Browsing by Author "Salman, Mo, advisor"
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Item Open Access Assessment of the introduction and spread of highly pathogenic avian influenza (H5N1) in Thailand: application of market chain analysis of poultry and the use of community-based disease prevention strategies(Colorado State University. Libraries, 2013) Limhapirom, Patchara, author; Salman, Mo, advisor; Keefe, Thomas, committee member; Wongsathapornchai, Kachen, committee memberAn analysis of the market chain and trade pathway for the small poultry production system was conducted in Ban Klang Subdistrict, Nakhon Phanom Mueang District, Nakhon Phanom Province, Thailand. The aim of the study was to determine the risk of highly pathogenic avian influenza (HPAI/H5N1) introduction and transmission along the poultry market chain, and then apply a community-based approach to prevent the introduction and spread of H5N1 along the identified chain. The focus was on the layer market chain because an outbreak of HPAI was reported 24 July 2006 at a layer farm in Banklang Subdistrict. Six human patients were suspected to be infected with Avian Influenza virus (AI), but no cases were reported after the surveillance was initiated (MOPH 2006). A cross-sectional analysis method was used to identify the poultry market chain and assess the risk of introduction and transmission of AI along that chain. For linking actors along the poultry market chain, the snowball sampling method was used. The data were collected by using a structured questionnaire and applying focus discussion group activity (FDG), which is part of the community-based approach, to the high-risk actors in the poultry market chain. Participants' level of knowledge, attitude and practice behaviors (KAP) regarding AI was assessed, as well as the risk of AI in the poultry market chain. From three layer product pathways—eggs, spent hens and disposal of layer manure—the findings demonstrated that the spent hens and disposal of layer manure are higher-risk pathways for the introduction and transmission of HPAI than the egg products pathway. The farmers (producers) have the highest risk of contracting the AI virus because of their constant proximity to poultry, while traders have the highest risk of transmitting the AI virus along the layer market chain as their business requires moving from farm to farm. A survey of KAP regarding AI showed that the majority of farmers had a high level of knowledge and positive practice behaviors. This was compared to traders where more than half had only moderate to low knowledge, and positive practice behaviors. The majority of farmers and traders, however, had a positive attitude toward policies of prevention and control of HPAI through a surveillance system in their community. The FDG demonstrated that other actors expected an efficient HPAI prevention system at the producer level. The results of this study showed that community involvement in an HPAI surveillance system should be considered for all related actors in the poultry market chain. In order to be effective, the policies should be followed and periodically monitored for compliance.Item Open Access Epidemiology and veterinary public policy(Colorado State University. Libraries, 2008) Zepeda Sein, Cristóbal Andrés, author; Salman, Mo, advisorOfficial Veterinary Services are increasingly required to base veterinary public policy decisions on scientific grounds, epidemiology and risk analysis play an important role in shaping these decisions. A formal, in-depth analysis of the multiple interactions between epidemiology, risk analysis and veterinary public policy was conducted to enable decision-makers to direct resources more efficiently and facilitate compliance with international agreements, in particular the Agreement on the Application of Sanitary and Phytosanitary Measures (SPS) of the World Trade Organization. The SPS Agreement recognizes the World Organization for Animal Health (OIE) as the international organization responsible for developing animal health standards. The OIE's Terrestrial Animal Health Code contains scientifically based recommendations for international trade in animals and animal products. However, to date, these recommendations have not been assessed from a risk-based perspective. The study is divided in two major sections: (1) the role of epidemiology in veterinary public policy and (2) the application of risk-based approaches to the assessment of international animal health standards. The first section addresses the international framework, risk analysis and its use worldwide, and the development of international standards. The second section focuses on quantitative risk assessment approaches for the international movement of animals and products, as well as the application of compartmentalization to aquaculture production systems emphasizing the use of a HACCP approach to biosecurity.Item Open Access Equine body weight estimation using three-dimensional images(Colorado State University. Libraries, 2015) Ku, Kyung-nyer, author; Traub-Dargatz, Josie L., advisor; Salman, Mo, advisor; Alciatore, David, committee member; Hess, Tanja, committee memberAccurately estimating the body weight (BW) of a horse is important in order to make appropriate management and treatment decisions. Most field equine veterinarians and experienced equine people, however, visually estimate BW because large animal scales are impractical for field use due to the weight (>80 kg), size (length >200 cm), and cost (>$1,000). There are some alternative BW estimation methods such as a weight tape or BW estimation using a combination of heart girth and body length measurements. These methods, however, have 5 - 15% or even higher margin of error. According to human studies, there is a high correlation between BW and body volume (BV). Correlation coefficient (R) between these two variables is 0.996-0.998. Our study was designed to develop methods to estimate the BW of horses by using 3D image based BV measurement. 3D imaging technology allows easy and accurate measurement of diverse indices of an object, including the volume. Recent development of Structure-light 3D scanning technology allows 3D scanning of an object as large as 3 by 3 square meter in a short time. In this study, 3D images of 22 and 11 horses were obtained by using 3D scanning (3DScan) and photogrammetry (2Dto3D), respectively. BV and trunk volume (TV) of the horses were measured from the obtained 3D images. Measurements of BW using five conventional methods (visual estimation, 2 weight tapes (Purina, Shell), estimated BW by using heart girth and body length (Carroll’s formula), and a large animal scale) were also conducted, and the data of body condition score (BCS), sex, coat color, and coat type of the horses were collected. Linear regression models to estimate the BW of the horse based on the volume and other independent variables were developed using regression model stepwise selection procedures (P<0.05). Variables selected in 3DScan method were BV, sex, and coat type, and, in 2Dto3D method, BV (TV) was selected. The coefficient of determination of the developed regression models were 0.95 and 0.78-0.82, respectively, and the average percent errors of the predicted BW compared to the true BW of horses were 2.07 % and 2.67 %, respectively. The accuracy of the 3DScan method was significantly more accurate than WT, Carroll’s formual, and VE (P<0.05). 3D image based BW measurement method had higher accuracy and convenience compared to conventional alternative BW measuring methods. Accurate and easy determination of BW using 3D images will allow for regular BW measurement in the field and allow optimal equine health management by equine stakeholders and practitioners. The 3D images obtained in this study were highly detailed. Further graphical analysis of the obtained 3D images will make it possible to use this technology on automatic evaluation of body condition score, equine conformation evaluation, breed registration, and the study of pharmacokinetics and dynamics of newly developed drugs. This research findings may also have utility for application to wild or zoo animals such as the elephant, rhinoceros, or even the tiger where hands on collection of body weight would be challenging.Item Open Access Evaluation of strategies for eradication of Aujeszky's disease (Pseudorabies) in commercial swine farms in Chiang-Mai and Lampoon provinces, Thailand(Colorado State University. Libraries, 2010) Ketusing, Naree, author; Salman, Mo, advisor; Olea-Popelka, Francisco, advisor; Keefe, Thomas, committee memberSeveral strategies for eradicating Aujeszky's disease (Pseudorabies) in Chiang-Mai and Lampoon Provinces, Thailand, were compared using a computer simulation model, the North American Animal Disease Spread Model (NAADSM). The duration of the outbreak, the number of infected herdss and the number destroyed herds were compared during these simulated outbreaks. Destruction, zoning for restricted movement and improved detection and vaccination strategies were studied. Destruction was found to be the most effective method to eradicate Pseudorabies. Although zoning and ring vaccination did not influence this model, the recommendations from this study are to apply both destruction and three zone (3, 8 and 16 kilometers) restricted movements along with enhanced detection and a 16 vaccination ring.Item Open Access Genetic natural resistance to brucellosis in Yellowstone National Park bison (Bison bison): a preliminary assessment(Colorado State University. Libraries, 2013) Herman, Julia Anne, author; Salman, Mo, advisor; Hill, Ashley, committee member; Huyvaert, Kathryn, committee member; Rhyan, Jack, committee memberAs a nationally recognized symbol of perseverance and survival, the American bison (Bison bison) continues to be the focus of many conservation efforts. This is particularly true in Yellowstone National Park (YNP) where genetic diversity and population dynamics are threatened by the presence of Brucella abortus infection, the causative agent of brucellosis. To further complicate management efforts, the potential for transmission of B. abortus to livestock surrounding the park could have effects on human and animal health in addition to negative economic impacts. Genetic natural resistance to infectious diseases such as brucellosis has been examined in bison and other species. Consideration of using genetic natural resistance as a management tool within YNP relies on its applicability to the population and effectiveness in identifying susceptible or resistant animals. The aim of this study was to further investigate genetic natural resistance to brucellosis in bison using the prion protein gene (PRNP). This could provide a genetic management tool for future populations by identifying resistant and susceptible genotypes to brucellosis that governing agencies could screen when selecting animals for removal. Animals used in this study were part of the Bison Quarantine Feasibility Study (BQFS), which was conducted by state and federal government agencies to explore alternative options for bison that leave the protection of the park's perimeters as part of the Interagency Bison Management Plan (IBMP). After completing the study, the bison involved will be released into areas of their historic range and managed as a conservation herd. In addition to investigating genetic natural resistance, other genetic aspects were analyzed in this quarantine herd. We evaluated genetic diversity at 42 microsatellite loci representing each of the nuclear chromosomes in the bison genome. These markers allowed us to determine parentage which helped quantify the genetic diversity contained in the conservation herd. It was also important to understand the genetic diversity of the herd and to determine if any genetic characteristics such as cattle DNA introgression or low genetic diversity may threaten the protected status of this herd. Previously developed mitochondrial and nuclear DNA microsatellite markers were applied to determine if any introgression of domestic cattle DNA is presen. PRNP examination provided conflicting results from previous bison PRNP studies, justifying further research into the importance of PRNP in genetic natural resistance. As a conservation herd, this group of bison demonstrates high retention of unique YNP genetic diversity, high percentage of adult animals contributing offspring, and no evidence of cattle DNA introgression. This study explains support for using YNP bison as stocking animals for future satellite herds under the condition that BQFS protocol is followed. Results of these genetic analyses provide a thorough description of a quarantined herd of YNP bison destined for release to brucellosis-free public lands.Item Open Access Investigation into disease events at the wildlife/livestock interface: lessons learned from bovine viral diarrhea virus in Colorado cervids(Colorado State University. Libraries, 2009) Duncan, Colleen, author; Salman, Mo, advisor; VanCampen, Hana, advisorInfectious agents may be transmitted between wild and domestic animals; these so called 'interface diseases' can have significant economic consequences. As such, effective tools and techniques with which to study disease in free ranging, wild animals is essential. Principles of wildlife disease surveillance were reviewed and it was concluded that while wildlife disease research may require unique logistical adaptations; basic principles of surveillance remain the same. A review of wildlife data sources utilized for surveillance suggests that information collected, and shared, is dependent on the group involved and that there are opportunities to improve the type and quality of material available. Bovine viral diarrhea virus (BVDV) is an important virus of domestic cattle that has recently been identified in wild ruminants worldwide. To investigate the presence, prevalence, distribution and significance of BVDV in wild cervids of Colorado a series of projects were conducted. Persistently infected (PI) deer were studied post mortem; immunohistochemical and molecular techniques used to look for viral antigen in deer tissue were found to be effective supporting the use of these tests in further studies. The prevalence and distribution of PI cervids in the state was evaluated using an opportunistic sampling technique; the prevalence is extremely low, but naturally occurring infection is present within Colorado. The cost associated with testing animals for an uncommon disease may be very high; techniques like pooling samples can help to keep costs down during such investigations. The sensitivity and specificity of RT-PCR on pooled samples was investigated in an experimental study and revealed that supernatant from a single positive deer skin sample may be diluted up to 10,000 times and still be detected. Another technique to focus research efforts on high risk areas is the use of simulation modeling. A stochastic risk assessment model was developed to identify regions in Colorado where PI cattle were likely to be born following exposure to a PI deer. Results of the model were consistent with both the cross-sectional survey for PI cervids and other reports on BVDV in wildlife of Colorado.Item Open Access Molecular epidemiology of Giardia and Cryptosporidium in dogs and cats in Chiang Mai, Thailand(Colorado State University. Libraries, 2013) Tangtrongsup, Sahatchai, author; Salman, Mo, advisor; Lappin, Michael, advisor; Ballweber, Lora, committee member; Reif, John, committee memberGiardia duodenalis and Cryptosporidium spp. are the common causes of diarrhea in humans and animals, including domestic and wildlife, throughout the world. The species complex G. duodenalis and the genus Cryptosporidium consist of host-adapted and zoonotic genotypes/species. Companion animals, especially dogs and cats, can be infected by the host-adapted as well as the zoonotic genotype/species of these organisms. Therefore, these animals have been questioned regarding their potential to serve as reservoirs for human transmission. In this dissertation, an epidemiological study of Giardia and Cryptosporidium as well as the molecular characterization of these organisms in dogs and cats in Chiang Mai, Thailand was completed. A greater understanding of the prevalence and risk factors associated with Giardia and Cryptosporidium infection can aid veterinarians in the control and prevention of these important diseases. Furthermore, the potential for zoonotic transmission will be reduced. In Chapter 1, Giardia and Cryptosporidium and its epidemiology in dogs and cats are reviewed as well as an update on the situation regarding giardiasis and cryptosporidiosis in Thailand. In Chapter 2, a preliminary study to determine the prevalence of Giardia and Cryptosporidium infection in dogs and cats in Chiang Mai, Thailand is described. Fecal samples were collected for two months (July and August, 2008). The genotype/species of these two organisms were determined as well as the risks associated with infection such as age, sex, diarrhea status, housing type and the presence of co-infection of Cryptosporidium (for Giardia infection) or the presence of Giardia in the case of Cryptosporidium infection. It was shown that Giardia and Cryptosporidium infections were common in dogs in Chiang Mai and that dogs could be a potential reservoir for zoonotic transmission to humans. In Chapter 3, the larger cross-sectional study is described. Samples were collected a year later from August 2009 to February 2010. The objectives were to determine the effect of seasonality (wet months or rainy vs. dry months or winter), to determine the potential risk factors associated with Giardia and Cryptosporidium infections, as well as to determine the genotype/species of these organisms. The results suggested that Giardia infection in dogs was prevalent in the rainy season, whereas seasonality was not significantly associated with Cryptosporidium infection. Young dogs, dogs living in crowded settings, dogs having diarrhea or chronic diarrhea, and dogs shedding Cryptosporidium oocysts had a high risk for Giardia infection. Risk factors associated with Cryptosporidium infection in dogs were age less than one year and dogs having diarrhea. Giardia duodenalis assemblage A and C. parvum were identified in this study; however, the potential role in zoonotic transmission could not be determined. Chapter 4 presents a brief report on the comparison of sugar and sedimentation concentration techniques prior to immunofluorescent assay to detect Giardia cysts and Cryptosporidium oocysts. Concentration of fecal samples may enhance the detection of cysts and oocysts. However, in frozen samples the spherical structure of Giardia cysts or Cryptosporidium oocysts may be affected by the freeze-and-thaw process; therefore, the use of sugar concentration technique may not appropriate for frozen fecal samples. Chapter 5 compares the PCR assays using different target genes in detecting Giardia and Cryptosporidium in dogs and cats from Chiang Mai, Thailand. Three PCR assays for Giardia were compared, including the PCR targeting to glutamate dehydrogenase (gdh), triose phosphate isomerase (tpi), and β-giardin gene. Three PCR assays for Cryptosporidium, a heat shock protein targeting PCR and two PCR assays to detect SSU-rRNA (one step PCR vs nested PCR assays), were compared. Giardia gdh and Cryptosporidium one-step SSU-rRNA PCR assays had the highest amplification rates. Using a multilocus analysis approach, most of the Giardia isolates were dog genotypes, whereas 30%-40% of Cryptosporidium species were C. parvum. This finding may suggest a potential role of zoonotic transmission of Cryptosporidium from dogs and cats in this region of Thailand. The research described in this dissertation raises the knowledge in the field of canine and feline giardiasis and cryptosporidiosis. The results provide additional prevalence and risk analysis results for dogs and cats in Chiang Mai, Thailand. The molecular analyses suggest that the use of multilocus analysis is superior to using only one locus. In addition, the results also suggest that sugar flotation was not appropriate as a concentrating method for frozen fecal material and that sedimentation should be used when freezing of the sample is necessary.Item Open Access One health in the U.S. military: a review of existing systems and recommendations for the future(Colorado State University. Libraries, 2014) Evans, Rebecca I., author; Salman, Mo, advisor; Lappin, Michael, committee member; Hayne, Stephen, committee member; Peel, Jennifer, committee memberBackground: The merging of the former U.S. Army Veterinary Command (VETCOM) with the former U.S. Army Center for Health Promotion and Preventive Medicine (USACHPPM) into the U.S. Army Public Health Command (USAPHC) in 2011 created an opportunity for the military to fully embrace the One Health concept. That same year, the USAPHC began work on a Zoonotic Disease Report (ZDR) aimed at supporting critical zoonotic disease risk assessments by combining zoonotic disease data from human, entomological, laboratory, and animal data sources. The purpose of this dissertation is to facilitate the creation of a military Zoonotic Disease Surveillance program that combines disease data from both military human and animal sources. Methods: Five of the most commonly used human military medical data systems were systematically reviewed using a standardized template based on Centers for Disease Control and Preventive Medicine (CDC) guidelines. The systems were then compared to each other in order to recommend the one(s) best suited for use in the USAPHC ZDR. The first stage of the comparison focused on each system's ability to meet the specific goals and objectives of the ZDR, whereas the second stage applied capture-recapture methodology to data system queries in order to evaluate each system's data quality (completeness). A pilot study was conducted using Lyme borreliosis to investigate the utility of military pet dogs as sentinel surveillance for zoonotic disease in military populations. Canine data came from 3996 surveys collected from 15 military veterinary facilities from 1 November 2012 through 31 October 2013. Surveys simultaneously collected Borrelia burgdorferi (Bb) seroprevalence and canine risk factor data for each participating pet dog. Human data were obtained by querying the Defense Medical Surveillance System for the same 15 military locations and the same time period. The correlation of military pet dog Bb seroprevalence and military human Lyme disease (borreliosis) data was estimated using the Spearman Rank Correlation. The difference between military pet dog data and civilian pet dog data was examined through the use of the chi-squared test for proportions. Multivariable logistic regression was then used to investigate the potential for identified risk factors to impact the observed association. Results: The comparison of human military medical data systems found the Military Health System Management Analysis and Reporting Tool (M2) data system most completely met the specific goals and objects of the ZDR. In addition, completeness calculation showed the M2 data source to be the most complete source of human data; 55% of total captured cases coming from the M2 system alone. The pilot study found a strong positive correlation between military human borreliosis data and military pet dog Bb seroprevalence data by location (rs = 0.821). The study showed reassuring similarities in pet dog seroprevalence by location for the majority of sites, but also showed meaningful differences between two locations, potentially indicating military pet dogs as more appropriate indicators of Lyme disease risk for military populations than civilian pet dog data. Unfortunately, whether canine Bb seroprevalence is influenced by the distribution of identified risk factors could not be determined due to limited study power. Conclusions: Based on this study M2 was recommended as the primary source of military human medical data for use in the Public Health Command Zoonotic Disease Report. In addition, it was recommended that Service member pet dog data be incorporated as a sensitive and convenient measure of zoonotic disease risk in human military populations. The validity of the data, however, should be evaluated further with either larger sample sizes and/or a zoonotic disease with higher prevalence.Item Open Access Peri-slaughter ecology of Escherichia coli O157 and Salmonella enterica in feedlot beef cattle(Colorado State University. Libraries, 2008) Dewell, Grant Alan, author; Salman, Mo, advisorRisk factors for prevalence of E. coli O157 prior to slaughter and the genotypic relationship between feedlot and slaughter isolates were investigated. The odds of E. coli O157 positive fecal samples from cattle fed brewers grains were 6 times that for cattle not fed brewers grains. The odds of E. coli O157 positive fecal samples from cattle from Central Nebraska was 9 times that for cattle from Eastern Colorado. Within the sampled pens, 64% of the hide samples at the abattoir corresponded to a feedlot isolate. For carcass samples, 59% of isolates had a corresponding feedlot isolate. Transportation of cattle from the feedlot to the slaughter plant could influence hide contamination of Escherichia coli O157 or Salmonella enterica. Cattle held in E. coli O157 positive lairage pens had eight times greater relative risk of having E. coli O157 positive hide samples compared to cattle held in culture-negative pens. Cattle that were held in lairage pens contaminated with feces had three times greater relative risk for E. coli O157 positive hide samples and twice the relative risk for S. enterica positive hide samples compared to cattle held in clean pens. Cattle that were transported for long distances (> 160.9 km) had twice the relative risk of having E. coli O157 positive hide samples and twice the relative risk of having S. enterica positive hide samples compared to cattle transported shorter distances. Cattle with positive Salmonella enterica hide samples at the feedlot had almost twice the relative risk of having S. enterica positive hide samples compared to cattle without S. enterica positive feedlot hide samples. Cattle transported in trailers with positive S. enterica samples had over twice the relative risk of having S. enterica positive hide samples compared to cattle transported in culture negative trailers. Cattle held off feed longer than 18 hours before loading had a greater relative risk of having S. enterica positive hide samples compared to cattle held off feed for shorter times. Cattle that were agitated during loading had twice the relative risk of having S. enterica positive hide samples compared to cattle that were calm.Item Open Access RNA interference as an alternative preventive measure for avian influenza in poultry(Colorado State University. Libraries, 2014) Linke, Lyndsey M., author; Salman, Mo, advisor; Landolt, Gabriele, committee member; Olea-Popelka, Francisco, committee member; Wilusz, Jeffrey, committee memberAvian influenza virus (AIV) is a viral pathogen that causes a wide range of disease in poultry, from subclinical to severe clinical illness and can often result in death. In 1878, AIV was first described as a disease affecting poultry. Nearly 80 years later this disease-causing agent was identified as influenza A virus and a member of the family Orthomyxoviridae. AIV was not considered a significant human pathogen until 1997, when high pathogenic AIV H5N1 emerged from the wildfowl reservoir and was directly transmitted from domestic poultry to humans. Despite a long history of outbreaks in animals, this incident propelled AIV into a globally recognized disease associated with socioeconomic and animal health consequences. Each AIV outbreak highlights ways to improve upon current control strategies and stimulates new ideas for developing novel approaches and technologies to better mitigate AIV outbreaks worldwide. AIV is a dynamic pathogen to study. Host range and adaptation, pathogenicity, pathology, molecular composition, and the epidemiology of AIV all make this virus particularly challenging to control in poultry. Vaccines against AIV are available but the protection they provide for poultry is limited, especially when administered at the onset or in the midst of an outbreak. The most efficacious vaccines must be administered subcutaneously or intramuscularly, an impediment to successfully immunizing large numbers of poultry in a short window of time. Frequently, improper storage and handling leads to vaccine failure. To elicit efficient protection the vaccine must be HA-subtype specific to the outbreak virus. Often stockpiles of vaccines become obsolete and new vaccines must be generated. This is a time consuming process and can take months to secure and additional time to disseminate and administer. In the naive animal, protective antibody production takes two to three weeks to acquire following vaccination. Even if the decision to vaccinate during an outbreak is rapid and an appropriate vaccine is available for immediate use in poultry, vaccination alone would do little to protect against the threat of infection and break the chain of transmission, especially in areas lacking appropriate biosecurity measures. These limitations convey a genuine need to develop a prophylactic that would offer universal protection against any subtype or strain of AIV and would provide rapid protection in the face of an outbreak. Using RNA interference (RNAi) methodologies, this dissertation focuses on developing an innovative antiviral prophylactic that works rapidly to protect poultry against AIV shedding and transmission. The innovation behind this prophylactic technology lies in combining RNAi with the transkingdom RNAi (tkRNAi) delivery platform. This anti-AIV technology specifically targets conserved viral gene segments using small interfering RNA (siRNA) generated and delivered to chicken mucosal respiratory tissues using the tkRNAi system. The work presented in this dissertation details the steps taken to show proof of concept for using this technology to prevent AIV replication and shedding in vitro using an avian cell model and in vivo using commercial chickens. The overarching vision for this anti-AIV technology is to provide a cost effective means to protect commercial and backyard flocks against AIV outbreaks. The long-term goal is to promote this prophylactic as a complement to vaccination with the intention of developing a more effective and robust control plan against AIV in poultry. If this technology is successful, it could be applied in the face of an outbreak to reduce the shedding and transmission of virus within poultry, between farms, and across borders, thereby improving animal health and reducing the economic impact of outbreaks worldwide. Additionally, this work could provide the framework and valuable evidence for developing a similar anti-influenza prophylactic for humans.Item Open Access Silvopastoral system for sustainable cattle production in the tropics of Mexico(Colorado State University. Libraries, 2017) Erales Villamil, José Alberto, author; Salman, Mo, advisor; Reid, Robin S., committee member; Solorio Sánchez, Francisco J., committee member; Van Metre, David C., committee member; Zepeda, Cristobal, committee memberTraditional production system has exhausted natural resources and depleted soil nutrients reducing farm productivity and forcing farmers to expand farm lands, which, increases deforestation and pollution. Global warming and an increasing global population pose additional strain to the already fragile global food security, making it urgent for innovative production systems to be developed. Such systems, adapted to local circumstances and designed to reduce deforestation and increase food production, must emerge to provide an expanding global food demand while enabling preservation of natural resources. In Mexico, a five-year research project, derived from a national initiative has proposed a silvopastoral model for the Tepalcatepec valley, in the State of Michoacan, as an alternative to conventional livestock ranching in the tropics. The primary objective for this research project was to characterize the advantages and disadvantages of an alternative livestock farming model, the silvopastoral system. One hundred and fifteen farmers in the Tepalcatepec valley were surveyed to characterize their farms, their family demographics, main cattle breed, crops farmed, cattle diet, measures of animal performance (productivity) commercialization (marketing practices) and animal health management practices. An analysis of the progress of the various national SPS initiatives was also performed in order to identify gaps in research, collaboration, stakeholder education, and application of SPS farming in Mexico. A systems analysis was conducted on the research project using the information compiled from the team of scientists surveyed. Components related to carbon capture, biodiversity, soil quality, nutrient recycling, and larger-scale cycles such as water cycle need to be incorporated into future research. An accurate measure of the true economic and ecological impact of SPS farming is an essential goal. Improved communication among scientists, government agencies, and stakeholders is also essential for successful research into SPS farming. The animal health component of the five-year Mexican national SPS project is the focus of this dissertation. Traditional livestock health practices on participating small farms were characterized, and common health problems of cattle were identified. A community based livestock syndromic surveillance system was developed, implemented, and observed for two years on five selected farms. Observations from farmers and veterinarians were triangulated to validate data on animal health collected by laypeople. For each farm under study, monthly cumulative incidence per animal category (calf, grower or adult), the most frequent disease syndrome, and the syndrome that carried the greatest economic impact were calculated. Most Rho correlation coefficients for farmer's and veterinarian's observations were high. Farmers that implemented the silvopastoral model were considered typical of those who practiced this farming method elsewhere within the region. Because participating farms shared production system, husbandry, livestock health status, disease preventive measures, products, and commercialization channels, they were considered an epidemiological compartment for quantitative risk analysis. Six different scenarios were created and analyzed using the software @Risk™ to measure the risk of introduction of bovine tuberculosis into this epidemiological compartment. The Mexican national program for control and eradication of bovine tuberculosis norm, regional prevalence on bovine tuberculosis, and current cultural practices in Tepalcatepec valley were considered for this analysis. The introduction of replacement heifers or sires into the farms, and the probability of the introduction of at least one infected animal was estimated. The least probable scenario for the introduction of tuberculosis into this compartment was the introduction of at least one infected animal, despite the prevalence of source herd, after applying tuberculin caudal fold test and cervical comparative test in parallel. Although some farmers are aware that the silvopastoral system is profitable, environmental friendly, and socially acceptable, initial investment appears to be the first barrier for adoption. Alternatives for funding SPS development are needed such as preferable interest rates, credit, and loans; notably, an accurate assessment of the costs for establishment of SPS should be more thoroughly studied. The initial three years of SPS implementation have the highest amount on investment; for those years, special attention should be placed on recording the contributions of timber and/or fruit to financial returns, since these products may be the key for offsetting the cost of SPS implementation Further research is needed to more accurately measure the economic, ecological, animal health, and human health impact of the silvopastoral model of farming in the tropics. An ample variety of species combinations, suitable for silvopastoral production, should be studied and different arrays proposed to encourage scaling up the model. Research funding is scarce; however, public awareness of the need for a change in production practices and the allure of environmental friendly-produced animal products can produce a market-driven change in these small-scale food production operations. This could engender greater research support from industry and government sources, as well as non-governmental organizations dedicated to promoting sustainable agricultural practices in a changing global environment.Item Open Access Surveillance and diagnosis of transmissible spongiform encephalopathies in the United States(Colorado State University. Libraries, 2007) Dennis, Michelle Marie, author; Salman, Mo, advisorSince limited knowledge of transmissible spongiform encephalopathies (TSEs) restricts treatment and successful control interventions, and since some may cause fatal food-borne disease in humans, the United States (U.S.) has established TSE surveillance programs to support control efforts and to protect agriculture-based economy. The enhanced BSE surveillance system was conducted to characterize the extent of the presence of BSE in the U.S. cattle population in order to reassure consumers and trading partners of the U.S. BSE status. Given the level of importance and the cost of the enhanced BSE surveillance program, surveillance system evaluation was conducted to provide feedback for improving future surveillance and to determine the extent to which the system had met its objectives. Recommendations were made to improve efficiency and quality of future BSE surveillance systems. The enhanced BSE surveillance certainly met its stated objectives. Surveillance interests in the U.S. were subsequently re-directed towards efficiently assuring that BSE control measures remain effective, and to maintain assurance of trading partners of the U.S. BSE status. A plan for ongoing BSE surveillance was constructed using the standards and guidelines for animal health surveillance established by the National Surveillance Unit (NSU). Results derived from the enhanced BSE surveillance system and its evaluation prompted appriopriate adaptations for maintenance surveillance methods. Conditions which naturally degrade prions need to be elucidated to facilitate disposal of prion-contaminated biowastes. In order to determine whether long-term heating could destroy prions, the immunodetection of protease-resistant, disease-associated prion protein (PrPres) was evaluated in brain from chronic wasting disease (CWD)-affected elk. Using 3 diagnostic assays for CWD, progressive loss of PrPres immunodetectability, which increased with incubation temperature, was demonstrated when brain homogenates were incubated at 37, 55, and 80° C over a period of 200 days. Disposal systems which use heat over time may effectively degrade prions. Furthermore, the validity of test results derived from tissues which have been exposed to such conditions is questionable. In the U.S., scrapie surveillance uses PrPres immunohistochemistry (IHC) applied to tissues collected postmortem. The only live animal test available, PrPres IHC applied to third eyelid biopsy, is limited by comparatively lower sensitivity, high frequency of inconclusive test results, and the limited amount of tissue available for repeat testing. A study evaluated PrP res IHC applied to recto-anal mucosa associated lymphoid tissue (RAMALT) biopsy for scrapie diagnosis in live sheep. Biopsy-related complications were rare. The sensitivity of RAMALT biopsy PrPres IHC ranged from 87.5-89.3%, and approximated or exceeding that applied to third eyelid biopsy. The use of PrPres IHC applied to RAMALT biopsies for scrapie diagnosis in live high-risk sheep is expected to improve the surveillance activities that support the success of the U.S. National Scrapie Eradication Program.Item Open Access The animal health components of a biosurveillance system(Colorado State University. Libraries, 2023) Tan, Alwyn, author; Salman, Mo, advisor; McCluskey, Brian, committee member; VandeWoude, Susan, committee memberBiosurveillance defines a One Health approach of gathering, integrating, interpreting, and communicating information related to health hazards or diseases affecting human, animal, or plant health and their environment to achieve early detection and warning, situational awareness, and better decision making. Animal health surveillance is an important component within biosurveillance systems comprising a continuum of activities from detecting biological threats, to analyzing relevant data, to managing identified threats, and embracing a One Health concept. Despite ongoing health surveillance activities conducted by various stakeholders in different One Health sectors, numerous health crises continue to occur, affecting the health of humans and animals, the livelihoods of people, the economy, their environment, and social harmony. Zoonotic agents caused a large proportion of these health crises, and nations spent large amounts of resources on disease detection and control measures to safeguard the health of their citizens against these agents. This thesis will explore how the animal health community can strengthen biosurveillance in the following sections: 1) the components of a biosurveillance system from an animal health perspective and opportunities for the animal health surveillance community to enhance biosurveillance; 2) a pilot study on the use of air-sampling as a novel method for animal health surveillance; 3) a scoping review on behavioral barriers, enablers, and interventions for animal owners and producers reporting animal diseases to veterinary authorities; and 4) theoretical demonstration of a biosurveillance system.Item Open Access The burden of acute gastrointestinal illness and foodborne illness caused by five major pathogens among nondeployed active duty US Army service members 2014-2015(Colorado State University. Libraries, 2016) Mullaney, Sara Beth, author; Salman, Mo, advisor; Hyatt, Doreene, committee member; McCluskey, Brian, committee member; Rao, Sangeeta, committee memberTo view the abstract, please see the full text of the document.Item Open Access The use of on-line continuing education modules to improve awareness of African horse sickness among U.S. equine veterinarians(Colorado State University. Libraries, 2011) Wiedenheft, Alyson M., author; Traub-Dargatz, Josie, advisor; Salman, Mo, advisor; Gillette, Shana, committee member; O'Keefe, Garrett, committee memberU.S. equine veterinary practitioners will likely be responsible for the detection and reporting of a foreign animal disease (FAD) incursion, such as African horse sickness (AHS), into the U.S. On-line continuing education is one method of increasing awareness about FADs among equine veterinarians by providing a consistent message that can be conveniently accessed by most veterinarians. Two major types of on-line continuing education include webinar and text formatted modules. An on-line educational assessment study for equine veterinarians was developed to determine baseline knowledge of AHS as well as the effectiveness of webinar versus text formatted education modules. The results from this study imply that the participants were not initially prepared to recognize and report a suspect case of AHS. Additionally, the webinar and text formatted modules were equally effective in educating the equine veterinarians about AHS. The low voluntary participation rate in the study implies that on-line continuing education is not currently the best method for preparing equine veterinarians in the U.S. for an FAD outbreak. If equine veterinarians become more willing to participate in on-line education based on the new requirements for accreditation, or if incentives/penalties are used to promote on-line continuing education participation, this continuing education method may become more accepted by U.S. equine veterinarians in the future.Item Open Access Uses of quantitative spatial analysis and epidemiological simulation modeling for assessing control strategies for foot-and-mouth disease(Colorado State University. Libraries, 2012) Premashthira, Sith, author; Salman, Mo, advisor; Hill, Ashley, committee member; Reich, Robin, committee member; Wagner, Bruce, committee memberThis study addressed issues related to a hypothetical outbreak of foot-and-mouth disease (FMD) comparing a limited control measure to additional control strategies where there were limited control strategies within FMD virus free area. The central United States was selected as the study area, and the spatial pattern of FMD and its determinants were observed after FMD was introduced into the center of the area. The research reported the magnitude of the outbreaks in different scenarios having different control strategies. The first four chapters in this dissertation cover the sequence of research methods, and the final chapter includes the results and discussion. Chapter 1 reviews aspects of epidemiology of FMD, epidemiological simulation modeling, and spatial analysis with the focus on FMD in terms of disease control. The review stimulated some ideas to generate parameters for the FMD simulation modeling that was done in Chapter 2. Chapter 2 explains the process for generating parameters for a hypothetical outbreak of FMD in the central Unites States. The process included gathering location study premises in the study area from many sources and a simulator. The disease stage and transmission parameters of FMD were estimated from reviews and statistical analyses of data distribution, adjusted for study premises size. The sensitivity analysis of important parameters was analyzed by comparing disease spread for various values of the input parameters. Chapter 3 examines the practical plans in place for FMD control and eradication. The baseline scenario was set up from the base parameters from Chapter 2 and included some limited control strategies. The additional five strategies included additional intensive disease control measures such as restricted animal movement, additional animal destruction, or ring vaccination. The baseline and extra five scenarios were simulated in a simulator and their magnitude was observed, including epidemic duration and estimated number of destroyed and/or vaccinated animals. Chapter 4 identifies the simulated outbreak region and its spatial determinants in the baseline scenario. The density estimation of affected areas was determined and illustrated by maps. Additional quantitative spatial methods such as spatial continuity, autocorrelation, and autoregressive model were analyzed to explain spatial trends and factors related to the affected areas. Chapter 5 concludes the important findings of this research. The overall conclusion summarizes the results from the previous chapters. A hypothetical outbreak of FMD in a large study area such as the one in this research should identify the premises of livestock as the unit of interest. The spread of FMD in the area may be primarily caused by indirect contact rather than direct contact and airborne transmission. The change of parameters in the indirect contact rates was sensitive to the outcome of the simulation. All additional disease control strategies were better than the baseline scenario in terms of reducing the magnitude of the outbreak, but not in shortening the epidemic duration. For example, restricted animal movement was the best strategy to reduce magnitude of the outbreak, but it lengthened the epidemic duration. The kernel density estimation method demonstrated that the outbreak would spread throughout most of the study area. More affected premises in each county arose when higher numbers of livestock premises were in it and neighboring zones.