David Hall

• Doctor of Philosophy
• University of Calgary

Simple Summary Simple Summary: Hormonal treatment seems less effective than expected, and it is not a cost-efficient option for solving an anestrous problem in dairy cows under field conditions in tropical countries. To assess whether this evidence is correct, this retrospective study retrieved the clinical records of anestrous cows that received h...

An economic simulation was carried out over 183 milk-producing countries to estimate the global economic impacts of 12 dairy cattle diseases and health conditions: mastitis (subclinical and clinical), lameness, paratuberculosis (Johne's disease), displaced abomasum, dystocia, metritis, milk fever, ovarian cysts, retained placenta, and ketosis (subc...

Endemic infectious diseases remain a major challenge for dairy producers worldwide. For effective disease control programs, up-to-date prevalence estimates are of utmost importance. The objective of this study was to estimate the herd-level prevalence of bovine leukemia virus (BLV), Salmonella Dublin, and Neospora caninum in dairy herds in Alberta,...

This retrospective study aimed to evaluate the performance of the hormone treatment protocols, determine the factors associated with pregnancy success after hormone treatment, and compare the cost-efficiencies of two types of hormone treatment among cyclic and noncyclic anestrous dairy cows. The clinical records of 279 anestrous cows who received h...

Simple Summary Bacterial infections can often lead to complications in wound healing. The overuse of antimicrobial drugs can cause antimicrobial resistance, making it necessary to find alternative therapeutic options for wound care. Platelet-rich fibrin (PRF) has been used for tissue regeneration, but until now, its application for antimicrobial ac...

Intro: Although Canada is officially free of bovine tuberculosis and brucellosis, wood bison in Wood Buffalo National Park are a known reservoir of these and other zoonotic diseases. Several issues complicate the situation: wood bison are a threatened species; the species is an important cultural and food resource for indigeneous communities; and t...

Approximately 10% of Albertans rely on well water for domestic purposes. The responsibility of water testing and stewardship is left to private well owners. Few well water owners conduct routine testing of their well water supplies. Drive times to public water testing facilities may be an important factor limiting a well owner’s ability to conduct...

Johne’s disease, or paratuberculosis, is an infectious disorder of the intestines that can affect domestic and wild ruminants that is caused by an infection with Mycobacterium avium subspecies paratuberculosis (MAP). Although the economic losses due to Johne’s disease in dairy cattle herds and the benefits and costs of various potential control pra...

Background In Southeast Asia from 2004 to 2006, highly pathogenic avian influenza (HPAI) resulted in culling 45 million birds and jeopardizing sustainable agricultural production. HPAI is highly virulent; small‐scale farms present a high‐risk environment for disease transmission between animals and humans. We investigated how attitudes toward HPAI...

Johne’s disease (JD), or paratuberculosis, is an infectious disorder primarily associated with cattle and sheep and resulting in significant economic losses for dairy producers. The dairy cattle herd-level prevalence in Canada has recently been estimated to be greater than 40%, but the willingness to pay for JD control practices such as testing-and...

[This corrects the article DOI: 10.3389/fvets.2020.614727.].

Johne's disease (JD or paratuberculosis) control programs have been established in many dairy-producing regions. However, the effectiveness (reduction of within-herd prevalence) and the relative economic impact as measured by, for example, the ratio of benefits to costs (BCR) across a comprehensive selection of regions and potential control practic...

Johne’s disease (JD), or paratuberculosis, is an infectious inflammatory disorder of the intestines primarily associated with domestic and wild ruminants including dairy cattle. The disease, caused by an infection with Mycobacterium avium subspecies paratuberculosis (MAP) bacteria, burdens both animals and producers through reduced milk production,...

Paratuberculosis or Johne’s disease (JD) prevalence in Australia is low at the cow-level with varying herd-level prevalence. Control strategies incorporating vaccination are limited, suggesting opportunities for changes in regulatory oversight. In order to study this further, we examined the economic benefits of participation in JD control programm...

In Bhutan, dog-mediated rabies has been successfully eliminated from most regions of the country but remains endemic in the Southern region and sporadic incursions are also reported in the East. Elimination of rabies from the southern part of Bhutan is challenged by the porous border with the neighboring states of India which facilitates free and u...

The effects of the number of frozen-thawed ram sperm per single and double intra-cervical artificial insemination (AI) on fertility in ewes were studied. A total of 89 non-pregnant ewes were synchronized for oestrus with two doses of 100 μg PGF2α (Cloprostenol) 9 days apart. The ewes were randomly assigned to one of four groups; D200 (n = 23; doubl...

Approximately 238,000 to 450,000 Albertans rely on private water wells for their water needs. In Canada, private well owners are responsible for monitoring and maintaining the quality of their water well, yet studies in Alberta indicate that owners do not undertake regular well maintenance or testing. This survey obtained information regarding farm...

Health problems can arise from consuming contaminated well water. Well water testing can help prevent negative health outcomes associated with consuming contaminated water. The aim of this study was to understand the factors influencing well owner decisions to conduct water testing through the theoretical lens of the Health Belief Model. We conduct...

Background An estimated four million and 43 million people in Canada and the USA use private water supplies. Private water supplies are vulnerable to waterborne disease outbreaks. Private water supplies in Canada and the USA are often unregulated and private water management is often a choice left to the owner. Perceptions of water quality become i...

Water wells are important in providing water for rural populations that are far removed from municipal water supplies. Over 400,000 rural Albertans use water wells for domestic purposes. The responsibility of well water management lies with well owners. Perceptions of well water quality become important in influencing the adoption of well water man...

Rabies remains a disease of significant zoonotic and economic concern in rabies endemic areas of Bhutan. Rabies outbreaks in livestock threaten the livelihoods of subsistence farming communities and pose a potential public health threat. As a part of identifying approaches to prevent rabies in cattle, a Knowledge, Attitude, and Practice (KAP) surve...

Questions used for assessing particpant’s knowledge about rabies. (DOCX)

Questions used for assessing participant’s attitude towards rabies prevention and control in humans and animals. (DOCX)

Data collected during the survey and used for analysis. (XLSX)

Strobe checklist used for our study. (DOC)

Background An outbreak of highly pathogenic avian influenza (HPAI) between 2004 and 2006 resulted in the culling of 45 million birds, and has jeopardised sustainable agricultural production in southeast Asia. HPAI is highly virulent, and small-scale farms present a high-risk environment for disease transmission between animals and humans. The purpo...

Background: Rabies is eliminated from the northern and central parts of Bhutan, but it remains endemic in the southern region that shares a porous border with India. Control programs are challenged by free cross-border movement of dogs. Annually around 17 cases of rabies in dogs are reported. Frequent spill-over infection from dogs to cattle and ot...

The integrated livestock, crops, and fish (VAC) model of integrated small scale agriculture has been important to economic and ecological sustainability in Vietnam for many centuries. Recently, emerging waterborne diseases including avian influenza as well as the potential for zoonotic disease arising from small scale farms have jeopardized the VAC...

Water is essential for life. In rural Alberta, approximately 600,000 people rely on private groundwater or stored water for drinking purposes. Up to 25% of such water systems fail current drinking water quality parameters. Waterborne pathogens can be transmitted by consumption of untreated/improperly treated groundwater. This study aims to better u...

Background: More than 70 million Vietnamese rely on small-scale farming for some form of household income. Water on many of those farms is contaminated with waste, including animal manure, partly due to non-sustainable waste management. This increases the risk of water-related zoonotic disease transmission. The purpose of this research was to exam...

Understanding the sources and use of information from hatching egg and broiler chicken producers, their constraints, and unmet information needs can help define future research agendas. This report presents the results from a qualitative study using interviews of 11 hatching egg producers and 12 broiler producers in Alberta, Canada. Patterns were r...

Chapter 7 reviews New Zealand’s diversification to new dairy export markets together with the many obstacles to that diversification. The realisation that the British market would not grow gave a prime incentive for diversification. The increased sale of milk powder and by-products to Asia and the Americas made New Zealand’s overseas earnings from...

Examining policy options to mitigate the risk of rabies occurring in cattle in Bhutan.

Rabies is a fatal viral zoonosis responsible for ~59000 human deaths and massive economic losses globally a 95% of human fatalities are reported from Asia and Africa and 99% are dog mediated Rabies, once endemic across Bhutan, is now restricted only to the southern parts of the country Bhutan is a small Himalayan country located in Asia, where 7...

One Health refers to an interdisciplinary approach to solving complex problems at the interface of human and animal health and the wider ecosystem. It represents an integrated and collaborative approach and addresses diverse issues such as the detection and management of emerging and re-emerging infectious and non-infectious diseases, food and wate...

We report on monitoring and evaluation (M&E) methods research for One Health projects, based on a project (Building EcoHealth Capacity in Asia) in Southeast Asia. Methods for M&E included development of progress markers, use of pre- and post-workshop and on-line questionnaires, interviews, small group discussions, gap analysis, performance indicato...

The application of the ‘One Health’ concept to the development and delivery of science based policy is not new but it has been revived in the past decade with a growing awareness of the need to engage interdisciplinary teams to solve complex problem. The composition of these teams depends very much on the issue(s) to be addressed but for emerging d...

Interest has increased considerably in the last five years in transdisciplinary approaches to addressing the precipitating factors of emerging infectious and zoonotic diseases. During this time, several One Health and ecohealth initiatives have begun in Asia. This paper reports on recommendations coming out of one such initiative (the Building E...

The Western Pacific Region, the most populous of six regional groupings of World Health Organization (WHO) member states, has seen the emergence of a series of novel zoonotic infections in the last decade. This has focused attention on addressing underlying risks and vulnerabilities in the complex interactions among people, animals, and environment...

Newly emerging infectious diseases (nEIDs) have increased rapidly presenting alarming challenges to global health. We argue that for effective management of global health a basic strategy should include at least three essential tactical forms: actions of a directly focused nature, institutional coordination, and disciplinary integration in approach...

This study describes the development, implementation, and psychometric assessment of the multiple mini-interview (MMI) for the inaugural class of veterinary medicine applicants at the University of Calgary Faculty of Veterinary Medicine (UCVM). The MMI is a series of approximately five to 12 10-minute interviews that consist of situational events....

The economic impact of adopting herd health programs for mastitis and reproduction by small‐scale dairy producers of Central Thailand was assessed using a policy analysis matrix (PAM). Following a reduction in the incidence of bovine disease on adopter farms, an increase in private net profits is observed. More importantly the social costs of suppo...

Global consumption, production, and trade of livestock products have increased rapidly in the last two decades and are expected to continue. At the same time, safety concerns regarding human and animal disease associated with livestock products are increasing. Efforts to increase public health safety standards aimed at legitimately reducing the ris...

The economic impact of adopting herd health programs for mastitis and reproduction by small-scale dairy producers of Central Thailand was assessed using a policy analysis matrix (PAM). Following a reduction in the incidence of bovine disease on adopter farms, an increase in private net profits is observed. More importantly the social costs of suppo...

Beef cattle producers were surveyed in Texas and Nebraska to investigate perceptions of sources of risk, the effectiveness of risk management strategies, and interest in further risk management education, particularly production risk, using probit analysis. Important decision variables identified are age, prior use of risk management tools, previou...

Beef cattle producers were surveyed in Texas and Nebraska to investigate perceptions of sources of risk, the effectiveness of risk management strategies, and interest in further risk management education, particularly production risk, using probit analysis. Important decision variables identified are age, prior use of risk management tools, previou...

A new application of an optimization tool, dynamic programming (DP), is described to model the economics of animal health control programs. To demonstrate the value of this technique, a model is applied to determine optimal net benefits of controlling East Coast fever (ECF) in Malawi Zebu cattle in the Lilongwe plateau. The objective function was t...