This review addresses the progress that has been made in ruminant health research over the last 6... more This review addresses the progress that has been made in ruminant health research over the last 60 yr, with an emphasis on Irish research. The review focuses on the economically important infectious diseases of dairy and beef cattle and of sheep, calf diseases, regulated and non-regulated infectious diseases, lameness, mastitis and parasitoses. The progress to date, current knowledge and future challenges are all addressed. Paradigm shifts have occurred in many of these diseases, the most profound of which is the change from increasing antimicrobial usage (AMU) to the realisation of the challenge of antimicrobial resistance (AMR) and the current reduction in AMU. Another major change in thinking is the move away from focus on the pathogen exclusively towards a more holistic view of the roles of host immunity and adequacy of management. In the last 60 yr, many new diseases have emerged but in parallel many new technologies have rapidly evolved to monitor and control these threats to ...
Background Bovine Viral Diarrhoea Virus (BVDV) infection remains endemic in many countries worldw... more Background Bovine Viral Diarrhoea Virus (BVDV) infection remains endemic in many countries worldwide. Ireland, in common with several other European counties, commenced an BVDV eradication programme in the last decade, Managing eradication programmes requires careful monitoring of diseases prevalence and understanding factors associated with disease exposure to ensure eradication programmes remain evidence based and tailored to the evolving epidemiological situation. Methods In this study, we explore the seroprevalence of BVDV exposure over a four-year period (2017 to 2020) in Ireland from a cohort of animals (n = 6,449) under 30 months of age sampled at slaughter, who were born subsequent to the commencement of a compulsory national eradication programme. Temporal trends and risk factor analysis were undertaken using multilevel logit regression models. Results There was a declining temporal trend in seroprevalence over the sample years of the study, and risk varied at both county- ...
ABSTRACTObjectivesThe aim of this study was to conduct a scoping review of estimates of the relat... more ABSTRACTObjectivesThe aim of this study was to conduct a scoping review of estimates of the relative infectiousness of asymptomatic persons infected with SARS-CoV-2 compared with symptomatic individuals.DesignRapid scoping review of literature available until 8thApril 2020.SettingInternational studies on the infectiousness of individuals infected with SARS-CoV-2ParticipantsStudies were selected for inclusion if they defined asymptomatics as a separate cohort distinct from pre-symptomatics and if they provided a quantitative measure of the infectiousness of asymptomatics relative to symptomatics.Primary outcome measuresThe relative number of secondary cases produced by an average primary case, the relative probability of transmitting infection upon contact, and the degree of viral shedding.ResultsVery few studies reported estimates of relative infectiousness of asymptomatic compared with symptomatic individuals. Significant differences exist in the definition of infectiousness. Viral...
A mandatory national Irish bovine viral diarrhoea (BVD) eradication programme, coordinated by Ani... more A mandatory national Irish bovine viral diarrhoea (BVD) eradication programme, coordinated by Animal Health Ireland, commenced in 2013. Key decisions and programme review are undertaken by a cross-industry Implementation Group (BVDIG) supported by a Technical Working Group. Ear notch tissue is collected from all new-born calves using modified official identity tags, supplemented by additional blood sampling, including for confirmatory testing of calves with initial positive results and testing of their dams. Testing is delivered by private laboratories in conjunction with the National Reference Laboratory, with all results reported to a central database. This database manages key elements of the programme, issuing results to herdowners by short message service messaging supplemented by letters; assigning and exchanging animal-level statuses with government databases of the Department of Agriculture, Food and the Marine to enable legislated restrictions on animal movements; assigning...
ObjectivesCoronavirus disease (COVID-19) caused by the SARS-CoV-2 virus is spreading rapidly worl... more ObjectivesCoronavirus disease (COVID-19) caused by the SARS-CoV-2 virus is spreading rapidly worldwide and threatening the collapse of national health care systems. The development of effective resource models are critical for long term health planning. The aim was to evaluate the available literature, to consider parameters affecting hospital resources, to effectively guide health policy and planning for future waves of infection.DesignA detailed search of the literature, using Google Scholar, PubMED, MedRxiv and BioRxiv, was conducted for the time period 1stDec 2019 to 31stMay 2020; using appropriate keywords: resultant articles were scrutinised in detail, and appraised for reported data pertaining to hospitalization and hospital length of stay (LOS).ResultsDisease presentation was described in China; 81 % mild, 14 % moderate and 5 % severe. The experience, thus far, in Europe and the USA are suggestive of a higher degree of severity. Initial reports suggest high hospitalisation a...
ObjectivesOur objective was to review the literature on the inferred duration of the infectious p... more ObjectivesOur objective was to review the literature on the inferred duration of the infectious period of COVID-19, caused by SARS-COV-2 virus, and provide an overview of the variation depending on the methodological approach.DesignRapid scoping review. Literature review with fixed search terms, up to 1st April 2020. Central tendency and variation of the parameter estimates for infectious period in (a) asymptomatic (b) symptomatic cases from (i) virological studies (repeated testing), (ii) tracing studies (iii) modelling studies were gathered. Narrative review of viral dynamics.Information sourcesSearch strategies developed and the following searched: PubMed, Google Scholar, MedRxiv, BioRxiv. Additionally, the Health Information Quality Authority (Ireland) viral load synthesis was utilised, which screened literature from PubMed, Embase, ScienceDirect, NHS evidence, Cochrane, medRxiv and bioRxiv, HRB open databases.ResultsThere was substantial variation in the estimates, and how infe...
ABSTRACTBackgroundReliable estimates of the incubation period are important for decision making a... more ABSTRACTBackgroundReliable estimates of the incubation period are important for decision making around the control of infectious diseases. Knowledge of the incubation period distribution can be used directly to inform decision-making or as inputs into mathematical models.ObjectivesThe aim of this study was to conduct a rapid systematic review and meta-analysis of estimates of the incubation periods of COVID-19.DesignRapid systematic review and meta-analysis of observational researchData sourcesPublications on the electronic databases PubMed, Google Scholar, MedRxiv and BioRxiv were searched. The search was not limited to peer-reviewed published data, but also included pre-print articles.Study appraisal and synthesis methodsStudies were selected for meta-analysis if they reported either the parameters and confidence intervals of the distributions fit to the data, or sufficient information to facilitate calculation of those values. The majority of studies suitable for inclusion in the...
ObjectiveTo estimate the proportion of pre-symptomatic transmission of SARS-CoV-2 infection that ... more ObjectiveTo estimate the proportion of pre-symptomatic transmission of SARS-CoV-2 infection that can occur and timing of transmission relative to symptom onset.Setting/designSecondary analysis of international published data.Data sourcesMeta-analysis of COVID-19 incubation period and a rapid systematic review of serial interval and generation time, which are published separately.ParticipantsStudies were selected for analysis if they had transparent methods and data sources and they provided enough information to simulate full distributions of serial interval or generation time. Twenty-three estimates of serial interval and five of generation time from 17 publications were included.MethodsSimulations were generated of incubation period and of serial interval or generation time. From these, transmission times relative to symptom onset were calculated and the proportion of pre-symptomatic transmission was estimated.Outcome measuresTransmission time of SARS-CoV-2 relative to symptom ons...
Many ruminants are solely or mostly dependant for their nutrients, including essential elements, ... more Many ruminants are solely or mostly dependant for their nutrients, including essential elements, on the forage available to them, either in its natural state or conserved as hay or silage. A soil and herbage survey was carried out in April and September 2007, in a 3.1 km×3.0 km grid, incorporating 106 and 46 sampling points, respectively, on the Castlecomer Plateau, Co. Kilkenny, Ireland. The aim was to determine the nutrient and heavy metal status of soil and herbage in the sampling area, and to examine the concentrations observed for their potential to impact on animal performance. Low soil pH and high soil lime requirements were identified within the sampling area. The concentrations of Ca, Cu, Se and Zn were low in both soil and herbage. These conditions are similar to those found on other farms in Ireland. Fluoride was detected in 61 of the 97 herbage samples in April 2007, but only four exceeded 40 mg/kg dry matter, the maximum tolerable level for cattle. Mineral imbalances (C...
Problem-based learning (PBL) replicates life experiences to stimulate learning, the integration o... more Problem-based learning (PBL) replicates life experiences to stimulate learning, the integration of knowledge, and lifelong learning skills, all of which are requirements for veterinary medical education. As the curricular content of veterinary schools expands to immense proportions following advances in medical knowledge and biotechnology, it becomes impracticable to ensure that all students at the beginning of their careers have such a wide knowledge base. Students who are faced with vast amounts of information to learn by rote, much of which may seem irrelevant to their prospective career, may become disillusioned with their chosen course, hence the temptation to convert to a PBL curriculum. The PBL strategy of teaching is becoming increasingly popular in veterinary faculties worldwide, encompassing both curriculum content and a process of learning. In PBL, clinical cases are carefully selected to provoke deep student learning by the acquisition of both basic scientific and clinic...
Uterine bacterial infection after parturition causes endometritis, perturbs ovarian function and ... more Uterine bacterial infection after parturition causes endometritis, perturbs ovarian function and leads to infertility in cattle. Although endometritis is caused by mixed infections, endometrial pathology is associated with the presence of Arcanobacterium pyogenes. The aims of the present study were to determine the effects of A. pyogenes on endometrial function in vitro, and on uterine and ovarian function in vivo. Heat-killed A. pyogenes did not affect the production of prostaglandin F2alpha (PGF) or prostaglandin E(2) (PGE) from endometrial explants, or purified populations of endometrial epithelial or stromal cells. However, the explants produced more PGF and PGE than controls when treated with a bacteria-free filtrate (BFF) cultured from A. pyogenes. Similarly, BFF stimulated PGF and PGE production by epithelial and stromal cells, respectively. So, BFF or control PBS was infused into the uterus of heifers (n=7 per group) for 8 days, starting the day after estrus. Emergence of th...
ABSTRACT Key factors affecting fertility in seasonal-calving Irish dairy herds EA Lane 1, MA Crow... more ABSTRACT Key factors affecting fertility in seasonal-calving Irish dairy herds EA Lane 1, MA Crowe 1, S Coughlan 2, SJ More 1 1 School of Veterinary Medicine, University College Dublin, Ireland and 2 Irish Cattle Breeding Federation, Bandon, Co. Cork, Ireland Development of a national strategy to improve dairy herd reproductive performance should be based on the analysis of current performance. To determine the relative importance of herd, cow and management factors on reproductive indices in Irish seasonal-calving dairy herds, breeding records for 71,273 cows in 920 herds were collected in 2009. After accounting for the heirarchical nature of the data, backward-stepwise multivariate logistic regression analysis was performed to determine the relative effect of cow, herd and management factors on key reproductive indices. Mean (± SEM) 6-week and 12-week pregnancy rates were 47 % (± 0.19) and 64 % (± 0.18), respectively. Estimated breeding value (fertility; P < 0.001), average somatic cell count (P < 0.001), age (P < 0.001), timing of calving relative to start of breeding season (P < 0.001), herd oestrous detection efficiency (P < 0.001), a history of abnormal repeat intervals (P < 0.001) and length of post partum interval (P < 0.001) were each associated with a lowered 6-week pregnancy rate. The existing spread in calving and the quality of oestrous detection were the most influential factors, along with the duration of the voluntary waiting period, in reducing fertility performance in seasonal-calving dairy herds.
In Ireland, an estimated 15% of Irish soils exceed the EU threshold limit for soil Cd of 1mg/kg. ... more In Ireland, an estimated 15% of Irish soils exceed the EU threshold limit for soil Cd of 1mg/kg. The aim was to determine the concentrations of Cd and other heavy metals (As, Hg and Pb) in kidneys collected from cattle at slaughter. Systematic sampling of eligible animals (animals that were born and reared until slaughter in the same Irish county) at the time of slaughter was conducted, until a threshold number of animals from all 26 counties and 6 age categories was reached. A predictive surface of soil Cd was generated, by kriging the Cd values of 1310 previously reported soil samples. A linear regression weighted model was developed to model kidney Cd concentration, using the risk factors of age, sex, breed, province and estimated soil Cd concentration. Kidney Cd (n=393) concentrations varied between 0.040 and 8.630 mg/kg wet weight; while concentrations of As, Hg and Pb were low. The estimated weighted proportion of animals with a high (≥1 mg/kg) kidney Cd concentration was 11.2...
This review addresses the progress that has been made in ruminant health research over the last 6... more This review addresses the progress that has been made in ruminant health research over the last 60 yr, with an emphasis on Irish research. The review focuses on the economically important infectious diseases of dairy and beef cattle and of sheep, calf diseases, regulated and non-regulated infectious diseases, lameness, mastitis and parasitoses. The progress to date, current knowledge and future challenges are all addressed. Paradigm shifts have occurred in many of these diseases, the most profound of which is the change from increasing antimicrobial usage (AMU) to the realisation of the challenge of antimicrobial resistance (AMR) and the current reduction in AMU. Another major change in thinking is the move away from focus on the pathogen exclusively towards a more holistic view of the roles of host immunity and adequacy of management. In the last 60 yr, many new diseases have emerged but in parallel many new technologies have rapidly evolved to monitor and control these threats to ...
Background Bovine Viral Diarrhoea Virus (BVDV) infection remains endemic in many countries worldw... more Background Bovine Viral Diarrhoea Virus (BVDV) infection remains endemic in many countries worldwide. Ireland, in common with several other European counties, commenced an BVDV eradication programme in the last decade, Managing eradication programmes requires careful monitoring of diseases prevalence and understanding factors associated with disease exposure to ensure eradication programmes remain evidence based and tailored to the evolving epidemiological situation. Methods In this study, we explore the seroprevalence of BVDV exposure over a four-year period (2017 to 2020) in Ireland from a cohort of animals (n = 6,449) under 30 months of age sampled at slaughter, who were born subsequent to the commencement of a compulsory national eradication programme. Temporal trends and risk factor analysis were undertaken using multilevel logit regression models. Results There was a declining temporal trend in seroprevalence over the sample years of the study, and risk varied at both county- ...
ABSTRACTObjectivesThe aim of this study was to conduct a scoping review of estimates of the relat... more ABSTRACTObjectivesThe aim of this study was to conduct a scoping review of estimates of the relative infectiousness of asymptomatic persons infected with SARS-CoV-2 compared with symptomatic individuals.DesignRapid scoping review of literature available until 8thApril 2020.SettingInternational studies on the infectiousness of individuals infected with SARS-CoV-2ParticipantsStudies were selected for inclusion if they defined asymptomatics as a separate cohort distinct from pre-symptomatics and if they provided a quantitative measure of the infectiousness of asymptomatics relative to symptomatics.Primary outcome measuresThe relative number of secondary cases produced by an average primary case, the relative probability of transmitting infection upon contact, and the degree of viral shedding.ResultsVery few studies reported estimates of relative infectiousness of asymptomatic compared with symptomatic individuals. Significant differences exist in the definition of infectiousness. Viral...
A mandatory national Irish bovine viral diarrhoea (BVD) eradication programme, coordinated by Ani... more A mandatory national Irish bovine viral diarrhoea (BVD) eradication programme, coordinated by Animal Health Ireland, commenced in 2013. Key decisions and programme review are undertaken by a cross-industry Implementation Group (BVDIG) supported by a Technical Working Group. Ear notch tissue is collected from all new-born calves using modified official identity tags, supplemented by additional blood sampling, including for confirmatory testing of calves with initial positive results and testing of their dams. Testing is delivered by private laboratories in conjunction with the National Reference Laboratory, with all results reported to a central database. This database manages key elements of the programme, issuing results to herdowners by short message service messaging supplemented by letters; assigning and exchanging animal-level statuses with government databases of the Department of Agriculture, Food and the Marine to enable legislated restrictions on animal movements; assigning...
ObjectivesCoronavirus disease (COVID-19) caused by the SARS-CoV-2 virus is spreading rapidly worl... more ObjectivesCoronavirus disease (COVID-19) caused by the SARS-CoV-2 virus is spreading rapidly worldwide and threatening the collapse of national health care systems. The development of effective resource models are critical for long term health planning. The aim was to evaluate the available literature, to consider parameters affecting hospital resources, to effectively guide health policy and planning for future waves of infection.DesignA detailed search of the literature, using Google Scholar, PubMED, MedRxiv and BioRxiv, was conducted for the time period 1stDec 2019 to 31stMay 2020; using appropriate keywords: resultant articles were scrutinised in detail, and appraised for reported data pertaining to hospitalization and hospital length of stay (LOS).ResultsDisease presentation was described in China; 81 % mild, 14 % moderate and 5 % severe. The experience, thus far, in Europe and the USA are suggestive of a higher degree of severity. Initial reports suggest high hospitalisation a...
ObjectivesOur objective was to review the literature on the inferred duration of the infectious p... more ObjectivesOur objective was to review the literature on the inferred duration of the infectious period of COVID-19, caused by SARS-COV-2 virus, and provide an overview of the variation depending on the methodological approach.DesignRapid scoping review. Literature review with fixed search terms, up to 1st April 2020. Central tendency and variation of the parameter estimates for infectious period in (a) asymptomatic (b) symptomatic cases from (i) virological studies (repeated testing), (ii) tracing studies (iii) modelling studies were gathered. Narrative review of viral dynamics.Information sourcesSearch strategies developed and the following searched: PubMed, Google Scholar, MedRxiv, BioRxiv. Additionally, the Health Information Quality Authority (Ireland) viral load synthesis was utilised, which screened literature from PubMed, Embase, ScienceDirect, NHS evidence, Cochrane, medRxiv and bioRxiv, HRB open databases.ResultsThere was substantial variation in the estimates, and how infe...
ABSTRACTBackgroundReliable estimates of the incubation period are important for decision making a... more ABSTRACTBackgroundReliable estimates of the incubation period are important for decision making around the control of infectious diseases. Knowledge of the incubation period distribution can be used directly to inform decision-making or as inputs into mathematical models.ObjectivesThe aim of this study was to conduct a rapid systematic review and meta-analysis of estimates of the incubation periods of COVID-19.DesignRapid systematic review and meta-analysis of observational researchData sourcesPublications on the electronic databases PubMed, Google Scholar, MedRxiv and BioRxiv were searched. The search was not limited to peer-reviewed published data, but also included pre-print articles.Study appraisal and synthesis methodsStudies were selected for meta-analysis if they reported either the parameters and confidence intervals of the distributions fit to the data, or sufficient information to facilitate calculation of those values. The majority of studies suitable for inclusion in the...
ObjectiveTo estimate the proportion of pre-symptomatic transmission of SARS-CoV-2 infection that ... more ObjectiveTo estimate the proportion of pre-symptomatic transmission of SARS-CoV-2 infection that can occur and timing of transmission relative to symptom onset.Setting/designSecondary analysis of international published data.Data sourcesMeta-analysis of COVID-19 incubation period and a rapid systematic review of serial interval and generation time, which are published separately.ParticipantsStudies were selected for analysis if they had transparent methods and data sources and they provided enough information to simulate full distributions of serial interval or generation time. Twenty-three estimates of serial interval and five of generation time from 17 publications were included.MethodsSimulations were generated of incubation period and of serial interval or generation time. From these, transmission times relative to symptom onset were calculated and the proportion of pre-symptomatic transmission was estimated.Outcome measuresTransmission time of SARS-CoV-2 relative to symptom ons...
Many ruminants are solely or mostly dependant for their nutrients, including essential elements, ... more Many ruminants are solely or mostly dependant for their nutrients, including essential elements, on the forage available to them, either in its natural state or conserved as hay or silage. A soil and herbage survey was carried out in April and September 2007, in a 3.1 km×3.0 km grid, incorporating 106 and 46 sampling points, respectively, on the Castlecomer Plateau, Co. Kilkenny, Ireland. The aim was to determine the nutrient and heavy metal status of soil and herbage in the sampling area, and to examine the concentrations observed for their potential to impact on animal performance. Low soil pH and high soil lime requirements were identified within the sampling area. The concentrations of Ca, Cu, Se and Zn were low in both soil and herbage. These conditions are similar to those found on other farms in Ireland. Fluoride was detected in 61 of the 97 herbage samples in April 2007, but only four exceeded 40 mg/kg dry matter, the maximum tolerable level for cattle. Mineral imbalances (C...
Problem-based learning (PBL) replicates life experiences to stimulate learning, the integration o... more Problem-based learning (PBL) replicates life experiences to stimulate learning, the integration of knowledge, and lifelong learning skills, all of which are requirements for veterinary medical education. As the curricular content of veterinary schools expands to immense proportions following advances in medical knowledge and biotechnology, it becomes impracticable to ensure that all students at the beginning of their careers have such a wide knowledge base. Students who are faced with vast amounts of information to learn by rote, much of which may seem irrelevant to their prospective career, may become disillusioned with their chosen course, hence the temptation to convert to a PBL curriculum. The PBL strategy of teaching is becoming increasingly popular in veterinary faculties worldwide, encompassing both curriculum content and a process of learning. In PBL, clinical cases are carefully selected to provoke deep student learning by the acquisition of both basic scientific and clinic...
Uterine bacterial infection after parturition causes endometritis, perturbs ovarian function and ... more Uterine bacterial infection after parturition causes endometritis, perturbs ovarian function and leads to infertility in cattle. Although endometritis is caused by mixed infections, endometrial pathology is associated with the presence of Arcanobacterium pyogenes. The aims of the present study were to determine the effects of A. pyogenes on endometrial function in vitro, and on uterine and ovarian function in vivo. Heat-killed A. pyogenes did not affect the production of prostaglandin F2alpha (PGF) or prostaglandin E(2) (PGE) from endometrial explants, or purified populations of endometrial epithelial or stromal cells. However, the explants produced more PGF and PGE than controls when treated with a bacteria-free filtrate (BFF) cultured from A. pyogenes. Similarly, BFF stimulated PGF and PGE production by epithelial and stromal cells, respectively. So, BFF or control PBS was infused into the uterus of heifers (n=7 per group) for 8 days, starting the day after estrus. Emergence of th...
ABSTRACT Key factors affecting fertility in seasonal-calving Irish dairy herds EA Lane 1, MA Crow... more ABSTRACT Key factors affecting fertility in seasonal-calving Irish dairy herds EA Lane 1, MA Crowe 1, S Coughlan 2, SJ More 1 1 School of Veterinary Medicine, University College Dublin, Ireland and 2 Irish Cattle Breeding Federation, Bandon, Co. Cork, Ireland Development of a national strategy to improve dairy herd reproductive performance should be based on the analysis of current performance. To determine the relative importance of herd, cow and management factors on reproductive indices in Irish seasonal-calving dairy herds, breeding records for 71,273 cows in 920 herds were collected in 2009. After accounting for the heirarchical nature of the data, backward-stepwise multivariate logistic regression analysis was performed to determine the relative effect of cow, herd and management factors on key reproductive indices. Mean (± SEM) 6-week and 12-week pregnancy rates were 47 % (± 0.19) and 64 % (± 0.18), respectively. Estimated breeding value (fertility; P < 0.001), average somatic cell count (P < 0.001), age (P < 0.001), timing of calving relative to start of breeding season (P < 0.001), herd oestrous detection efficiency (P < 0.001), a history of abnormal repeat intervals (P < 0.001) and length of post partum interval (P < 0.001) were each associated with a lowered 6-week pregnancy rate. The existing spread in calving and the quality of oestrous detection were the most influential factors, along with the duration of the voluntary waiting period, in reducing fertility performance in seasonal-calving dairy herds.
In Ireland, an estimated 15% of Irish soils exceed the EU threshold limit for soil Cd of 1mg/kg. ... more In Ireland, an estimated 15% of Irish soils exceed the EU threshold limit for soil Cd of 1mg/kg. The aim was to determine the concentrations of Cd and other heavy metals (As, Hg and Pb) in kidneys collected from cattle at slaughter. Systematic sampling of eligible animals (animals that were born and reared until slaughter in the same Irish county) at the time of slaughter was conducted, until a threshold number of animals from all 26 counties and 6 age categories was reached. A predictive surface of soil Cd was generated, by kriging the Cd values of 1310 previously reported soil samples. A linear regression weighted model was developed to model kidney Cd concentration, using the risk factors of age, sex, breed, province and estimated soil Cd concentration. Kidney Cd (n=393) concentrations varied between 0.040 and 8.630 mg/kg wet weight; while concentrations of As, Hg and Pb were low. The estimated weighted proportion of animals with a high (≥1 mg/kg) kidney Cd concentration was 11.2...
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