at herd level or an average of EUR 1.22 per cow, and (iii) opportunities to enhance the effectiveness of the current programme, particularly in terms of time to eradication, through enforced compliance with PI removal as currently outlined in programme recommendations. The assembled information provides scientific arguments, contributing to an informed debate of the pros and cons of a change in eradication strategy in Ireland., (Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.)
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- 2018
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22. A discussion of calibration techniques for evaluating binary and categorical predictive models.
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Fenlon C, O'Grady L, Doherty ML, and Dunnion J
- Subjects
- Calibration, Predictive Value of Tests, ROC Curve, Logistic Models, Models, Biological, Veterinary Medicine methods
- Abstract
Modelling of binary and categorical events is a commonly used tool to simulate epidemiological processes in veterinary research. Logistic and multinomial regression, naïve Bayes, decision trees and support vector machines are popular data mining techniques used to predict the probabilities of events with two or more outcomes. Thorough evaluation of a predictive model is important to validate its ability for use in decision-support or broader simulation modelling. Measures of discrimination, such as sensitivity, specificity and receiver operating characteristics, are commonly used to evaluate how well the model can distinguish between the possible outcomes. However, these discrimination tests cannot confirm that the predicted probabilities are accurate and without bias. This paper describes a range of calibration tests, which typically measure the accuracy of predicted probabilities by comparing them to mean event occurrence rates within groups of similar test records. These include overall goodness-of-fit statistics in the form of the Hosmer-Lemeshow and Brier tests. Visual assessment of prediction accuracy is carried out using plots of calibration and deviance (the difference between the outcome and its predicted probability). The slope and intercept of the calibration plot are compared to the perfect diagonal using the unreliability test. Mean absolute calibration error provides an estimate of the level of predictive error. This paper uses sample predictions from a binary logistic regression model to illustrate the use of calibration techniques. Code is provided to perform the tests in the R statistical programming language. The benefits and disadvantages of each test are described. Discrimination tests are useful for establishing a model's diagnostic abilities, but may not suitably assess the model's usefulness for other predictive applications, such as stochastic simulation. Calibration tests may be more informative than discrimination tests for evaluating models with a narrow range of predicted probabilities or overall prevalence close to 50%, which are common in epidemiological applications. Using a suite of calibration tests alongside discrimination tests allows model builders to thoroughly measure their model's predictive capabilities., (Copyright © 2017 Elsevier B.V. All rights reserved.)
- Published
- 2018
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23. A comparison of 4 predictive models of calving assistance and difficulty in dairy heifers and cows.
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Fenlon C, O'Grady L, Mee JF, Butler ST, Doherty ML, and Dunnion J
- Subjects
- Animals, Cattle Diseases physiopathology, Decision Support Techniques, Dystocia epidemiology, Dystocia physiopathology, Female, Incidence, Ireland epidemiology, Machine Learning, Pregnancy, Cattle physiology, Cattle Diseases epidemiology, Dairying methods, Dystocia veterinary, Models, Theoretical, Parturition
- Abstract
The aim of this study was to build and compare predictive models of calving difficulty in dairy heifers and cows for the purpose of decision support and simulation modeling. Models to predict 3 levels of calving difficulty (unassisted, slight assistance, and considerable or veterinary assistance) were created using 4 machine learning techniques: multinomial regression, decision trees, random forests, and neural networks. The data used were sourced from 2,076 calving records in 10 Irish dairy herds. In total, 19.9 and 5.9% of calving events required slight assistance and considerable or veterinary assistance, respectively. Variables related to parity, genetics, BCS, breed, previous calving, and reproductive events and the calf were included in the analysis. Based on a stepwise regression modeling process, the variables included in the models were the dam's direct and maternal calving difficulty predicted transmitting abilities (PTA), BCS at calving, parity; calving assistance or difficulty at the previous calving; proportion of Holstein breed; sire breed; sire direct calving difficulty PTA; twinning; and 2-way interactions between calving BCS and previous calving difficulty and the direct calving difficulty PTA of dam and sire. The models were built using bootstrapping procedures on 70% of the data set. The held-back 30% of the data was used to evaluate the predictive performance of the models in terms of discrimination and calibration. The decision tree and random forest models omitted the effect of twinning and included only subsets of sire breeds. Only multinomial regression and neural networks explicitly included the modeled interactions. Calving BCS, calving difficulty PTA, and previous calving assistance ranked as highly important variables for all 4 models. The area under the receiver operating characteristic curve (ranging from 0.64 to 0.79) indicates that all of the models had good overall discriminatory power. The neural network and multinomial regression models performed best, correctly classifying 75% of calving cases and showing superior calibration, with an average error in predicted probability of 3.7 and 4.5%, respectively. The neural network and multinomial regression models developed are both suitable for use in decision-support and simulation modeling., (Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)
- Published
- 2017
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24. The creation and evaluation of a model to simulate the probability of conception in seasonal-calving pasture-based dairy heifers.
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Fenlon C, O'Grady L, Butler S, Doherty ML, and Dunnion J
- Abstract
Background: Herd fertility in pasture-based dairy farms is a key driver of farm economics. Models for predicting nulliparous reproductive outcomes are rare, but age, genetics, weight, and BCS have been identified as factors influencing heifer conception. The aim of this study was to create a simulation model of heifer conception to service with thorough evaluation., Methods: Artificial Insemination service records from two research herds and ten commercial herds were provided to build and evaluate the models. All were managed as spring-calving pasture-based systems. The factors studied were related to age, genetics, and time of service. The data were split into training and testing sets and bootstrapping was used to train the models. Logistic regression (with and without random effects) and generalised additive modelling were selected as the model-building techniques. Two types of evaluation were used to test the predictive ability of the models: discrimination and calibration. Discrimination, which includes sensitivity, specificity, accuracy and ROC analysis, measures a model's ability to distinguish between positive and negative outcomes. Calibration measures the accuracy of the predicted probabilities with the Hosmer-Lemeshow goodness-of-fit, calibration plot and calibration error., Results: After data cleaning and the removal of services with missing values, 1396 services remained to train the models and 597 were left for testing. Age, breed, genetic predicted transmitting ability for calving interval, month and year were significant in the multivariate models. The regression models also included an interaction between age and month. Year within herd was a random effect in the mixed regression model. Overall prediction accuracy was between 77.1% and 78.9%. All three models had very high sensitivity, but low specificity. The two regression models were very well-calibrated. The mean absolute calibration errors were all below 4%., Conclusion: Because the models were not adept at identifying unsuccessful services, they are not suggested for use in predicting the outcome of individual heifer services. Instead, they are useful for the comparison of services with different covariate values or as sub-models in whole-farm simulations. The mixed regression model was identified as the best model for prediction, as the random effects can be ignored and the other variables can be easily obtained or simulated.
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- 2017
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25. Relative importance of herd-level risk factors for probability of infection with paratuberculosis in Irish dairy herds.
- Author
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McAloon CG, Doherty ML, Whyte P, More SJ, O'Grady L, Citer L, and Green MJ
- Subjects
- Animals, Bayes Theorem, Cattle, Cattle Diseases microbiology, Dairying, Female, Logistic Models, Paratuberculosis microbiology, Risk Assessment, Risk Factors, Cattle Diseases epidemiology, Paratuberculosis epidemiology
- Abstract
Control of paratuberculosis is challenging due to the relatively poor performance of diagnostic tests, a prolonged incubation period, and protracted environmental survival. Prioritization of herd-level interventions is not possible because putative risk factors are often not supported by risk factor studies. The objective for this study was to investigate the relative importance of risk factors for an increased probability of herd paratuberculosis infection. Risk assessment data, comprehensive animal purchase history, and diagnostic test data were available for 936 Irish dairy herds. Both logistic regression and a Bayesian β regression on the outcome of a latent class analysis were conducted. Population attributable fractions and proportional reduction in variance explained were calculated for each variable in the logistic and Bayesian models, respectively. Routine use of the calving area for sick or lame cows was found to be a significant explanatory covariate in both models. Purchasing behavior for the previous 10 yr was not found to be significant. For the logistic model, length of time calves spend in the calving pen (25%) and routine use of the calving pen for sick or lame animals (14%) had the highest attributable fractions. For the Bayesian model, the overall R
2 was 16%. Dry cow cleanliness (7%) and routine use of the calving area for sick or lame cows (6%) and had the highest proportional reduction in variance explained. These findings provide support for several management practices commonly recommended as part of paratuberculosis control programs; however, a large proportion of the observed variation in probability of infection remained unexplained, suggesting other important risks factors may exist., (Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)- Published
- 2017
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26. Significant re-emergence and recirculation of Schmallenberg virus in previously exposed dairy herds in Ireland in 2016.
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Collins ÁB, Barrett DJ, Doherty ML, McDonnell M, and Mee JF
- Subjects
- Animals, Bunyaviridae Infections epidemiology, Bunyaviridae Infections virology, Cattle, Cattle Diseases virology, Communicable Diseases, Emerging epidemiology, Communicable Diseases, Emerging virology, Dairying, Enzyme-Linked Immunosorbent Assay veterinary, Female, Ireland epidemiology, Antibodies, Viral blood, Bunyaviridae Infections veterinary, Cattle Diseases epidemiology, Communicable Diseases, Emerging veterinary, Orthobunyavirus immunology
- Abstract
Schmallenberg virus (SBV) circulation was investigated in 25 previously exposed dairy herds in Ireland in 2016. A population of 1,550 spring-2014-born animals, which had been monitored for SBV infection in 2014 and 2015 as part of a previous SBV surveillance study, were resampled for evidence of SBV infection during 2016. A total of 366 blood samples were collected in the 25 study herds (15 samples per herd) between 3 March 2017 and 10 March 2017 (before the 2017 vector-active season) and analysed for SBV antibodies using a competitive ELISA kit (IDVet). A total of 256 animals tested seropositive, an AP of 69.9% (95% CI: 65.1-74.4) and TP of 77.7% (95% CI: 72.3%-82.8%) when correcting for imperfect test characteristics. These results demonstrate that a new epidemic of SBV circulation occurred in these previously exposed herds in Ireland in 2016., (© 2017 Blackwell Verlag GmbH.)
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- 2017
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27. Schmallenberg virus: Predicting within-herd seroprevalence using bulk-tank milk antibody titres and exploring individual animal antibody titres using empirical distribution functions (EDF).
- Author
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Collins ÁB, Grant J, Barrett D, Doherty ML, Hallinan A, and Mee JF
- Subjects
- Animals, Bunyaviridae Infections epidemiology, Cattle, Enzyme-Linked Immunosorbent Assay, Female, Lactation, Seroepidemiologic Studies, Antibodies, Viral blood, Bunyaviridae Infections veterinary, Cattle Diseases epidemiology, Milk virology, Orthobunyavirus immunology
- Abstract
Schmallenberg virus (SBV) is transmitted by Culicoides spp. biting midges and can cause abortions and congenital malformations in ruminants and milk drop in dairy cattle. Estimating true within-herd seroprevalence is an essential component of efficient and cost-effective SBV surveillance programs. The objectives of this study were: (1) determine the correlation between bulk-tank milk (BTM)-ELISA results and within-herd seroprevalence, (2) evaluate the ability of BTM-ELISA results to predict within-herd seroprevalence and (3) explore the distributions of individual animal serology results using novel statistical methodology. BTM samples (n=24) and blood samples (n=4019) collected from all lactating cows contributing to the BTM in 26 Irish dairy herds (58-444 cows/herd) in 2014 located in a region exposed to SBV in 2012/2013, were analysed for SBV-specific antibodies using IDVet
® ELISA kits. The correlation between BTM-ELISA results and within-herd seroprevalence was determined by calculating Pearson's correlation coefficient. Linear regression models were used to assess the ability of BTM-ELISA results to predict within-herd seroprevalence. The distributions of individual animal serology results were explored by determining the empirical distribution functions (EDF) of the individual animal serum ELISA results in each herd. EDFs were compared pairwise across herds, using the Kolmogorov-Smirnov statistical test. Herds with similar BTM-ELISA results, herds with similar within-herd seroprevalence and herds with similar mean-herd serology ELISA results were stratified in order to explore their respective paired-herd EDF comparisons. Statistical significance was set at p<0.05. Twenty-two herds were BTM-ELISA-positive (within-herd seroprevalence 30.6-100%) and two herds were BTM-ELISA-negative (within-herd seroprevalence 10.7 and 16.2%) indicating BTM-ELISA-negative herds can have seropositive animals present. BTM-ELISA results were highly correlated (r=0.807, p<0.0001) with, and predictive of (R2 =0.832, p<0.0001) of within-herd seroprevalence. Predictions were most accurate for upper-range BTM-ELISA antibody titres, while they were less accurate at higher and lower antibody titres. This is likely a result of the overall high within-herd seroprevalence. In herds with similar BTM-ELISA results 82% of the paired-herd EDF comparisons were significantly different. In herds with similar within-herd seroprevalence and in herds with similar mean-herd serology ELISA results, 46% and 47% of the paired-herd EDF comparisons were significantly different, respectively. These results demonstrate that BTM antibody titres are highly predictive of within-herd seroprevalence in an SBV exposed region. Furthermore, exploring the serum EDFs revealed that the variation observed in the predicted within-herd seroprevalence in the regression models is likely a result of individual animal variation in serum antibody titres in these herds., (Copyright © 2017 Elsevier B.V. All rights reserved.)- Published
- 2017
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28. The creation and evaluation of a model predicting the probability of conception in seasonal-calving, pasture-based dairy cows.
- Author
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Fenlon C, O'Grady L, Doherty ML, Dunnion J, Shalloo L, and Butler ST
- Subjects
- Animals, Breeding statistics & numerical data, Cattle, Dairying, Female, Ireland, Lactation, Milk, Poaceae, Pregnancy, Fertilization physiology, Models, Statistical, Probability, Seasons
- Abstract
Reproductive performance in pasture-based production systems has a fundamentally important effect on economic efficiency. The individual factors affecting the probability of submission and conception are multifaceted and have been extensively researched. The present study analyzed some of these factors in relation to service-level probability of conception in seasonal-calving pasture-based dairy cows to develop a predictive model of conception. Data relating to 2,966 services from 737 cows on 2 research farms were used for model development and data from 9 commercial dairy farms were used for model testing, comprising 4,212 services from 1,471 cows. The data spanned a 15-yr period and originated from seasonal-calving pasture-based dairy herds in Ireland. The calving season for the study herds extended from January to June, with peak calving in February and March. A base mixed-effects logistic regression model was created using a stepwise model-building strategy and incorporated parity, days in milk, interservice interval, calving difficulty, and predicted transmitting abilities for calving interval and milk production traits. To attempt to further improve the predictive capability of the model, the addition of effects that were not statistically significant was considered, resulting in a final model composed of the base model with the inclusion of BCS at service. The models' predictions were evaluated using discrimination to measure their ability to correctly classify positive and negative cases. Precision, recall, F-score, and area under the receiver operating characteristic curve (AUC) were calculated. Calibration tests measured the accuracy of the predicted probabilities. These included tests of overall goodness-of-fit, bias, and calibration error. Both models performed better than using the population average probability of conception. Neither of the models showed high levels of discrimination (base model AUC 0.61, final model AUC 0.62), possibly because of the narrow central range of conception rates in the study herds. The final model was found to reliably predict the probability of conception without bias when evaluated against the full external data set, with a mean absolute calibration error of 2.4%. The chosen model could be used to support a farmer's decision-making and in stochastic simulation of fertility in seasonal-calving pasture-based dairy cows., (Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)
- Published
- 2017
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29. Johne's disease in the eyes of Irish cattle farmers: A qualitative narrative research approach to understanding implications for disease management.
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McAloon CG, Macken-Walsh Á, Moran L, Whyte P, More SJ, O'Grady L, and Doherty ML
- Subjects
- Adult, Aged, Agriculture, Animals, Cattle, Cattle Diseases transmission, Health Knowledge, Attitudes, Practice, Humans, Interviews as Topic, Male, Middle Aged, Paratuberculosis transmission, Cattle Diseases prevention & control, Farmers psychology, Paratuberculosis prevention & control
- Abstract
Bovine Johne's Disease (JD) is a disease characterised by chronic granulomatous enteritis which manifests clinically as a protein-losing enteropathy causing diarrhoea, hypoproteinaemia, emaciation and, eventually death. Some research exists to suggest that the aetiologic pathogen Mycobacterium avium subspecies paratuberculosis may pose a zoonotic risk. Nationally coordinated control programmes have been introduced in many of the major milk producing countries across the world. However, JD is challenging to control in infected herds owing to limitations of diagnostic tests and the long incubation period of the disease. Internationally, research increasingly recognises that improved understanding of farmers' subjective views and behaviours may inform and enhance disease management strategies and support the identification and implementation of best practice at farm level. The aim of this study was to use qualitative research methods to explore the values and knowledges of farmers relative to the control of JD at farm level. The Biographical Narrative Interpretive Method (BNIM) was used to generate data from both infected and presumed uninfected farms in Ireland. Qualitative analysis revealed that cultural and social capital informed farmers' decisions on whether to introduce control and preventive measures. Cultural capital refers to the pride and esteem farmers associate with particular objects and actions whereas social capital is the value that farmers associate with social relationships with others. On-farm controls were often evaluated by farmers as impractical and were frequently at odds with farmers' knowledge of calf management. Knowledge from farmers of infected herds did not disseminate among peer farmers. Owners of herds believed to be uninfected expressed a view that controls and preventive measures were not worthy of adoption until there was clear evidence of JD in the herd. These findings highlight important barriers and potential aids to prevention and control in both infected and uninfected herds., (Copyright © 2017 Elsevier B.V. All rights reserved.)
- Published
- 2017
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30. An investigative framework to facilitate epidemiological thinking during herd problem-solving.
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More SJ, Doherty ML, and O'Grady L
- Abstract
Veterinary clinicians and students commonly use diagnostic approaches appropriate for individual cases when conducting herd problem-solving. However, these approaches can be problematic, in part because they make limited use of epidemiological principles and methods, which has clear application during the investigation of herd problems. In this paper, we provide an overview of diagnostic approaches that are used when investigating individual animal cases, and the challenges faced when these approaches are directly translated from the individual to the herd. Further, we propose an investigative framework to facilitate epidemiological thinking during herd problem-solving. A number of different approaches are used when making a diagnosis on an individual animal, including pattern recognition, hypothetico-deductive reasoning, and the key abnormality method. Methods commonly applied to individuals are often adapted for herd problem-solving: 'comparison with best practice' being a herd-level adaptation of pattern recognition, and 'differential diagnoses' a herd-level adaptation of hypothetico-deductive reasoning. These approaches can be effective, however, challenges can arise. Herds are complex; a collection of individual cows, but also additional layers relating to environment, management, feeding etc. It is unrealistic to expect seamless translation of diagnostic approaches from the individual to the herd. Comparison with best practice is time-consuming and prioritisation of actions can be problematic, whereas differential diagnoses can lead to 'pathogen hunting', particularly in complex cases. Epidemiology is the science of understanding disease in populations. The focus is on the population, underpinned by principles and utilising methods that seek to allow us to generate solid conclusions from apparently uncontrolled situations. In this paper, we argue for the inclusion of epidemiological principles and methods as an additional tool for herd problem-solving, and outline an investigative framework, with examples, to effectively incorporate these principles and methods with other diagnostic approaches during herd problem-solving. Relevant measures of performance are identified, and measures of case frequencies are calculated and compared across time, in space and among animal groupings, to identify patterns, clues and plausible hypotheses, consistent with potential biological processes. With this knowledge, the subsequent investigation (relevant on-farm activities, diagnostic testing and other examinations) can be focused, and actions prioritised (specifically, those actions that are likely to make the greatest difference in addressing the problem if enacted). In our experience, this investigative framework is an effective teaching tool, facilitating epidemiological thinking among students during herd problem-solving. It is a generic and robust process, suited to many herd-based problems.
- Published
- 2017
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31. Personal and Professional Characteristics of Music Educators: One Size Does Not Fit All.
- Author
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Doherty ML and van Mersbergen M
- Subjects
- Adult, Age Factors, Female, Humans, Illinois epidemiology, Male, Middle Aged, Occupational Diseases diagnosis, Occupational Diseases physiopathology, Prevalence, Risk Factors, Sex Factors, Surveys and Questionnaires, Teacher Training, Voice Disorders diagnosis, Voice Disorders physiopathology, Young Adult, Music, Occupational Diseases epidemiology, Occupational Health, Teaching, Voice Disorders epidemiology, Voice Quality
- Abstract
Objectives/hypothesis: The prevalence of voice disorders among various educator groups is well known, and voice disorders among music educators are higher than the general classroom educators. Music educators vary with respect to behavioral and personality factors, personal characteristics, type of music taught, job-specific environment, and governmental professional expectations. This study aims to identify risk factors for voice disorders in a heterogeneous population of music educators., Study Design: An online survey was conducted with 213 respondents., Methods: Survey questions addressed demographics, level of education, years of music teaching experience, specialty training, primary teaching assignments and instrument, vocal health behaviors, and diagnoses of voice disorders. Summary statistics and group comparisons are reported., Results: Those whose primary instrument was voice reported a greater frequency of voice disorders. Female and older music educators also had a higher prevalence of voice disorders., Conclusions: Music educators are a heterogeneous group of individuals who require more careful consideration in the prevention and treatment of occupational voice problems., (Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.)
- Published
- 2017
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32. Post-epidemic Schmallenberg virus circulation: parallel bovine serological and Culicoides virological surveillance studies in Ireland.
- Author
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Collins ÁB, Barrett D, Doherty ML, Larska M, and Mee JF
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- Animals, Bunyaviridae Infections veterinary, Bunyaviridae Infections virology, Cattle, Cattle Diseases epidemiology, Enzyme-Linked Immunosorbent Assay veterinary, Ireland epidemiology, Orthobunyavirus isolation & purification, Seroepidemiologic Studies, Serologic Tests veterinary, Bunyaviridae Infections epidemiology, Cattle Diseases virology, Ceratopogonidae virology, Epidemics veterinary
- Abstract
Background: Schmallenberg virus (SBV) emerged in northern-Europe in 2011 resulting in an epidemic of ruminant abortions and congenital malformations throughout the continent. In the years following the epidemic there have been reports of SBV overwintering and continued circulation in several European countries. When the population-level of immunity declines in exposed regions, re-introduction of SBV could result in further outbreaks of Schmallenberg disease. The aims of this study were to determine the SBV seroprevalence in previously exposed Irish dairy herds in 2014 and to investigate if SBV continued to circulate in these herds in the three years (2013-2015) following the Irish Schmallenberg epidemic. Whole-herd SBV serosurveillance was conducted in 26 herds before (spring) and following the 2014 vector-season (winter), and following the 2015 vector-season (winter). In spring 2014, 5,531 blood samples were collected from 4,070 cows and 1,461 heifers. In winter 2014, 2,483 blood samples were collected from 1,550 youngstock (8-10 months old) and a subsample (n = 933; 288 cows, 645 heifers) of the seronegative animals identified in the spring. Youngstock were resampled in winter 2015. Culicoides spp. were collected in 10 herds during the 2014 vector-season and analysed for SBV; a total of 138 pools (3,048 Culicoides) from 6 SBV vector species were tested for SBV RNA using real-time PCR., Results: In spring 2014, animal-level seroprevalence was 62.5 % (cows = 84.7 %; heifers = 0.6 %). Within-herd seroprevalence ranged widely from 8.5 %-84.1 % in the 26 herds. In winter 2014, 22 animals (0.9 %; 10 cows, 5 heifers, 7 youngstock) originating in 17 herds (range 1-4 animals/herd) tested seropositive. In winter 2015 all youngstock, including the 7 seropositive animals in winter 2014, tested seronegative suggesting their initial positive result was due to persistence of maternal antibodies. All of the Culicoides pools examined tested negative for SBV-RNA., Conclusions: SBV appears to have recirculated at a very low level in these herds during 2013 and 2014, while there was no evidence of SBV infection in naïve youngstock during 2015. A large population of naïve animals was identified and may be at risk of infection in future years should SBV re-emerge and recirculate as it has done in continental Europe.
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- 2016
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33. Genetic parameters for both a liver damage phenotype caused by and antibody response to phenotype in dairy and beef cattle.
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Twomey AJ, Sayers RG, Carroll RI, Byrne N, Brien EO, Doherty ML, McClure JC, Graham DA, and Berry DP
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- Abattoirs, Animals, Cattle, Cattle Diseases economics, Fascioliasis economics, Fascioliasis genetics, Fascioliasis parasitology, Female, Lactation, Linear Models, Liver pathology, Male, Pregnancy, Red Meat, Cattle Diseases genetics, Cattle Diseases parasitology, Fasciola hepatica physiology, Fascioliasis veterinary
- Abstract
is a helminth parasite of economic importance to the global cattle industry, with documented high international herd prevalence. The objective of the present study was to generate the first published genetic parameter estimates for liver damage caused by as well as antibody response to in cattle. Abattoir data on the presence of live , or -damaged livers, were available between the years 2012 and 2015, inclusive. A second data set was available on cows from 68 selected dairy herds with a blood ELISA test for antibody response to in autumn 2015. Animals were identified as exposed by using herd mate phenotype, and only exposed animals were retained for analysis. The abattoir data set consisted of 20,481 dairy cows and 75,041 young dairy and beef animals, whereas the study herd data set consisted of 6,912 dairy cows. (Co)variance components for phenotypes in both data sets were estimated using animal linear mixed models. Fixed effects included in the model for both data sets were contemporary group, heterosis coefficient, recombination loss coefficient, parity, age relative to parity/age group, and stage of lactation. An additional fixed effect of abattoir by date of slaughter was included in the model for the analysis of the abattoir data. Direct additive genetic effects and a residual effect were included as random effects for all analyses. After data edits, the prevalence of liver damage caused by in cows and young cattle was 47% and 20%, respectively. The prevalence of a positive antibody response to in cows from the study herd data was 36% after data edits. The heritability of as a binary trait for dairy cows in abattoir data and study herd data was 0.03 ± 0.01 and 0.09 ± 0.02, respectively; heritability in young cattle was 0.01 ± 0.005. The additive genetic SD of as a binary trait was 0.069 and 0.050 for cows and young cattle from the abattoir data, respectively, and 0.112 from the study herd cows. The genetic correlation between liver damage caused by in young cattle and cows from the abattoir data was 0.94 ± 0.312 and the genetic correlation between liver damage caused by in cows and positive antibody response to in cows in the study herd data was 0.37 ± 0.283.
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- 2016
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34. Relationship between selected perinatal paratuberculosis management interventions and passive transfer of immunity in dairy calves.
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McAloon CG, Whyte P, O'Grady L, Lorenz I, Green MG, Hogan I, Johnson A, and Doherty ML
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- Animals, Blood Proteins analysis, Cattle blood, Cattle Diseases epidemiology, Cohort Studies, Colostrum immunology, Female, Ireland epidemiology, Logistic Models, Male, Paratuberculosis epidemiology, Peripartum Period, Pregnancy, Serum Globulins analysis, Zinc Sulfate analysis, gamma-Glutamyltransferase blood, Animals, Newborn immunology, Cattle immunology, Cattle Diseases prevention & control, Dairying methods, Endemic Diseases veterinary, Immunity, Maternally-Acquired, Paratuberculosis prevention & control
- Abstract
The objective of this cohort study was to assess the relationship between perinatal calf management practices relevant to the control of paratuberculosis and passive transfer of immunoglobulin in calves born in an endemically infected Irish dairy herd. Data from 176 calves were used to assess the effect of time spent in the calving area, individual versus non-designated calving and colostrum pasteurisation on serum total protein, zinc sulphate turbidity, globulin and γ-glutamyltransferase. In addition, the effects of colostrum quality, volume of colostrum fed, method of colostrum administration and calving season on passive transfer were quantified. Serum samples were collected as part of routine herd health monitoring from calves aged between one and seven days. Multivariate linear and logistic regression models were used to assess the effect of each variable on the test result and failure of passive transfer as determined using a cut-off point for each diagnostic test. Colostrum pasteurisation and calving area were not significantly associated with passive transfer, whereas increased time spent in the calving pen was consistently associated with a detrimental effect. In addition, a strong seasonal effect was apparent, which appeared to be unrelated to colostrum quality and calf management. The authors are unaware of published studies documenting such a significant seasonal effect on passive transfer., (British Veterinary Association.)
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- 2016
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35. Bayesian estimation of prevalence of paratuberculosis in dairy herds enrolled in a voluntary Johne's Disease Control Programme in Ireland.
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McAloon CG, Doherty ML, Whyte P, O'Grady L, More SJ, Messam LL, Good M, Mullowney P, Strain S, and Green MJ
- Subjects
- Animals, Bayes Theorem, Cattle, Cattle Diseases microbiology, Enzyme-Linked Immunosorbent Assay veterinary, Ireland epidemiology, Models, Theoretical, Paratuberculosis microbiology, Prevalence, Cattle Diseases epidemiology, Dairying methods, Mycobacterium avium subsp. paratuberculosis physiology, Paratuberculosis epidemiology
- Abstract
Bovine paratuberculosis is a disease characterised by chronic granulomatous enteritis which manifests clinically as a protein-losing enteropathy causing diarrhoea, hypoproteinaemia, emaciation and, eventually death. Some evidence exists to suggest a possible zoonotic link and a national voluntary Johne's Disease Control Programme was initiated by Animal Health Ireland in 2013. The objective of this study was to estimate herd-level true prevalence (HTP) and animal-level true prevalence (ATP) of paratuberculosis in Irish herds enrolled in the national voluntary JD control programme during 2013-14. Two datasets were used in this study. The first dataset had been collected in Ireland during 2005 (5822 animals from 119 herds), and was used to construct model priors. Model priors were updated with a primary (2013-14) dataset which included test records from 99,101 animals in 1039 dairy herds and was generated as part of the national voluntary JD control programme. The posterior estimate of HTP from the final Bayesian model was 0.23-0.34 with a 95% probability. Across all herds, the median ATP was found to be 0.032 (0.009, 0.145). This study represents the first use of Bayesian methodology to estimate the prevalence of paratuberculosis in Irish dairy herds. The HTP estimate was higher than previous Irish estimates but still lower than estimates from other major dairy producing countries., (Copyright © 2016 Elsevier B.V. All rights reserved.)
- Published
- 2016
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36. Microbiological contamination of colostrum on Irish dairy farms.
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McAloon CG, Doherty ML, Donlon J, Lorenz I, Meade J, O'Grady L, and Whyte P
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- Animals, Cattle, Female, Ireland, Pregnancy, Colostrum microbiology, Dairying, Farms
- Published
- 2016
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37. The effect of paratuberculosis on milk yield--A systematic review and meta-analysis.
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McAloon CG, Whyte P, More SJ, Green MJ, O'Grady L, Garcia A, and Doherty ML
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- Animals, Cattle, Cattle Diseases economics, Cattle Diseases microbiology, Feces microbiology, Female, Lactation, Milk microbiology, Mycobacterium avium subsp. paratuberculosis genetics, Paratuberculosis economics, Paratuberculosis microbiology, Cattle Diseases physiopathology, Milk metabolism, Mycobacterium avium subsp. paratuberculosis isolation & purification, Paratuberculosis physiopathology
- Abstract
Bovine paratuberculosis is a disease characterized by chronic granulomatous enteritis causing protein-losing enteropathy. Adverse effects on animal productivity are key drivers in the attempt to control paratuberculosis at the farm level. Economic models require an accurate estimation of the production effects associated with paratuberculosis. The aim of this study was to conduct a systematic review and meta-analysis to investigate the effect of paratuberculosis on milk production. A total of 20 effect estimates from 15 studies were included in the final meta-analysis. Substantial between-study heterogeneity was observed. Subgroup analysis by case definition and study design was carried out to investigate heterogeneity. The majority of between-study variation was attributed to studies that defined cases on serology. Calculation of a pooled effect estimate was only appropriate for studies that defined cases by organism detection. A reduction in milk yield, corrected for lactation number and herd of origin of 1.87 kg/d, equivalent to 5.9% of yield, was associated with fecal culture or PCR positivity in individual cows., (Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)
- Published
- 2016
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38. Profiling oral and digital lesions in sheep in Ireland.
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FitzGerald WG, Cassidy JP, Markey BK, and Doherty ML
- Abstract
Background: During the FMD outbreak in Ireland and the UK in 2001, there was significant uncertainty amongstveterinary practitioners and government veterinary inspectors surrounding the clinical diagnosis of FMD insheep. This situation was complicated by reports of idiopathic oral ulcers that closely resembled FMD ongross appearance which at that time were referred to as ovine mouth and gum obscure disease., Methods: A field and abattoir study was carried out to determine the frequency, appearance and significance of oraland digital lesions in sheep in Ireland. A total of 3, 263 sheep were examined in 22 flocks, including 1, 969lambs and 1, 294 adults. A further 2,403 animals were examined by abattoir inspections. Animals bearing lesions of interest were identified, samples of the lesions were taken and subsequently examined by bacteriology, electron microscopy, serology, immunohistochemistry and histopathology., Results: Forty four oral and 20 digital lesions were identified and characterised. Oral lesions were recorded mostfrequently in lambs, where the most common cause was orf virus infection. The majority of the oral lesions recorded in the adults was idiopathic and consistent with a diagnosis of idiopathic oral ulceration. A variety of digital lesions was observed, consistent with scald, foot-rot and contagious ovine digital dermatitis (CODD). All of the animals with lesions were seronegative to FMD virus (FMDV)., Conclusions: There was no difficulty in differentiating these lesions from those caused by FMDV on the basis of flockhistory and careful clinical examination.
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- 2015
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39. Bovine congenital erythropoietic protoporphyria in a crossbred limousin heifer in Ireland.
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McAloon CG, Doherty ML, O'Neill H, Badminton M, and Ryan EG
- Abstract
An unusual case of an 11-month-old, black Limousin-cross heifer, with an 8-month history of episodic seizures and photosensitisation, was referred by a veterinary practitioner to the Farm Animal Section of the UCD Veterinary Hospital, School of Veterinary Medicine, University College Dublin, Ireland, in August 2014. Following an investigation, a diagnosis of Bovine Congenital Erythropoietic Protoporphyria (BCEPP) was made. To the authors' knowledge this is the first report of such a case in Ireland. BCEPP should be considered as a differential diagnosis in young animals displaying periodic seizures and/or photosensitisation.
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- 2015
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40. The effect of Lameness before and during the breeding season on fertility in 10 pasture-based Irish dairy herds.
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Somers JR, Huxley J, Lorenz I, Doherty ML, and O'Grady L
- Abstract
Background: The effects of lameness on fertility have been documented frequently but few data are available from seasonally breeding, pasture-based herds (such as those used in Ireland) where cows are housed during the winter months but managed at pasture for the remainder of the year. This study determined the prevalence of lameness in a group of 786 cows in 10 pasture-based Irish dairy herds before, during and after the breeding season and assessed the relationship between lameness and the reproductive performance in these herds through serial locomotion scoring during the grazing period., Results: Lameness prevalences of 11.6 % before, 14.6 % during and 11.6 % after the breeding season were found and these compared favourably to results from housed cattle and are similar to other studies carried out in grazing herds. A Cox proportional hazards model with locomotion score as time varying covariate was used. After controlling for the effect of farm, month of calving, body condition score at calving, body condition score loss after calving and economic breeding index, cows identified as lame during the study were less likely to become pregnant. Cows lame before the earliest serve date but no longer lame during the breeding season, cows becoming lame after the earliest serve date and cows identified lame both before and after this date were respectively 12 %, 35 % and 38 % less likely to become pregnant compared to cows never observed lame during the study. However, these findings were only significant for cows becoming lame after the earliest serve date and cows lame both before and after the start of breeding., Conclusions: This study found that the reproductive efficiency was significantly (p < 0.05) lower in cows becoming lame during the breeding season and cows lame before and during the breeding season compared to non-lame cows. Cows no longer lame during the breeding season had a lower Submission Rate to first serve within 3 weeks of earliest serve date. However, the Pregnancy Rate was not significantly (p > 0.05) lower in these animals compared to cows never diagnosed as lame. In addition to lameness status, nutritional status and genetics were found to influence the reproductive performance in pasture-based Irish dairy herds.
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- 2015
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41. Nematode control in suckler beef cattle over their first two grazing seasons using a targeted selective treatment approach.
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O'Shaughnessy J, Earley B, Mee JF, Doherty ML, Crosson P, Barrett D, and de Waal T
- Abstract
Background: With concerns over the development of anthelmintic resistance in cattle nematode populations, we must re-examine our approach to nematode control in cattle. Targeted selective treatments (TST), whereby individual animals are treated instead of entire groups, are being investigated as an alternative. The study objective was to determine if anthelmintic usage could be reduced using a TST-based approach to nematode control in spring-born suckler beef cattle over their first and second grazing seasons (SGS) without affecting performance. In the first grazing season (FGS), 99 calves with an initial mean (s.d.) calf age and live weight on day 0 (June 28(th) 2012) of 107 (23.1) days and 160 (32.5) kg, respectively, were used. The study commenced on day 0 when calves were randomised and allocated to one of two treatments; 1), standard treatment (control) and 2), TST. Control calves were treated subcutaneously with ivermectin on days 0, 41 and 82 in the FGS. All calves were treated with ivermectin on day 124 and housed on day 133. In the SGS, only heifer calves from the FGS were used and control heifers were treated with ivermectin on day 393. Animals were weighed, blood and faecal sampled every three weeks. The TST animals were treated with ivermectin if thresholds based on a combination of plasma pepsinogen concentrations, faecal egg count and/or the presence of Dictyocaulus viviparus larvae in faeces (FGS only) were reached., Results: No TST calves reached the treatment threshold criteria in the FGS. The FGS average daily live weight gain (ADG ± s.e.m.) for control and TST group calves was 0.89 ± 0.02 kg and 0.94 ± 0.02 kg day(-1), respectively (P = 0.17). In the SGS, all heifers were treated with ivermectin on day 431 due to clinical signs of respiratory disease. The ADG for control and TST heifers from turnout on day 321 to day 431 was 0.90 ± 0.04 and 0.80 ± 0.04 kg day(-1), respectively (P = 0.03)., Conclusions: Spring-born FGS suckler beef calves require minimal anthelmintic treatment to maintain performance. In contrast, clinical parasitic disease may develop in the SGS unless appropriate anthelmintic treatment is provided.
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- 2015
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42. Development of a HACCP-based approach to control paratuberculosis in infected Irish dairy herds.
- Author
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McAloon CG, Whyte P, More SJ, O'Grady L, and Doherty ML
- Subjects
- Animals, Cattle, Female, Ireland, Risk Assessment, Cattle Diseases prevention & control, Dairying methods, Hazard Analysis and Critical Control Points methods, Paratuberculosis prevention & control
- Abstract
Paratuberculosis is a challenging disease to control at farm level, in part due to the poor sensitivity of diagnostic tests and a prolonged incubation period. Simulation studies have highlighted on-farm management to be the most important factor in preventing on-farm spread. A risk assessment (RA) and management plan (MP) approach (collectively, RAMP) has been adopted around the world as the most appropriate method of controlling disease in infected farms. However, there are problems with RAMP that remain to be resolved. The RA relies heavily on farmer recollection and estimation resulting in subjectivity and substantial inter-observer variability. MPs consist of a series of qualitative, farm specific recommendations showing how management can be improved. However, MP assessment is generally conducted informally, and progress is monitored through 'end-point' diagnostic testing of adult animals and repeated risk assessments. Hazard analysis and critical control point (HACCP) has been developed as a proactive alternative to end-point testing. We hypothesise that farm-based HACCP systems may be a useful alternative to RAMP on farms where more intensive monitoring and evaluation of controls for paratuberculosis is required. Therefore, the objective of this methodological study was to develop a HACCP-based system for paratuberculosis control. Critical control points (CCPs) relating to peri-parturient area management, calving, new-born calf management and colostrum management were identified as areas where additional control could be exerted above existing methods. Novel monitoring systems were developed for each CCP, along with targets and corrective actions. This system is intended for use in high prevalence herds, or farms where more robust monitoring of key control points may be beneficial. It is currently being trialled on infected commercial dairy herds in Ireland., (Copyright © 2015 Elsevier B.V. All rights reserved.)
- Published
- 2015
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43. Controlling nematodes in dairy calves using targeted selective treatments.
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O'Shaughnessy J, Earley B, Mee JF, Doherty ML, Crosson P, Barrett D, and de Waal T
- Subjects
- Animals, Anthelmintics administration & dosage, Cattle, Cattle Diseases prevention & control, Feces parasitology, Nematode Infections drug therapy, Nematode Infections prevention & control, Parasite Egg Count, Temperature, Time Factors, Anthelmintics therapeutic use, Cattle Diseases parasitology, Nematoda classification, Nematode Infections veterinary
- Abstract
With increasing concerns of anthelmintic resistance in cattle nematode populations worldwide, there is a need to explore alternative approaches to nematode control. One alternative approach is the use of targeted selective treatments (TST) where only individual animals are treated instead of the entire group. This study reports the findings of a TST approach in dairy calves conducted over their first grazing season (FGS) to control both gastrointestinal nematode and lungworm challenge. Ninety-six calves with an initial mean (s.d.) age and live weight of 130 (28.3) days and 120 (23.6)kg, respectively, were randomised by breed, age and live weight to one of two treatments; Control (n=24; ×2) and TST (n=24; ×2). Control calves were treated three times at pasture with ivermectin by subcutaneous injection. Individual calves in the TST group were treated at pasture with ivermectin when one of the following thresholds was met: (1) positive for lungworm larvae using the modified Baermann technique or (2) positive or negative for lungworm larvae using the modified Baermann technique with plasma pepsinogen concentration (PP) ≥ two international units of tyrosine/litre and faecal egg count (FEC) ≥ 200 strongyle eggs per gram of faeces. Calves were rotationally grazed from July 3rd 2012 (day 0) to November 2nd 2012 (day 122) when calves were housed. Calves were weighed and sampled (blood and faecal) every three weeks. There was an effect of treatment and time on both FEC [treatment (P=0.023), time (P<0.001)] and PP [treatment (P=0.002), time (P<0.001)]. Both FEC and PP were higher in TST calves. There was a 50% reduction in anthelmintic use in TST calves compared to control calves. Clinical signs of lungworm infection, confirmed by the modified Baermann technique, were evident in TST calves on days 62 and 63 of the study. The average daily live weight gain for control and TST calves was 0.50 (0.02)kg day(-1) and 0.47 (0.03)kg day(-1), respectively (P=0.41). Thus, performance in dairy calves can potentially be maintained with fewer anthelmintic treatments but farmers need to be vigilant of the challenge posed by lungworm. Any future approach into the use of TST in FGS calves must take into consideration the relative importance of lungworm as a pathogen., (Copyright © 2015 Elsevier B.V. All rights reserved.)
- Published
- 2015
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44. Disease screening profiles and colostrum management practices on 16 Irish suckler beef farms.
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O'Shaughnessy J, Earley B, Barrett D, Doherty ML, Crosson P, de Waal T, and Mee JF
- Abstract
Background: Calf output is a key element in determining the profitability of a suckler beef enterprise. Infectious agents such as Bovine Virus Diarrhoea (BVD) virus, colostrum management and parasitic challenge can all affect calf output. Prior to the national BVD eradication programme, there was little published information on either the prevalence or effect of BVD in Irish beef herds. There is little published information on colostrum management practices in Irish commercial beef herds and there have also been few studies published on the prevalence of liver fluke or rumen fluke infection in Irish beef herds. Sixteen farms participating in the Teagasc/Farmers Journal BETTER farm beef programme were used in this study. Fourteen herds were screened for the presence of BVD virus in 2010 using RT-PCR. In 13 herds, blood samples were collected from calves (2-14 days of age) in November 2011 - April 2012 to determine their passive immune status using the zinc sulphate turbidity (ZST) test, while in 12 herds, blood and faecal samples were taken in order to determine the level of exposure to gastrointestinal and hepatic helminths., Results: The overall prevalence of BVD virus-positive cattle was 0.98% (range 0 - 3% per herd, range 0.6 - 3.0% per positive herd). Eighteen of the 82 calves (22%) sampled had ZST values less than 20 units (herd mean range 17.0 - 38.5 units) indicating a failure of passive transfer. The overall animal-level (herd-level) prevalence of liver fluke and rumen fluke infection in these herds was 40.5% (100%) and 20.8% (75%), respectively., Conclusions: The potential costs associated with the presence of animals persistently infected with BVD virus through the increased use of antibiotics; the rate of failure of passive transfer of colostral immunoglobulins and the high prevalence of liver fluke infection in these herds highlight that some Irish suckler beef farms may not be realizing their economic potential due to a range of herd health issues. The use of farm-specific herd health plans should be further encouraged on Irish suckler beef farms.
- Published
- 2015
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45. Effect of feeding colostrum at different volumes and subsequent number of transition milk feeds on the serum immunoglobulin G concentration and health status of dairy calves.
- Author
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Conneely M, Berry DP, Murphy JP, Lorenz I, Doherty ML, and Kennedy E
- Subjects
- Animal Feed analysis, Animal Nutritional Physiological Phenomena, Animals, Cattle growth & development, Dose-Response Relationship, Drug, Female, Cattle physiology, Colostrum metabolism, Diet veterinary, Health Status, Immunoglobulin G blood, Milk metabolism, Weight Gain
- Abstract
Transfer of sufficient IgG to the newborn calf via colostrum is vital to provide it with adequate immunological protection and resistance to disease. The objectives of the present study were to compare serum IgG concentration and health parameters of calves (1) fed different volumes of colostrum [7, 8.5, or 10% of body weight (BW)] within 2h of birth and (2) given 0, 2, or 4 subsequent feedings of transition milk (i.e., milkings 2 to 6 postcalving). Ninety-nine dairy calves were fed 7, 8.5, or 10% of BW in colostrum within 2h of birth and given 0, 2, or 4 subsequent feedings of transition milk. The concentration of IgG in the serum of calves was measured at 24, 48, 72, and 642 h of age by an ELISA. The apparent efficiency of absorption for IgG was determined. Health scores were assigned to calves twice per week and all episodes of disease were recorded. The effect of experimental treatment on calf serum IgG concentration differed by the age of the calf. Calves fed 8.5% of BW in colostrum had a greater mean serum IgG concentration than calves fed 7 or 10% of BW at 24, 48, and 72 h of age. At 642 h of age, serum IgG concentrations of calves fed 8.5% of BW (24.2g/L) and calves fed 10% of BW (21.6g/L) did not differ, although the serum IgG concentration of calves fed 8.5% of BW was still greater than that of calves fed 7% of BW (20.7 g/L). No difference in serum IgG concentration existed between calves fed 7% of BW and those fed 10% of BW at any age. No significant effect of number of subsequent feedings of transition milk on calf serum IgG concentration was detected. The apparent efficiency of absorption of calves fed 8.5% of BW in colostrum (38%) was greater than calves fed 7% of BW in colostrum (26%) and tended to be greater than in calves fed 10% of BW (29%). Calves fed further feedings of transition milk after the initial feeding of colostrum had a lower odds (0.62; 95% confidence interval: 0.41 to 0.93) of being assigned a worse eye/ear score (i.e., a more copious ocular discharge or pronounced ear droop) and a lower odds (0.5; 95% confidence interval: 0.32 to 0.79) of being assigned a worse nasal score (i.e., a more copious and purulent nasal discharge) during the study period relative to calves that received no further feedings of transition milk. In conclusion, calves fed 8.5% of BW in colostrum within 2h of birth achieved a greater concentration of IgG in serum in the first 3 d of life than calves fed either 7 or 10% of BW. Feeding calves transition milk subsequently reduced their odds of being assigned a worse eye/ear and nasal score., (Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)
- Published
- 2014
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46. Type 2 diabetes in a rapidly urbanizing region of Ghana, West Africa: a qualitative study of dietary preferences, knowledge and practices.
- Author
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Doherty ML, Owusu-Dabo E, Kantanka OS, Brawer RO, and Plumb JD
- Subjects
- Adult, Aged, Female, Focus Groups, Ghana, Health Education, Humans, Male, Middle Aged, Regional Health Planning, Urbanization, Caregivers, Diabetes Mellitus, Type 2 prevention & control, Feeding Behavior, Health Knowledge, Attitudes, Practice
- Abstract
Background: Urban centers in Sub-Saharan Africa, such as Kumasi, Ghana, are especially impacted by the dual burden of infectious and non-communicable disease (NCD), including a rise in type 2 diabetes mellitus (T2DM) prevalence. To develop effective intervention programs, the World Health Organization recommends more research to better understand the relationship between food consumption and the escalation of non-communicable disease such as T2DM. This study provides qualitative information about current food knowledge, attitudes and practices among T2DM patients and their caregivers in the region of Kumasi, Ghana., Methods: In this qualitative study, three focus groups discussions of 30 persons total and 10 individual interviews were used to assess food preferences, knowledge, attitudes and practices of patients with T2DM as well as caregivers responsible for food preparation. Participants included both urban and rural dwellers. Hospital-based health talks were observed, a dietician was interviewed, and educational documents were collected. Themes were identified and coded using Nvivo10 software., Results: Findings suggest that messages regarding sweetened foods, fats, use of seasonings and meal timing are followed. However, confusion exists regarding the impact of fruits, food portioning, plantains and processed foods on health outcomes for diabetic patients. Results also revealed a problem-solving approach to increasing vegetable consumption, and a concern about unhealthy food preferences among younger generations., Conclusions: Education about the impact of commonly available carbohydrates on blood sugar should be emphasized; messaging on portion sizes and certain foods should be more consistent; the economic benefits of local vegetable consumption should be promoted; and a research-informed, T2DM prevention campaign should be developed specifically for younger generations.
- Published
- 2014
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47. Nematode control in spring-born suckler beef calves using targeted selective anthelmintic treatments.
- Author
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O'Shaughnessy J, Earley B, Mee JF, Doherty ML, Crosson P, Barrett D, Macrelli M, and de Waal T
- Subjects
- Animals, Animals, Suckling, Cattle, Cattle Diseases drug therapy, Feces parasitology, Female, Male, Nematode Infections drug therapy, Nematode Infections parasitology, Seasons, Weather, Anthelmintics therapeutic use, Cattle Diseases parasitology, Nematode Infections veterinary
- Abstract
As anthelmintic resistance is increasingly being reported in cattle worldwide, there is a need to explore alternative approaches to gastrointestinal nematode control in cattle. A novel approach is the use of targeted selective treatments (TST) where only individual animals are treated instead of the entire group. The study objective was to determine if anthelmintic usage could be reduced using a TST-based approach in rotationally grazed first-grazing season suckler beef calves without affecting calf performance. Eighty-eight spring-born suckler beef calves, naïve to anthelmintics, with an initial mean (s.d.) age and live weight of 159 (22.4) days and 221 (42.4) kg, respectively, were used. All calves were vaccinated at pasture against dictyocaulosis at 8 and 12 weeks old. On August 9th 2013 (Week 0), when the trial began, calves were randomised by age, weight, sex, dam breed and sire breed to one of two treatments: (1) standard treatment (positive control) (n=44) and (2) TST (n=44). Samples collected one week prior to the start of the study were used as baseline covariates. Each treatment group was replicated once. All calves in the control groups were treated subcutaneously with levamisole on Week 0 and on Week 6. Individual calves in the TST groups were only eligible for treatment at pasture with the same product if predetermined thresholds were reached [plasma pepsinogen ≥ 2.0 international units of tyrosine/litre and faecal egg count ≥ 200 eggs per gram of faeces]. The trial concluded at housing on Week 13. Data were analysed using repeated measures mixed models ANOVA (PROC MIXED) (SAS 9.3). No calves in the TST groups were treated for gastrointestinal nematodes during the study period as they did not reach pre-determined treatment thresholds. Mean (sem) calf daily live weight gain for control and TST groups was 0.90 (±0.04) and 0.92 (±0.03) kg, respectively (P=0.68). Using an ELISA to detect antibodies to Dictyocaulus viviparus at Week 11, 81% of calves were seropositive. Gastrointestinal nematode challenge in spring-born suckler beef calves under these conditions can potentially be controlled with minimal anthelmintic treatments whilst not significantly impairing calf performance, provided appropriate control measures are taken to prevent dictyocaulosis from occurring., (Copyright © 2014 Elsevier B.V. All rights reserved.)
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- 2014
- Full Text
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48. Aspects of bovine herpesvirus 1 and bovine viral diarrhoea virus herd-level seroprevalence and vaccination in dairy and beef herds in Northern Ireland.
- Author
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Cowley DJ, Graham DA, Guelbenzu M, Doherty ML, and More SJ
- Abstract
Background: Infections with bovine herpesvirus 1 (BoHV-1) and bovine viral diarrhoea (BVD) virus cause diseases of cattle with a worldwide distribution. The primary objective of the present study was to describe aspects of herd-level BoHV-1 and BVDV seroprevalence (based on testing of pooled sera) and control on farms in Northern Ireland, including vaccine usage. An indirect antibody ELISA test (SVANOVA, Biotech AB, Uppsala, Sweden) was applied to serum pools which were constructed from serum samples taken for a cross-sectional study of a convenience sample of 500 Northern Irish dairy and beef cow herds in 2010, for which vaccination status was determined by telephone survey. The herd-level seroprevalence of BoHV-1 and BVDV in Northern Ireland was estimated in non-vaccinating herds and associations between possible risk factors (herd type and herd size (quartiles)) and herd-level prevalence were determined using chi-squared analysis., Results: The herd-level seroprevalence (of BoHV-1 and BVDV) in non-vaccinating herds was 77.3% (95% CI: 73.6-80.9%) and 98.4% (95% CI: 97.3-99.5%) respectively in the cross-sectional study. A significant difference existed in BoHV-1 herd-level seroprevalence between dairy and beef herds (74.7% vs 86.5% respectively; p < 0.02) though not for BVDV seroprevalence (98.5% vs 98.3% respectively; p > 0.91). A significant association was found between herd size (quartiles) and herd-level classification for BoHV-1 herd-level seroprevalence based on cut-off percentage positivity (COPP) (p < 0.01) while no such association was found for BVDV (p = 0.22). 15.5% and 23.8% of farmers used BoHV-1 and BVDV vaccines, respectively. BoHV-1 vaccine was used in 30% of dairy herds and in 11% of beef herds, while BVDV vaccine was used in 46% and 16% of dairy and beef herds, respectively., Conclusions: The results from this study indicate that the true herd-level seroprevalences to bovine herpesvirus 1 and bovine virus diarrhoea virus in non-vaccinating herds in Northern Northern Ireland are 77.3% (95% CI: 73.6-80.9%) and 98.4% (95% CI: 97.3-99.5%), respectively. The present study will assist in guiding regional policy development and establish a baseline against which the progress of current and future control and eradication programmes can be measured.
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- 2014
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49. Detection of anthelmintic resistance on two Irish beef research farms.
- Author
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O'Shaughnessy J, Earley B, Mee JF, Doherty ML, Crosson P, Barrett D, Prendiville R, Macrelli M, and de Waal T
- Subjects
- Animals, Anthelmintics therapeutic use, Cattle, Cattle Diseases parasitology, Feces parasitology, Helminthiasis, Animal parasitology, Helminths drug effects, Ireland, Male, Parasite Egg Count veterinary, Parasitic Sensitivity Tests veterinary, Anthelmintics pharmacology, Cattle Diseases drug therapy, Drug Resistance, Helminthiasis, Animal drug therapy
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- 2014
- Full Text
- View/download PDF
50. Development and review of the voluntary phase of a national BVD eradication programme in Ireland.
- Author
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Graham DA, Lynch M, Coughlan S, Doherty ML, O'Neill R, Sammin D, and O'Flaherty J
- Subjects
- Animals, Bovine Virus Diarrhea-Mucosal Disease epidemiology, Cattle, Ireland epidemiology, Program Development, Program Evaluation, Bovine Virus Diarrhea-Mucosal Disease prevention & control, Disease Eradication organization & administration, National Health Programs organization & administration, Voluntary Programs organization & administration
- Abstract
The voluntary phase of an industry-led national Bovine Viral Diarrhoea (BVD) eradication programme began in Ireland on January 1, 2012 with the goal of progressing to a compulsory programme in 2013. The development and implementation of the programme in 2012 was informed by a review of current and prior eradication programmes elsewhere in Europe and extensive stakeholder consultation. The programme was based on tissue tag testing of newborn calves in participating herds, with the status of the mothers of calves with positive or inconclusive results requiring clarification. Participating herd owners were required to comply with a series of guidelines, including not selling cattle suspected of being persistently infected. For herds compliant with the guidelines, the results from 2012 counted as one of three years of tag testing anticipated in the compulsory phase of the programme. Testing was carried out in laboratories designated for this purpose by the cross-industry BVD Implementation Group that oversees the programme. Results were reported to a central database managed by the Irish Cattle Breeding Federation, and the majority of results were reported to farmers' mobile telephones by SMS message. A detailed review of the programme was conducted, encompassing the period between January 1, 2012 and July 15, 2012, based on results from approximately 500,000 calves. This paper describes the establishment and structure of the programme, and the outcomes of the review, including findings at herd and animal level.
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- 2014
- Full Text
- View/download PDF
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