Environmental and Economic Impacts of Improved Antibiotics Stewardship in Poultry Systems

Lead Research Organisation: University of Edinburgh
Department Name: The Roslin Institute

Abstract

To address AMR, there is consensus on the need to reduce antimicrobial use (AMU) in food animal production. Intensive poultry production is characterised by high AMU and associated environmental risks to human health through direct and indirect (environmental) transmission - e.g. from livestock waste. As in other LMIC countries there are emerging challenges in designing regulatory structures and priorities based on robust evidence of effectiveness and cost of different voluntary and mandatory interventions across different parts of the supply chain. This proposal offers five linked interdisciplinary work packages exploring different elements related to drivers of AMU, pathways to resistance, and economic costs of alternative mitigation measures and their effectiveness in terms of reducing AMR risks. The project adopts novel perspectives in terms of the development of antimicrobial stewardship across all industry actors (e.g. breeders, feeding, pharmaceutical, veterinarians, farmers, retailers). We also use a theoretical framework (a marginal abatement cost curve) to represent relative cost-effectiveness of mitigation measures. Further project elements will share experience on research and training methods and science-policy translation between countries.
Activities:
WP1 Supply/value chain characterisation: To define stewardship in terms of supply chain relationships and to model value chains in economic terms, development of farm scale economic models to test costs of interventions. Identification of different mitigation measures to reduce AMU, modelling propensity to adopt alternative AMU practices.
WP2 AMR prevalence of AMR in target farms/systems: In selected groups of farms to identify /confirm AMR hotspots prevalence and pathways in farms & supply chains using bacteriological and metagenomic approaches to evaluate the consequences and relationship between AMR and different productive performances, considering resource consumption and residue generation, with the aim to model and characterise each group regarding its environmental impact (GHG emissions, pollution risk to in soil and water, and potential consequences).
WP3 Characterising AMU reduction interventions: Evaluating the effectiveness of alternative mitigation measures identified in WP1.
WP4 Cost-benefit analysis and scenarios: Development of a marginal abatement cost curve showing relative cost-effectiveness of alternative interventions targeting AMU.
WP5 Decision support for industry policy, scenarios & integration: Developing industry support tool and supply chain guidance on AM stewardship plan across poultry industry stakeholders for promotion of adoption of CE measures. Evaluating potential regulatory interventions targeting AMU.
The project seeks to understand and co-design cost-effective interventions across all supply chain actors that have a role on the stewardship of AMs, and can potentially influence on-farm behaviours, directly or indirectly. There is a need to understand how the action of the different actors might be combined to reduce AM use in production. The project will develop economic and behavioural methodologies as a basis for informing Argentinian field studies that seek to understand AMU drivers. It will test various responses (behavioural interventions), and evaluate the pathways to impacts; i.e. how these interventions and reduced use might actually reduce AMR, and what the broader economic costs and benefits of such scenarios might be. Much of the project will involve raising awareness of the role of economics among scientists, industry, regulators, and other policy makers, with a series of research, and policy meetings and joint events in both countries. It will also develop a consistent framework for representing the costs and benefits of measures to modify antimicrobial use in agriculture. This in turn will offer lessons for the development of LMIC strategies for managing antimicrobial use in poultry production.

Technical Summary

There is a need to regulate use of antimicrobial medicines in food animal production. Focusing poultry supply chains, this project adopts a One Health approach to understand and quantify the environmental and economic impacts (costs and benefits) of modified antimicrobial use and to co-design system interventions that are feasible, acceptable and cost-effective for producers. We take a whole supply/value chain perspective, using economic and social research methods to understand the role of all actors and transfer of value from breeding to retail, to define these interventions. . We will also quantify the abundance and diversity of AMR along this chain, supported by in vivo and in vitro studies. Samples will be collected and microbiological and metagenomic data will be analysed in collaboration with University of Edinburgh, as part of postdoctoral training/exchanges. Our interdisciplinary research will inform rational use and the development of decision support tools to inform production (e.g. on farm). We will develop the notion of antimicrobial stewardship as an industry (voluntary) approach, but we also consider other mandatory and market-based policy scenarios for measure compliance. Our methodologies will consider industry-wide effects and will be appropriate for use in other LMIC contexts for data collection and prioritisation of poultry sector antimicrobial use (AMU) interventions. This project suggest a marginal abatement cost framework as an integrative element for other projects funded under this call.

Planned Impact

We identify the following beneficiary groups:

Public:
The ultimate long-term impact targeted by this project is to reduce AMR through improved global stewardship of antimicrobial drugs in poultry production worldwide. This change will contribute to the maintenance of a global common pool resource (antimicrobials) and hence the beneficiaries are the global population - i.e. the general public depending on efficacy of antimicrobials to control bacterial diseases in humans and animals. The project will deliver increased awareness of the complex interplay between supply chain actors in terms of delivering stewardship of valuable drugs, and will provide an integrated tool/system to promote rational AMU in the context of cost-effective poultry/livestock production. It also points to the need to the best way to collect limited data in LMICs.

Livestock industry:
Livestock farmers, meat processors and retailers are obliged to produce meat and eggs that are safe and in a manner that does not adversely affect animal welfare, the environment or public health. The stewardship of antimicrobials is a major challenge facing the industry and public attitudes towards current farming practices. This project will clarify the different costs and benefits of AMU, and addresses the behavioural barriers to change in this sector by studying the role of different supply chain actors and will propose interventions that can be used to drive down AMU within the industry.

Vets:
Vets are notionally part of our AMU stewardship "supply chain" and will be beneficiaries of additional training in the control of AMR, following the guides developed by the research team. This evidence will be of use to veterinary and medical stakeholders seeking to implement a One Health approach to AMR. Note that this project is addressing an area that is characterized by significant data gaps.

One Health stakeholders:
AMR has been described as the quintessential One Health challenge requiring an improved understanding of antimicrobial use in animal and human medicine. We have noted numerous national and international strategies addressing AMR, but none of these provides a convincing framework for assessing economics (cost-effectiveness) and behavioral change in supply chains. We expect our results to be of interest to several international organizations including OIE, WHO, FAO and OECD.

Educators:
Further direct beneficiaries are educators especially in the veterinary sector who seeking tools and techniques for developing veterinary curricula to include effective behavioral interventions and social science methods in general. We are aiming to develop these tools for delivery in veterinary training (i.e. continuing professional development) worldwide.
Public health regulators:
Beyond the long-term behavioral objective, the project seeks to understand the effectiveness of other policy instruments (e.g. tradable antimicrobial credits). Information on the potential effectiveness of these instruments will be of benefit to health regulators in all countries seeking the most cost-effective policy approach to regulating antimicrobial use.

Academics:
Academics will benefit from this research in terms of development of joint interdisciplinary publications, gaining demonstrable interdisciplinary experience and in terms of training opportunities for younger postdoctoral project partners.

UKRI/CONICET:
AMR offers a variety of challenges that cannot be addressed without an understanding of the social and economic drivers of antimicrobial use in human and animal systems and the environment. The research councils will benefit from developing an example of truly cross-disciplinary research in this One Health area. UKRI is seeking to develop the area of biosocial science and we suggest that this project will contribute significantly in framing the relevant scientific and policy questions linking social drivers with biological outcomes.
 
Description Poultry supply chain models developed and key entry points for antimicrobial control identified. This information is part of a systematic review conducted for VMD and curently in submission to an international journal.
This study is now published as a systematic review of livestock system entry points for control of antimicrobial use (see Frontiers publication). The content is being used as an on going dialogue with poultry producers in Argentina
Exploitation Route identifying control point in livestock systems is of use to VMD and SENASA in Argentina
Sectors Agriculture

Food and Drink

Government

Democracy and Justice

Retail

 
Description They have fed into a wider policy debate on AMR that was the subject of a funded OECD CRP symposium at the University of Edinburgh in May 2023. We attracted the Chief Scientific Advisor at the Scottish Government to give a keynote and government staff attended the symposium
Sector Agriculture, Food and Drink
Impact Types Economic

Policy & public services

 
Title AM WTP_Lisrel routine 
Description A routine created in Lisrel Software package depicting relationships in the theoretical framework on causal factors influencing consumer choice/willingness to pay for AM free poultry meat. The routine follows the structure of a structural choice model and includes causality assumptions, and choice/WTP. The routine is created specifically for this project. The generic model will be estimated with survey data collected from the Argentinian and British consumers, when available, with potential subsequent modifications to be made to the algorithm based on data response to model assumptions. 
Type Of Material Computer model/algorithm 
Year Produced 2022 
Provided To Others? No  
Impact The model will be estimated with primary survey data collected from the Argentinian and British consumers. The impact within the project is expected in WP4 (scenarios to simulation trade model). Potential impact beyond the project - it is expected that the model will contribute to the literature on causal factors of AM use related choice/WTP (consumer demand), which is currently still incipient. 
 
Title AM behaviour_Lisrel routine 
Description A routine created in Lisrel Software package depicting relationships in the theoretical framework on causal factors influencing poultry farmer intentions and behaviour as regards use of AM alternative measures to control disease on farm. The routine follows the structure of a structural equation model and includes causality assumptions, measurement model, structural model, and technical assumptions. Technical assumptions are related to the DWLS estimation method. The routine is created specifically for this project. The generic model will be estimated with survey data collected from the Argentinian poultry farmers, when available, with potential subsequent modifications to be made to the algorithm based on data response to model assumptions. 
Type Of Material Computer model/algorithm 
Year Produced 2021 
Provided To Others? No  
Impact The model will be estimated with primary survey data collected from the Argentinian poultry farmers. The impact within the project is expected in WP1 (farm analysis) and WP4 (scenarios to simulation trade model). Potential impact beyond the project - it is expected that the model will contribute to the literature on causal factors of AM use related behaviours in agricultural primary production, which is currently still incipient. 
 
Title AM behaviour_questionnaire 
Description The questionnaire follows a combination of theoretical frameworks of attitudes, intentions and behaviour. Questionnaire items are designed to be tested using structural equation modelling, and follow SEM technical requirements in terms of e.g. number and representation (reflexive or formative) of indicators per latent variable. The observed variable section will be appended (pre-survey data collection) into a separate form for collection of farm production data directly feeding into the farm production model. 
Type Of Material Data analysis technique 
Year Produced 2021 
Provided To Others? No  
Impact The questionnaire will be applied to a primary survey of Argentinian poultry farmers and data collected will be fed into the Lisrel routine for estimation of behavioural relationships (required for analysis in WP1 and WP4), with some raw data used directly (after pre-processing) into the farm production analysis (WP1). We will publish the questionnaire as part of an article on the behavioural analysis and thus it may have an impact on the research community working on the topic. 
 
Title AM behaviour_questionnaire - consumer WTP 
Description The questionnaire follows a combination of theoretical frameworks of attitudes, intentions and choice. Questionnaire items are designed to be tested using structural choice modelling, and follow SCM technical requirements in terms of e.g. number and representation (reflexive or formative) of indicators per latent variable, and building the choice variable (willingness to pay). The questionnaire includes sections feeding into assessment of causal relationships (SEM) and choice/WTP (SCM). 
Type Of Material Data analysis technique 
Year Produced 2022 
Provided To Others? No  
Impact The questionnaire will be applied to two primary surveys of Argentinian and British consumers and data collected will be fed into the Lisrel routine for estimation of choice/WTP. We will publish the questionnaire as part of an article on the SCM analysis and thus it may have an impact on the research community working on the topic. 
 
Title Choice experiment of WTP for antimicrobial (AM) alternatives - Argentinian consumers 
Description Choice experiment of WTP for AMR alternatives - Argentinian consumers (sample of 1000 observations) In the choice task, respondents were successively shown 9 choice sets. Each choice set comprises two chicken breast meat alternatives and an opt-out alternative. Each chicken alternative was described in terms of five attributes and their levels. The choice experiment efficient design (36 choice cards blocked in four blocks) was generated using the software Ngene. The data were analysed using the conditional logit model (CL). The impact of providing respondents with additional information (i.e., pros and cons of the use of antibiotics in poultry farming) on their WTP was estimated by adding an interaction term in the model specification. 
Type Of Material Computer model/algorithm 
Year Produced 2024 
Provided To Others? No  
Impact This model contributes to the literature on consumer demand for food products produced without antimicrobial use by (1) assessing consumers' preferences not only for a reduced or non-use of antibiotics in poultry farming but also the use of natural alternatives to antibiotics, (2) assessing how consumers' WTP for antibiotic-free chicken meat compares to their WTP for other desirable chicken meat attributes (i.e., "environmental sustainability" "healthiness of the meat", and "Origin"), (3) assess the impact of providing consumers with additional information on the pros and cons of antibiotic use in poultry farming on their WTP. 
 
Title Choice experiment of WTP for antimicrobial (AM) alternatives - UK consumers 
Description Choice experiment of WTP for AMR alternatives - UK consumers (sample of 1000 observations) In the choice task, respondents were successively shown 9 choice sets. Each choice set comprises two chicken breast meat alternatives and an opt-out alternative. Each chicken alternative was described in terms of five attributes and their levels. The choice experiment efficient design (36 choice cards blocked in four blocks) was generated using the software Ngene. The data were analysed using the conditional logit model (CL). The impact of providing respondents with additional information (i.e., pros and cons of the use of antibiotics in poultry farming) on their WTP was estimated by adding an interaction term in the model specification. 
Type Of Material Computer model/algorithm 
Year Produced 2024 
Provided To Others? No  
Impact This model contributes to the literature on consumer demand for food products produced without antimicrobial use by (1) assessing consumers' preferences not only for a reduced or non-use of antibiotics in poultry farming but also the use of natural alternatives to antibiotics, (2) assessing how consumers' WTP for antibiotic-free chicken meat compares to their WTP for other desirable chicken meat attributes (i.e., "environmental sustainability" "healthiness of the meat", and "Origin"), (3) assess the impact of providing consumers with additional information on the pros and cons of antibiotic use in poultry farming on their WTP. 
 
Title Poultry Production Economic Model (PPEM) 
Description The PPEM is a farm level optimising model that maximizes farm net profit. The model has three stages of poultry production (Starter, Grower, and Finisher). The farm net profit is determined by poultry stage, revenue per bird, price of restock, variable costs, feed costs, water costs, labour costs, costs of treatment, fixed costs. Farm net profit under two scenarios are compared to determine the economic impact of the alternative growth promoter used in this study. A sensitivity analysis was conducted to test the influence of the price of alternative growth promoter across scenarios. The results suggest that there is a small but positive increase in farm net profits for both farm types under the tanin treatment. Due to a higher weight gain, production levels in both farm types shown a small improvement when alternative growth promoter was used. The farms were projected to have higher water and labour costs and a substantially higher feed cost under the AGP- treatment compared to the AGP+ treatment. The sensitivity analysis showed that the price of tanin can be up to 3 times the current price of AGPs to be economically feasible to adopt. 
Type Of Material Computer model/algorithm 
Year Produced 2023 
Provided To Others? No  
Impact Emergence of several alternatives to AGPs in a positive step forward in tackling antimicrobial resistance in poultry sector. The usage of a commercial tannin product (SilvaFeed/Nutri-P) is one of such option. This research conducted on Argentinian farms showed the use of tanin to have economic benefits on poultry farms. This is due to higher weight gain, lower mortality and improved feed conversion on trials used on both commercial and experimental Argentinian farms. Research undertaken recently shows improvement in poultry production under different alternative growth promoters. The economic feasibility of such alternatives is however, based on relative price of alternatives compared to the prices of AGPs. It is estimated that alternative growth promoter used in this study stays economically feasible if the price of such alternative is less than 4 times the price of AGPs used on farms. 
 
Title Structural equation model of WTP for antimicrobial (AM) alternatives - Argentinian consumers 
Description A structural equation model (SEM) was built around hypotheses which test findings from the literature around causal relationships between various determinants of consumption behaviour and intentions in relation to antimicrobial use in the food purchased. It was built (statistical software package LISREL 8.80) to test and estimate the conceptual model. SEM is a multivariate technique used to test hypotheses concerning relationships between factors influencing decision-making processes. The use of SEM in this study aims to test the relationships between the latent variables specified in the conceptual model, where the latent constructs are multi-dimensional and unobservable and built on/measured by observable variables; moreover, it caters to measurement error, increasing estimation accuracy; and most importantly, it allows concurrent estimation of direct and indirect effects, thus explaining a larger proportion of the variance in the target latent variables than other techniques used in causal analysis. Target variables include willingness to buy more/pay more for chicken meat products produced with less/without antibiotics (built on 3 items on a range of antibiotic use level), and preferences towards interventions for alternative control of disease on poultry farms (training to support the uptake of biosecurity, financial support to enhance animal welfare, financial support to encourage the industry to reduce the use of antibiotics through a focus on, for example, vaccination programmes, investment in research for replacing ineffective antibiotics, legislation restricting the use of antibiotics, increased consistency in consumer pressure on the food industry to reduce the use of antibiotics, campaigns informing consumers on the risks of picking up resistant bacteria). The model was estimated on the Argentinian sample (1000 observations) with acceptable values for all goodness of fit indicators. The model run on the Argentinian sample solves for 59 percent of the variance in willingness to buy more/pay more for chicken meat products produced with less/without antibiotics, and 54 percent of the variance in preferences towards interventions for alternative control of disease on poultry farms. All relationships included in the model are statistically significant, with the highest effect being the knowledge variables, awareness of antibiotics use on poultry farms, and perceived ability to understand the relationship between antibiotics use, transmission and resistance. The effect of the latter on preferences towards interventions to alternative control is mediated through risk perceptions about antibiotics use on poultry farms, then environmental/ food safety / health and welfare concerns linked to antibiotics use on poultry farms. Similarly, the effect of perceived ability to understand 'no antibiotic' labelling on chicken meat products on willingness to pay more for lower/no use of antibiotics is mediated through perceived usefulness of antibiotic use labelling on chicken meat products, then frequency of purchasing chicken raised without antibiotics (labelled). Stated consumption of organic chicken meat (percentage in total consumption of chicken meat) has a strong direct effect on both behaviour and intentions of purchasing food produced with less antibiotics. A lower influence, still statistically significant, derive from perceptions of trust in institutions responsible for food production or labelling, and the perceived expectations of peers. 
Type Of Material Computer model/algorithm 
Year Produced 2024 
Provided To Others? No  
Impact This is the first causality model (SEM) applied to a representative sample of the Argentinian consumers to assess the effect of factors a priori identified in the literature on willingness to purchase food produced with less antibiotics at higher price, and their preferences towards interventions for alternative control of disease on farm. 
 
Title Structural equation model of WTP for antimicrobial (AM) alternatives - UK consumers 
Description A structural equation model (SEM) was built around hypotheses which test findings from the literature around causal relationships between various determinants of consumption behaviour and intentions in relation to antimicrobial use in the food purchased. It was built (statistical software package LISREL 8.80) to test and estimate the conceptual model. SEM is a multivariate technique used to test hypotheses concerning relationships between factors influencing decision-making processes. The use of SEM in this study aims to test the relationships between the latent variables specified in the conceptual model, where the latent constructs are multi-dimensional and unobservable and built on/measured by observable variables; moreover, it caters to measurement error, increasing estimation accuracy; and most importantly, it allows concurrent estimation of direct and indirect effects, thus explaining a larger proportion of the variance in the target latent variables than other techniques used in causal analysis. Target variables include willingness to buy more/pay more for chicken meat products produced with less/without antibiotics (built on 3 items on a range of antibiotic use level), and preferences towards interventions for alternative control of disease on poultry farms (training to support the uptake of biosecurity, financial support to enhance animal welfare, financial support to encourage the industry to reduce the use of antibiotics through a focus on, for example, vaccination programmes, investment in research for replacing ineffective antibiotics, legislation restricting the use of antibiotics, increased consistency in consumer pressure on the food industry to reduce the use of antibiotics, campaigns informing consumers on the risks of picking up resistant bacteria). The model was estimated on the UK sample (1000 observations) with acceptable values for all goodness of fit indicators. The model run on the UK sample solves for 68 percent of the variance in willingness to buy more/pay more for chicken meat products produced with less/without antibiotics, and 72 percent of the variance in preferences towards interventions for alternative control of disease on poultry farms. All relationships included in the model are statistically significant, with the highest effect being the knowledge variables, awareness of antibiotics use on poultry farms, and perceived ability to understand the relationship between antibiotics use, transmission and resistance. The effect of the latter on preferences towards interventions to alternative control is mediated through risk perceptions about antibiotics use on poultry farms, then environmental/ food safety / health and welfare concerns linked to antibiotics use on poultry farms. Similarly, the effect of perceived ability to understand 'no antibiotic' labelling on chicken meat products on willingness to pay more for lower/no use of antibiotics is mediated through perceived usefulness of antibiotic use labelling on chicken meat products, then frequency of purchasing chicken raised without antibiotics (labelled). Stated consumption of organic chicken meat (percentage in total consumption of chicken meat) has a strong direct effect on both behaviour and intentions of purchasing food produced with less antibiotics. A lower influence, still statistically significant, derive from perceptions of trust in institutions responsible for food production or labelling, and the perceived expectations of peers. 
Type Of Material Computer model/algorithm 
Year Produced 2024 
Provided To Others? No  
Impact This is the first causality model (SEM) applied to a representative sample of the UK consumers to assess the effect of factors a priori identified in the literature on willingness to purchase food produced with less antibiotics at higher price, and their preferences towards interventions for alternative control of disease on farm. 
 
Title Survey database on antimicrobial (AM) alternatives - Argentina (consumers) 
Description The data was collected during December 2023 - January 2024 through an online survey representative by age, gender, employment status, education level, and geographical distribution of Argentinian consumers, with a sample of 1000 respondents. Filters applied included stated full/partial responsibility for the grocery shopping in the household, being an omnivore or flexitarian, and having had consumed chicken meat in the past 3 months. 
Type Of Material Database/Collection of data 
Year Produced 2024 
Provided To Others? No  
Impact This is the first database representative of the Argentinian population of consumers of poultry meat to identify their views and willingness to pay for AMR alternatives in the Argentinian poultry sector. It includes variables representing a comprehensive range of factors a priori identified in the literature to influence consumers' willingness to purchase food produced with less antibiotics at higher price, and their preferences towards interventions for alternative control of disease on farm. 
 
Title Survey database on antimicrobial (AM) alternatives - UK (consumers) 
Description The data was collected during December 2023 - January 2024 through an online survey representative by age, gender, employment status, education level, and geographical distribution of UK consumers, with a sample of 1000 respondents. Filters applied included stated full/partial responsibility for the grocery shopping in the household, being an omnivore or flexitarian, and having had consumed chicken meat in the past 3 months. 
Type Of Material Database/Collection of data 
Year Produced 2024 
Provided To Others? No  
Impact This is the first database representative of the UK population of consumers of poultry meat to identify their views and willingness to pay for AMR alternatives in the UK poultry sector. It includes variables representing a comprehensive range of factors a priori identified in the literature to influence consumers' willingness to purchase food produced with less antibiotics at higher price, and their preferences towards interventions for alternative control of disease on farm. 
 
Description Invited talk to the EconWomen student association of the University of Edinburgh 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Undergraduate students
Results and Impact Luiza Toma was invited to give a talk on methodological approaches to behaviours and efficiency to the EconWomen student association of the University of Edinburgh
Year(s) Of Engagement Activity 2022