# Qualitative studies on farm managers perception of risk from HPAIV and implementation of biosecurity measures on UK poultry farms

Paniz Hosseini<sup>a,*</sup>, Ivo Syndicus<sup>b</sup>, Eve Houghton<sup>b</sup>, Pablo Alarcon<sup>b</sup>, Guillaume Fournie<sup>b,c,d</sup>, Javier Guitian<sup>b</sup>, Andy Paterson<sup>e</sup>, Ashley C. Banyard<sup>f,g</sup>, Ian H. Brown<sup>g,h</sup>, Richard Hepple<sup>e</sup>, James L.N. Wood<sup>a</sup>

## ARTICLE INFO

### Keywords:

- Biosecurity
- Avian influenza
- Poultry
- Qualitative
- UK

## ABSTRACT

The epidemic of high pathogenicity avian influenza (HPAI) H5N1 in the United Kingdom and Northern Europe from 2021 to 2023 has dwarfed all previous incursions. This fact has driven the need to review biosecurity behaviours and perceptions of virus incursions on commercial poultry farms. This study used qualitative methods to evaluate farm managers' perceptions of biosecurity and their implementation of measures as recommended by the Animal and Plant Health Agency (APHA). Thirteen farm managers across different regions of England and Wales were recruited between May and September 2023 to take part in the study. Qualitative semi-structured interviews were held with managers to discuss various topics relating to biosecurity and avian influenza (AI). Biosecurity measures being used across the farm by managers and staff were also observed to help understand biosecurity behaviours. Interviews were transcribed and analysed to identify themes and patterns amongst the data, along with extensive notes collated during the farm visits. Findings showed that farms' use of biosecurity with respect to disinfection regimes and use of foot dips were both well cited and observed. Similarly, farm managers were all highly likely to refer to the use of farm-specific and shed-specific rubber boots, while also citing stricter requirements for visitors and delivery/maintenance. Biosecurity concerning the layout of the premises, fencing, access to changing rooms and the general age and maintenance of buildings and sheds required significant improvement across many farms. Additionally, farm managers expressed strong feelings of

**Glossary of abbreviations:** AI, Avian Influenza: "Also known as 'bird flu' - a disease primarily affecting birds which is caused by a virus of the Orthomyxoviridae family" Pan American Health Organization, 2024; AIPZ, Avian Influenza Prevention Zones: "Legal requirement for all bird keepers whether they have pet birds, commercial flocks, specialist collection or just a few birds in a backyard flock to follow strict biosecurity measures to prevent bird flu and stop it spreading" Department for Environment, Food and Rural Affairs and Animal and Plant Health Agency, 2023; APHA, Animal and Plant Health Agency: "An executive agency, sponsored by the Department for Environment, Food & Rural Affairs, the Welsh Government and the Scottish Government" Animal and Plant Health Agency, 2024; C&D, Cleaning & disinfection: "a process that removes and kills germs on equipment and surfaces. C&D, when done correctly, is a cost-effective way to protect animal and human health" The Center for Food Security & Public Health, 2021; DEFRA, Department for Environment Food and Rural Affairs: "Defra is a ministerial department, supported by 35 agencies and public bodies" Department for Environment, Food & Rural Affairs, 2025; HPAI, High Pathogenicity Avian Influenza: "Avian influenza A viruses are classified into the following two categories: low pathogenicity avian influenza LPAI A viruses, and highly pathogenic avian influenza HPAI A viruses. The categories refer to molecular characteristics of a virus and the virus' ability to cause disease and mortality in chickens in a laboratory setting" CDC, 2024; HPAIV, High Pathogenicity Avian Influenza Virus: "Caused by subtypes H5 and H7 of type A, causes serious illness in birds that can spread rapidly, resulting in high death rates in different species of birds" Pan American Health Organization, 2024; PPE, Personal Protective Equipment: "Equipment worn to minimize exposure to hazards that cause serious workplace injuries and illnesses. These injuries and illnesses may result from contact with chemical, radiological, physical, electrical, mechanical, or other workplace hazards" Occupational Safety and Health Administration, 2024.

<footnote><sup>a</sup> Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, United Kingdom</footnote>

<footnote><sup>b</sup> Department of Pathobiology and Population Sciences, Royal Veterinary College, Hawkshead Lane, Brookmans Park, Hatfield AL9 7TA, United Kingdom</footnote>

<footnote><sup>c</sup> INRAE, VetAgro Sup, UMR EPIA, Université de Lyon, Marcy l'Étoile, France</footnote>

<footnote><sup>d</sup> INRAE, VetAgro Sup, UMR EPIA, Université Clermont Auvergne, Saint-Genes-Champanelle, France</footnote>

<footnote><sup>e</sup> APHA Field Epidemiology team, (APHA-Weybridge), Woodham Lane, Addlestone, Surrey KT15 3NB, UK</footnote>

<footnote><sup>f</sup> Department of Virology, Animal and Plant Health Agency, (APHA-Weybridge), Woodham Lane, Addlestone, Surrey KT15 3NB, United Kingdom</footnote>

<footnote><sup>g</sup> WOAH/FAO International Reference Laboratory for Avian Influenza, Animal and Plant Health Agency (APHA-Weybridge), Woodham Lane, Addlestone, Surrey KT15 3NB, United Kingdom</footnote>

<footnote><sup>h</sup> The Pirbright Institute, Ash Road, Pirbright, Woking, Surrey GU24 0NF, United Kingdom</footnote>

<footnote>* Corresponding author.</footnote>

<footnote>E-mail address: ph586@cam.ac.uk (P. Hosseini).</footnote>
stress and anxiety in recent years, particularly those who had experienced an AI outbreak recently. We argue that factors such as risk perceptions, remits of control, feelings of responsibility and autonomy, and consequences on mental health, are all factors that can inform how farm managers respond to outbreaks and implement or sustain biosecurity on farms. A greater emphasis on providing regular and tailored training and educational resources for the industry would be beneficial as would further services focusing on reducing the burden on farmers' mental health. This research provides insight into the application and shortcomings of biosecurity implementation on commercial poultry farms. It also identifies farmer perceptions and experiences shaping implementation on farms. However, this highlights that the onus for improving biosecurity cannot remain solely with farm managers and workers. Further research exploring the role of other stakeholders in the industry would help bridge remaining gaps in our understanding of biosecurity implementation.

# 1. Introduction

Highly Pathogenic Avian Influenza (HPAI), caused by H5 or H7 influenza type of avian influenza (AI) viruses, is a disease affecting birds which can cause rapid mortality in infected poultry flocks (Spekreijse et al., 2011). Since 2021, high pathogenicity avian influenza virus (HPAIV), particularly the H5N1 strain, has caused global epizootics that have initiated across Europe and were subsequently disseminated globally by migratory birds (Alkie et al., 2023; Charostad et al., 2023; European Food Safety Authority (EFSA) et al., 2023; Fusaro et al., 2024). The spread of the H5N1 virus represents an ongoing global threat to poultry and wildlife, causing economic losses within the poultry industry as well as concerns over its zoonotic potential and conservation threat (Bennison et al., 2024; Harvey et al., 2023; Rehman et al., 2023; Tajudeen et al., 2021). Since 2024, its incursion into US dairy herds has further raised the spectre of potential zoonotic transmission (Ly, 2024).

Associated with the movement of infected wild bird species via migratory pathways, the UK poultry industry has been faced with hundreds of H5N1 outbreaks since the first outbreak in October 2021 (James et al., 2023) with over 370 confirmed cases in farms and over 2000 wild birds testing positive for H5N1 since October 2020 (Animal and Plant Health Agency, 2024). The scale of the epidemic has raised questions regarding why so many farm breakdowns have occurred, when it had been assumed that preventive measures on farm, termed biosecurity, should effectively limit them.

The Animal and Plant Health Agency (APHA) defines the term “Biosecurity” as a “set of precautions that aim to prevent the introduction and spread of harmful organisms.” (Forestry Commission, Animal and Plant Health Agency, 2023). Biosecurity is increasingly recognised as vital to prevent many farm disease incursions, most notably for example, during the foot and mouth disease outbreak in the UK in 2001 (Heffernan et al., 2008). In the UK, APHA and Department for Environment Food and Rural Affairs (DEFRA) in particular have emphasised the importance of biosecurity since the 2021 HPAI incursions commenced (Department for Environment, Food and Rural Affairs, 2023a). Although most biosecurity measures are implemented at the discretion of farmers, additional temporary legal requirements were introduced and have been enforced periodically for poultry and captive bird keepers by DEFRA since 2021. One major example of this includes the declaration of Avian Influenza Prevention Zones (AIPZ), which were introduced in October 2022 to help reduce the spread of HPAI amongst poultry premises at most geographic and temporal risk of AI incursion (Department for Environment, Food and Rural Affairs, 2022). AIPZs enforcement re-emphasised the importance of using effective biosecurity measures across poultry farms, ensuring that, for example, poultry keepers were adhering to mandatory “minimum” biosecurity, and keepers with 500 or more birds had “enhanced” biosecurity in place for their poultry/captive birds. Examples of the latter included restricting access for non-essential people on site; re-stating that workers must change their clothing and footwear before entering bird areas and cleaning and disinfecting more regularly (Department for Environment, Food and Rural Affairs, 2023a) (Department for Environment, Food and Rural Affairs and Animal and Plant Health Agency, 2023a, 2023b). Particularly significant was a legal requirement for all poultry, including

free-range and other captive birds to be housed or kept separate from wild birds(Department for Environment, Food and Rural Affairs, 2022). These measures were introduced in the autumn of 2021 and 2022 and then relaxed in April 2023 when case numbers were declining (Department for Environment, Food and Rural Affairs, 2023b).

Biosecurity is often viewed as perimeter or “external” biosecurity, in which the focus has been on mitigating and preventing risk coming onto the farm from outside (Maxwell, 2023). Here, biosecurity measures have focused on limiting spread by, for example, regular disinfection points at the entrance of the farm, wheel washing/disinfection, providing visitors with Personal Protective Equipment (PPE), putting on clean rubber boots before entering the farm etc (Tilli et al., 2022) and ensuring that incoming animal movements are only from ‘secure’ premises. In existing literature, some researchers have claimed that there is currently too much focus on keeping pathogens out and limiting disease incursions from outside of the farm environment, but a lack of focus on what may be allowing disease spread within the farm itself (Hinchliffe, 2013). Where HPAI incursions from wild birds are the main threat, focus on measures that separate farmed birds from contamination on the farm become more important than where the risk is elsewhere in the poultry industry. Quantitative surveys have characterised the different biosecurity measures used on poultry farms (Guinat et al., 2020; Van Steenwinkel et al., 2011), but our understanding of the actual implementation of biosecurity measures on UK poultry farms remains suboptimal.

Here we describe outputs from a study that focussed on assessing and understanding farm managers’ perceptions and use of biosecurity in relation to AI in Great Britain. Themes and patterns from interviews and observations of on-farm biosecurity are presented and used to suggest how on-farm biosecurity practices can be impacted by a wide range of factors.

# 2. Material and methods

## 2.1. Study group and selection of participants

Farm managers across commercial poultry farms in England and Wales were recruited using purposive sampling. Farm managers were chosen to participate given their role in decision making for their farm surrounding the threat of AI, along with their role in managing and implementing biosecurity measures on farm. Participants were contacted during the spring of 2023 through companies and trade associations representing the poultry industry. Individuals were then contacted via phone or email (either directly or through initial contacts) and asked if they were interested in participating in the study, while also being provided with a study information sheet and consent form. Arrangements to conduct the interview and observations in person on the farms were then made after contact.

A purposive sampling method was used whereby farms from a range of geographical locations, poultry type and farm size were also selected (Table 1). These farms included “case farms” - defined as any commercial poultry farm which had an outbreak of AI since 2021 to the time of data collection – and “non-case farms” - defined as any commercial poultry farm that had not previously experienced an outbreak of AI.
<table><caption>**Table 1**
Farms involved in the study, arranged alphabetically by geographical location.</caption><thead><tr><th>Geographical location</th><th>Poultry type</th><th>Farm size by number of birds*</th><th>Case or non-case</th></tr></thead><tbody><tr><td>Cambridgeshire</td><td>Turkey (free range)</td><td>40,000</td><td>Case (2022)</td></tr><tr><td>Essex</td><td>Turkey</td><td>20,000</td><td>Non-case</td></tr><tr><td>Herefordshire</td><td>Broiler breeder rearing</td><td>42,000</td><td>Non-case</td></tr><tr><td>Herefordshire</td><td>Layer breeder</td><td>33,000</td><td>Non-case</td></tr><tr><td>Lincolnshire</td><td>Layer (free range)</td><td>16,000</td><td>Case (2021)</td></tr><tr><td>Norfolk</td><td>Broiler</td><td>158,000</td><td>Non-case</td></tr><tr><td>Norfolk</td><td>Broiler</td><td>155,000</td><td>Case (2022)</td></tr><tr><td>Norfolk</td><td>Broiler breeder</td><td>25,000</td><td>Case (2022)</td></tr><tr><td>Norfolk</td><td>Duck</td><td>49,000</td><td>Non-case</td></tr><tr><td>Suffolk</td><td>Duck</td><td>85,000</td><td>Case (2022)</td></tr><tr><td>South Wales</td><td>Broiler</td><td>160,000</td><td>Non-case</td></tr><tr><td>Yorkshire</td><td>Turkey</td><td>50,000</td><td>Case (2021)</td></tr><tr><td>Yorkshire</td><td>Turkey</td><td>12,000</td><td>Case (2021)</td></tr></tbody></table>

## 2.2. Ethics and consent

The study received ethical approval from the Social Science Research Ethical Review Board at the Royal Veterinary College (URN: SR2022 – 0130) and the by the Departmental Ethics & Welfare Committee at the Department of Veterinary Medicine in the University of Cambridge (Ref: CR627). Informed consent for participation and voice recording was provided verbally and in writing through signature by each farm manager at the start of the interview. All direct quotes from interviews from individual participants in this paper are anonymised.

## 2.3. Study/interview design

The study used a range of qualitative methods to gather data relating to biosecurity use and perceptions. This included a semi-structured interview with the farm manager from each of the selected farms, along with observations of the on-farm implementation of biosecurity and the general biosecurity and infrastructure of the premises. Interviews and observations were held in person on each farm and were informed by an ethnographic approach. This meant treating the entire process of visiting farms as generating potentially relevant insights by attentiveness to clues obtained through observations and any informal conversations. This approach was piloted on six farms at the outset in March 2023 to help develop the interview guide and allow improvements to the interview style, questions, and techniques. Farm visits with one qualitative researcher took place between May and September 2023. All the interviews were audio recorded and field notes were taken to document observations during the visits.

The interviews involved a range of open-ended questions focusing on a variety of topics, including the farm manager's background, production cycles on the farm, biosecurity measures used on the farm, biosecurity measures added since the increase in the number of outbreaks across the UK, relationships with companies and other actors, experiences surrounding any AI outbreaks, and any mitigation measures recommended for the future. After the interviews were conducted and with permission from the farm manager, a tour of the farm was provided, enabling the researcher to conduct more detailed observations to assess the biosecurity used on site by the farm manager and other members of staff (if observed), while also asking further questions surrounding the overall structure of the farm and day-to-day activities. This was to help provide a better understanding of not only the farm from that described in the interview, but also to identify where biosecurity measures were being used effectively on the day. Using informal conversations surrounding the topics of interest as part of an ethnographic approach also

helped to understand the participants experiences, perspectives, and everyday practices, rather than only assessing the observable biosecurity measures in place. APHA's resources on biosecurity (e.g. checklists) helped to gain an understanding of the specific areas of biosecurity to observe and focus on during the visits.

## 2.4. Data analysis

Interviews were transcribed and anonymised manually to remove identifiable information such as names of people, companies, and neighbouring farms. Each interview transcription was cross-checked with the recordings to ensure accuracy. Interviews, field notes and other information gathered were analysed to generate patterns and themes amongst the data, along with the generation of ideas in relation to the topic. The analysis of the interview transcripts was conducted using NVivo 12, whilst analysis of the field notes was conducted by hand. Analysis of the transcripts was conducted by two researchers, whereby the first research conducted the main analysis and the second cross-checked to identify any other themes or patterns of interest.

# 3. Results

A total of thirteen interviews were conducted with poultry farm managers across England and Wales in the spring and summer months of 2023. Interviews lasted between 45 minutes to an hour and explored a range of topics. Our research set out to capture farm managers' perceptions of biosecurity measures and how they implemented them. The results here capture the main themes, patterns, and observations to have emerged from the data analysis.

## 3.1. Biosecurity practices – perimeter (external biosecurity)

The use and uptake of biosecurity measures varied across farms, but certain measures were more commonly cited and followed than others across the farms visited.

Below we present findings on the most notable biosecurity practices which would also typically fall under the perimeter biosecurity remit, whereby measures limiting the risk of bringing disease or pathogens into the farm itself are followed.

### 3.1.1. Disinfection routines

The regular use of foot dips and wheel washers were reported as a common measure to be followed for the farm managers and staff. Observations showed that foot dips were often clean and placed outside the changing area before entering the farm, followed by another foot dip once exiting the changing area once in farm-specific boots and clothing. Farm managers also frequently cited the use of wheel washers, ensuring that they had stricter rules for visitors and delivery vehicles entering the farm. They described always having used these measures but increasing their use of them more frequently in recent years to enhance protection.

### 3.1.2. Personal Protective Equipment (PPE) and changing areas

The use of overalls and site-specific clothing was reported to be followed commonly by many of the farm managers, who viewed the use of such PPE as an effective way to help ensure protection against AI, especially when used by visitors. Nonetheless, the use and availability of site clothing varied upon the changing rooms placed at the entrance, with some farms having good access to a range of clean overalls for anyone entering the premises, while others did not. In one instance, a farm was only able to provide a previously worn disposable overall in the changing room at the point of entrance, as they had no fresh ones available.

Farm managers also changed into the appropriate overalls and rubber boots before entering the farm during the observations, and this was also commonly cited. The types of changing areas ranged across farms, with some placed at the entrance before entering the premises, and

<footnote>* Farm size by number of birds in total sheds at the time of data collection. It is important to note that the maximum number of birds kept on farms is dependent on the type of poultry in the UK.</footnote>
others being placed inside the premises. However, some were poorly located (further information in 3.2.1) and in one instance, there was no changing area present on the farm entirely, and this meant that visitors had to change into disposable overalls outside the sheds, with improper access to rubber boots and other PPE, such as masks and gloves.

### 3.1.3. Farm-specific rubber boots

Rubber boots were very commonly cited and used across the farms. Of these, it was very clear that farm-specific rubber boots were required to be worn by all farm managers, staff and all visitors entering the premises. Most farm-specific rubber boots were provided and expected to be worn at the entrance of the farm in changing areas that were located at the entrance of the premises. However, in certain cases, the farm-specific rubber boots were worn after entering the farm, and this was due to the placement of certain changing areas, which were located in the farm after entering the premises, rather than at the entrance (as cited in 3.2.1).

### 3.1.4. Fencing

Most farms did not have perimeter fences, suggesting a risk from other animals, wildlife and people entering. Farm managers that had no perimeter fence expressed this to be a biosecurity issue, as they would have no means of stopping foxes, deer, badgers and other animals from entering.

When asked why they had not had fencing around their farm, farm managers acknowledged that this would be too costly and would require further engagement or financial investment by either the company or the owner of the site, in cases where the farm was being leased:

> "There's only so many times you can tell people to put a fence round, but we don't own this farm, it's a leased farm, so it's a whole process of who's paying for it, when's it being done, and it gets talked about every year and not sorted." (F8)

### 3.1.5. Signage

In addition, there was a lack of biosecurity being communicated through signs and posters around farms. For example, only five farms had good signage surrounding hand washing, disinfection, and symptoms of colds and influenza in birds and humans, and this was mainly noticeable across non-case farms when entering the premises. The use of signs and posters were only cited by three farm managers during the interviews.

## 3.2. Biosecurity practices – non-perimeter (internal biosecurity)

### 3.2.1. Changing areas

Some farms had changing areas after one entered the premises, but these were sometimes poorly located, placed after entering the main farm area, rather than before. In these cases, individuals had to walk across the farmyard in outdoor shoes and clothes before changing into site-specific clothing and shoes. Such changing areas were not always very tidy or well organised, with some offering little in the range of clean rubber boots and boot washing areas. Such examples varied between farms but were found across several sites. Additionally, two farms did not provide the researcher with access to their changing areas, meaning they had to get changed in other areas, such as the office space, after entering the farm premises. Though this could in certain cases be related to the farm's security protocol, it also raised questions regarding other visitors and delivery drivers also having to get changed in such areas, or if instead they were given access to the changing areas.

### 3.2.2. Shed-specific rubber boots and PPE

The requirement of putting on shed-specific rubber boots and changing from regular farm-specific rubber boots after entering the premises, were another very popular biosecurity measure both observed and cited by farm managers, especially surrounding visitors and

deliveries, when entering new sheds or buildings:

> "You don't go in there (bird area) without your overalls, gloves and your wellies (rubber boots) on. I am fairly strict with anyone that comes here, it's straight away, because we don't want it back here." (F10)

To further emphasise the importance of changing into shed-specific rubber boots, some farms had implemented stricter rules. For example, one farm had presented a new strategy to ensure that all staff on the farm were following the boot-changing requirements by providing outdoor vs indoor footwear in different colours. This meant that if someone had not changed into their outdoor footwear after coming out of a shed, the farm manager would be able to detect and ensure that they were being told to change into the appropriate footwear and encourage staff to change into shed-specific footwear when entering each new shed or building:

> "We've got white boots and green boots, so green boots for outside and white boots for inside so it's easy for me to spot... if I see somebody outside with the white boots on, he shouldn't be in there." (F11)

The use of shed-specific rubber boots was both cited often and observed frequently. However, the access and availability of shed-specific rubber boots sometimes varied. Some farms had good access to fresh rubber boots in each shed, but others did not have a range of clean rubber boots available, nor access to boot brushes for cleaning before disinfecting (C&D).

Farm managers also cited changing overalls or clothing again after entering each specific shed, but this varied considerably, with some farms only having the requirement to dip or change rubber boots before entering a new bird area in the sheds, rather than also changing clothing. The use of face masks and gloves were also seemingly not implemented often across the farms, despite being cited as important as an additional protective barrier for the farm managers.

### 3.2.3. Barriers in sheds

Barriers (sometimes referred to as “annexes”) were often placed to separate two areas within a shed. These barriers varied by farm, with some taking the form of adjoining rooms, while others involved the use of a physical barrier (e.g., a plank of wood). The barriers were used to transition between the outside/dirty zone to the inside/clean zone before entering the bird area, meaning once one entered the shed, they had to then change into their shed-specific rubber boots at the line of transition, followed by overalls. While most farms had barriers/annexes in place, some were of much higher quality than others. For example, while some farms only had a small physical barrier to separate between a clean vs dirty section of the shed, other farms had swing over hygiene barriers, such as a bench, meaning it was not possible to physically step over without sitting on the wall and swinging one's legs over. Other farms had a designated area to wash hands, change rubber boots and overalls and access PPE, hand sanitiser etc. before entering the bird areas. The variation in the barrier system in the sheds was often linked to financial elements, or prioritisation of the owner or company.

### 3.2.4. Foot dip placement and disinfection within the farm

Farm managers frequently noted that foot dips were used often and placed around their farm to prevent diseases such as AI, including outside of the various farm buildings which had frequent workers or visitors entering and exiting, along with additional foot dips prior to entering the bird areas. This was to help prevent AI entering the sheds and was also well observed across the farms:

> "So that's another annex (barrier) built. Extra foot dips I put in place up here, whereas they just had one before you stepped in the shed before." (F12)

> "So he'll (delivery driver) go in and out and drive from inside, outside, inside, outside the shed, back and forwards, so I just make sure – I've got a bin like that with a bucket inside full of disinfectant (...) so it's like before
> you go in the shed you have to jump off, make sure the concrete is absolutely covered in disinfectant so if there is any slight chance of anything, it'll be disinfected.” (F1)

While farm managers stated that disinfection routines were an important factor for them, the overall cleanliness of farms remained very variable. There were a few instances where farms had dirt, muck, feathers and feed spillage around the general premises, though this was mainly due to a recent culling, delivery or thinning (partial depopulation in broilers that have achieved weight in advance of full depopulation to slaughter). Some observations showed staff on farms following disinfection routines, such as washing and disinfecting areas outside of sheds, at the time of the visit. Similarly, hand sanitising stations were frequently seen across the premises, though the use of them on the day varied.

Observations showed that farm managers and staff used foot dips often and that they were well positioned across the farm, often being placed both outside and inside of the sheds and specifically at points of transition throughout the premises. However, it was noted in some instances that farm managers were less likely to use the foot dips around their farm as consistently as they expected visitors and other staff members to follow. When asked how often foot dip solutions were changed, the average answer was three to four days a week, while observations showed that most foot dips were clean and freshly changed, though it is difficult to determine how often they were being replenished after rain or potential contamination by organic matter.

### 3.2.5. Wild bird biosecurity and age/maintenance of buildings

One of the main biosecurity observations was surrounding the age and maintenance of the buildings and sheds across most of the farms. On some farms that had had AI, farm buildings and sheds had been built in the 1960s/1970s with few to no improvements since. Farm managers stated that while they attempted to maintain the buildings by checking for and fixing leaks, holes and roofing problems, they noted that buildings were sometimes too old and required modernising or replacing:

> "And the sheds, they're really old, and it's surprising I got results out of these sheds." (F4)

> "I think new sheds would be a massive benefit." (F12)

It was found that most of the farms that hadn't had an incursion of AI had also recently improved their buildings, either in the past 10 years or since the threat of AI in the past few years. This was also found consistently across all the family-owned businesses in the study, which had very strong biosecurity (including one case-farm which was family-owned but had newer sheds).

In the case of the maintenance of sheds and buildings, there were also instances where biosecurity preventing wild birds was not managed well on certain farms, with observations showing holes and gaps in sheds and poor meshing and netting around the buildings. On farms which were not kept as tidy or clean, birds such as pigeons were often spotted, suggesting that other wild birds could be present at other points in time. There were also few instances where materials such as bedding were stored outside or were not well protected, potentially attracting wild birds or animals to the site. Some farms were unable to keep bedding and materials stored away from wild birds and other animals, as there was insufficient building space for them.

## 3.3. Perceptions about AI, risk factors and associated biosecurity

### 3.3.1. Farm managers knowledge of AI

During the interviews, farm managers were asked about their confidence in their knowledge of AI and biosecurity in recent years. Most noted that they felt confident about the use of biosecurity but did not feel confident around their knowledge of AI, particularly the more recent strains. This included factors such as clinical signs of infection,

infection routes and pathways, and incubation periods. As such, farm managers still noted that they would benefit and like to learn more about the topic:

> "If you can learn something more, then yes, I'd be willing to go and sit and learn more about it. I don't know how it spreads; I think it spreads through contact, it has to be, doesn't it?" (F1)

Some farm managers reported that they were starting to learn more about AI as the situation in the UK escalated. This included learning more through discussions with other farmers, companies, veterinarians and other production stakeholders - due to the amount of information being shared and AI being a very current topic - and others actively seeking further information by themselves, particularly where questions were being asked by worried members of staff. Farm managers found that they were learning more about the disease and its potential spread, even if they were not necessarily accessing any formal guidelines or updated training on the subject through DEFRA or poultry companies:

> "I probably know more than I think I know. I don't really know, because I've been doing it so long it's kind of, it's just there. So, yeah, and I learn stuff all the time, like with the avian influenza, the side effects and how quickly it goes through the birds and stuff like that, it's all new, you learn stuff all the time." (F9)

Farm managers that had experienced an outbreak said they knew more about the disease and the signs to look out for if their birds were infected or sick because of that experience. Some felt this meant that they were more able to advise other farmers in the industry. Outbreaks on their farms also triggered some managers to actively seek more information about AI:

> Interviewer: So you wanted to learn more ever since having an outbreak?

> FM: Yeah.

> I: But before, did you want to learn?

> FM: No, not really. I didn't have an outbreak, so I didn't care.

> I: So you think the experience has taught you more about the virus itself?

> FM: Of course, yeah. [Company] did meetings about that as well, so even our farmers, which have never had it, they know about it now because they went over it in the meeting. That was good actually." (F3)

### 3.3.2. Thoughts and beliefs on biosecurity & risk factors

Farm managers strongly believed that following biosecurity protocols made a significant difference in terms of preventing AI, along with reducing the chances of other diseases on their farm. However, there were some risks that farm managers associated most with the spread of AI which they believed could lead to an outbreak, even with good use of biosecurity.

#### 3.3.2.1. Airborne transmission.
One of the most prominent findings from this research was surrounding the discourse amongst farm managers around the potential airborne spread of AI. Almost every farm manager interviewed believed that one of the biggest risk factors surrounding the spread of the disease involved spread of the virus through the air, including through dust particles, droplets and speed and direction of wind. Some managers believed that nearby farms that had an outbreak could pose a risk to them too, as they strongly believed the disease would be transmitted through the air between farms within a few miles.

Case farms often believed that the airborne spread of the disease was what caused them to have the outbreak. Some had regular conversations regarding this with other people in the industry, who sometimes echoed this thought:

> "(Farm name) is directly opposite of this farm, right at the other side, the wind was blowing this way from their farm when they had an outbreak
(...) That's when the government vet said that Sunday night, he said, "There's your problem."" (F2)

"(...) there was a farm in (location). They went down with bird flu, and then I thought, that is too close. That is really close (...) So that doesn't 100 % tell me, but I've got an inkling that it can be airborne. Because that was a week before I got bird flu." (F4)

In cases where there was a strong belief around the airborne transmission of AI, farm managers stated that very little could be done in terms of biosecurity to control the spread of the disease as it would be difficult to control something such as wind or bad weather. In particular, many case farm managers thought they could not have done anything more to prevent their farm from becoming infected:

"I mean, if it's airborne(...) obviously, of course if it's airborne, then whatever you do, you can't reduce air into the buildings, you know." (F2)

### 3.3.2.2. Wild birds.
Similar to above, farm managers often expressed concerns surrounding the risks from the number of infected wild birds present, particularly in certain coastal regions:

"You could have pheasants or pigeons, all those sorts of birds – corvids, all the corvids, the jackdaws, and the rooks, all those. There's a lot of those around at the moment and if you give them a food source, they are in." (F11)

Managers who had their farms close to the sea, a river or other water sources, and close to forests and other wildlife, often noted this to be an issue in terms of controlling wild birds:

> Interviewer: "Did you see them (wild birds) a lot before you had that outbreak as well?

> FM: Yeah, of course. Yeah, it's middle of the nowhere and all the fields, forests(...) so yeah, all the time. "

When asked how they thought that wild bird contact could be limited on their farm, only two of the managers referred to mitigation measures such as the use of scarecrows, or other more tailored biosecurity measures which could also limit the indirect/direct contact of wild birds. Similar to airborne transmission, farm managers often expressed that they could do very little to stop the risk from wild birds, and they sometimes referred to luck as a factor. For example, some farm managers believed that they did as much as they could to prevent an AI outbreak, but experienced an outbreak in the end due to bad luck:

"There is a limited amount you can actually do about it. [laughing] You can't just eliminate them all, can you? They are going to keep coming in. All you can do is try and control what comes in and out of the buildings" (F6)

### 3.3.2.3. Driving and walking disease onto farms.
When asked why bio-security measures such as using foot dips, changing rubber boots and disinfection were most frequently used, farm managers believed that the biggest risk factor associated with AI was someone "walking" or "driving" the virus onto the farm or into the bird areas; using these biosecurity measures in particular were therefore likely to limit this risk:

"You will walk... Walk it or drive it into a shed, that's the only way it's going to get in." (F1)

"But here there could be a risk of treading in it (...) That's the only way, I think, this could come in here." (F11)

## 3.4. Experiences of AI outbreaks - associated challenges and changes

Farm managers operating on case farms were asked about the challenges faced during AI outbreaks, while farm managers on non-case

farms were asked about challenges during the time where outbreaks were frequently occurring. They were also asked about any changes made to their farm during this time period. The following topics were the most frequently cited:

### 3.4.1. Mental health

One of the most significant findings from this research showed the impact of AI on the mental health of many farm managers. They expressed their constant stress and anxiety surrounding the possibility of having an outbreak, either for the first time or again after restocking their farm post-outbreak, while others noted that they were worried that anytime a bird died, it could signal something more serious:

"It's quite a lot in one go, and of course, that's a mental worry as well. If you are on the farm and suddenly you see all these dead birds, and you start thinking - well is it bird flu, or isn't it?" (F11)

Farm managers from case farms expressed how difficult it was to also witness the death of their birds and how they would not want to see their birds suffering like that again. Witnessing this had made many of the farm managers feel low, upset and in some cases, depressed:

"Now it's like these, you work with them every day, and it's like they're yours, in a way. You know, I go in there and talk to them and you've looked after them all that time, and then, you know, that happens, it's horrendous." (F10)

They also noted the difficulty of the entire situation, in terms of increasing their workload and responsibility and impacting the company and other members of staff. There were also instances where farm managers felt feelings of loneliness and isolation during the stages of the outbreak:

"You felt isolated because obviously no one could come on site, so the only communications I had with my manager or with [area manager] is via phone, which is a big change when used to seeing people every day (...) It is really difficult." (F12)

"Well as I say, I think you are on your own. You get it, you're on your own." (F5)

Similarly, farm managers from case farms expressed feelings of blame, sometimes expressing how it was their fault that they had an outbreak, despite trying their best and always caring for the welfare of their birds. In these instances, they noted that they felt their mental health being impacted as they did not want to be perceived as individuals who did not care about their farm, staff, company and poultry:

"I'm very passionate about what I do and I felt like it was my fault that they got the bird flu. I felt guilty that I couldn't go round to ease their stress and their disease". (F12)

"Managers are very respectful to the birds. And you've got to think of the manager, like I said, it brought a tear to my eye. The last thing you want is to be interrogated, to thinking it's your fault." (F4)

Farm managers also expressed guilt for having an outbreak, often believing that they were responsible if other nearby farms (or farms in the same company) also experienced an outbreak of AI as well. This was also echoed by some non-case farms, who felt anxious about this becoming a possibility if they were to experience an outbreak at a later point. Moreover, farm managers from both case and non-case farms expressed how stressed they felt about the possibility of being out of work if there were to have an outbreak, and what this would mean for them financially moving forward:

"If this farm shuts, where does that leave me? Where does it leave me and my family?" (F1)

### 3.4.2. Improvements made to farms since AI outbreaks

Farm managers on case farms were asked if any improvements had
been made to their biosecurity since having an outbreak, or since the threat of AI in recent years for those on non-case farms.

Some measures were reportedly improved across both case and non-case farms, including the use of meshing around the bird areas and sheds, increasing the use and change of foot dip solutions, and reducing the number of visitors allowed onto the farm. In addition to this, both non-case and case farms no longer allowed drivers and the delivery teams enter the bird areas.

As mentioned previously, foot dips were said to have been used before but had now increased in number across the farm as a direct consequence of the recent threat of having an outbreak. This also included not only increasing the number of foot dips across the farm, but also placing them before and after the barriers within the sheds:

*"Extra foot dips in there and I've increased the change of foot dips because it was twice a week, so we do them three times a week." (F12)*

The small number of non-case farms interviewed cited having added stronger biosecurity to their farm in recent years when compared to most of the case farms in the sample, and the observations also showed this. This included further investment into modernising sheds and buildings around the farm, building extra areas for changing into farm clothing, adding more site-specific equipment, including further shed-specific clothing/rubber boots. Some non-case farms had added fencing to the farm, and others added extra buildings to store materials such as bedding and safely away from wild birds and animals, all within the past 5 or so years:

*"We were already fairly tight on biosecurity, but we have certainly got tighter." (F6)*

On the other hand, most case farms followed biosecurity practices which could be managed at a greater frequency but without being as costly as the infrastructural changes such as modernising sheds or adding new buildings. They were more likely to cite having introduced stricter measures on boot changing in sheds and around the farm, changing overalls more frequently, using PPE more often and changing solutions in foot dips more regularly than before. Some also added double barrier systems through barriers/annexes around the farm, particularly in sheds before entering the bird areas. Farm managers from case farms also expressed their desire to invest into the farm through the addition of, for example, shower facilities and poly-tunnels, whereby the entire farm would be remodelled and be strongly wild bird proof, while also reducing the risk of transmission from constantly having to walk inside and outside when moving between sheds. However, the addition of such facilities would require a large financial investment, normally from an external source (such as companies or owners). While many farm managers on case farms expressed wanting to invest in some of the above biosecurity improvements, particularly surrounding infrastructure, the likelihood of these changes having been made at the time of the research was much lower than most of the non-case farms. Case farm managers often cited their unsuccessful communication with companies or owners in trying to suggest infrastructural improvements, which they thought would sometimes play a large role.

Farm managers from case farms stated that they started following biosecurity better and taking the use of protocols more seriously after experiencing an outbreak, from the fear of not wanting to experience such an event again. In such cases, some farm managers expressed that their previous use of biosecurity was not always colloquial, and that their AI outbreaks created an eye-opening experience for them and their staff:

*Before it (biosecurity) was really bad, now it's absolutely perfect [laughs] (...) I had three separate sites and so we didn't change overalls between farms. How I'm clothed now, I'd be walking in all of them, so we could take bird flu inside like that. Now we have to use hand sanitisers, plastic gloves, or rubber gloves, all the time and change them (...) We have added*

*a double barrier system now and covered foot dips as well. Everything's really improved now." (F3)*

### 3.5. Relationships shaping on-farm practices and experiences

Another common theme to emerge from the data, particularly from the interviews, was surrounding the relationships between farm managers and other groups of people, and how this may have impacted the use of biosecurity on the farm.

#### 3.5.1. Company

The relationship and communication between farm managers and the company they were associated with was frequently cited in the interviews. The relationships and communication levels between farm managers and companies varied considerably. When asked about the level of communication and type of communication farm managers had with the company, some cited the use of emails as their main form of communication, while others used telephone calls and emails together. Overall, most farms had one representative of the company that they worked closely with, or communicated any issues/concerns with, on a regular basis, and often met with them in person on the farm:

*"They are always on the phone. You can always contact them." (F12)*

The level of support farm managers reported receiving from the companies varied between farms. They acknowledged the level of stress and anxiety faced at the time of an AI outbreak, or instances where they were placed in a prevention zone due to nearby farms having outbreaks. In these cases, many noted that the company were very supportive, ensuring that they were communicating more regularly than their normal routine.

However, some farm managers expressed negative experiences with their respective companies. For example, they noted that they expected more support from the company, especially during the time of the outbreak where the farm was shut down and many sudden changes were being made. These changes included, for example, having security guards present on the site to stop anyone entering the premises, having the number of staff cut down or being sent home, carrying out disinfection routines across the premises, birds being culled to avoid further infection, and having many new people present on the farm (e.g. government veterinarians). These sudden changes often put the farm manager in stressful positions, while increasing the burden of work which was required on the farm. In these instances, some expressed that further involvement from their companies would have better distributed the responsibility in an already stressful period of time:

*"I do think that to have had our labour reduced by 50 percent is pretty rough. But that's not something that was down to us. And we've taken a hit for it. I know they've (company) taken a hit for it as well." (F4)*

#### 3.5.2. Owner / contractor

Some farm managers discussed their relationship with the owner of the farm, in cases where this was applicable. Unlike their companies, most farm managers did not have much communication with the owner of the premises, and others had difficulties in negotiating biosecurity related matters with them. Some also expressed that their companies also had some problems communicating with the owners. In such cases, farm managers noted that it was difficult to know who was responsible for biosecurity changes, out of the owner and companies. Other times, they stated that waiting for the owner to finalise a decision would often take up time without much change ever being made. This was not universal, and one farm manager noted that they had good communication with the owner, who often was present and willing to invest in the farm, including in newly built sheds and buildings which were seen on the day of the visit.
### 3.5.3. Other members of staff

The relationship between farm managers and their staff members generally differed widely. Some noted that they had no problems with their staff following the biosecurity rules, and that they were good at listening to any changes that were needed.

Two farm managers noted that they had put their members of staff in charge of ensuring that specific biosecurity measures were being followed by everyone on the farm. For example, one manager stated that they had put each member of staff in charge of their own sheds, including the biosecurity in each. The farm manager found this to be effective and encouraged the staff to follow biosecurity well, because they felt more responsible for the state of their shed (including cleanliness and the welfare of the birds they oversaw):

> "It makes it personal to them. And they all have their own houses, so it makes it personal that, "This is my house. I've got to look after it. If it's not doing well, it's on me." A bit of ownership to the job." (F9)

Other farm managers noted that biosecurity-related problems had arisen on their farm because of their staff. For example, staff members who were not regularly on the farm (such as contractors), were less likely to follow biosecurity measures, despite receiving the training and oversight from the manager. They also noted that in some instances, it was difficult to ensure contractors and farm staff who did not speak English were following the biosecurity on the farm well. In one case, the manager had seen staff members not following boot changing requirements and decided to provide training materials to the staff in their first language. They suggested that this made a difference and improved the overall biosecurity being used on the farm.

The age and length of experience of the staff members on the farm was also cited, where farm managers noted that younger members of staff were less likely to take biosecurity seriously. Similarly, staff members that had less years of experience in poultry farming were also less likely to follow biosecurity as thoroughly as staff members who had worked on the farm for a longer period:

> "But they (older staff members) all know... they've been here a long time and they do all know. It's only when you get sort of like a new person or a younger person... we've got a few younger people around that... you have to keep an eye on them, they don't seem to sort of worry about it (AI). (F11)

## 4. Discussion

This research has captured the different biosecurity measures used across poultry farms during the recent AI outbreaks and reveals that there was not a consistent standard of biosecurity maintained across farms in England and Wales. Some biosecurity measures were more frequently observed across all farms, particularly biosecurity measures such as the use of foot dips, regular disinfection routines, change of PPE and rubber boots, and restrictions surrounding visitors and deliveries. However, the physical structures to support effective biosecurity measures were frequently not evident including the layout of the premises, the renewal and maintenance of buildings and sheds, fencing around the premises, signage and posters, and biosecurity for wild bird exclusion.

Considering what connects the biosecurity measures that are more consistently applied and those which are not- alongside farm manager reports of their experiences and perceptions of biosecurity and AI- enables us to identify several potential factors contributing to how biosecurity is ultimately implemented on farms. In this section, we discuss how two such factors - perceptions of risk and feelings of responsibility and autonomy - may have played a significant role in farm managers' use of biosecurity at farm-level.

### 4.1. Perceptions of risk and remits of control

Risk perception refers to an individual's judgment and assessment of

hazards that might pose immediate or long-term threats to their health and well-being (Stone, 2014). As research on this topic suggests, not all people perceive a risky situation in the same way, and the lens through which individuals may interpret their risk environment can be affected by various factors (Mankad, 2016). Similarly, while one can perceive a risk, they may have differing views and beliefs on whether a risk is possible to control. These individual risk perceptions and views on remits of control are shaped by intrapersonal factors - such as individual beliefs, experiences and knowledge - and interpersonal factors - such as an individual's interaction with others, often affected by cultural norms and societal expectations. Understanding these influences can help to explain a person's behaviour with respect to disease prevention and many papers in recent years have found that risk perceptions play a considerable role in biosecurity use (Høg et al., 2019; Rimi et al., 2017; Scott et al., 2018; Suit-B et al., 2021).

In the context of this study, farm managers' views and use of biosecurity was influenced by their personal perceptions of risk surrounding AI. This could have contributed to the effective use of certain measures over others or explain why some measures were not deemed as vital as others. For example, farm managers' perceptions of risk often changed once they had experienced an outbreak, during which time they experienced challenges and fears which they did not wish to face again. This included, for example, the negative impact of the outbreak on a financial level, and the negative impact on many of the farm managers reported mental health. Despite these negative experiences, outbreaks were also associated by many as periods of learning, where managers gained new information, they used to inform their approach to biosecurity moving forward. In some cases, this impacted understanding of remits of control, leading managers to adopt or better maintain biosecurity measures which they were not following initially.

In this study, managers on both case and non-case farms all perceived a risk from AI. This unsurprisingly confirms that while experiencing an outbreak can have direct consequences for perceptions of risk and biosecurity implementation (Toma et al., 2015), people develop clear risk perceptions without any direct experience of the risk itself. Their perceptions of risk were informed by exposure to biosecurity concerns over time through their work in the sector at large, including information and guidelines shared by companies, government agencies and between farms. Thus, managers made a link between their time spent in their sector and their handling of biosecurity. This association between risk perception and experience over time emerged most acutely in manager's descriptions of different staff approaches to biosecurity. They explained that staff members who had less years of experience in the industry were sometimes less likely to follow biosecurity measures thoroughly. Their lack of exposure or knowledge regarding the threat from disease outbreaks and how it linked with their day-to-day work suggested that they did not perceive a risk from AI to the same extent as others working on the farm. Though limited, other research in the field has also found a link between the age or length of experience of farmers and their level of biosecurity compliance (Cui et al., 2019; Cui and Liu, 2016; Huang et al., 2016; Racicot et al., 2012). Interestingly, Racicot et al. (2012) found in their study of biosecurity compliance on Canadian poultry farms that individuals with less than five years of experience had lower biosecurity compliance. However, they also found that when experience increased, the strength of the relationship with compliance decreased instead (Racicot et al., 2012). It would be interesting to assess this area further.

How people respond to risks is also informed by where they believe the risk comes from or their knowledge of transmission pathways. During this study, it emerged that farm managers strongly believed that one of the biggest risk factors associated with AI was the possibility of the virus being walked or driven onto the farm from an external source. In turn, this meant that they were more likely to follow biosecurity measures which limited this risk, and this could explain why there was a large trend surrounding the adoption of operational biosecurity measures such as the limitation of visitors and deliveries onto the farm, ensuring all vehicles were being washed down, disinfecting regularly
and using foot dips more regularly (on both case and non-case farms). However, it could also be argued that such measures are being reported as followed more consistently across farms due to the general emphasis on perimeter biosecurity within the poultry or wider animal farming industry, which has focused on stopping external threats from entering the premises, rather than also focusing closely on the biosecurity measures within the facilities themselves (Biocheck, 2024). As other research on biosecurity has also found, internal biosecurity on farms is often reported as slightly weaker than external biosecurity or biosecurity at the point of entrance(Laanen et al., 2013; Tilli et al., 2022), though some papers have interestingly also found that biosecurity relating to disinfection tends to be strong across both (Tilli et al., 2022). Literature on this topic is currently very limited, and it would therefore be of value to assess this potential emphasis on perimeter biosecurity further. Similarly, although helpful to use regular disinfection regimes as cited by many farm managers, the efficacy of measures such as the use of foot dips has been questioned in literature on the topic over the years, particularly as a standalone measure. For example, research conducted by Hauck et al. (2017) found that most tested footbaths in their study did not eliminate infective viral particles, particularly in relation to the HPAIV isolate, suggesting that foot dips alone are not capable of preventing pathogen introduction into commercial flock (Hauck et al., 2017). Similarly, Amass et al.'s (2000) study evaluating the efficacy of foot dips in biosecurity protocols found that the type of disinfectant being used is irrelevant if manure is not removed off the surface of boots prior to disinfection, and that contaminated foot dips increased boot contamination during cleaning (Amass et al., 2000). Nasr et al.'s (2018) study on the effectiveness of disinfectants commonly used in foot dips in poultry farms also found that there is a need to use freshly prepared disinfectant alongside the regular cleaning of foot dips, while boots should be strongly scraped before using foot dips to reduce organic load. Otherwise, applying foot dips on farms without using them properly can instead create a risk for disease spread and create a waste in resources (Nasr et al., 2018). Our study also found that there was an emphasis on wheel washing and disinfection across farms visited. However, while wheel washing can be helpful, disinfection mats, wheel dips or wheel sprays all require topping up and servicing, and their effectiveness is limited unless they are thoroughly cleaned to remove all organic matter from wheels or vehicles (Wrathall et al., 2004). In particular, when cleaning and disinfecting, it is important to pay attention to areas such as wheels and wheel arches, chassis and underbody, and the area where poultry are transported, including cages, sheeting or other covers on the vehicle (World Health Organization. Regional Office for South-East Asia, 2006). Given that the use of disinfection measures such as foot dips and wheel washing was so heavily cited in this research, it is essential that we ensure that farmers are being provided with the information on how best to make use of these measures in the most efficient way.

Risk perception is also shaped by knowledge. In the case of AI, farm
manager's beliefs surrounding transmission informed one of the most
common findings in the study: that farm managers believe in the
airborne transmission of AI between farms, particularly through
airborne particles during poor, windy weather. It is here that perceived
remits of control are shaped and play a significant role. Most farm
managers perceived airborne transmission of AI to be an uncontrollable
risk, and hence their response to it was minimal and sometimes it
undermined their overall attempts at maintaining biosecurity in other
areas of the farm. This belief was a common theme and area of discourse
in the community, and could be due to several reasons which should be
studied further, but one of the main reasons for this belief could be due
to AI outbreaks in other countries, such as the Netherlands, where
airborne infection between farms in very close proximity appeared to
have been a source of the spread (Boender et al., 2007). However, the
aerosolization and environmental survival of different viral subtypes
may impact upon the potential impact from aerosol spread. Assessment
of aerosolization of H5N1 in farms in England demonstrated that the risk
of aerosol spread was very small. Whilst infectious material could

readily be detected in air sampled within an infected poultry shed, air
and environmental samples taken outside the shed were all negative for
infectious material (James et al., 2023). Further, even where a virus may
have a greater ability to survive in the environment or be transported via
the aerosol route, the likelihood of this spread occurring in the context of
England and Wales is low, particularly as many poultry farms are not as
close to each other in proximity (James et al., 2023). Unlike the strong
connection farm managers made between disease being physically
walked onto farms and a workable response in the form of foot dips and
disinfection, biosecurity efforts relating to the potential airborne spread
of the disease felt less effective among those who had a powerful
perception of airborne risk that was beyond their remit of control. Thus,
biosecurity efforts were potentially being undermined by a perceived
lack of control over a risk that was actually very unlikely to really be a
problem.

While airborne transmission is a misleading risk perception shaping biosecurity practices (or lack thereof), the feeling of futility associated with this perceived risk also applies to much more pressing forms of transmission. For example, while farm managers believed that the presence of wild birds and their potential contact with the poultry would be a huge risk for their farm, there was also a general belief that not much could be done to prevent this risk. The feelings of futility associated with wild birds may not only undermine other biosecurity efforts as seen with the fear of airborne transmission, but also reveals a lack of knowledge or belief in biosecurity measures that could be used to address this risk. For example, certain biosecurity measures can be used to minimise the risk they pose such as ensuring feed and bedding stores are secure (Ssematimba et al., 2013). Scarecrows, hawk kites and propane canons have also been suggested as ways of keeping wild birds off the farm, though the efficacy of these measures is unclear (Delpont et al., 2018). Further, the location of farms, being close to water courses, small lakes and even sometimes having water features between sheds or on poultry ranges that attract wild bird activity is highly problematic when infection pressure is high in wild bird species.

4.2. Autonomy and responsibility

While remits of control help to explain why farm managers may not believe in or apply certain biosecurity measures, our research also revealed certain biosecurity measures that managers wanted to apply or improve but were not able to. This raises the question: if they see a risk and feel biosecurity could help to control it, why are they not applying it? Our research reveals that different amounts of autonomy and placing of responsibility contribute to this. While the section above addresses how risk perceptions surrounding disease prevention differ along with individuals' ability to control this risk, here we discuss how in other cases, some individuals can perceive a risk but instead may not believe they are the ones responsible for controlling it, or instead do not have that autonomy to do so.

As explored by Stock and Forney, farmers view autonomy as being
one's own boss, and this invokes a particular lifestyle connected to their
farming. However, they also acknowledge that having said autonomy
may not be accessible due to many constraints that limit this within
farming operations (Stock and Forney, 2014). These constraints became
apparent in our study when discussing the improvements managers
would like to make to biosecurity on their farms. Some managers
explained how the farm's buildings and sheds required attention, and
perceived the holes, gaps, leaks, and other maintenance issues in the
buildings as biosecurity risks. They also identified an effective solution -
modernising the buildings – but these opinions had not led to biosecurity
improvements on most farms. When asked why, farm managers noted
that such measures were dependent on financial investment from
external sources such as the company which owned the birds and
employed them, or from the owner of the premises. This is echoed in
existing literature that agrees many of the challenges farms face relates
to farmers lack of freedom and ability to control situations and make
changes to their farm, often linking these limitations to the state, regulations, financial organisations and the wider industry (Berlin, 1969; Stock and Forney, 2014). It is therefore important to consider the role of autonomy, which can be of value for a farmer's identity and which may be used as a tool to help mitigate, navigate and translate the experiences of being a farmer in a wider network of agricultural relations (Stock and Forney, 2014).

Lacking that ability to work autonomously does not automatically mean farm managers are incapable of implementing good biosecurity. Rather, it brings the relationships they are dependent on that limit their autonomy – such as those with a farm owner or company – to the fore when seeking to understand what is needed for biosecurity investments to happen. Having strong workable relationship with relevant stakeholders thus can become a vital aspect of good biosecurity on a given farm. For example, our study showed that in some instances, farm managers were able to advocate for structural biosecurity changes such as buildings and modernising of existing sheds after having an outbreak, particularly if they had good relationships with their company. Farm managers described calling company representatives to ask for new sheds for birds and new buildings for storing additional PPE, and the company following through with advice or investment to support manager's needs. However, not all farm managers have such relationships in place, which can be isolating and have negative consequences for biosecurity implementation where the manager is unable to take control of changes themselves. In these cases, a friction arises around questions of who is responsible for such changes. Where their capacity to work autonomously was limited and relationships differed between farms, it becomes hard for managers to know if it is only their role to ensure all biosecurity is met, or if this is to be distributed between different actors. Similar findings have been reported in other literature, with farmers strongly believing that other stakeholders should make greater contributions towards biosecurity, particularly on a financial level, and had differing views on who should be assigned responsibility for biosecurity (Heffernan et al., 2008; Higgins et al., 2018). Though farm managers in our study did not express that other stakeholders are the only ones responsible for biosecurity, there was a general belief that they would benefit from further support from various actors, and this could substantially impact the level of biosecurity some farmers are willing to follow.

Our research hypotheses that responsibility and autonomy may also be informed by factors such as ownership of farm. Family-owned farms in our study had some of the strongest biosecurity observed, including when considering the number of modernised sheds and buildings added in recent years. As suggested by Mankad (2016), factors such as place attachment is relevant to decision-making in the biosecurity context because farmers are likely to have a personal attachment to their farm and the community they are a part of, and this attachment may be even stronger if a family has been on the same land for generations(Mankad, 2016). Similarly, attachment to place is multifaceted for farmers, who live, work and socialize on their farm, and whose land are locations with history, emotions and symbolic meanings (Quinn and Halfacre, 2021). Thus, it could be suggested that farm managers operating their own family-owned farms may feel a greater sense of responsibility surrounding biosecurity matters and are often able to make more autonomous decisions than other farm managers, as they have been running their farm through many generations and may not be required to rely on the authorisation of different owners and companies.

Creating clarity over responsibility relating to biosecurity can already be seen to have a positive impact on a smaller scale among farm workers. On farms that had difficulty encouraging staff to follow biosecurity requirements initially, a farm manager in our study described how they were able to change this by giving staff members more "responsible" or authoritative roles on the farm. This included allowing staff to be assigned their own sheds, and dedicating specific tasks to each staff member which they were responsible for checking and ensuring

everyone else was following through. Staff members' commitment to following biosecurity effectively increased once they had more control, responsibility and authority over a matter. Such findings may be useful for future recommendations surrounding biosecurity and disease prevention across not only the poultry industry, but also wider agricultural and farming industries.

While clarity over responsibility can aid in biosecurity management, it is an area that involves scrutiny and balance to ensure it is fair and effective. As our results reveal, dealing with the threat or experience of AI outbreaks can have hugely negative impacts on a person's mental health. There were many instances where feelings of sadness, stress and anxiety were expressed amongst the farm managers interviewed, in part due to the isolation and feeling that the guilt and responsibility of actions linked to outbreak management fell to them alone. Therefore, additional support could have positive long-term consequences for the sector as, for some, feelings of blame, responsibility and guilt are enough to impact their enjoyment of the job and may discourage them from continuing in the industry. Similar research has found contrasting evidence of the mental health impact on biosecurity, suggesting that the duality behind stress effects can in some circumstances act as a motivator, leading to an increased risk perception and action, while for others it is likely to lead to tension, exhaustion and a feeling of hopelessness, which can then lead to reduced biosecurity (Delpont et al., 2021). Therefore, actively supporting farmers through these periods would also generate an additional avenue for farm managers to receive guidance that could improve their biosecurity implementation. It is important that these feelings are recognised and that farmers are provided with the programs and guidance that can ensure their wellbeing, mental health and resilience are addressed (Duong et al., 2019; Fraser et al., 2005).

## 5. Conclusion

This study aimed to understand the perceptions and use of biosecurity practices on commercial poultry farms in England and Wales in relation to AI. It adopted qualitative methods informed by ethnography to understand where and how biosecurity practices were followed and to understand, from a farm manager's perspective, some of the factors influencing the implementation of these measures.

This study found that the farm managers' perceptions of risk and beliefs on the controllability they have around certain biosecurity measures can significantly influence the level of biosecurity implementation taking place on farms. Similarly, the capacity of farm managers to act with autonomy and their feelings of responsibility can influence the extent to which certain biosecurity measures are being followed. We have shown how factors such as farm ownership, age and length of experience, knowledge of risks and biosecurity options, financial control, and relationships with other actors within the industry may all influence investment and management of biosecurity on farms. Thus, to follow biosecurity well, perception of risk, knowledge of where the risk stems from, and the ability to address threats directly or know who is there to take responsibility for it, are all required to ensure that biosecurity is being followed to the highest standard. In helping to reduce any gaps in the implementation of biosecurity use in relation to AI, it is important to consider factors such as length of experience and language barriers, and ensure recommendations are being tailored to acknowledge these. A greater emphasis on providing regular and updated training and educational resources to farmers within the industry would also be beneficial, again tailored to the different groups of farmers within the industry. Moreover, the role of mental health was a very significant finding in this study and should be considered in further areas of work and within any future recommendations to ensure farmers' health needs are being met and that the constraints they feel during periods of disease outbreaks do not impact the enjoyment of their jobs.

As with any other research, this study has some potential limitations.
While an ethnographic approach to farm visits allows for in-depth in-
sights and observation of practices and behaviours in a setting, there is
always the risk of potential biases. In the context of this study, the main
risk of bias comes from farm managers behaviours on the day of the visit
potentially not reflecting that of their normal everyday routine, or
routine at the time of the outbreaks. For example, certain biosecurity
measures may have been presented more strongly than normal if the
farmer knew they were going to have research and observations take
place on the specific day. It is difficult to say to what extent this may
have been the case but remains an important factor to acknowledge.
While it is difficult to state that such findings would be representative of
all farms in England and Wales - given the small sample size - the
qualitative nature of the study has helped provide insight into valuable
information.

In addition to capturing details of the types of biosecurity measures being applied, this study's findings have enabled us to identify key factors that are impacting biosecurity implementation on poultry farms in England and Wales. These include risk perception, autonomy and responsibility. We have briefly introduced how these factors emerged in the results, and some of the existing literature that explains why these subjects are of such significance for biosecurity. More research assessing the socio-ecological factors linked to these topics would be beneficial. For example, learning more about what information farm managers and workers have and where they get it would help build upon this work that has identified risk perception as such a vital part of biosecurity management. Doing so would allow for a great evaluation of the current emphasis on perimeter biosecurity within the UK context and whether farmers' biosecurity behaviours fall in line with the certain measures preventing the introduction of diseases into the farm, rather than measures used to stop spread within the premises itself. It would also allow for considering of which messaging pathways are most effective when seeking to communicate new or changing biosecurity measures with anyone working on farms. Furthermore, tailoring future strategies to encourage and support enhanced biosecurity depending on ownership and management arrangements would be beneficial. Additionally, research on the roles and relationships other stakeholders within the poultry industry have and how this ultimately links to farm operations would help further the discussion of how responsibility is shared (or not) and managed. Based on the findings of this study and the specific areas that have emerged as influential in shaping biosecurity implementation on farms, future work expanding on these related topics could help to ensure better understanding of farmer management and support the prevention of future epidemics.

Funding

This research was part of the FluMap study, funded by the Biotech-
nology and Biological Sciences Research Council (BBSRC) (BB/
X00614X/1) and Department for Environment Food and Rural Affairs
(DEFRA). James Wood is supported by The Alborada Trust. Ashley
Banyard was also part funded by was funded by the UK Department for
the Environment, Food and Rural Affairs (Defra) and the devolved
Scottish and Welsh governments under grants (SV3032, SE2213,
SE2227 and SV3400).

CRediT authorship contribution statement

**Guitian Javier:** Writing – review & editing, Validation. **Fournie Guillaume:** Writing – review & editing, Validation, Supervision, Methodology, Funding acquisition, Conceptualization. **Banyard Ashley:** Writing – review & editing, Validation, Resources. **Paterson Andy:** Writing – review & editing, Validation, Supervision, Resources, Conceptualization. **Hepple Richard:** Writing – review & editing, Validation, Resources. **Brown Ian:** Writing – review & editing, Validation, Resources, Project administration, Funding acquisition, Conceptualization. **Hosseini Paniz:** Writing – review & editing, Writing – original

draft, Validation, Methodology, Investigation, Formal analysis, Data
curation, Conceptualization. **Wood James:** Writing – review & editing,
Validation, Supervision, Resources, Project administration, Methodol-
ogy, Funding acquisition, Conceptualization. **Houghton Eve:** Writing –
review & editing, Validation, Methodology, Conceptualization, Funding
acquisition. **Syndicus Ivo:** Writing – review & editing, Validation,
Methodology, Formal analysis, Conceptualization, Funding acquisition.
**Alarcon Pablo:** Writing – review & editing, Validation, Supervision,
Methodology, Conceptualization.

Declaration of Competing Interest

the authors declare no conflict of interest.

Acknowledgements

Many thanks to the farm managers, companies and trade associations
who were involved in the study for their invaluable time and
contribution.

References

Amass, S., Vyverberg, B., Ragland, D., Anderson, C., Stover, J., Beaudry, D., 2000. Evaluating the efficacy of boot baths in biosecurity protocols. J. Swine Health Prod. 8.

Animal and Plant Health Agency, 2024. Bird flu (avian influenza): cases in wild birds [WWW Document]. GOV.UK. URL [https://www.gov.uk/government/publications/avian-influenza-in-wild-birds] (accessed 4.11.24).

Bennison, A., Byrne, A.M.P., Reid, S.M., Lynton-Jenkins, J.G., Mollett, B., Silva, D.D., Peers-Dent, J., Finlayson, K., Hall, R., Blockley, F., Blyth, M., Falchieri, M., Fowler, Z., Fitzcharles, E.M., Brown, I.H., James, J., Banyard, A.C., 2024. Detection and spread of high pathogenicity avian influenza virus H5N1 in the Antarctic Region. https://doi.org/10.1101/2023.11.23.568045.

Berlin, I., 1969. Two concepts of liberty. Four Essays on Liberty. Oxf. Univ. Press, pp. 118-172.

Biocheck, 2024. Home | Biocheck.UGent [WWW Document]. URL [https://biocheckgent.com/en] (accessed 7.1.24).

Boender, G.J., Hagenaars, T.J., Bouma, A., Nodelijk, G., Elbers, A.R.W., de Jong, M.C.M., van Boven, M., 2007. Risk maps for the spread of highly pathogenic avian influenza in poultry. PLoS Comput. Biol. 3, e71. https://doi.org/10.1371/journal.pcbi.0030071.

Cui, B., Liu, Z.P., 2016. Determinants of knowledge and biosecurity preventive behaviors for highly pathogenic avian influenza risk among chinese poultry farmers. Avian Dis. 60, 480–486. https://doi.org/10.1637/11361-010116-Reg.

Cui, B., Liu, Z.P., Ke, J., Tian, Y., 2019. Determinants of highly pathogenic avian influenza outbreak information sources, risk perception and adoption of biosecurity behaviors among poultry farmers in China. Prev. Vet. Med. 167, 25–31. https://doi.org/10.1016/j.prevetmed.2019.03.018.

Delpont, M., Blondel, V., Robertet, L., Duret, H., Guerin, J.-L., Vaillancourt, J.-P., Paul, M.C., 2018. Biosecurity practices on foie gras duck farms, Southwest France. Prev. Vet. Med. 158, 78–88. https://doi.org/10.1016/j.prevetmed.2018.07.012.

Delpont, M., Racicot, M., Durivage, A., Fornili, L., Guerin, J.-L., Vaillancourt, J.-P., Paul, M.C., 2021. 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. Transbound. Emerg. Dis. 68, 51–61. https://doi.org/10.1111/tbed.13462.

Department for Environment, Food and Rural Affairs, 2022. Declaration of an Avian Influenza Prevention Zone - including housing measures (England) [WWW Document]. URL [https://assets.publishing.service.gov.uk/media/63877fbad3bf7f737a827901/Avian_Influenza Prevention Zone Declaration mandatory biosecurity_housing_measures_-England_from_7_November_2022.pdf](https://assets.publishing.service.gov.uk/media/63877fbad3bf7f737a827901/Avian Influenza Prevention Zone Declaration mandatory biosecurity_housing_measures_-England_from_7_November_2022.pdf).

Department for Environment, Food and Rural Affairs, 2023a. Highly pathogenic avian influenza (HPAI) in the UK and Europe [WWW Document]. URL [https://assets.publishing.service.gov.uk/media/63bd54458fa8f55e362ce02f/hpai-europe-number38-230104.pdf](https://assets.publishing.service.gov.uk/media/63bd54458fa8f55e362ce02f/hpai-europe-number38-230104.pdf) (accessed 4.11.24).

Department for Environment, Food and Rural Affairs, 2023b. Bird keepers must maintain scrupulous biosecurity standards as housing measures set to be lifted [WWW Document]. GOV.UK. URL [https://www.gov.uk/government/news/bird-keepers-must-maintain-scrupulous-biosecurity-standards-as-housing-measures-set-to-be-lifted] (accessed 4.11.24).

Department for Environment, Food and Rural Affairs, Animal and Plant Health Agency, 2023a. Avian Influenza Prevention Zone (AIPZ) including biosecurity measures: the whole of England [WWW Document]. GOV.UK. URL [https://www.gov.uk/animal-disease-cases-england/avian-influenza-prevention-zone-aipz-including-housing-measures-the-whole-of-england] (accessed 7.5.24).

Department for Environment, Food and Rural Affairs, Animal and Plant Health Agency, 2023b. Bird flu (avian influenza): poster for bird keepers [WWW Document]. GOV. UK. URL [https://www.gov.uk/government/publications/bird-flu-avian-influenza-posters-for-bird-keepers] (accessed 4.11.24).
Duong, T.T., Brewer, T.D., Luck, J., Zander, K.K., 2019. Understanding biosecurity threat perceptions across Vietnamese smallholder farmers in Australia. Crop Prot. 117, 147–155. https://doi.org/10.1016/j.cropro.2018.11.022.

European Food Safety Authority (EFSA), Aznar, I., Kohnle, L., Stoicescu, A., van Houtum, A., Zancanaro, G., 2023. Annual report on surveillance for avian influenza in poultry and wild birds in Member States of the European Union in 2022. EFSA J. 21, e8480. https://doi.org/10.2903/j.efsa.2023.8480.

Forestry Commission, Animal and Plant Health Agency, 2023. How biosecurity can prevent the introduction and spread of tree pests and diseases [WWW Document]. GOV.UK. URL (https://www.gov.uk/guidance/prevent-the-introduction-and-spre ad-of-tree-pests-and-diseases) (accessed 4.11.24).

Fraser, C.E., Smith, K.B., Judd, F., Humphreys, J.S., Fragar, L.J., Henderson, A., 2005. Farming and mental health problems and mental illness. Int. J. Soc. Psychiatry 51, 340–349. https://doi.org/10.1177/0020764005060844.

Guinat, C., Comin, A., Kratzer, G., Durand, B., Delesalle, L., Delpont, M., Guérin, J.-L., Paul, M.C., 2020. Biosecurity risk factors for highly pathogenic avian influenza (H5N8) virus infection in duck farms, France. Transbound. Emerg. Dis. 67, 2961–2970. https://doi.org/10.1111/tbed.13672.

Harvey, J.A., Mullinax, J.M., Runge, M.C., Prosser, D.J., 2023. The changing dynamics of highly pathogenic avian influenza H5N1: next steps for management & science in North America. Biol. Conserv. 282, 110041. https://doi.org/10.1016/j. biocon.2023.110041.

Hauck, R., Crossley, B., Rejmanek, D., Zhou, H., Gallardo, R.A., 2017. Persistence of Highly Pathogenic and Low Pathogenic Avian Influenza Viruses in Footbaths and Poultry Manure. Avian Dis. 61, 64–69.

Heffernan, C., Nielsen, L., Thomson, K., Gunn, G., 2008. An exploration of the drivers to bio-security collective action among a sample of UK cattle and sheep farmers. Prev. Vet. Med. 87, 358–372. https://doi.org/10.1016/j.prevetmed.2008.05.007.

Higgins, V., Bryant, M., Hernández-Jover, M., Rast, L., McShane, C., 2018. Devolved Responsibility and On-Farm Biosecurity: Practices of Biosecure Farming Care in Livestock Production. Sociol. Rural. 58, 20–39. https://doi.org/10.1111/ soru.12155.

Hinchliffe, S., 2013. The Insecurity of Biosecurity: Remaking emerging infectious diseases. In: Dobson, A., Barker, K., Taylor, S.L. (Eds.), Biosecurity: The Socio- Politics of Invasive Species and Infectious Diseases. Routledge, London, pp. 199–213.

Høg, E., Fournié, G., Hoque, Md.A., Mahmud, R., Pfeiffer, D.U., Barnett, T., 2019. Competing biosecurity and risk rationalities in the Chittagong poultry commodity chain, Bangladesh. BioSocieties 14, 368–392. https://doi.org/10.1057/s41292-018- 0131-2.

Huang, Z., Zeng, D., Wang, J., 2016. Factors affecting Chinese broiler farmers' main preventive practices in response to highly pathogenic avian influenza. Prev. Vet. Med. 134, 153–159. https://doi.org/10.1016/j.prevetmed.2016.10.013.

James, J., Warren, C.J., De Silva, D., Lewis, T., Grace, K., Reid, S.M., Falchieri, M., Brown, I.H., Banyard, A.C., 2023. The role of airborne particles in the epidemiology of Clade 2.3.4.4b H5N1 high pathogenicity avian influenza virus in commercial poultry production units. Viruses 15, 1002. https://doi.org/10.3390/v15041002.

Laanen, M., Persoons, D., Ribbens, S., de Jong, E., Callens, B., Strubbe, M., Maes, D., Dewulf, J., 2013. Relationship between biosecurity and production/antimicrobial treatment characteristics in pig herds. Vet. J. 198, 508–512. https://doi.org/ 10.1016/j.tvjl.2013.08.029.

Ly, H., 2024. Highly pathogenic avian influenza H5N1 virus infections of dairy cattle and livestock handlers in the United States of America. Virulence 15, 2343931. https:// doi.org/10.1080/21505594.2024.2343931.

Mankad, A., 2016. Psychological influences on biosecurity control and farmer decision-making. A review. Agron. Sustain. Dev. 36, 40. https://doi.org/10.1007/s13593- 016-0375-9.

Maxwell, K., 2023. Biosecurity photobook highlights good practice. Br. Poult. Counc. (https://britishpoultry.org.uk/biosecurity-photobook/) (URL).

Nasr, S., Ismael, E., Laban, S., Ismail, E., Hamoud, M., Zaki, M., Zahran, O., 2018. Effectiveness of some disinfectants commonly used in footbaths inside poultry farms. PP01-6 J. Agric. Vet. Sci. 11. https://doi.org/10.9790/2380-1109020106.

Quinn, C.E., Halfacre, A.C., 2021. Place matters: An investigation of farmers' attachment to their land. Hum. Ecol. Rev. 20, 117–132. https://doi.org/10.3316/ informit.326263345357534.

Racicot, M., Venne, D., Durivage, A., Vaillancourt, J.-P., 2012. Evaluation of the relationship between personality traits, experience, education and biosecurity compliance on poultry farms in Québec, Canada (online). Prev. Vet. Med. 103 (2), 201–207. https://doi.org/10.1016/j.prevetmed.2011.08.011.

Rehman, S., Effendi, M.H., Witaningruma, A.M., Nnabuikeb, U.E., Bilal, M., Abbas, A., Abbas, R.Z., Hussain, K., 2023. Avian influenza (H5N1) virus, epidemiology and its effects on backyard poultry in Indonesia: a review. F1000Research 11, 1321. https:// doi.org/10.12688/f1000research.125878.2.

Rimi, N.A., Sultana, R., Muhsina, M., Uddin, B., Haider, N., Nahar, N., Zeidner, N., Sturm-Ramirez, K., Luby, S.P., 2017. Biosecurity conditions in small commercial chicken farms, Bangladesh 2011-2012. EcoHealth 14, 244–258. https://doi.org/ 10.1007/s10393-017-1224-2.

Scott, A.B., Singh, M., Groves, P., Hernandez-Jover, M., Barnes, B., Glass, K., Moloney, B., Black, A., Toribio, J.-A., 2018. Biosecurity practices on Australian commercial layer and meat chicken farms: performance and perceptions of farmers. PLoS ONE 13, e0195582. https://doi.org/10.1371/journal.pone.0195582.

Spekreijse, D., Bouma, A., Koch, G., Stegeman, J.A., 2011. Airborne transmission of a highly pathogenic avian influenza virus strain H5N1 between groups of chickens quantified in an experimental setting. Vet. Microbiol. 152, 88–95. https://doi.org/ 10.1016/j.vetmic.2011.04.024.

Ssematiimba, A., Hagenaars, T.J., de Wit, J.J., Ruiterkamp, F., Fabri, T.H., Stegeman, J. A., de Jong, M.C.M., 2013. Avian influenza transmission risks: Analysis of biosecurity measures and contact structure in Dutch poultry farming. Prev. Vet. Med. 109, 106–115. https://doi.org/10.1016/j.prevetmed.2012.09.001.

Stock, P.V., Forney, J., 2014. Farmer autonomy and the farming self. J. Rural Stud. 36, 160–171. https://doi.org/10.1016/j.jrurstud.2014.07.004.

Stone, D., 2014. Risk Perception. In: Wexler, P. (Ed.), Encyclopedia of Toxicology (Third Edition). Academic Press, Oxford, p. 184. https://doi.org/10.1016/B978-0-12- 386454-3.00981-7.

Suit-B, Y., Hassan, L., Krauss, S.E., Ooi, P.T., Ramanoon, S.Z., Yasmin, A.R., Epstein, J.H., 2021. Mental Model of Malaysian Pig Farmers in Implementing Disease Prevention and Control Practices. Front. Vet. Sci. 8, 695702. https://doi.org/10.3389/ fvet.2021.695702.

Tajudeen, Y., Nimat, A.-B., Oladunjoye, I., 2021. Emerging Strain (H5N8) of Highly Pathogenic Avian Influenza Virus: An Impending Pandemic Threat. Int. J. Infect. Dis. 7. https://doi.org/10.23937/2474-3658/1510217.

Tilli, G., Laconi, A., Galuppo, F., Mughini-Gras, L., Piccirillo, A., 2022. Assessing Biosecurity Compliance in Poultry Farms: A Survey in a Densely Populated Poultry Area in North East Italy. Animals 12, 1409. https://doi.org/10.3390/ani12111409.

Toma, L., Low, J.C., Vosough Ahmadi, B., Matthews, L., Stott, A.W., 2015. An analysis of cattle farmers' perceptions of drivers and barriers to on-farm control of Escherichia coli O157. Epidemiol. Infect. 143, 2355–2366. https://doi.org/10.1017/ S0950268814003045.

Van Steenwinkel, S., Ribbens, S., Ducheyne, E., Goossens, E., Dewulf, J., 2011. Assessing biosecurity practices, movements and densities of poultry sites across Belgium, resulting in different farm risk-groups for infectious disease introduction and spread. Prev. Vet. Med. 98, 259–270. https://doi.org/10.1016/j.prevetmed.2010.12.004.

World Health Organization. Regional Office for South-East Asia. (2006). Public health interventions for prevention and control of avian influenza. WHO Regional Office for South-East Asia. (https://iris.who.int/handle/10665/205700).

Worthall, Anthony E., Simmons, Hugh A., Bowles, Dianna J., Jones, Sam, 2004. Biosecurity strategies for conserving valuable livestock genetic resources. Reprod., Fertil. Dev. 16, 103–112. https://doi.org/10.1071/RD03083.