Highly pathogenic avian influenza management policy in domestic poultry: from reacting to preventing.

The emergence of clade 2.3.4.4b H5N1 highly pathogenic avian influenza (HPAI) viruses in 2021 has led to unprecedented epidemics in poultry, changing epidemiological patterns of year-round infections in resident wild avifauna and more frequent spill-over events to mammals. Given this situation, it is important that we recognise that traditional HPAI management strategies are no longer sufficient, and policy changes are required. Poultry vaccination has emerged as a crucial intervention in the current control of HPAI, as evidenced by France's nationwide campaign targeting domestic ducks. However, due to the logistical challenges and potential trade implications of vaccination, broader structural reforms appear also necessary. These include a shift from farm-level to territorial-level biosecurity approaches, putting into practice the concept of 'regional biosecurity'. Given the role duck farm density has played in successive HPAI epidemics in France, there is a need to think about the spatial distribution of poultry farms as a structural component of regional biosecurity and to consider the reduction of farm concentration as a measure to prevent viral spread. The integration of regional biosecurity and poultry vaccination into prevention strategies should impact the way poultry are produced and traded in the future.

Making the invisible visible: Effectiveness of a training program to increase awareness and biosecurity compliance in poultry barn anterooms, using glowing substances.

Biosecurity is the cornerstone of prevention strategies to limit infectious pathogen spread between poultry farms. However, poor compliance of biosecurity measures is often observed when entering or exiting barns. The lack of knowledge, understanding, risk perception or technical skill are often described for anteroom-related biosecurity errors (i.e., not respecting anteroom zoning in relation to changing boots, clothing, and hand sanitation). In this study, we designed and assessed the efficacy of an intervention aiming at improving biosecurity compliance in anterooms, using substances glowing under ultraviolet light, which mimic microbiological contamination. Training exercises offered in a single session were proposed to 145 participants with an interest in animal farming (veterinary students, agricultural students, poultry farmers and poultry farm advisors). The exercises' efficacy was assessed by measuring the change in attitude and intentions of participants about specific biosecurity measures. The participants' attitudes and intentions were quantified using a questionnaire before and after training. The change in score was assessed in a multivariate linear regression model to measure the effect of various parameters on this change. The attitudes and intentions of participants were statistically improved (p < 0.05) and were affected by the initial attitude and intention score, the gender of the participants and the status of the participant (type of student or activity in the poultry industry). The use of this exercise material, perceived as playful and engaging, could be included in the framework of biosecurity training for all stakeholders of the poultry industry.

Needs and capabilities for improving poultry production and health management in Indonesia.

In Indonesia, the development of the poultry industry is facing numerous challenges. Major constraints include high disease burdens, large fluctuations in farm input and output prices, and inadequate biosecurity. Timely and reliable information about animal production and health can help stakeholders at all levels of the value chain make appropriate management decisions to optimize their profitability and productivity while reducing risks to public health. This study aimed to describe the challenges in the Indonesian poultry industry, assess stakeholders' needs and capabilities in terms of generating and using poultry information for making production and health management decisions, and identify levers for improvement. Interviews were conducted with a diversity of key informants and value chain actors in five Indonesian provinces. Thematic analysis was applied with an interpretivist approach to gain an in-depth understanding of the lived experiences of various stakeholders and their opinions as to what might constitute appropriate solutions. Our findings indicate that market and political instability, ineffective management of poultry data, and limited inter-sectoral collaboration are limiting the development of the sector. Increased intersectoral cooperation is needed to implement standards for data collection and sharing across the industry, provide education and practical training on the use of information technologies for farm management, and accelerate research and innovation. Our study can contribute to the development of data-driven tools to support evidence-based decision-making at all levels of the poultry system.

A qualitative analysis of the unwritten rules influencing antibiotic prescribing practices among French poultry veterinarians.

Background: It is now recognized that a better understanding of prescriber behaviour is needed to improve antimicrobial stewardship programmes. Most studies conducted in the livestock sector have focused on farmers' perspectives, while the prescribing habits of veterinarians have remained overlooked. Objective: Our study explored the psychosocial determinants associated with antibiotic prescribing practices in the French poultry sector by analysing the informal norms and unwritten rules that influence veterinarians' prescribing decisions. Methods: A qualitative study was conducted in four French regions in February 2021. Using the biographical narrative interpretive method, semi-structured interviews were conducted with 16 poultry veterinarians with varying professional experience. Three main themes were retained for data analysis: (i) compliance with and deviations from prescribing recommendations, (ii) the influence of fellow veterinarians on antibiotic decisions and (iii) the key role of veterinary corporate groups. Results: When prescribing antibiotics, junior veterinarians were strongly influenced by senior veterinarians who acted as role models driving clinical practices. Prescribing habits were shared through peer networks in which veterinarians participated throughout their careers. Finally, veterinary corporate groups helped to shape veterinarians' prescribing habits by promoting existing guidelines and even producing in-house recommendations. Conclusions: We show that, in parallel with official guidelines, prescribing habits circulate among veterinarians and are shared in professional circles. Therefore, antimicrobial stewardship interventions should focus not only on official guidelines and communication channels, but also unwritten professional rules and organizations influencing veterinarians' prescribing practices.

A systematic review of mechanistic models used to study avian influenza virus transmission and control.

The global spread of avian influenza A viruses in domestic birds is causing increasing socioeconomic devastation. Various mechanistic models have been developed to better understand avian influenza transmission and evaluate the effectiveness of control measures in mitigating the socioeconomic losses caused by these viruses. However, the results of models of avian influenza transmission and control have not yet been subject to a comprehensive review. Such a review could help inform policy makers and guide future modeling work. To help fill this gap, we conducted a systematic review of the mechanistic models that have been applied to field outbreaks. Our three objectives were to: (1) describe the type of models and their epidemiological context, (2) list estimates of commonly used parameters of low pathogenicity and highly pathogenic avian influenza transmission, and (3) review the characteristics of avian influenza transmission and the efficacy of control strategies according to the mechanistic models. We reviewed a total of 46 articles. Of these, 26 articles estimated parameters by fitting the model to data, one evaluated the effectiveness of control strategies, and 19 did both. Values of the between-individual reproduction number ranged widely: from 2.18 to 86 for highly pathogenic avian influenza viruses, and from 4.7 to 45.9 for low pathogenicity avian influenza viruses, depending on epidemiological settings, virus subtypes and host species. Other parameters, such as the durations of the latent and infectious periods, were often taken from the literature, limiting the models' potential insights. Concerning control strategies, many models evaluated culling (n = 15), while vaccination received less attention (n = 6). According to the articles reviewed, optimal control strategies varied between virus subtypes and local conditions, and depended on the overall objective of the intervention. For instance, vaccination was optimal when the objective was to limit the overall number of culled flocks. In contrast, pre-emptive culling was preferred for reducing the size and duration of an epidemic. Early implementation consistently improved the overall efficacy of interventions, highlighting the need for effective surveillance and epidemic preparedness.

"It's a habit. They've been doing it for decades and they feel good and safe.": A qualitative study of barriers and opportunities to changing antimicrobial use in the Indonesian poultry sector.

Interventions to change antimicrobial use (AMU) practices can help mitigate the risk of antimicrobial resistance (AMR) development. However, changing AMU practices can be challenging due to the complex nature of the factors influencing AMU-related behaviours. This study used a qualitative approach to explore the factors that influenced decision-making on AMU by farmers and other actors in the Indonesian poultry sector. Thirty-five semi-structured interviews were conducted with farmers, technical services staff from the private sector, and representatives of associations, universities, and international organisations in Central Java, West Java, and East Java. Thematic analysis identified three patterns of influence on AMU: how farmers used information to make AMU-related decisions, the importance of farmers' social and advisory networks, and the motivations driving changes in AMU behaviours. Key barriers identified included a lack of shared understanding around when to use antibiotics, financial pressures in the poultry sector, and a lack of engagement with government veterinary services. Potential opportunities identified included high farmer awareness of AMU, identification of private sector actors and peer networks as the stakeholders with established relationships of trust with farmers, and the importance of farmers' conceptions of good farming practices, which could be engaged with to improve AMU practices.

Monitoring biosecurity in poultry production: an overview of databases reporting biosecurity compliance from seven European countries.

Compliance with required on-farm biosecurity practices reduces the risk of contamination and spread of zoonotic and economically important diseases. With repeating avian influenza epidemics in the poultry industry, the need to monitor and improve the overall level of biosecurity is increasing. In practice, biosecurity compliance is assessed by various actors (e.g., academic, private and public institutions), and the results of such assessments may be recorded and gathered in databases which are seldom shared or thoroughly analyzed. This study aimed to provide an inventory of databases related to the assessment of biosecurity in poultry farms in seven major poultry-producing European countries to highlight challenges and opportunities associated with biosecurity data collection, sharing, and use. The institutions in charge of these databases were contacted and interviewed using a structured questionnaire to gather information on the main characteristics of the databases and the context of their implementation. A total of 20 databases were identified, covering the gamut of poultry species and production types. Most databases were linked to veterinary health authorities or academia, and to a lesser extent interbranch organizations. Depending on the institutions in charge, the databases serve various purposes, from providing advice to enforcing regulations. The quality of the biosecurity data collected is believed to be quite reliable, as biosecurity is mostly assessed by trained farm advisors or official veterinarians and during a farm visit. Some of the databases are difficult to analyze and/or do not offer information concerning which biosecurity measures are most or least respected. Moreover, some key biosecurity practices are sometimes absent from certain databases. Although the databases serve a variety of purposes and cover different production types, each with specific biosecurity features, their analysis should help to improve the surveillance of biosecurity in the poultry sector and provide evidence on the benefits of biosecurity.

Impact of palmiped farm density on the resilience of the poultry sector to highly pathogenic avian influenza H5N8 in France.

We analysed the interplay between palmiped farm density and the vulnerability of the poultry production system to highly pathogenic avian influenza (HPAI) H5N8. To do so, we used a spatially-explicit transmission model, which was calibrated to reproduce the observed spatio-temporal distribution of outbreaks in France during the 2016-2017 epidemic of HPAI. Six scenarios were investigated, in which the density of palmiped farms was decreased in the municipalities with the highest palmiped farm density. For each of the six scenarios, we first calculated the spatial distribution of the basic reproduction number (R0), i.e. the expected number of farms a particular farm would be likely to infect, should all other farms be susceptible. We also ran in silico simulations of the adjusted model for each scenario to estimate epidemic sizes and time-varying effective reproduction numbers. We showed that reducing palmiped farm density in the densest municipalities decreased substantially the size of the areas with high R0 values (> 1.5). In silico simulations suggested that reducing palmiped farm density, even slightly, in the densest municipalities was expected to decrease substantially the number of affected poultry farms and therefore provide benefits to the poultry sector as a whole. However, they also suggest that it would not have been sufficient, even in combination with the intervention measures implemented during the 2016-2017 epidemic, to completely prevent the virus from spreading. Therefore, the effectiveness of alternative structural preventive approaches now needs to be assessed, including flock size reduction and targeted vaccination.

Different kettles of fish: Varying patterns of antibiotic use on pig, chicken and fish farms in Lao PDR and implications for antimicrobial resistance strategies.

The rapid intensification of the livestock sector in Southeast Asia has been found to be associated with an expanding use of antibiotics (ABU) and the rise of antimicrobial resistance (AMR) in both humans and livestock. This study aimed to explore the views and practices of commercial pig, poultry and fish farmers regarding antibiotics in Lao People's Democratic Republic, where data on antibiotic use and AMR remain scarce. A multistage cluster sampling method, based on the random selection of villages in two provinces of Vientiane, was used. A total of 364 farmers, corresponding to 454 farm units, were surveyed using a questionnaire and farm visits. This study found a widespread use of antibiotics (261 out of the 454 farm units used antibiotics). The predominance of antibiotics considered critically important antibiotics for human medicine was of great concern. Results from a logistic regression model showed that antibiotics were found less frequently in fish farm units compared to pig and poultry farm units, and more frequently in specialized farms than in livestock-fish farms. Multiple factor analysis and hierarchical cluster analysis revealed three profiles of farmers, each with distinct patterns on knowledge, attitudes and practices regarding ABU and AMR. Cluster 1 held a positive attitude regarding preventive measures and information about antibiotics. In cluster 2, there was a view that antibiotics should be used for prophylactic treatment such as disease prevention. Cluster 3 was characterized by farmers with weak knowledge who were unfamiliar with antibiotics and uncertain about details concerning antibiotic use. This cluster was associated with a significantly lower use of antibiotics than the two other clusters in the regression model. The results of this study may help the Laotian government to adapt strategies to control AMR by focusing on the use of critical antibiotics and prophylactic treatments and by tailoring measures to farmers' profiles.

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.

Two major epidemics of highly pathogenic avian influenza virus H5N8 and H5N1 in domestic poultry in France, 2020-2022.

The spread of highly pathogenic avian influenza (HPAI) viruses worldwide has serious consequences for animal health and a major economic impact on the poultry production sector. Since 2014, Europe has been severely hit by several HPAI epidemics, with France being the most affected country. Most recently, France was again affected by two devastating HPAI epidemics in 2020-21 and 2021-22. We conducted a descriptive analysis of the 2020-21 and 2021-22 epidemics, as a first step towards identifying the poultry sector's remaining vulnerabilities regarding HPAI viruses in France. We examined the spatio-temporal distribution of outbreaks that occurred in France in 2020-21 and 2021-22, and we assessed the outbreaks' spatial distribution in relation to the 2016-17 epidemic and to the two 'high-risk zones' recently incorporated into French legislation to strengthen HPAI prevention and control. There were 468 reported outbreaks during the 2020-21 epidemic and 1375 outbreaks during the 2021-22 epidemic. In both epidemics, the outbreaks' distribution matched extremely well that of 2016-17, and most outbreaks (80.6% and 68.4%) were located in the two high-risk zones. The southwestern high-risk zone was affected in both epidemics, while the western high-risk zone was affected for the first time in 2021-22, explaining the extremely high number of outbreaks reported. As soon as the virus reached the high-risk zones, it started to spread between farms at very high rates, with each infected farm infecting between two and three other farms at the peaks of transmission. We showed that the spatial distribution model used to create the two high-risk zones was able to predict the location of outbreaks for the 2020-21 and 2021-22 epidemics. These zones were characterized by high poultry farm densities; future efforts should, therefore, focus on reducing the density of susceptible poultry in highly dense areas.

Characterisation of chicken farms in Vietnam: A typology of antimicrobial use among different production systems.

The usage of antimicrobials in livestock production is a driver for antimicrobial resistance worldwide. Reducing the use of antibiotics in the animal sector is a priority and requires a change in practices. Vietnam has diverse husbandry and antimicrobial use practices. The objective of this study was to determine the socio-economic and technical factors associated with antibiotic usage patterns on chicken farms in the north and south of Vietnam. Semi-structured interviews (n = 34) and on-farm questionnaires (n = 125) were conducted to collect socio-economic, technical, biosecurity, health management, and antibiotic usage data. Using Multivariate Corresponding Analysis, we identified three production systems (A, B, C) and three patterns of antibiotic usage (1, 2, 3). Group A raised indoor exotic chickens in an intensive setting and was associated with group 1, which used antibiotics according to company recommendations for both treatment and prevention. Group C raised free-range chickens for their own consumption and was associated with group 2, which used antibiotics according to drugstore advice for treatment. Finally, group B was a market-oriented, semi-confined system associated with group 3, which practiced experience-based antibiotic use and overuse. Farms in the south of Vietnam were associated with group 3 and those in the north with group 2. The prediction of antibiotic usage patterns based on farming practices could lead to the identification of a group of farms to be targeted in order to foster the more prudent use of antibiotics in Vietnam.

Highly Pathogenic Avian Influenza A(H5N8) Clade 2.3.4.4b Virus in Dust Samples from Poultry Farms, France, 2021.

Avian influenza A(H5N8) virus has caused major epizootics in Europe since 2016. We conducted virologic analysis of aerosol and dust collected on poultry farms in France during 2020-2021. Our results suggest dust contributes to viral dispersal, even early in an outbreak, and could be a valuable surveillance tool.

Phylodynamic analysis of the highly pathogenic avian influenza H5N8 epidemic in France, 2016-2017.

In 2016-2017, France experienced a devastating epidemic of highly pathogenic avian influenza (HPAI) H5N8, with more than 400 outbreaks reported in poultry farms. We analyzed the spatiotemporal dynamics of the epidemic using a structured-coalescent-based phylodynamic approach that combined viral genomic data (n = 196; one viral genome per farm) and epidemiological data. In the process, we estimated viral migration rates between départements (French administrative regions) and the temporal dynamics of the effective viral population size (Ne) in each département. Viral migration rates quantify viral spread between départements and Ne is a population genetic measure of the epidemic size and, in turn, is indicative of the within-département transmission intensity. We extended the phylodynamic analysis with a generalized linear model to assess the impact of multiple factors-including large-scale preventive culling and live-duck movement bans-on viral migration rates and Ne. We showed that the large-scale culling of ducks that was initiated on 4 January 2017 significantly reduced the viral spread between départements. No relationship was found between the viral spread and duck movements between départements. The within-département transmission intensity was found to be weakly associated with the intensity of duck movements within départements. Together, these results indicated that the virus spread in short distances, either between adjacent départements or within départements. Results also suggested that the restrictions on duck transport within départements might not have stopped the viral spread completely. Overall, we demonstrated the usefulness of phylodynamics in characterizing the dynamics of a HPAI epidemic and assessing control measures. This method can be adapted to investigate other epidemics of fast-evolving livestock pathogens.

Biosecurity measures in French poultry farms are associated with farm type and location.

The severe impact of recently reported Highly Pathogenic Avian Influenza (HPAI) outbreaks have emphasized the need to better monitor biosecurity practices among the different French poultry production systems. Between October 2016 and September 2018, a large national cross-sectional study was carried out in France to assess biosecurity levels in high-risk poultry farms and identify farm biosecurity profiles, using Multiple Correspondence and Hierarchical Cluster Analyses. Results indicate that there is substantial room for improvement in cleaning and disinfection, anteroom management and delimitation of farm and production units for more than 50 % of the 1,004 analyzed farms. The farm biosecurity profile showing the highest level of biosecurity included commercial intensive poultry farms (gallinaceous poultry farms, in North-Western France), and those with a recent history of HPAI outbreak (duck farms, in South-Western France). The farms biosecurity profiles showing the lowest level of biosecurity included farms with multiple species (duck and gallinaceous poultry) or multiple production types (broilers and egg-layers), located in regions with a lower poultry density and without a recent history of HPAI outbreak. Outcomes provide support to adapt biosecurity improvement and inspection plans.

Inferring within-flock transmission dynamics of highly pathogenic avian influenza H5N8 virus in France, 2020.

Following the emergence of highly pathogenic avian influenza (H5N8) in France in early December 2020, we used duck mortality data from the index farm to investigate within-flock transmission dynamics. A stochastic epidemic model was fitted to the daily mortality data and model parameters were estimated using an approximate Bayesian computation sequential Monte Carlo (ABC-SMC) algorithm. The model predicted that the first bird in the flock was infected 5 days (95% credible interval, CI: 3-6) prior to the day of suspicion and that the transmission rate was 4.1 new infections per day (95% CI: 2.8-5.8). On average, ducks became infectious 4.1 h (95% CI: 0.7-9.1) after infection and remained infectious for 4.3 days (95% CI: 2.8-5.7). The model also predicted that 34% (50% prediction interval: 8%-76%) of birds would already be infectious by the day of suspicion, emphasizing the substantial latent threat this virus could pose to other poultry farms and to neighbouring wild birds. This study illustrates how mechanistic models can help provide rapid relevant insights that contribute to the management of infectious disease outbreaks of farmed animals. These methods can be applied to future outbreaks and the resulting parameter estimates made available to veterinary services within a few hours.

What can phylodynamics bring to animal health research?

Infectious diseases are a major burden to global economies, and public and animal health. To date, quantifying the spread of infectious diseases to inform policy making has traditionally relied on epidemiological data collected during epidemics. However, interest has grown in recent phylodynamic techniques to infer pathogen transmission dynamics from genetic data. Here, we provide examples of where this new discipline has enhanced disease management in public health and illustrate how it could be further applied in animal health. In particular, we describe how phylodynamics can address fundamental epidemiological questions, such as inferring key transmission parameters in animal populations and quantifying spillover events at the wildlife-livestock interface, and generate important insights for the design of more effective control strategies.

Optimizing the early detection of low pathogenic avian influenza H7N9 virus in live bird markets.

In Southeast Asia, surveillance at live bird markets (LBMs) has been identified as crucial for detecting avian influenza viruses (AIV) and reducing the risk of human infections. However, the design of effective surveillance systems in LBMs remains complex given the rapid turn-over of poultry. We developed a deterministic transmission model to provide guidance for optimizing AIV surveillance efforts. The model was calibrated to fit one of the largest LBMs in northern Vietnam at high risk of low pathogenic H7N9 virus introduction from China to identify the surveillance strategy that optimizes H7N9 detection. Results show that (i) using a portable diagnostic device would slightly reduce the number of infected birds leaving the LBM before the first detection, as compared to a laboratory-based diagnostic strategy, (ii) H7N9 detection could become more timely by sampling birds staying overnight, just before new susceptible birds are introduced at the beginning of a working day, and (iii) banning birds staying overnight would represent an effective intervention to reduce the risk of H7N9 spread but would decrease the likelihood of virus detection if introduced. These strategies should receive high priority in Vietnam and other Asian countries at risk of H7N9 introduction.

Determinants of biosecurity practices in French duck farms after a H5N8 Highly Pathogenic Avian Influenza epidemic: The effect of farmer knowledge, attitudes and personality traits.

Biosecurity is crucial for infectious disease prevention, more importantly in the absence of vaccination. The need for improving the implementation of biosecurity practices was highlighted in French duck farms following the 2016-2017 H5N8 Highly Pathogenic Avian Influenza (HPAI) epidemic. Farmers have multiple reasons for not implementing biosecurity practices: external (time, money) and internal (socio-psychological). The purpose of this study was to determine how sets of socio-psychological factors (i.e. knowledge on biosecurity and avian influenza transmission, attitudes, personality traits, social background) affect the adoption of on-farm biosecurity practices. Biosecurity practices and socio-psychological determinants were assessed during 127 duck farm visits, in South West France, using both questionnaires and on-farm observations. Factorial analysis of mixed data (FAMD) and hierarchical clustering analysis (HCA) identified three groups of farmers with different socio-psychological profiles: the first group was characterized by minimal knowledge, negative attitudes towards biosecurity, little social pressure and a low level of conscientiousness. The second group was characterized by more extensive experience in poultry production, higher stress and social pressure. The third group was characterized by less experience in poultry production, better knowledge and positive attitudes towards biosecurity, increased self-confidence and orientation towards action. The first group had a significantly lower adoption of biosecurity measures than the two other groups. A better understanding of the factors involved in farmers' decision-making could improve the efficiency of interventions aiming at improving and maintaining the level of on-farm biosecurity in the duck industry.

Transition Pathways Toward the Prudent Use of Antimicrobials: The Case of Free-Range Broiler Farmers in France.

Reducing antimicrobial use (AMU) on farms is key for controlling the rise of resistant bacteria that have the potential capacity to infect humans via direct animal contact or via the food chain or the environment. To reduce AMU, antimicrobials must be used in a prudent and rational manner. Extensive efforts have been made recently to identify the cognitive and behavioral barriers to the appropriate use of antimicrobials by various livestock sector stakeholders. However, most studies carried out thus far have only partly captured the dynamic and systemic dimension of the processes involved in changes of practices related to AMU on farms. To shed light on the transition pathways implemented to reduce AMU, a qualitative study was conducted in France based on 28 semi-structured interviews with farmers, technicians and veterinarians from the free-range broiler production sector. Based on the thematic analysis of verbatims, we identified technical improvements which are key contributors to reduced AMU. We also highlighted some gaps in knowledge regarding AMU and antimicrobial resistance. We found that, rather than individual motivations alone, the extent to which farmers are embedded in collective organizations is decisive for changes in practices, and downstream operators (distributors and slaughterers) play a key role in the beginning of AMU transition pathways. As a result, we show that change in AMU requires a global rethinking of the overall socio-technical system rather than modifications of a single element in a farming system. Our results also highlight that transition pathways toward reduced AMU cannot just rely on trigger events, but also involves medium or long-term processes, with actors' experiences and practices being modified on an incremental basis over time. Our study sheds light on the need for multi and trans-disciplinary research involving the social sciences to analyze interactions between stakeholders and the collective actions implemented to tackle the challenge of AMU reduction.