Comparison between dairy cow disease incidence in data registered by farmers and in data from a disease-recording system based on veterinary reporting

Evaluation of multifactorial digestive disorders in a dairy herd at different stages of lactation

The manager of a large dairy herd (total confinement, total mixed ration feeding, 10130 kg milk sold per cow and year) requested a workup of a digestive disorder problem that had been ongoing for several years. The cows were at all stages of lactation, and the incidence proportion (events/100 cows at risk) of digestive disorders was approximately 5 to 10%. The clinical picture included an abnormal demeanor of varying severity and signs that differed among the cows. The latter included decreased milk production and physical activity, low body condition score, abnormal rumen motility and stratification, small intestinal dilatation, diarrhea, undigested fiber particles in the feces, fever and abdominal pain.The following approach was used to investigate the digestive disorder problem:1. The herd was assessed for production levels, housing requirements, feeding protocols and animal health management. The latter comprised evaluation of different animal scores, metabolic profile analysis, diagnosis of disease, culling records and slaughter data. The results revealed risk factors concerning the feeding and animal health monitoring, (e. g. in dry matter intake and silage quality management, disease detection and diagnosis in fresh cows). The assessment also identified a high occurrence of digestive disorders of unknown origin.2. Fifteen cows that represented the ongoing digestive disorder problem were selected to undergo clinical examination, hematological analysis, urinalysis, and ultrasonography of the ventral abdomen. The clinical examinations revealed different digestive disorders, which were mainly inflammatory in nature, in all the cows. Eight cows had localized reticuloperitonitis and 13 had left displaced abomasum with different degrees of displacement and adhesions between the abomasum and reticulum attributable to reticuloperitonitis.Our results revealed a multifactorial problem caused by several risk factors relating to animal health and feeding management protocols that resulted in different types of digestive disorders. The wires from damaged tires used to hold the pit silo tarps in place were identified as a possible traumatic cause of the reticuloperitonitis. Treatment, prevention and follow-up of the different conditions were discussed.

Recording of calf diseases for potential use in breeding programs: a case study on calf respiratory illness and diarrhea

Calf diseases remain a challenge for dairy producers from both an economic and welfare perspective. Genetically selecting for disease resistance in calves is a promising approach that could contribute to sustainable dairy farming. Genetic evaluations, however, require well-defined and consistently recorded phenotypes to be successful. Therefore, this study aimed to understand the current state of calf disease recording on Ontario farms. Calf disease records of respiratory illness and diarrhea were available from the national milk recording organization (Lactanet Canada, Guelph, Ontario, Canada) from 2009 to 2020. A case study was conducted to describe calf disease diagnoses and recording practices by surveying a subset of 13 Ontario dairy producers. The percentage of milk recorded farms that recorded calf respiratory illness and calf diarrhea increased from 2.6% in 2009 to 11.1% in 2020. Potential sources of data loss were identified along the information chain from farm to genetic evaluation database. Clear definitions and thresholds to diagnose calf disease, standard operating procedures for data recording, as well as a data transfer pipeline, which includes exchange formats, are needed to facilitate the inclusion of calf health traits in genetic evaluations.

Towards a Framework for High-Performance Simulation of Livestock Disease Outbreak: A Case Study of Spread of African Swine Fever in Vietnam

Simple Summary

Disease transmission simulation programs in veterinary epidemiology in general and in simulation of African swine fever in particular are often very diverse and require great computing power. However, such programs often share similar workflows from processing input/output data, performing simulations, or storing data. Our paper proposes a common architectural framework for livestock disease transmission simulation programs in order to both improve simulation performance and reduce the effort of developing new simulation programs. Our framework was evaluated with a simulation program of African swine fever transmission currently raging in Vietnam and some other countries around the world. The results from the evaluation experiments not only demonstrate the effectiveness of the framework in terms of performance but also have practical consulting value for decision makers in Vietnam and for international colleagues.

Abstract

The spread of disease in livestock is an important research topic of veterinary epidemiology because it provides warnings or advice to organizations responsible for the protection of animal health in particular and public health in general. Disease transmission simulation programs are often deployed with different species, disease types, or epidemiological models, and each research team manages its own set of parameters relevant to their target diseases and concerns, resulting in limited cooperation and reuse of research results. Furthermore, these simulation and decision support tools often require a large amount of computational power, especially for models involving tens of thousands of herds with millions of individuals spread over a large geographical area such as a region or a country. It is a matter of fact that epidemic simulation programs are often heterogeneous, but they often share some common workflows including processing of input data and execution of simulation, as well as storage, analysis, and visualization of results. In this article, we propose a novel architectural framework for simultaneously deploying any epidemic simulation program both on premises and on the cloud to improve performance and scalability. We also conduct some experiments to evaluate the proposed architectural framework on some aspects when applying it to simulate the spread of African swine fever in Vietnam.

Factors influencing the performance of voluntary farmer disease reporting in passive surveillance systems: A scoping review

The impacts of exotic disease incursions on livestock industries can be mitigated by having robust surveillance systems in place that decrease the time between disease introduction and detection. An important component of this is having farmers routinely observe their animals for indications of clinical disease, recognise the existence of problems, and then decide to notify their veterinarian or animal health authorities. However, as highlighted by this literature review, farmers are believed to be underreporting clinical events due to factors such as (1) uncertainty around the clinical signs and situations that warrant reporting, (2) fear over the social and economic consequences from both positive and false positive reports, (3) negative beliefs regarding the efficacy and outcomes of response measures, (4) mistrust and dissatisfaction with animal health authorities, (5) absence of sufficiently attractive financial and non-financial incentives for submitting reports, and (6) poor awareness of the procedures involved with the submission, processing, and response to reports. There have been few formal studies evaluating the efficacy of different approaches to increasing farmer engagement with disease reporting. However, there is a recognised need for any proposed solutions to account for farmer knowledge and experience with assessing their own farm situation as well as the different identities, motivations, and beliefs that farmers have about their role in animal health surveillance systems. Empowering farmers to take a more active role in developing these solutions is likely to become even more important as animal health authorities increasingly look to establish public-private partnerships for biosecurity governance.

Potential and Challenges of Community-Based Surveillance in Animal Health: A Pilot Study Among Equine Owners in Switzerland

Animal owners' potential to observe and report clinical signs, as the persons with the closest contact to their animals, is an often neglected source of information in surveillance. Allowing community members other than health care professionals, such as animal owners, to report health events can contribute to close current surveillance gaps and enhance early detection. In the present study, we tested a community-based surveillance (CBS) approach in the equine community in Switzerland. We aimed at revealing the attitudes and intentions of equine owners toward reporting clinical signs by making use of an online questionnaire. We further set up and operated an online CBS tool, named Equi-Commun. Finally, we investigated potential reasons for the lack of its use by applying qualitative telephone interviews. The majority of the respondents of the online questionnaire (65.5%, 707/1,078) answered that they could see themselves reporting clinical observations of their equine. The multivariate logistic regression analysis indicated that French-speaking equine owners and those belonging to the positive attitude cluster are more likely to report to a CBS tool. Equi-Commun operated between October 2018 and December 2019 yet received only four reports. With the addition of qualitative interviews, we identified three critical, interlinked issues that may have led to the non-use of Equi-Commun within the Swiss equine community: (1) for successfully implementing CBS, the need for surveillance within the community of interest must be given; (2) the respective population under surveillance, here the equine, needs to show enough clinical cases for owners to be able to maintain the memory of an existing tool and its possible use; and (3) targeted and high effort communication of the system is key for its success. While CBS relying only on lay animal owners, complementary to existing surveillance systems, could potentially provide a good proxy of timely surveillance data, it is questionable whether the added value of generated surveillance knowledge is in balance with efforts necessary to implement a successful system. With this study, we showcased both the potential and challenges of CBS in animal health, as this may be of relevance and guidance for future initiatives.

Associations between Bovine Coronavirus and Bovine Respiratory Syncytial Virus Infections and Productivity, Health Status and Occurrence of Antimicrobial Resistance in Swedish Dairy Herds

Bovine respiratory syncytial virus (BRSV) and bovine coronavirus (BCoV) affect dairy herds worldwide. In this study, effects on herd health, morbidity, and antimicrobial resistance (AMR) were assessed. Herds were considered free of infection (FREE), recently infected (RI) or past steadily infected (PSI) based on antibody testing of milk from primiparous cows. Data from farm records, national databases, and AMR of fecal Escherichia coli from calves were used as outcome variables. Compared to BRSV FREE herds: BRSV PSI herds had significantly higher odds of cough in young stock, a higher proportion of quinolone-resistant E. coli (QREC), but a lower proportion of cows with fever. BRSV RI herds had significantly higher odds of diarrhea in calves and young stock, a higher proportion of QREC and higher odds of multidrug-resistant E. coli. Compared to BCoV FREE herds: BCoV PSI herds had significantly higher odds of cough in all ages, and of diarrhea in young stock and cows, and a higher proportion of cows with fever. BCoV RI herds had significantly higher odds of diarrhea in young stock and cows and of cough in all ages. The results support previous research that freedom from BRSV and BCoV is beneficial for animal welfare and farm economy and possibly also mitigates AMR.

Hyperketonemia Predictions Provide an On-Farm Management Tool with Epidemiological Insights

Simple Summary

In dairy cows, the transition to lactation period is metabolically challenging. Elevated blood ketone bodies, known as hyperketonemia or ketosis, is a postpartum metabolic disorder that is associated with negative energy balance, greater comorbidity risk, and decreased milk production. Research to understand the etiology of hyperketonemia has highlighted risk factors and unfavorable outcomes; however, analysis of real-world data is valuable for determining the outcomes across a region. Dairy herd improvement data from herds with diverse size and production were analyzed to determine potential risk factors for and production outcomes of hyperketonemia in the Midwest region (US). Cows predicted to have hyperketonemia had greater previous lactation dry period length, somatic cell count, and dystocia, which may represent risk factors for ketosis. Cows with predicted hyperketonemia had lower milk yield and milk protein but greater milk fat and somatic cell count in the current lactation. Culling rate within 60d of calving, days open, and artificial inseminations were all greater in cows predicted to have hyperketonemia. Prevalence of hyperketonemia decreased linearly in herds with greater rolling herd average milk yield. This work demonstrates the impact of hyperketonemia on production variables which underscores the importance on continued work to reduce hyperketonemia prevalence.

Abstract

Prediction of hyperketonemia (HYK), a postpartum metabolic disorder in dairy cows, through use of cow and milk data has allowed for high-throughput detection and monitoring during monthly milk sampling. The objective of this study was to determine associations between predicted HYK (pHYK) and production parameters in a dataset generated from routine milk analysis samples. Data from 240,714 lactations across 335 farms were analyzed with multiple linear regression models to determine HYK status. Data on HYK or disease treatment was not solicited. Consistent with past research, pHYK cows had greater previous lactation dry period length, somatic cell count, and dystocia. Cows identified as pHYK had lower milk yield and protein percent but greater milk fat, specifically greater mixed and preformed fatty acids (FA), and greater somatic cell count (SCC). Differential somatic cell count was greater in second and fourth parity pHYK cows. Culling (60d), days open, and number of artificial inseminations were greater in pHYK cows. Hyperketonemia prevalence decreased linearly in herds with greater rolling herd average milk yield. This research confirms previously identified risk factors and negative outcomes associated with pHYK and highlights novel associations with differential SCC, mixed FA, and preformed FA across farm sizes and production levels.

Use of welfare outcome information in three types of dairy farm inspection reports

Objective

The aim of this study was to examine the use of outcome-based observations within Assured Dairy Farm scheme (ADF), Soil Association Organic Standards (SA), and cross compliance (CC) farm assessment reports.

Methods

A total of 449 ADF reports, 37 SA reports and 26 CC reports were analyzed and their objective comments categorized as either resource-based or outcome-based.

Results

A mean of 61.0% of ADF questions were responded to with comments, in comparison to 25.0% of SA and, 21.0% of CC report questions. The SA and CC reports had significantly more outcome-based comments than the ADF (p<0.001). The assessors’ tendency of choosing resource-based approach was revealed in the questionnaire results.

Conclusion

Generally, the comments were comprehensive and contained professional judgements. Large numbers of comments provided in the ADF reports were mostly compliant and resource-based evidence, which serves as proof of assessment rather than aiding the certifying process. The inclusion of specific welfare outcome measures in the SA inspection likely increased the use of outcome-based comments in the reports, irrespective of whether the farm achieved compliance with a given standards. The CC scheme, on the other hand, focused on providing outcome-based evidence to justify noncompliant decisions.

Evaluation of the usefulness at national level of the dairy cattle health and production recording systems in Great Britain

The aim of this study was to formally evaluate, qualitatively, the ability of existing recording systems to generate accurate and reliable estimates of the frequency of selected health conditions in the dairy herd of Great Britain. Fifty-nine recording systems were identified, of which 36 had their key characteristics defined through a web-based questionnaire. Nineteen of them were further assessed following the SERVAL, a SuRveillance EVALuation framework against a set of 12 attributes: benefit, bias, communication, coverage, data collection, data management, data analysis, data completeness, flexibility, multiple utility, representativeness and stability/sustainability. The evaluated systems showed considerable differences in their coverage, implementation and objectives. There were overlaps in recorded conditions, with Johne's disease, bovine viral diarrhoea, mastitis and lameness being recorded by most of the systems. Selection bias, data ownership and lack of integration of data from different systems appeared to be a key limitation on the future use of existing systems for nationwide monitoring. The results showed that even though the individual systems can provide reliable estimates of dairy health for individual farmers, none of the systems alone could provide accurate and reliable estimates for any of the conditions of interest at national level.

Risk factors for antimicrobial resistance in fecal Escherichia coli from preweaned dairy calves

The primary objective of this study was to investigate calf and farm factors associated with antimicrobial-resistant Escherichia coli in the feces of preweaned dairy calves in Sweden. In particular, we investigated the effects of feeding calves colostrum and milk from cows treated with antimicrobials. The secondary objective was to describe the prevalence of resistant E. coli in feces of preweaned dairy calves in Sweden. Fecal samples from 3 calves, aged 7 to 28d, from 243 farms were analyzed for the within-sample prevalence of E. coli resistant to nalidixic acid, streptomycin, and cefotaxime using selective agars supplemented with antimicrobials. In addition, resistance to 12 antimicrobials was tested in one randomly selected E. coli isolate per calf. Information was collected from the farmers via questionnaires regarding the use of colostrum and milk from cows treated with antimicrobials as calf feed and other uses of antimicrobials in the herd. Multivariable zero-inflated negative binomial and logistic regression models were used to assess the effect of various risk factors for shedding of resistant E. coli. Escherichia coli resistant to streptomycin, nalidixic acid, or cefotaxime were isolated from 90, 49, and 11% of the calves, respectively. Resistance to at least one antimicrobial was found in a random isolate of E. coli from 48% of the calves. Feeding colostrum from cows treated with antimicrobials at drying off did not affect the prevalence of resistant E. coli. In contrast, feeding milk from cows treated with antimicrobials during lactation resulted in significantly more nalidixic acid- and streptomycin-resistant E. coli than when such milk was discarded; no significant effect was seen for other resistance traits. Furthermore, an interaction was found between feeding milk from cows treated with antimicrobials and use of fluoroquinolones in cows. In general, the prevalence of resistance was lower for older calves and calves on small farms. Other factors that were associated with the shedding of resistant E. coli were administration of oral dihydrostreptomycin to calves, administration of systemic tetracycline and ceftiofur to cows and calves, housing of the calves, predominant breed of the herd, and geographic location of the farm. The presence of resistant E. coli in calves was clearly due to multiple factors, but minimizing the feeding of milk from cows treated with antimicrobials during lactation should lower the prevalence of resistant E. coli in the gastrointestinal tract of the calves.

Survey of the UK veterinary profession: common species and conditions nominated by veterinarians in practice

The practice of evidence-based veterinary medicine involves the utilisation of scientific evidence for clinical decision making. To enable this, research topics pertinent to clinical practice need to be identified, and veterinary clinicians are best placed to do this. The main aim of this study was to describe the veterinary population, the common species and conditions veterinary clinicians nominated they saw in practice and how much information clinicians perceived was available in the literature for these. A questionnaire was distributed to all Royal College of Veterinary Surgeons registered veterinarians agreeing to be contacted for research purposes (n=14,532). A useable response rate of 33 per cent (4842/14,532) was achieved. The most commonly seen species reported by vets were dogs, cats and rabbits followed by equines and cattle. Overall, skin conditions were most commonly mentioned for small animals, musculoskeletal conditions for equines and reproduction conditions for production animals. Veterinary clinicians perceived there was a higher level of information available in the literature for conditions in dogs, cattle and equines and lower levels for rabbits and guinea pigs. The results from this study can be used to help define the research needs of the profession to aid the incorporation of evidence in veterinary practice.

Evaluating somatic cell scores with a Bayesian Gaussian linear state-space model

Because accurate characterization of health state is important for managing dairy herds, we propose to validate the use of a linear state-space model (LSSM) for evaluating monthly somatic cell scores (SCSs). To do so, we retrieved SCS from a dairy database and collected reports on clinical mastitis collected in 20 farms, during the period from January 2008 to December 2011 in the Walloon region of Belgium. The dependent variable was the SCS, and the independent variables were the number of days from calving, year of calving and parity. The LSSM also incorporated an error-free underlying variable that described the trend across time as a function of previous clinical and subclinical status. We computed the mean sum of squared differences between observed SCS and median values of the posterior SCS distribution and constructed the receiver operating characteristic (ROC) curve for SCS thresholds going from 0 to 6. Our results show SCS estimates are close to observed SCS and area under the ROC curve is higher than 90%. We discuss the meaning of the parameters in light of our current knowledge of the disease and propose methods to incorporate, in LSSM, this knowledge often expressed in the form of ordinary differential equations.

Why Do So Many Calves Die on Modern Dairy Farms and What Can We Do about Calf Welfare in the Future?

Poor bovine neonatal survival rates are an international animal welfare issue. The key modifiable risk factors associated with such loss are age at first calving in primiparae, calf breed, gender and gestation length and calving management. The primary causes of mortality in the perinatal period are calving problems, in particular dystocia, defined as both difficult and abnormal calvings. Calf loss rates are rising on modern dairy farms in many countries internationally. High calf loss rates are often not recognised at national or at farm-level; recording needs to be improved. Improving bovine neonatal survival requires re-prioritization of this issue. Stakeholders need to be made cognisant of this prioritization. Actions to effect change need to occur at both national and farm-levels. National-level actions need firstly to address raising awareness of the issue. Farm-level actions need to focus on identifiable problem farms through targeted surveillance. Application of existing knowledge to alter modifiable risk factors is the key to improving calf welfare in the future. Research also has a role to play in filling knowledge gaps in particular about the 'unexplained stillbirth'.

Questionnaire-based study to assess the association between management practices and mastitis within tie-stall and free-stall dairy housing systems in Switzerland

BACKGROUND

Prophylactic measures are key components of dairy herd mastitis control programs, but some are only relevant in specific housing systems. To assess the association between management practices and mastitis incidence, data collected in 2011 by a survey among 979 randomly selected Swiss dairy farms, and information from the regular test day recordings from 680 of these farms was analyzed.

RESULTS

The median incidence of farmer-reported clinical mastitis (ICM) was 11.6 (mean 14.7) cases per 100 cows per year. The median annual proportion of milk samples with a composite somatic cell count (PSCC) above 200,000 cells/ml was 16.1 (mean 17.3) %. A multivariable negative binomial regression model was fitted for each of the mastitis indicators for farms with tie-stall and free-stall housing systems separately to study the effect of other (than housing system) management practices on the ICM and PSCC events (above 200,000 cells/ml). The results differed substantially by housing system and outcome. In tie-stall systems, clinical mastitis incidence was mainly affected by region (mountainous production zone; incidence rate ratio (IRR) = 0.73), the dairy herd replacement system (1.27) and farmers age (0.81). The proportion of high SCC was mainly associated with dry cow udder controls (IRR = 0.67), clean bedding material at calving (IRR = 1.72), using total merit values to select bulls (IRR = 1.57) and body condition scoring (IRR = 0.74). In free-stall systems, the IRR for clinical mastitis was mainly associated with stall climate/temperature (IRR = 1.65), comfort mats as resting surface (IRR = 0.75) and when no feed analysis was carried out (IRR = 1.18). The proportion of high SSC was only associated with hand and arm cleaning after calving (IRR = 0.81) and beef producing value to select bulls (IRR = 0.66).

CONCLUSIONS

There were substantial differences in identified risk factors in the four models. Some of the factors were in agreement with the reported literature while others were not. This highlights the multifactorial nature of the disease and the differences in the risks for both mastitis manifestations. Attempting to understand these multifactorial associations for mastitis within larger management groups continues to play an important role in mastitis control programs.

Data quality in the Norwegian dairy herd recording system: agreement between the national database and disease recording on farm

The majority of herds in Norway participate in the national dairy herd recording system. For disease events, this involves transferring information registered on farm, using individual cow health cards (CHC), to the central cattle database (CCD). Before using data from such a database, validation with an aim of describing data quality should be performed, but is rarely done. In this study, diagnostic events from CHC and CCD from 74 dairy herds were compared. Events in 2008 from female cattle with minimum age of 1 yr were included (n=1,738). Discrepancies between the 2 data sources and assessment of data quality were evaluated using agreement between events on CHC and in CCD, calculating completeness and correctness for the CCD, and using a multivariable regression model for agreement (1/0). The agreement evaluation described the concordance between the 2 data sources, whereas the calculations of completeness and correctness depended on a reference data source assumed to be more reliable. Completeness of the CCD was defined as the proportion of diagnostic events on the CHC that was recorded therein. Correctness was defined as the proportion of the CCD events that was also recorded on the CHC, and with the same date and diagnostic code. The agreement was up to 87.5%, the majority of disagreement being caused by unreported events on the CHC (between 10 and 12% of all events). Completeness of the CCD was regarded as high, between 0.87 and 0.88, and correctness excellent, between 0.97 and 0.98. The multivariable regression model found 4 factors that increased the odds for diagnostic events being in agreement between CHC and CCD. These were the events occurring during the 305-d lactation period; the herd size being 75 cows or less; the event occurring during the spring, summer, or winter rather than autumn; and lastly, the diagnostic code for the disease event being preprinted on the CHC, involving a simple check mark as opposed to writing a 3-digit code. The model found a high degree of clustering within herd. In conclusion, disease data in the Norwegian national database for dairy cows are valid to use for epidemiologic research, having in particular an excellent correctness, but it is of concern that at least 10% of data are missing. The proportion of unreported data should be taken into consideration whenever data from this database are used. Reasons for discrepancies found are important to be aware of in any work aiming to improve data transfer from farm to central databases.

Completeness of the disease recording systems for dairy cows in Denmark, Finland, Norway and Sweden with special reference to clinical mastitis

Background

In the Nordic countries Denmark, Finland, Norway and Sweden, the majority of dairy herds are covered by disease recording systems, in general based on veterinary registration of diagnoses and treatments. Disease data are submitted to the national cattle databases where they are combined with, e.g., production data at cow level, and used for breeding programmes, advisory work and herd health management. Previous studies have raised questions about the quality of the disease data. The main aim of this study was to examine the country-specific completeness of the disease data, regarding clinical mastitis (CM) diagnosis, in each of the national cattle databases. A second aim was to estimate country-specific CM incidence rates (IRs).

Results

Over 4 months in 2008, farmers in the four Nordic countries recorded clinical diseases in their dairy cows. Their registrations were matched to registrations in the central cattle databases. The country-specific completeness of disease registrations was calculated as the proportion of farmer-recorded cases that could be found in the central database. The completeness (95% confidence interval) for veterinary-supervised cases of CM was 0.94 (0.92, 0.97), 0.56 (0.48, 0.64), 0.82 (0.75, 0.90) and 0.78 (0.70, 0.85) in Denmark, Finland, Norway and Sweden, respectively. The completeness of registration of all CM cases, which includes all cases noted by farmers, regardless of whether the cows were seen or treated by a veterinarian or not, was 0.90 (0.87, 0.93), 0.51 (0.43, 0.59), 0.75 (0.67, 0.83) and 0.67 (0.60, 0.75), respectively, in the same countries. The IRs, estimated by Poisson regression in cases per 100 cow-years, based on the farmers’ recordings, were 46.9 (41.7, 52.7), 38.6 (34.2, 43.5), 31.3 (27.2, 35.9) and 26.2 (23.2, 26.9), respectively, which was between 20% (DK) and 100% (FI) higher than the IRs based on recordings in the central cattle databases.

Conclusions

The completeness for veterinary-supervised cases of CM was considerably less than 100% in all four Nordic countries and differed between countries. Hence, the number of CM cases in dairy cows is underestimated. This has an impact on all areas where the disease data are used.

Breed influences on in vitro development of abattoir-derived bovine oocytes

Background

There is a discrepancy in the reproductive performance between different cattle breeds. Using abattoir-derived ovaries and data base information we studied the effects of breed on in vitro fertilization and early embryo development.

Methods

The in vitro developmental competence of oocytes from cattle (n = 202) of Swedish Red (SR), Swedish Holstein (SH) and mixed beef breeds was compared, retrospectively tracing donors of abattoir-derived ovaries using a combination of the national animal databases and abattoir information. Age was significantly lower and carcass conformation score was higher in the beef breeds than in the dairy breeds.

Cumulus oocyte complexes (n = 1351) were aspirated from abattoir-derived ovaries from animals of known breed (visual inspection confirmed through databases), age (databases), and abattoir information. Oocytes were matured, fertilized (frozen semen from two dairy bulls) and cultured according to conventional protocols. On day 8, blastocysts were graded and the number of nuclei determined.

Results

Cleavage rate was not different between the breeds but was significantly different between bulls. The percentage of blastocysts on day 8 was significantly higher when the oocyte donor’s breed was beef or SR than SH. There was no significant difference in blastocyst grades or stages between the breeds, but the number of nuclei in day 8 blastocysts was significantly lower in SH compared to the beef.

Conclusions

The use of abattoir-derived ovaries from animals whose background is traceable can be a valuable tool for research. Using this approach in the present study, oocyte donor breed was seen to affect early embryo development during in vitro embryo production, which may be a contributing factor to the declining fertility in some dairy breeds seen today.

Evidence-based practice? An evolution is necessary for bovine practitioners, teachers, and researchers

We suggest a definition of evidence-based veterinary medicine that takes into account its objectives and practicality. We view it as an information tool that does not replace experience but helps to improve background knowledge and solve clinical foreground questions. It could be defined as the use of accurate, informative, and clear summarized information (abstracts) of high-level research studies that is obtained quickly via free-access databases available via the Internet and that is provided by a proactive veterinary scientific community in search of transparency, accountability, and evidence.

Can pre-collected register data be used to identify dairy herds with good cattle welfare?

Abstract

Use of information on disease diagnoses from databases for animal health economic, welfare and food safety purposes: strengths and limitations of recordings

Many animal health, welfare and food safety databases include data on clinical and test-based disease diagnoses. However, the circumstances and constraints for establishing the diagnoses vary considerably among databases. Therefore results based on different databases are difficult to compare and compilation of data in order to perform meta-analysis is almost impossible. Nevertheless, diagnostic information collected either routinely or in research projects is valuable in cross comparisons between databases, but there is a need for improved transparency and documentation of the data and the performance characteristics of tests used to establish diagnoses. The objective of this paper is to outline the circumstances and constraints for recording of disease diagnoses in different types of databases, and to discuss these in the context of disease diagnoses when using them for additional purposes, including research. Finally some limitations and recommendations for use of data and for recording of diagnostic information in the future are given. It is concluded that many research questions have such a specific objective that investigators need to collect their own data. However, there are also examples, where a minimal amount of extra information or continued validation could make sufficient improvement of secondary data to be used for other purposes. Regardless, researchers should always carefully evaluate the opportunities and constraints when they decide to use secondary data. If the data in the existing databases are not sufficiently valid, researchers may have to collect their own data, but improved recording of diagnostic data may improve the usefulness of secondary diagnostic data in the future.

Veterinary syndromic surveillance: Current initiatives and potential for development

This paper reviews recent progress in the development of syndromic surveillance systems for veterinary medicine. Peer-reviewed and grey literature were searched in order to identify surveillance systems that explicitly address outbreak detection based on systematic monitoring of animal population data, in any phase of implementation. The review found that developments in veterinary syndromic surveillance are focused not only on animal health, but also on the use of animals as sentinels for public health, representing a further step towards One Medicine. The main sources of information are clinical data from practitioners and laboratory data, but a number of other sources are being explored. Due to limitations inherent in the way data on animal health is collected, the development of veterinary syndromic surveillance initially focused on animal health data collection strategies, analyzing historical data for their potential to support systematic monitoring, or solving problems of data classification and integration. Systems based on passive notification or data transfers are now dealing with sustainability issues. Given the ongoing barriers in availability of data, diagnostic laboratories appear to provide the most readily available data sources for syndromic surveillance in animal health. As the bottlenecks around data source availability are overcome, the next challenge is consolidating data standards for data classification, promoting the integration of different animal health surveillance systems, and also the integration to public health surveillance. Moreover, the outputs of systems for systematic monitoring of animal health data must be directly connected to real-time decision support systems which are increasingly being used for disease management and control.

Risk factors associated with observed clinical lumpy skin disease in Ethiopia

A cross-sectional study based on a questionnaire survey was conducted to determine the distribution of lumpy skin disease (LSD) and associated risk factors in three main agro-climatic zones of Ethiopia. A total of 330 questionnaire surveys were collected from 44 peasant associations (PA) distributed in 15 districts. Across agro-climate zones, herd-level LSD prevalence in the midland agro-climate was significantly higher 55.2% [95% confidence interval (CI) 47.5-62.6] than in highland and lowland agro-climate zones. Overall observed LSD prevalence at animal-level was 8.1% (95% CI 7.3-8.9) and observed mortality was 2.12% (95% CI 1.73-2.6). The odds ratio (OR) of LSD occurrence in midland vs. highland and lowland vs. highland zones was 3.86 (95% CI 2.61-5.11) and 4.85 (95% CI 2.59-7.1), respectively. Significantly high risk of LSD occurrence was associated with communal grazing and watering management (OR 4.1, 95% CI 2.02-6.18) and introduction of new cattle (OR 8.5, 95% CI 6.0-11.0). Our findings describe the distribution of LSD in different agro-climates in Ethiopia along with associated risk factors, and can help shed light on the epidemiology of LSD in other African countries suffering from the disease.

Validation of computerized diagnostic information in a clinical database from a national equine clinic network

BACKGROUND

Computerized diagnostic information offers potential for epidemiological research; however data accuracy must be addressed. The principal aim of this study was to evaluate the completeness and correctness of diagnostic information in a computerized equine clinical database compared to corresponding hand written veterinary clinical records, used as gold standard, and to assess factors related to correctness. Further, the aim was to investigate completeness (epidemiologic sensitivity), correctness (positive predictive value), specificity and prevalence for diagnoses for four body systems and correctness for affected limb information for four joint diseases.

METHODS

A random sample of 450 visits over the year 2002 (nvisits=49,591) was taken from 18 nation wide clinics headed under one company. Computerized information for the visits selected and copies of the corresponding veterinary clinical records were retrieved. Completeness and correctness were determined using semi-subjective criteria. Logistic regression was used to examine factors associated with correctness for diagnosis.

RESULTS

Three hundred and ninety six visits had veterinary clinical notes that were retrievable. The overall completeness and correctness were 91% and 92%, respectively; both values considered high. Descriptive analyses showed significantly higher degree of correctness for first visits compared to follow up visits and for cases with a diagnostic code recorded in the veterinary records compared to those with no code noted. The correctness was similar regardless of usage category (leisure/sport horse, racing trotter and racing thoroughbred) or gender.For the four body systems selected (joints, skin and hooves, respiratory, skeletal) the completeness varied between 71% (respiration) and 91% (joints) and the correctness ranged from 87% (skin and hooves) to 96% (respiration), whereas the specificity was >95% for all systems. Logistic regression showed that correctness was associated with type of visit, whether an explicit diagnostic code was present in the veterinary clinical record, and body system. Correctness for information on affected limb was 95% and varied with joint.

CONCLUSION

Based on the overall high level of correctness and completeness the database was considered useful for research purposes. For the body systems investigated the highest level of completeness and correctness was seen for joints and respiration, respectively.

Validation of a national disease recording system for dairy cattle against veterinary practice records

In Sweden, morbidity in dairy cattle is monitored through a national disease recording system. This system gives valuable information for research as well as advisory work and genetic evaluation. Our main objective was to evaluate the completeness in the disease recording system. Farm copies of veterinary records (n=851) from 112 herds, from March 2003 to April 2004, were compared with the information registered in the recording system. The evaluation of completeness was performed at two stages: (i) in the raw data transferred from the Swedish Board of Agriculture (SBA) to the Swedish Dairy Association (for records, cases and diagnostic events) and (ii) in the dairy disease database (DDD) at the Swedish Dairy Association (for diagnostic events). The evaluation was stratified by record type: manual and computerized records from state-employed veterinarians and private veterinarians, respectively. The completeness was high both for records (95-100%) and cases (90-99%) except manual records from private veterinarians (76% for records and 74% for cases). The overall completeness for diagnostic events was 75% in the DDD, with significant differences between record types. For all record types other than manual records from private veterinarians, the majority of diagnostic events lost disappeared after registration in the raw data from the SBA. The reasons for loss found suggest that there is potential for improvement. A multilevel logistic regression analysis showed that the completeness of diagnostic events in the DDD depended on region, diagnosis and veterinary employment. The random effect of veterinarian accounted for 35% of the modeled variation. Future studies are needed to assess how the differential misclassification affect estimates based on the data, and how to account for it.

Herd and cow characteristics affecting the odds of veterinary treatment for disease - a multilevel analysis

Background

Research has indicated that a number of different factors affect whether an animal receives treatment or not when diseased. The aim of this paper was to evaluate if herd or individual animal characteristics influence whether cattle receives veterinary treatment for disease, and thereby also introduce misclassification in the disease recording system.

Methods

The data consisted mainly of disease events reported by farmers during 2004. We modelled odds of receiving veterinary treatment when diseased, using two-level logistic regression models for cows and young animals (calves and heifers), respectively. Model parameters were estimated using three procedures, because these procedures have been shown, under some conditions, to produce biased estimates for multi-level models with binary outcomes.

Results

Cows located in herds mainly consisting of Swedish Holstein cows had higher odds for veterinary treatment than cows in herds mainly consisting of Swedish Red cows. Cows with a disease event early in lactation had higher odds for treatment than when the event occurred later in lactation. There were also higher odds for veterinary treatment of events for cows in January and April than in July and October. The odds for veterinary treatment of events in young animals were higher if the farmer appeared to be good at keeping records. Having a disease event at the same date as another animal increased the odds for veterinary treatment for all events in young animals, and for lameness, metabolic, udder and other disorders, but not for peripartum disorders, in cows. There were also differences in the odds for veterinary treatment between disease complexes, both for cows and young animals.

The random effect of herd was significant in both models and accounted for 40–44% of the variation in the cow model and 30–46% in the young animal model.

Conclusion

We conclude that cow and herd characteristics influence the odds for veterinary treatment and that this might bias the results from studies using data from the cattle disease database based on veterinary practice records.

Milk yield, udder health and reproductive performance in Swedish organic and conventional dairy herds

Organic dairy farming is an expanding segment of the dairy sector where cow management differs from the conventional model in many respects. Thus, a comparative evaluation of disease and welfare status in organically and conventionally managed dairy cows is required. Assessment of milk yield, udder health and reproductive performance (RP) was done in 20 organically and 20 conventionally managed Swedish dairy herds. In accordance with earlier findings we confirmed lower milk yield in organic cows. Udder health and RP were chosen as indicators of animal health in view of their clinical relevance and the availability of appropriate data bases providing good background knowledge for further animal health assessment. No obvious differences were found in the investigations of somatic cell count (SCC) profiles or time to veterinary-treated cases of mastitis between organically and conventional managed cows. Pregnancy success at first insemination, an appropriate measurement of RP with biological interpretation and background, did not reveal any difference between management types, whereas the hazard rate-ratio (HR) of having a calving-interval was significantly lower (HR=0·71) in organically managed cows. The calving-interval is an important financial determinator in dairy production, but it is not considered an optimal indicator of biologic relevance as it partially reflects farmer decisions. In conclusion, the organically managed cows in this study did not differ from conventionally managed cows in udder health or RP, with the exception of calving interval.