Towards a Better Use of Antimicrobials on Farms: Insights from a Participatory Approach in the French Pig and Poultry Sectors.

Despite the strong decrease in antimicrobial use in the French poultry and pig sectors over the last decade, room for improvement remains. A participatory approach was set up in France, involving representatives of veterinarians, the pig and poultry industries, technical institutes, the French Ministry of Agriculture, and researchers, to further improve how antimicrobials are used on farms. By successively defining a shared, long-term vision of future antimicrobial use on farms, identifying lock-in mechanisms impeding this future vision from being realized, and articulating practical questions on how to move in the desired direction, the group rapidly reached a consensus. The results highlight the need for consensual standardized monitoring tools that would allow farmers and veterinarians to jointly monitor the health, welfare, antimicrobial resistance, and antimicrobial use on farms. Other results relate to better communication and training for citizens regarding animal health, animal welfare, and proper antimicrobial use; some benefits but also counterproductive effects of antibiotic-free labels that imperil animal health and welfare; the economic competitiveness of farms on international markets; and the economic sustainability of farm animal veterinary practices. These results call for a concerted way to produce tools for farmers and veterinarians and the broader involvement of other food sector actors.

What Matters in Piglets' Exposure to Antibiotics Administered through Drinking Water?

A number of drugs are given in drinking water in piglet farming, although this way of administering drugs leads to significant and uncontrolled variability in exposures. Three main explanations for this variability have been described in the literature: (1) the drinking behavior of animals, (2) the drug concentration in water, and (3) the inter-individual variability in the pharmacokinetic (PK) parameters. This article assesses the relative importance of these three sources of exposure variability for doxycycline and amoxicillin using pharmacokinetic simulations and by observing watering behavior, and analyzes the consequences of this exposure variability. The water consumption behavior was by far the most important factor as it led to a variation in exposures of up to a factor of 7 between piglets. The second most influential factor was the drug concentration in the drinking water with variations ranging from -43.3% to +48.7% at the beginning and the end of the pipeline. Finally, the between-individual variation in PK parameters depends on the drug, but had a low impact on exposure variability. In the most variable case (doxycycline), the mean ratio between the 10% less exposed and the 10% most exposed piglets varied from 3.7 without PK parameters variability to 6 with PK variability. For both drugs, this study also showed that only a small percentage of the piglets (36%) could be considered as well exposed in case of infection by Actinobacillus pleuropneumoniae or Pasteurella multocida. There may be some existing technical ways to reduce this important variability. However, their cost and ease of implementation merit examination.

An efficient cephalosporin stewardship programme in French swine production.

By 2010, systems set up to monitor the antimicrobial resistance of pathogenic bacteria and antimicrobial usage identified a sustained increase regarding third- and fourth-generation cephalosporin resistance in French pig production. This sector mobilised and collectively committed to responsible action in the following months. This led to a multi-professional voluntary stewardship programme that was started in 2011. A consensus of veterinary opinion led to the definition of restrictive rules on the prescription of the third- and fourth-generation cephalosporins targeted by the antimicrobial stewardship programme (ASP). All pig sector professionals, including farmers, were informed. Existing monitoring systems for usage and resistance were supplemented by data from the records of veterinarians' cephalosporin deliveries and from individual pig farm surveys investigating antimicrobial usage. The second step, from 2014, entailed regulatory measures that consolidated the programme by setting quantitative reduction objectives and specifying the terms and conditions for prescribing and dispensing a list of critical antimicrobial molecules including cephalosporins. All the data sources confirmed a significant fall of more than 90% in cephalosporin usage in the French pig production sector between 2010 and 2016. Monitoring systems recorded that the resistance of commensal and pathogenic Escherichia coli isolates also tended to decrease over the same period. The stewardship programme proved highly effective in reducing usage and containing resistance, illustrating the efficiency of a well-defined multi-professional strategy.

Monitoring of Farm-Level Antimicrobial Use to Guide Stewardship: Overview of Existing Systems and Analysis of Key Components and Processes.

The acknowledgment of antimicrobial resistance (AMR) as a major health challenge in humans, animals and plants, has led to increased efforts to reduce antimicrobial use (AMU). To better understand factors influencing AMR and implement and evaluate stewardship measures for reducing AMU, it is important to have sufficiently detailed information on the quantity of AMU, preferably at the level of the user (farmer, veterinarian) and/or prescriber or provider (veterinarian, feed mill). Recently, several countries have established or are developing systems for monitoring AMU in animals. The aim of this publication is to provide an overview of known systems for monitoring AMU at farm-level, with a descriptive analysis of their key components and processes. As of March 2020, 38 active farm-level AMU monitoring systems from 16 countries were identified. These systems differ in many ways, including which data are collected, the type of analyses conducted and their respective output. At the same time, they share key components (data collection, analysis, benchmarking, and reporting), resulting in similar challenges to be faced with similar decisions to be made. Suggestions are provided with respect to the different components and important aspects of various data types and methods are discussed. This overview should provide support for establishing or working with such a system and could lead to a better implementation of stewardship actions and a more uniform communication about and understanding of AMU data at farm-level. Harmonization of methods and processes could lead to an improved comparability of outcomes and less confusion when interpreting results across systems. However, it is important to note that the development of systems also depends on specific local needs, resources and aims.

How Input Parameters and Calculation Rules Influence On-Farm Antimicrobial Use Indicators in Animals.

A variety of indicators of antimicrobial use are available in veterinary medicine, their choice should depend on the study objective as none has been recognized as the most appropriate metric. Calculation of indicators of antimicrobial use is based on a number of parameters (e.g., treatment dose or weight at treatment) that can be informed using theoretical (also called "standard") or actual (also called "used") values. Although few studies compare the application of several indicators to the same antimicrobial data, the obtained results lead to apparent discrepancies or contradictions. This study aimed to investigate antimicrobial use at the weaning stage in French pig farms and, more specifically, the impact the sources of information regarding doses, body weight at treatment and treatment length, had on the indicators results. A cross-sectional survey was conducted, and data collected from 70 farms made it possible to calculate four indicators at the weaning stage using different input values. The indicator values did not show significant differences when calculated based on the theoretical dose and length of treatment (as recommended by the summary of product characteristics) or when calculated based on the dose used and treatment length as applied by the farmer. However, all of the indicators showed significant differences when calculated using the standard theoretical weight (15 kg) or actual weight (P < 0.05). It appears that if data collection plans cannot be harmonized, clarification of indicator calculations in the literature is needed to allow comparisons between studies.

Reliable estimation of antimicrobial use and its evolution between 2010 and 2013 in French swine farms.

BACKGROUND: There has been a strong implication of both the French swine industry and the national authorities on reducing the use of antimicrobials in swine production since 2010. The annual monitoring of antimicrobial sales by the French Veterinary Medicines Agency (Anses-ANMV) provides estimates but not detailed figures on actual on-farm usage of antimicrobials in swine production. RESULTS: In order to provide detailed information on the 2010 and 2013 antimicrobial use in the French swine industry, the methodology of cross-sectional retrospective study on a representative sample of at least 150 farms has been elected. The analysis of the collected data shows a strong and significant decrease in antimicrobial exposure of pigs between 2010 and 2013. Over three years, the average number of days of treatment significantly decreased by 29% in suckling piglets and by 19% in weaned piglets. In fattening pigs, the drop (- 29%) was not statistically significant. Only usage in sows did increase over that period (+ 17%, non-significant), which might be associated with the transition to group-housing of pregnant sows that took place at the time. Also, over that period, the use of third- and fourth generation cephalosporins in suckling piglets decreased by 89%, and by 82% in sows, which confirms that the voluntary moratorium on these classes of antimicrobials decided at the end of 2010 has been effectively implemented. CONCLUSIONS: The methodology of random sampling of farms appears as a precise and robust tool to monitor antimicrobial use within a production animal species, able to fulfil industry and national authorities' objectives and requirements to assess the outcome of concerted efforts on antimicrobial use reduction. It demonstrates that the use of antimicrobials decreased in the French swine industry between 2010 and 2013, including the classes considered as critical for human medicine.

Field evaluation of piglet vaccination with a Mycoplasma hyopneumoniae bacterin as compared to a ready-to-use product including porcine circovirus 2 and M. hyopneumoniae in a conventional French farrow-to-finish farm.

BACKGROUND: A controlled randomized trial was performed on a well-managed conventional French 180-sow farm. The trial compared the growth performances of piglets vaccinated at weaning (single shot) either with a commercial monovalent Mycoplasma hyopneumoniae bacterin vaccine or with a commercial bivalent vaccine (Porcilis® PCV M Hyo) against M. hyopneumoniae and porcine circovirus 2 (PCV2). The farm's porcine reproductive and respiratory syndrome status was stable, and most diseases (enzootic pneumonia, atrophic rhinitis, post-weaning multisystemic wasting syndrome) were controlled by routine vaccination. RESULTS: During the post-weaning phase, the growth performances of the piglets vaccinated with the bivalent vaccine were not significantly different from those vaccinated with the monovalent vaccine. However, during the fattening phase the group vaccinated with the bivalent vaccine had a significantly improved ADG (+34 g/d, p = 0. 047), resulting in a 5-day earlier shipment to slaughter. The group also had a shorter and lower PCV2 load in serum during the fattening period, and an improved lung lesions score. In both groups, three pigs died during the peak PCV2 viraemia (16-23 weeks of age). Immunohistochemistry of the lymph nodes showed that in the group vaccinated with the bivalent vaccine, none of these pigs had PCV2-like lesions, while 2 out of the 3 from the other group did. Results suggest that the added PCV2 valence in the vaccination protocol helps countering the negative impact of subclinical PCV2 infection on growth. The calculated return on investment of the added PCV2 vaccine valence was €1.7 extra revenue per slaughtered pig (€ 39 additional revenue per sow and per year), despite the fact that the cost of the bivalent vaccine was higher than the monovalent M. hyopneumoniae vaccine. CONCLUSION: In this healthy conventional sow farm, the combined M. hyopneumoniae and PCV2 vaccination was efficacious, convenient to administer and profitable.

Learning Processes and Trajectories for the Reduction of Antibiotic Use in Pig Farming: A Qualitative Approach.

Since 2011, French public policy has been encouraging a reduction in the use of antibiotics in animal farming. The aim of this article is to look at how some farms have already managed to lower their consumption of antibiotics, and to highlight the levers of change in farming health practices. Our research uses a qualitative study based on 21 semi-structured interviews with farmers and veterinarians in the French pig-farming sector. We use the notion of "trajectory of change" to examine, over time, the intersection of the technical, economic, social and organisational determinants which affect the reduced use of antibiotics. The "learning process" concept makes it possible to take account of the way in which the actors assimilate, appropriate and implement new health practices. We have identified three interdependent levels of learning: technical learning, cognitive learning and organisational learning.