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Modern pork production uses a variety of tools to ensure the health, welfare and productivity of pigs. Therapeutic (treatment and prevention of disease) use and use for enhancing growth and feed efficiency (growth promotion) are the two options for use on the farm. Collecting meaningful and accurate antibiotic use data faces significant challenge because of the number and variety of production systems, the need for broad stakeholder analysis of the data and the lack of consistent and science-based definitions of antibiotic use categories. The National Animal Health Monitoring System (NAHMS) is one mechanism that estimates uses based on a statistical sample of the nation's swine herd. If, based on sound science, additional information on antibiotic use is considered necessary, stakeholders should discuss the best implementation strategies to achieve the desired result. Producers continue in their science-based commitment to ensure the safety of pork and to maintain consumer confidence.

Bacterial antimicrobial resistance is a problem common to both animal and public health. An important public policy issue is to develop and implement prudent use practices where antimicrobials are used. As policy develops, there are questions regarding the use of antimicrobials in animal agriculture and whether these uses constitute prudent use. A series of papers assessing the risk to the public health from agricultural use of antimicrobials have consistently concluded that risk estimation is hampered by the lack of data that describe the amount, types, and uses of antimicrobials in animal agriculture. The absence of information has spurred efforts to develop a framework to collect these data. However, the reasons and benefit of collecting these data should be carefully defined. The dairy industry, contrasted to other major animal commodities, is not focused on meat production but on milk production. Milk production is constrained by disease and antimicrobial treatment is a common management tool, but unlike many other animal agricultural systems where the value and safety of the product is measured in the future; the value of milk is zero when an antimicrobial is used in a lactating cow and milk must be discarded because of residues. While there are exceptions, e.g. non-lactating cow therapy, this difference results in antimicrobials being used sporadically and directed at therapy rather than prophylactic uses. In the dairy industry, antimicrobial use data and its consequences may exist in sufficient detail or could be estimated from existing datasets without the expense of additional surveys. Finally, the main food product milk is mainly pasteurized and all shipments of milk from the farm to the processing plant are tested for the presence of antimicrobials. This makes the likelihood of farm-origin antimicrobials or bacteria appearing in finished product very low. This suggests that the use and quantity of antimicrobials in the dairy system has little impact on public health. This does not imply that the dairy industry does not have a significant role in developing guidelines for appropriate and careful application of antimicrobials, but the effort and cost to collect additional data should be used to fund efforts that improve our diagnostic and managerial skills. These data would change the use of antimicrobials by decreasing the rates of disease and ultimately decreasing prophylactic, metaphylactic and therapeutic use of antimicrobial. These studies and outcome are as important to the dairy industry as to public health.

Economics seeks to understand and explain the allocation of resources within society and to suggest appropriate policy to achieve goals such as optimal efficiency. Relating antimicrobial use and antibiotic resistance is a complex task and requires very clear and careful analyses of many relationships. To address these relationships, antibiotic use data must be linked with other basic data. Ideally, a complex relational database needs to be developed. These must include data on: antimicrobial usage, farm-level animal productivity, basic disease, basic farm management, consumer response, and antimicrobial resistance at multiple levels (farm, during process, on a variety of both animal, vegetable and grain-derived food products, from humans, from other animal species, and from the environment) among other data. Such a complex relational database can help with the attribution and risk assessment process. Also these linked data are needed in order to develop the economic production models and other economic models, as well as control for confounding so that there is both adequate and appropriate statistical control. Antimicrobial usage data may become economically important for reasons unrelated to animal productivity and animal health. With expanding global trade of animals and animal products, there have been changes in restrictions and regulations associated with the movement of products. Future trade opportunities may be linked to antimicrobial usage. The European Union banned the use of antimicrobials for growth-promoting purposes based on perceived risk and on public opinion. Monitoring antimicrobial use, disease occurrence, and resistance patterns following changes in usage that are a result of either policy changes or response to new information will help in the understanding of the complex relationships in microbial and disease ecology. There is a lot of evidence substantiating the productivity and profitability gains to producers from the use of antimicrobials. There is also evidence for the potential gains to consumers, both from an economic perspective as well as from a health perspective. Economists can help identify the implications of these relationships both at a micro- and macro-economic level; both relative to producer and to consumer welfare. We are at a pivotal time in history with sufficient analytical expertise and tools to address this complex issue from a scientific perspective. Linking various agencies so there can be coordination of data collection and data sharing is needed to successfully address this topic.

The total quantity of use in companion animals is generally believed to be relatively small in comparison with antimicrobial use in food animals. Use in companion animals is principally for treatment, whereas the greater proportion of use in food animals is for prophylaxis, metaphylaxis and growth promotion. Therefore, it is important to collect data on end use in companion animals so that overall estimates of use in companion animals can be generated and separated from estimates for food animals. However, data from antimicrobial use in companion animals are extremely limited and no serious attempts to collect such data have ever been made in the United States. The lack of usage data in is concomitant with the dearth of information on antimicrobial resistance in companion animals. Companion animals have been involved in the transmission to humans of, or become infected with, foodborne zoonotic bacteria such as Salmonella and Campylobacter. Companion animals are an integral part of the ecology of antimicrobial resistance through their contact with food animals and exposure to antimicrobials for disease treatment and through contact with humans and the environment. In the practice of companion animal medicine, antimicrobial use data are important for understanding the potential impact on companion animal heath posed by antimicrobial resistance transferred from food animals, humans and the environment, and the threat to humans and other companion animals posed by antimicrobial use in companion animals. Basic information on the patterns and quantities of antimicrobial use in combination with resistance surveillance data, could help companion animal veterinarians understand the potential for development, or evidence of, an antimicrobial resistance problem in their practices, the role of companion animals in the overall epidemiology of antimicrobial resistance, and for comparison with local, regional, or national data. The combination of data from either a sentinel site system of clinics or a use survey with national data from the pharmaceutical industry should provide sufficient data to credibly estimate the total volume and patterns of antimicrobial use in companion animal medicine. The time and effort for use monitoring or to complete a survey would likely become burdensome. Practice management software now utilized at most companion animal clinics could be used to generate antimicrobial use data as well as patient population data as surrogate for the true population at risk for patient encounters in a companion animal practice.

Food animal veterinarians practice in a variety of settings with considerable differences between the settings. Due to variability, aggregate data from surveillance of antimicrobial use is not very useful to practitioners unless correlated information is provided, such as the relative disease status, ages of animals, and purpose of use. Of greater utility is use data as it relates to a specific farm or production system. Of greater importance to clinical practitioners is a meaningful surveillance system that tracks trends in antimicrobial resistance in common pathogens causing animal diseases.

Epidemiologists studying antimicrobial resistance are often interested in analyzing the association between antimicrobial resistance and antimicrobial use in animals, and on the impact of antimicrobial use in animals on the occurrence of resistance in bacteria affecting human populations. Given the various potential antimicrobial use data sources, it seems likely there will be some variability in the utility of the data for interpreting trends in antimicrobial resistance and investigating the relationship between antimicrobial use in animals and antimicrobial resistance in bacteria affecting human health. From an epidemiologic perspective, the major issues related to incorporation of antimicrobial use data into antimicrobial resistance monitoring programs are the further development of epidemiologic methods for collecting, quantifying, analyzing and interpreting use data; an open and realistic consideration of the limitations of the data; developing an understanding of scaling, temporal and spatial heterogeneity issues; and the interpretative problems of ecologic and atomistic fallacy. Given the many potential biases in antimicrobial use data, attempts to relate levels of antimicrobial use to levels of antimicrobial resistance should be done with caution until the data are better understood and the aforementioned issues have been addressed.

There has been renewed concern in recent years about the use of antibiotics in food animal production and the potential risk it may pose to public health due to transfer of antibiotic resistance factors via the food supply. Although a legitimate concern, it bears reminding that this debate is not new. It has been ongoing for decades, yet there is still no documented case of human treatment failure due to antibiotic resistant bacteria acquired from USDA-inspected meat and poultry. This fact strongly suggests that the issue is not the imminent threat as has been portrayed by certain individuals or advocacy groups. The poultry industry as a whole has been using antibiotics responsibly for several decades, and there are strong beneficial arguments for their continued use. Responsible public policy demands a science-based approach be utilized in the decision making process before attempting to restrict or remove certain products due to overestimated risks. Part of this scientific review should include antibiotic use data, however this information has definite limitations and shortcomings which need to be understood before attempting to make any valid antibiotic resistance associations.

The use of antimicrobials in domestic aquaculture is limited. There are only two approved and available antimicrobials for food fish (Terramycin for Fish) and Romet-30 and one approved for ornamental fish (nifurpirinol). These antimicrobials are only approved to treat specific diseases in specific aquatic animal species. Antimicrobial use data, as well as environmental fate information and analysis of barriers to transmission, are valuable for assessing qualitative or quantitative risk. In the US, the limited availability of antimicrobials and use in aquaculture suggests the best quantitative source of antimicrobial use information is directly from drug manufacturers.

The purpose of this study was to estimate the impacts of rapid and accurate tracing of cattle movements during a Foot-and-Mouth Disease (FMD) outbreak in the United States (US). To simulate introduction and spread of FMD we utilized InterSpread Plus, a spatially explicit disease transmission model, and a national livestock population file. The simulations began in one of four regions of the US via beef or dairy cattle as the index infected premises (IP). The first IP was detected 8, 14, or 21 days after introduction. The tracing levels were defined by the probability of a successful trace and the time to trace completion. We evaluated three tracing performance levels, a baseline that represents a mix of paper and electronic interstate shipment records, an estimated partial implementation of electronic identification (EID) tracing, and an estimated full implementation of EID tracing. To evaluate the potential to decrease the size of control areas and surveillance zones with full EID use, we compared the standard size for each to a reduced geographical area for each. The total number of IPs in an outbreak varied with the location of the index farms. Within index farm locations and across tracing performance levels, early detection (day 8) resulted in fewer IPs and a shorter duration of the outbreak. The impact of improving tracing was most evident within introduction region when detection was delayed (day 14 or 21). Full EID use decreased the 95th percentile but had a smaller impact on the median number of IPs. Improved tracing also decreased the number of farms impacted by control efforts in control areas (0–10 km) and surveillance zones (10–20 km) by decreasing outbreak size (total IPs). Decreasing the control area (0–7 km) and surveillance zone (7–14 km) sizes while using full EID tracing further decreased the number of farms under surveillance but increased the number of IPs slightly. Consistent with previous results, this supports the potential value of early detection and improved traceability to control FMD outbreaks. Further development of the EID system in the US is necessary to achieve the modeled results. Further research into the economic impacts of enhanced tracing and decreased zone sizes are needed to determine the full impact of these results. [ABSTRACT FROM AUTHOR]

Abstract: In 2003, the University of Florida (UF) College of Veterinary Medicine (CVM) created an Office of International Programs (OIP) in response to one of ten initiatives of the UF Strategic Plan: internationalization of the curriculum. The OIP has developed coursework that provides students with an opportunity for international exposure during the veterinary curriculum at three levels. In Level 1 (on campus) students can participate in a seminar series in global health: www.ufglobalhealth.org. This is an elective course offered to professional students at the UF Health Science Center (Dentistry, Medicine, Pharmacy, Public Health, and Veterinary Medicine). In Level 2 (abroad), students can participate in structured study abroad programs under the supervision of UF faculty and international scholars from collaborative institutions abroad. In Level 3 (on campus and abroad), students can participate in a certificate program in international veterinary medicine. This is a 15-credit program, parallel to the veterinary curriculum. By offering courses on campus and abroad, we want to empower the curriculum with a global perspective of the veterinary profession, as well as with a humanist education that can help students recognize the importance of respect for cultural differences and the reasons for different degrees of development and growth in the world. In addition, this paper presents the need for veterinary medicine and other disciplines in the health sciences to communicate with other disciplines in the social sciences and natural sciences to create development practitioners equipped with cross-disciplinary knowledge and skills needed to formulate, implement and evaluate solutions aimed at breaking the cycle of poverty and disease in low income societies. Finally, this paper makes a call to the American Veterinary Medical Association Council on Education to assess the need to recognize the importance of internationalization of the veterinary curriculum as a key standard for accreditation of colleges or schools of veterinary medicine. [Copyright &y& Elsevier]

Abstract: Bovine Spongiform Encephalopathy (BSE) rapidly evolved into an issue of major public concern particularly when, in 1996, evidence was provided that this disease had crossed the species barrier and infected humans in the UK with what has become known as “variant Creutzfeldt Jakob Disease” (vCJD). The aim of this paper is to describe the European Geographical BSE risk assessment (GBR) that was successfully used for assessing the qualitative likelihood that BSE could be present in a country where it was not yet officially recognized. It also discusses how this can lead to risk-based and therefore preventive management of BSE at national and international levels. The basic assumption of the GBR method is that the BSE agent is initially introduced into a country''s domestic cattle production system through the importation of contaminated feedstuffs or live cattle. This is referred to as an “external challenge”. The ability of the system to cope with such a challenge is, in turn, referred to as its “stability”: a stable system will not allow the BSE agent to propagate and amplify following its introduction, while an unstable system will. The BSE-status of a country assessed by this system was used by the European Commission as the basis for trade legislation rules for cattle and their products. The GBR was an invaluable tool in evaluating the potential global spread of BSE as it demonstrated how a disease could be transferred through international trade. This was shown to be a critical factor to address in reducing the spread and amplification of BSE throughout the world. Furthermore, GBR resulted in the implementation of additional measures and management activities both to improve surveillance and to prevent transmission within the cattle population. [Copyright &y& Elsevier]

Abstract: In 2010 the United States implemented the Veterinary Medicine Loan Repayment Program (VMLRP) to address perceived regional shortages in certain veterinary occupations, including food animal practice. With county as the unit of analysis, this paper describes a pair of models to evaluate factors associated with being designated a private practice shortage area in 2010. One model is used to explain food animal veterinarian location choices so as to provide an objective evaluation of comparative shortage. The other model seeks to explain the counties chosen as shortage areas. Model results are then used to evaluate the program. On the whole the program appears to perform quite well. For several states, however, VMLRP shortage designations are inconsistent with the food animal veterinarian location model. Comparative shortage is generally more severe in states that have no VMLRP designated private practice shortage counties than in states that do. [Copyright &y& Elsevier]

Abstract: This paper compares the behavior of two competing models for the transmission of pseudorabies virus in feral swine in the USA. In first model, horizontal (non-sexual) density dependent transmission is the only transmission modality. In the second model, the only transmission modality is sexual transmission between mature males and females. The comparison of model behavior was carried out to test the hypothesis that preferential sexual transmission of PRV in feral swine can account for the seroprevalence observed in the field. The observed range of seroprevalence of PRV in mature feral swine in the USA is consistent with a preferential sexual transmission only if the feral swine mating system is a random mating system or a polygynous system in which there is a relatively large rate of acquisition of new mates. The observed range of seroprevalence of PRV in mature feral swine in the USA is not consistent with a preferential sexual transmission if there is mate guarding. This is important because the National Pseudorabies Surveillance Plan deems monitoring the risk of PRV introduction from feral swine to be a “minor objective” both in terms of the scope of the plan and with respect to the resources allocated. The rationale for this statement was derived from experimental studies, which suggested that the PRV indigenous to feral swine in the USA is preferentially sexually transmitted. [Copyright &y& Elsevier]

Abstract: Leptospirosis is a re-emerging disease of dogs in the United States (U.S.). This paper reports the findings of a retrospective study conducted to determine if seroreactivity to Leptospira microscopic agglutination test (MAT) among dogs in the U.S. clustered in space and time. The study utilized canine sera submitted to a commercial laboratory for leptospiral MAT from January 2000 through December 2007. There were 31,869 serum samples submitted by veterinarians from 3156 zip code locations across the U.S. Results of MAT were considered positive at titers of ≥1:1600. Spatial and spatial-temporal scan statistics were used to identify statistically significant clusters of seroreactivity to Leptospira (overall and individual serovars) using recorded test request dates and locations of the centroid of the zip code reported for each serum sample. There were 2469 positive MAT results with a titer ≥1:1600 to at least one of seven Leptospira serovars. Two relevant spatial clusters of 26.3 and 246.5km radius were identified (P =0.001). The primary cluster was located in the northeastern part of Illinois including Chicago and surrounding areas (232 [14.4%] of 1612 MAT positive; RR=1.95). The secondary cluster covered the central part of Texas (292 [12.62%] of 2314 MAT positive; RR=1.71). Eight space-time clusters of overall MAT positivity were identified (29–335km radius; P =0.001–0.048 and RR=3.98–24.69) that covered different geographic locations for different time points. Spatial and space-time clusters for individual serovars were also identified for six serovars: eight each of Grippotyphosa and Pomona, seven of Bratislava, five of Autumnalis, and three each of Icterohaemorrhagiae and Canicola. In conclusion Leptospira seropositivity in dogs tended to have distinctive clusters in space and space-time. Most of the space-time clusters of overall Leptospira MAT seropositivity were associated with cluster events for individual serovars. Further investigation is warranted to explain individual serovar clusters detected in this study, as a complex interaction of incidental host, environment and reservoir host may be responsible for the occurrence of these serovar clusters. [Copyright &y& Elsevier]

Abstract: Johne''s disease (JD) is an incurable, chronic infectious disease prevalent in dairy herds throughout the US and the world. The substantial economic losses caused by JD have been well documented. However, information on the costs of controlling the disease is limited, yet necessary, if producers are to make sound decisions regarding JD management. The purpose of this paper is to describe a method for evaluating the cost-effectiveness of management changes to control JD on infected dairy farms. A 5-year longitudinal study of six dairy herds infected with JD was performed. Each herd implemented a JD control program upon study enrollment. Prevalence of JD within each herd was monitored with annual testing of all adult cows using fecal culture and/or serum ELISA. Individual cow production and culling information was collected to estimate the annual economic losses caused by JD. An economic questionnaire was developed and administered to each herd annually to estimate costs directly attributable to the JD control program. Based on the costs of the control program, and using the losses to estimate the potential benefits of the control program, the net present value (NPV) of the control program was calculated for each herd during the study and projected into the future for a total of 20 years. The NPV was calculated for four different scenarios: (1) assuming a linear decline in losses beyond the observed period of the study with JD eradication by year 20 of the control program; (2) assuming losses and JD prevalence remain constant at the rate equal to that of the last observed year while continuing the control program; (3) assuming linear increase in losses at rate equal to that in scenario 1 with no control program; and (4) assuming losses remain constant at same level as the beginning of the study with no control plan implemented. The NPV varied greatly across the herds. For scenario 1, only three herds had a positive NPV; and only two herds had a positive NPV under scenario two. In the absence of a control program, the NPV''s were always negative. The costs of the JD control programs implemented on these herds averaged $30/cow/year with a median of $24/cow/year. The annual losses due to JD averaged $79/cow/year with a median of $66/cow/year. Investing in a JD control program can be cost-effective. [Copyright &y& Elsevier]

Abstract: This paper provides condensed literature review and contextual information concerning antimicrobial use in animals and antimicrobial use data collection techniques. Information is summarized into the following topics: (I) antimicrobial use for animal growth promotion; (II) regulatory framework for approval of veterinary antimicrobials and feed additives in the United States; (III) animal health product manufacturing and distribution networks; (IV) existing estimates of animal antimicrobial use in the United States; (V) additional sources for animal use data in the United States; (VI) recommendations from international expert groups; (VII) animal antimicrobial use surveillance systems in other nations and (VIII) human use data collection systems in the United States. [Copyright &y& Elsevier]

Abstract: This paper describes the methodological options for food animal antimicrobial use data collection in the United States, including data priorities, methods, and limitations that were identified by a diverse group of expert stakeholders. Four major categories of antimicrobial use data were identified based on the source of information and its proximity to actual use: end-user data, prescription data, manufacturing data, and distribution data. Criteria were developed to aid in evaluating the overall utility of each methodological option, and an attempt was made to develop a qualitative, composite “overall usefulness” score for each option. Concensus was not reached on option scores, therefore, the experts individually rated six methodological options relative to the evaluation criteria, and provided comments and rationale for each response. The responses serve as a microcosm of the issues and stakeholder perspective: most relevant to animal antimicrobial use data collection in the United States. [Copyright &y& Elsevier]

Animal disease outbreaks, such as the recent outbreak of African Swine Fever in 2018, are a major concern for stakeholders across the food supply chain due to their potential to disrupt global food security, cause economic losses, and threaten animal welfare. As a result of their transboundary nature, discussions have shifted to preventive measures aimed at protecting livestock while ensuring food security and safety. Emergency assistance has been a critical response option during pandemics. However, this may not be sustainable in the long run because the expectation of government bailout may encourage risk taking behaviours. Our hypothesis is that an indemnity policy that is conditioned on showing biosecurity practices would increase compliance and reduce government expenditure during disease outbreaks. We developed and launched a survey from March to July 2022 targeted at swine producers across the US. From the survey, we examined livestock farmers' attitudes and intentions regarding biosecurity investment and assessed their attitudes towards the purchase of livestock insurance and reporting suspected infected livestock on their farm. We used a partial proportion odds model analysis to examine the model. Our analysis revealed that intention to call a veterinarian, trust in government agencies and risk perception of farmers were instrumental in the willingness to self-invest in biosecurity, purchase livestock insurance, and promptly report infected livestock on their farms. This provides evidence that biosecurity compliance would increase if indemnification was tied to a demonstration of effort to adopt biosecurity practices. We also show that individuals who have been in the industry for a longer period may become complacent and less likely to report outbreaks. Farmers with a higher share of income from their production operations bear a greater risk from their operational income and are more willing to report any suspected infections on their farms. The data suggest that motivating the willingness of farmers to invest in biosecurity while overcoming cost concerns is achievable., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

A workshop was conducted to elicit expert opinion on infection status and transmission of salmonella in pigs at the farm of origin, during transport and during lairage. A second objective was to compare opinions regarding risk factors for salmonella introduction and control at the farm level between experts from different countries. Thirty-six experts from 11 countries filled in a paper-and-pencil questionnaire during an international conference. Experts from all countries agreed on the risk of salmonella introduction related to live animals and the importance of general hygiene and all-in/all-out management for salmonella control. However, workshop participants from Denmark put more weight on factors related to feed while experts from USA rated factors related to rodents and people contact higher. The experts believed that 21-33% of pigs coming from a chronically infected farm would be infected with salmonella, but only one-third of the infected pigs would be shedders. Regarding transport and lairage, the US participants believed that contamination was occurring in the majority of pigs regardless of initial infection status and particularly during lairage; in contrast, the Danish experts were more optimistic with respect to the contamination and infection risk. US experts believed that the incidence of salmonella shedding would be high among pigs infected during transport and lairage and that an important proportion of 'carrier' pigs would start shedding. Our results reflect the differences in the level of salmonella infection and implemented control strategies between countries as well as the different philosophies that professionals have. The differences in opinion regarding salmonella dynamics could be due either to true differences in risk as a consequence of distinct management and transport practices in Denmark and USA or to a difference in perception.

Antimicrobials are essential for the prevention and treatment of bacterial infections in humans and animals. Subtherapeutic antimicrobials have been used as growth promoters for >40 years. The subject of antimicrobial resistance is not new but has gained increasing attention due to public-health concerns about multi-resistant pathogenic organisms. Numerous United States' activities do exist to address antimicrobial resistance. A surveillance system (the National Antimicrobial Resistance Monitoring System) was established in 1996 to monitor changes over time in resistance for 17 antibiotics in humans and animals. Educational campaigns have been created to promote the judicious therapeutic use of antimicrobials. Producer groups are developing guidelines for judicious therapeutic antimicrobial use for their prospective species. Basic and applied research programs are being expanded to answer many of the unsolved questions regarding development, persistence, and transmission of antimicrobial resistance. This paper focuses on a federal inter-agency public-health action plan to combat antimicrobial resistance; the plan was released for public comment in 2000. This plan addresses goals and actions to combat antimicrobial resistance in humans and agriculture in four areas: surveillance; research; prevention and control; product development.

The conditions for the food industry, in general, are changing. Especially in industrialized countries, the safety and quality of food is increasingly becoming an issue of concern to the consumer. This paper describes the impact of the farm-to-table concept and the implementation of HACCP plans throughout the food production chain on animal production and veterinary profession, using the example of the pork production chain.