A New Tool to Assess the Economic Impact of Q Fever on Dairy Cattle Farms.

To support farmers in their decisions related to Q fever, a dedicated economic assessment tool is developed. The present work describes the calculator, its economic rationale, and the supporting assumptions. The calculator integrates a yearly compartmental model to represent population dynamism and the main interactions between disorders linked to Q fever, especially reproductive disorders (abortion, retained foetal membranes, purulent vaginal discharge and endometritis, extra services, and calving-conception delays). The effects of the nontangible cost of the disease on human health, the welfare of the animals, and the workload of farmers were not integrated into the model. The model shows high-level sensitivity to the prevalence of Q fever in the herd prevaccination and to the costs of abortion and extra days of calving-conception intervals. Breakeven points, i.e., cost values that allow us to achieve positive vaccination benefits, are also reported. For herds with moderate or high prevalence rates of Q fever prevaccination (>30%), a vaccination benefit is observed. The vaccine should be considered a type of insurance in herds with low prevalence rates of Q fever prevaccination (≤20%). The calculator was developed to aid decision-making at the farm level, and no conclusion can be extrapolated as a generic trend based on the present work.

Effectiveness of rural internships for veterinary students to combat veterinary workforce shortages in rural areas.

Veterinarians are a pivotal force in addressing animal health and welfare surveillance, with a critical role in improving public health security and increasing the profits of livestock farmers. Yet, the veterinary profession is adversely affected by personnel shortages, particularly in rural areas. Since the health of people, animals and their shared environment are interconnected in a One Health perspective, a set of policies are required to ensure public health by attraction and retention of veterinarians in rural areas. In France, a tutored internship programme, financially subsiding students and mentors to execute a training period in remote rural areas, was promoted to better integrate and retain veterinary students ending their veterinary training. This paper aims to evaluate how veterinarians' tutored internships influences students' choices for rural practice, using three different statistical methods derived from causal inference theory. Using survey data for the period 2016-2020, we show that: (i) the average effect of the tutored internship on veterinarians' work in food animal sector is not significant; and that (ii) the tutored internship leads veterinarians with a low share of work in the food animal sector to have a rural practise after they graduated between 13 and 20% greater than those who did not participate in the tutored internship.

Strategies to reduce antimicrobials in livestock and aquaculture, and their impact under field conditions: a structured scoping literature review.

Antimicrobial resistance is a pandemic problem, causing substantial health and economic burdens. Antimicrobials are extensively used in livestock and aquaculture, exacerbating this global threat. Fostering the prudent use of antimicrobials will safeguard animal and human health. A lack of knowledge about alternatives to replace antimicrobials, and their effectiveness under field conditions, hampers changes in farming practices. This work aimed to understand the impact of strategies to reduce antimicrobial usage (AMU) in livestock and aquaculture, under field conditions, using a structured scoping literature review. The Extension for Scoping Reviews of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines (PRISMA-ScR) were followed and the Patient, Intervention, Comparison, Outcome, Time and Setting (PICOTS) framework used. Articles were identified from CAB Abstracts, MEDLINE and Scopus. A total of 7505 unique research articles were identified, 926 of which were eligible for full-text assessment; 203 articles were included in data extraction. Given heterogeneity across articles in the way alternatives to antimicrobials or interventions against their usage were described, there was a need to standardize these by grouping them in categories. There were differences in the impacts of the strategies between and within species; this highlights the absence of a 'one-size-fits-all' solution. Nevertheless, some options seem more promising than others, as their impacts were consistently equivalent or positive when compared with animal performance using antimicrobials. This was particularly the case for bioactive protein and peptides, and feed/water management. The outcomes of this work provide data to inform cost-effectiveness assessments of strategies to reduce AMU.

Risk factors associated with calf mortality in Western Canadian cow-calf operations.

This study examined the influence of management practices and herd demographics on calf mortality proportions in Western Canadian cow-calf operations, utilizing data from the second Western Canadian Cow-calf Survey. The survey was conducted between October 23, 2017, and February 28, 2018. The survey, which was open to all cow-calf producers across Western Canada, provided producer-reported data regarding calf death loss and corresponding herd-level factors. A fractional logit model was employed to identify significant factors associated with calf mortality proportions. The findings revealed that shorter breeding seasons (<63 days), calves born within the same season, and regular pregnancy checks for breeding females were negatively associated with calf mortality proportions. Conversely, regular breeding soundness evaluations for breeding bulls, traditional weaning methods, and vaccinating heifers for scours showed positive associations with increased calf mortality proportions. Herd operations where dams were vaccinated against clostridial and bovine respiratory diseases had lower calf mortality proportions. Notably, operations with experienced primary decision-makers holding off-farm jobs had lower predicted calf mortality proportions compared to those managed by full-time cattle producers. Higher predicted calf mortality proportions were observed in operations employing a backgrounding system. The study's limitations included potential biases due to its cross-sectional nature and reliance on producer-reported data, which might lead to an underestimation of calf mortality proportions. Also, the limited sample size and missing data might have affected the statistical significance of some variables. This study contributed to the research on cow-calf operation by using a fractional logit model to analyze the correlation between risk factors and calf mortality proportions, and by identifying novel herd-level risk factors. It provided a basis for future research aimed at developing empirically-based management strategies to optimize calf health outcomes.

Individual drivers and barriers to adoption of disease control and welfare practices in dairy and beef cattle production: a scoping review.

The implementation of disease control and welfare practices is an essential part of limiting disease exposure in livestock, however successful adoption of these practices seem to be low in both the beef and dairy cattle industries. The main objectives of this scoping review were to characterize literature published exploring beef and dairy cattle producers' perceptions on the implementation of various disease control and welfare practices, identify major themes of drivers and barriers that influence producers' adoption of these practices, and identify current gaps in knowledge. A total of 2,486 articles were obtained from two database literature searches and screened, from which 48 articles published between 2010 and 2021 were deemed eligible and charted. Europe was the most common region for articles (58%). A majority of articles focused solely on dairy producers (52%). A wide range of barriers and drivers which were categorized into 4 and 5 key themes, respectively. The most commonly mentioned driver was animal health, welfare, and safety, while the most common barrier was costs. Potential gaps in literature were identified, including the underrepresentation of beef producer perceptions relative to dairy producers in current literature.

Cost of lameness in dairy herds: An integrated bioeconomic modeling approach.

Foot disorders are costly health disorders in dairy farms, and their prevalence is related to several factors such as breed, nutrition, and farmer's management strategy. Very few modeling approaches have considered the dynamics of foot disorders and their interaction with farm management strategies within a holistic farm simulation model. The aim of this study was to estimate the cost of foot disorders in dairy herds by simulating strategies for managing lameness. A dynamic and stochastic simulation model (DairyHealthSim) was used to simulate the herd dynamics, reproduction management, and health events. A specific module was built for lameness and related herd-level management strategies. Foot disorder occurrences were simulated with a base risk for each etiology [digital dermatitis (DD), interdigital dermatitis, interdigital phlegmon, sole ulcer (SU), white line disease (WLD)]. Two state machines were implemented in the model: the first was related to the disease-induced lameness score (from 1 to 5), and the second concerned DD-state transitions. A total of 880 simulations were run to represent the combination of the following 5 scenarios: (1) housing (concrete vs. textured), (2) hygiene (2 different scraping frequencies), (3) the existence of preventive trimming, (4) different thresholds of DD prevalence detected and from which a collective footbath is applied to treat DD, and (5) farmer's ability to detect lameness (detection rate). Housing, hygiene, and trimming scenarios were associated with risk factors applied for each foot disorder etiologies. The footbath and lameness detection scenarios both determined the treatment setup and the policy of herd observance. The economic evaluation outcome was the gross margin per year. A linear regression model was run to estimate the cost per lame cow (lameness score ≥3), per case of DD and per week of a cow's medium lameness duration. The bioeconomic model reproduced a lameness prevalence varying from 26 to 98% depending on the management scenario, demonstrating a high capacity of the model to represent the diversity of the field situations. Digital dermatitis represented half of the total lameness cases, followed by interdigital dermatitis (28%), SU (19%), WLD (13%), and interdigital phlegmon (4%). The housing scenarios dramatically influenced the prevalence of SU and WLD, whereas scraping frequency and threshold for footbath application mainly determined the presence of DD. Interestingly, the results showed that preventive trimming allowed a better reduction in lameness prevalence than spending time on early detection. Scraping frequency was highly associated with DD occurrence, especially with a textured floor. The regression showed that costs were homogeneous (i.e., did not change with lameness prevalence; marginal cost equals average cost). A lame cow and a DD-affected cow cost €307.50 ± 8.40 (SD) and €391.80 ± 10.0 per year on average, respectively. The results also showed a cost of €12.10 ± 0.36 per week-cow lameness. The present estimation is the first to account for interactions between etiologies and for the complex DD dynamics with all the M-stage transitions, bringing a high level of accuracy to the results.

The Marginal Abatement Cost of Antimicrobials for Dairy Cow Mastitis: A Bioeconomic Optimization Perspective.

Maintaining udder health is the primary indication for antimicrobial use (AMU) in dairy production, and modulating this application is a key factor in decreasing AMU. Defining the optimal AMU and the associated practical rules is challenging since AMU interacts with many parameters. To define the trade-offs between decreased AMU, labor and economic performance, the bioeconomic stochastic simulation model DairyHealthSim (DHS)© was applied to dairy cow mastitis management and coupled to a mean variance optimization model and marginal abatement cost curve (MACC) analysis. The scenarios included three antimicrobial (AM) treatment strategies at dry-off, five types of general barn hygiene practices, five milking practices focused on parlor hygiene levels and three milk withdrawal strategies. The first part of economic results showed similar economic performances for the blanked dry-off strategy and selective strategy but demonstrated the trade-off between AMU reduction and farmers' workload. The second part of the results demonstrated the optimal value of the animal level of exposure to AM (ALEA). The MACC analysis showed that reducing ALEA below 1.5 was associated with a EUR 10,000 loss per unit of ALEA on average for the farmer. The results call for more integrative farm decision processes and bioeconomic reasoning to prompt efficient public interventions.

Economic evaluation of antimicrobial use practices in animal agriculture: a case of poultry farming.

Background: The growing evidence of the contribution of antimicrobial use (AMU) in animal agriculture to the public health threat of antimicrobial resistance has highlighted to policymakers the importance of the need for prudent AMU in animal production. Livestock farming is an economic process, where farmers are using inputs such as antimicrobials to minimize their losses. Objectives: Using a large and unique dataset combining time-series data on economic performance and health records in conventional broiler production in France, we identify how improved healthcare management and disease prevention impact economic performance, AMU reduction and health outcomes. Methods: We analyse the main characteristics of the economic performance of farms measured by the profit per m2, by performing advanced regression models investigating the relative importance of medication and veterinary procedures. Results: In our study, 50% of the treatments (expressed as number of new treatments) are attributable to only 30% of all flocks. There is an inverted U-shaped relationship between AMU and economic performance. This finding implies that the marginal profit of antimicrobials is decreasing, meaning that using antimicrobials is only profitable up to a certain threshold. Results also show that the profit increases as the number of preventive treatments increase. Conclusions: Our findings suggest that policies encouraging farmers to work upstream from the occurrence of disease have the potential to perform better than regulations, as they would maintain a profitable activity while diminishing AMU. Encouraging adequate infection control practices by subsidizing or providing other incentives would benefit farmers and society.

The gender wage gap in the French veterinary labor market.

Among the most important recent changes in the veterinary profession is the increasing percentage of women. Understanding trends driving the veterinary labor market is important to enable leaders in the veterinary profession and policy makers to plot strategic actions that will improve the profession. The objective of this paper was to estimate the gender pay gap in the veterinary labor market. We analyzed data from an anonymous online survey conducted in France in 2021 by the veterinary practitioner union. We assessed the gender gap pay using two regression approaches, ordinary least squares method and Blinder-Oaxaca decomposition, while controlling for all other variables (ceteris paribus). We provided evidence that male veterinarians earned wages approximately 9.3% higher (controlling for all other variables). This difference represented the "unexplained variance" that may be due to gender discrimination or unobserved characteristics.

Spatial evaluation of animal health care accessibility and veterinary shortage in France.

The decrease in the supply of veterinary healthcare in France adversely affects health of food-producing animals. In a One Health perspective, the health of people, animals and their shared environment are interconnected, and adequate supply of veterinary healthcare is required to ensure public health. Prevention of outbreaks and zoonotic diseases that may impact public health mobilizes a set of public policies, including strengthening veterinary workforce. These policies should be informed by quantification of animal health care accessibility, yet this has not been well characterized. The objective was to quantify the accessibility to veterinary healthcare for cattle, swine, and poultry sectors in France. A Two-Step Floating Catchment Area (2SFCA) approach was used to measure the level of accessibility to veterinary clinics. In the cattle sector, the 2SFCA score indicated relatively high accessibility in the north and south of France, but insufficient accessibility elsewhere. In the swine sector, there was high accessibility in the north east and in north of France, medium accessibility in the south west, and insufficient accessibility elsewhere. Finally, in the poultry sector, all regions had insufficient accessibility. Sensitivity analysis examining the effects of a change in spatial accessibility according to various travel time showed that the optimal threshold to compute 2SFCA score in cattle, swine and poultry sectors were respectively, 45, 60 and 60 min. According to a definition of "underserved area" derived from an official decree and the optimal thresholds to compute 2SFCA, the cattle, swine and poultry sector have on average 75.3, 89.9 and 98.3% underserved area, respectively. We provided evidence that the supply of animal health care was not sufficient and we proposed recommendations on how to assess animal health care accessibility, enabling modelling and visualization of the effects of potential public policies aimed at reducing veterinary shortages.

Correction: Consumer perceptions of antimicrobial use in animal husbandry: A scoping review.

[This corrects the article DOI: 10.1371/journal.pone.0261010.].

Impact of Peste des petits ruminants for sub-Saharan African farmers: A bioeconomic household production model.

Peste des petits ruminants (PPR), a contagious viral disease affecting small ruminants, has been targeted by the global community for eradication within the next 10 years. However, eradication will require substantial money, human resources, coordination among actors, and individual commitments. The objective was to estimate the cost of PPR at a household level, thereby providing information on the potential economic benefits of PPR eradication and the incentives for small ruminant keepers to actively participate in the PPR Global Eradication Programme. This study focused on four sub-Saharan countries: Ethiopia, Malawi, Mali and Rwanda. Publicly available household level data assembled by FAO were used. A bioeconomic model was built to estimate impacts of PPR for a standardized theoretical area, where each household raised an average small ruminant herd or flock. Model outputs were used to estimate, at a household level, income loss due to a PPR outbreak. We constructed various income scenarios to account for the variability of small ruminant income as a proportion of total household annual income. Household income losses ranged from 2% to 40% of total annual income; percentages varied depending on the income scenario and on the gross annual economic impact of PPR on small ruminant production, which ranged from 20% to 80%, based on results of the bioeconomic model. As expected, the more small ruminant production contributed to household income the greater the impact. Estimates provided herein warn decision makers that, given the heterogeneous impact of PPR on household income, the willingness of small ruminant decision makers to participate in the PPR Global Eradication Programme may vary widely and tailored approaches should be devised and implemented.

Multi-Criteria Decision Analysis for Assessing Social Acceptance of Strategies to Reduce Antimicrobial Use in the French Dairy Industry.

To respond to the antimicrobial resistance (AMR) threat, public health entities implement policies aiming to reduce antimicrobial use (AMU) in livestock systems, in which policy success and sustainability might be subject to the social acceptability of the novel regulatory environment. Therefore, consistent methods that gather and synthesize preferences of stakeholder groups are needed during the policy design. The objective of this study was to present a methodology for evaluating the acceptability of potential strategies to reduce AMU using multi-criteria decision analysis (MCDA) using French dairy industry as a model. Preference-ranking organization methods for enrichment evaluations were applied to rank stakeholders' acceptance of four different potential AMU reduction strategies: 1. Baseline AMU regulations in France; 2. Total interdiction of AMU; 3. Interdiction of prophylaxis and metaphylaxis AMU; and 4. Subsidies to reduce AMU by 25%. A total of 15 stakeholders (consumers, n = 10; farmers, n = 2; public health representatives, n = 3) representing the French dairy sector and public health administration participated in the acceptance weighting of the strategies in relation with their impact on environmental, economic, social, and political criteria. We established a MCDA methodology and result-interpretation approach that can assist in prioritizing alternatives to cope with AMR in the French dairy industry or in other livestock systems. Our MCDA framework showed that consumers and public health representatives preferred alternatives that consider the restriction of AMU, whereas farmers preferred to maintain baseline policy.

Consumer perceptions of antimicrobial use in animal husbandry: A scoping review.

Antimicrobial use in animal agriculture is often perceived to play a role in the emerging threat of antimicrobial resistance. Increased consumer awareness of this issue places pressure on animal husbandry to adopt policies to reduce or eliminate antimicrobial use. We use a scoping review methodology to assess research on consumer perceptions of antimicrobial drugs in meat products in the United States, Canada, or the European Union. Evaluating peer-reviewed and grey literature, we included studies for assessment if they met these topical and geographic requirements, involved primary data collection, and were originally published in English. Our screening process identified 124 relevant studies. Three reviewers jointly developed a data charting form and independently charted the contents of the studies. Of the 105 studies that measured consumer concern, 77.1% found that consumers were concerned about antimicrobial use in meat production. A minority of studies (29.8% of all studies) queried why consumers hold these views. These studies found human health and animal welfare were the main reasons for concern. Antimicrobial resistance rarely registered as an explicit reason for concern. A smaller group of studies (23.3%) measured the personal characteristics of consumers that expressed concern about antimicrobials. Among these studies, the most common and consistent features of these consumers were gender, age, income, and education. Regarding the methodology used, studies tended to be dominated by either willingness-to-pay studies or Likert scale questionnaires (73.64% of all studies). We recommend consideration of qualitative research into consumer views on this topic, which may provide new perspectives that explain consumer decision-making and mentality that are lacking in the literature. In addition, more research into the difference between what consumers claim is of concern and their ultimate purchasing decisions would be especially valuable.

The Association Between French Veterinary Practice Characteristics and Their Revenues and Veterinarian's Time Use.

The provision of healthcare by veterinarians consists of a blend of activities ensuring welfare for animals. It also contributes in the control of infectious diseases and food safety. In general practices, most of the activities generate incomes for veterinarians, notably acts (consultations, surgery, etc.) and sales (drugs, pet food, etc.). Increased size of veterinary practices and the arrival of corporate companies modify the veterinary landscape in many countries. In a context of rapid growth of the companion animal health market, the question of the profitability of veterinary activities is relevant. Indeed, beyond a certain threshold, veterinarians may be tempted to leave behind food-producing animals' acts and focus on companion animals' acts, which are generally recognized to be more profitable and more attractive for new generations of veterinarians. A survey was conducted in French veterinary mixed practices, and a regression analysis was used to quantify the relationships between the turnover and the characteristics of veterinary practices, the time to perform veterinary acts, and the characteristics of veterinarians. We found that the characteristics of veterinary practices are positively associated with the turnover and the price of acts, and that there was an association between the status of veterinarians (associate, collaborator, or employee) and the time required to perform companion animals' and food-producing animals' acts. The present study is the first study showing the association between the characteristics of veterinary practices and the turnover, by investigating the price of veterinary acts and the time required.

Analysis of the demand for pet insurance among uninsured pet owners in the United States.

BACKGROUND: Although cost is often a barrier to providing optimal veterinary care, only a minority of pet owners use insurance to help cover veterinary costs. We sought to estimate consumer demand and preferences for pet insurance and how educating owners on treatment costs and disease risk affects pet insurance uptake. METHODS: We surveyed 306 dog owners across the United States without pet insurance, including a choice experiment, used ordinary least squares regression to estimate the demand for pet insurance, and conjoint analysis to estimate the pet insurance feature preferences. RESULTS: Pet insurance uptake increased by 12.3% after veterinary treatment cost and canine cancer risk information was presented to participants. We found that, on average, pet owners were willing to pay $24 more per month for a preventive care service in pet insurance. Forty-four percent of participants were willing to spend up to $1000 to prolong their pet's life a year, while 46% of the sample were willing to spend $3000 or more. CONCLUSIONS: Our results suggest that providing pet owners' information about the costs and likelihood of disease can increase their willingness to pay for pet insurance. Coverage of preventive care was the most valuable feature in pet insurance among those presented to dog owners.

Could Contracts between Pharmaceutical Firms and French Veterinarians Bias Prescription Behaviour: A Principal-Agency Theory Approach in the Context of Oligopolies.

In France, veterinarians can both prescribe and deliver veterinary medicines, which is a questionable situation from the perspective of antimicrobial use (AMU) reduction to avoid antimicrobial resistance (AMR). This situation places veterinarians in direct commercial relationships with the pharmaceutical industry as purchase contracts are signed between veterinarians and pharmaceutical companies. The aim of the present work is to analyse the relationships between veterinarians and pharmaceutical firms in the oligopoly market context of French veterinary medicine to determine whether the prescription behaviour of practitioners can be biased by joint prescription and delivery. Therefore, we develop an analysis based on principal-agent theory. Contracts between pharmaceutical companies and veterinarians during the 2008-2014 period were analysed based on 382 contracts related to 47 drugs belonging to eight main pharmaceutical firms (2320 observations). The price per unit after rebate of each drug and contract was calculated. The descriptive analysis demonstrated high disparity among the contracts across pharmaceutical firms with regard to the provisions of the contracts and how they are presented. Then, linear regression was used to explain the price per unit after rebate based on the explanatory variables, which included the yearly purchase objective, year, type of drug and type of rebate. The decrease in price per unit after rebate for each extra €1000 purchase objective per drug category was established to be €0.061 per 100 kg body weight for anticoccidiosis treatments, €0.029 per 100 kg body weight for anti-inflammatories, €0.0125 per 100 kg body weight and €0.0845 per animal for antiparasitics, and €0.031 per animal for intramammary antimicrobials. Applying agency theory reveals that veterinarians can be considered agents in the case of monopolistic situations involving pharmaceutical firms; otherwise, veterinarians are considered principals (oligopolistic situations in which at least several medicines have similar indications). The present study does not provide evidence suggesting that joint prescription and delivery may introduce any potential prescription bias linked to conflicts of interest under the market conditions during the 2008-2014 period.

Individual Behaviors and COVID-19 Lockdown Exit Strategy: A Mid-Term Multidimensional Bio-economic Modeling Approach.

As of mid-2020, eradicating COVID-19 seems not to be an option, at least in the short term. The challenge for policy makers consists of implementing a suitable approach to contain the outbreak and limit extra deaths without exhausting healthcare forces while mitigating the impact on the country's economy and on individuals' well-being. To better describe the trade-off between the economic, societal and public health dimensions, we developed an integrated bioeconomic optimization approach. We built a discrete age-structured model considering three main populations (youth, adults and seniors) and 8 socio-professional characteristics for the adults. Fifteen lockdown exit strategies were simulated for several options: abrupt or progressive (4 or 8 weeks) lockdown lift followed by total definitive transitory final unlocking. Three values of transmission rate (Tr) were considered to represent individuals' barrier gesture compliance. Optimization under constraint to find the best combination of scenarios and options was performed on the minimal total cost for production losses due to contracted activities and hospitalization in the short and mid-term, with 3 criteria: mortality, person-days locked and hospital saturation. The results clearly show little difference between the scenarios based on the economic impact or the 3 criteria. This means that policy makers should focus on individuals' behaviors (represented by the Tr value) more than on trying to optimize the lockdown strategy (defining who is unlocked and who is locked). For a given Tr, the choices of scenarios permit the management of the hospital saturation level with regard to both its intensity and its duration, which remains a key point for public health. The results highlight the need for behavioral or experimental economics to address COVID-19 issues through a better understanding of individual behavior motivations and the identification of ways to improve biosecurity compliance.

The economics of antimicrobial resistance in veterinary medicine: Optimizing societal benefits through mesoeconomic approaches from public and private perspectives.

Antimicrobial resistance (AMR) is a global public health threat driven by a combination of factors, including antimicrobial use (AMU) and interactions among microorganisms, people, animals and the environment. The emergence and spread of AMR in veterinary medicine (AMR-V) arising from AMU in veterinary medicine (AMU-V) can be linked to individuals' economic behaviour and institutional context. We highlight the limitations of current microeconomic approaches and propose a mesoeconomic conceptual model of AMR-V that integrates actors' strategic and routine behaviours in their context from a dynamic perspective using the concepts of externality, globality and futurity. The global solution to AMR-V management relies on a trade-off between i) the global externality assessment of AMU-V with respect to AMR-V (public perspective) and ii) farm- or value chain-level marginal abatement cost evaluation (private perspective). The improvements realized by the proposed mesoeconomic conceptual model include i) the simultaneous fight against the emergence and spread of AMR-V and ii) a local decrease in AMU-V without any loss of competitiveness for private actors due to the development of adequate production standards. A set of generic equations describing the stepwise change in the scale of analysis is finally proposed. This original contribution to the global challenge of AMR through a mesoeconomic approach bring substantial improvement for better AMU. This model can be considered a way to smoothly promote institutional change and a call for public policies that support public private partnership in the development of adequate incentives. The model requires further development prior to its application in a given value-chain or territory.

Economic effects of policy options restricting antimicrobial use for high risk cattle placed in U.S. feedlots.

The rising public health threat of antimicrobial resistance, the influence of food service companies, as well as the overall lack of positive image of using medical products in intensive farming are major drivers curbing antimicrobial use. In the future, government policies may affect practices of antimicrobial use in beef production in feedlots, a prominent current user of antimicrobials in animal agriculture, but also the agricultural industry generating the highest cash receipt in the U.S. Our objective was to estimate the cost effect from the following policies in feedlots: 1) using antimicrobials for disease prevention, control, and treatment; 2) using antimicrobials only for treatment of disease; and 3) not using antimicrobials for any reason. We modelled a typical U.S. feedlot, where high risk cattle may be afflicted by diseases requiring antimicrobial therapy, namely respiratory diseases, liver abscesses and lameness. We calculated the net revenue loss under each policy of antimicrobial use restriction. With moderate disease incidence, the median net revenue loss was $66 and $96 per animal entering the feedlot, for not using antimicrobials for disease prevention and control, or not using any antimicrobials, respectively, compared to using antimicrobials for disease prevention, control, and treatment. Losses arose mainly from an increase of fatality and morbidity rates, almost doubling for respiratory diseases in the case of antimicrobial use restrictions. In the case of antimicrobial use prohibition, decreasing the feeder cattle price by 9%, or alternatively, increasing the slaughter cattle price by 6.3%, would offset the net revenue losses for the feedlot operator. If no alternatives to antimicrobial therapy for prevention, control and treatment of current infectious diseases are implemented, policies that economically incentivize adoption of non-antimicrobial prevention and control strategies for infectious diseases would be necessary to maintain animal welfare and the profitability of beef production while simultaneously curbing antimicrobial use.