Animal Welfare Research Research Articles

Automated long-term monitoring of stereotypical movement in polar bears under human care using machine learning

The welfare of animals under human care is often assessed by observing behaviours indicative of stress or discomfort, such as stereotypical behaviour (SB), which often shows as repetitive, invariant pacing. Traditional behaviour monitoring methods, however, are labour-intensive and subject to observer bias. Our study presents an innovative automated approach utilising computer vision and machine learning to non-invasively detect and analyse SB in managed populations, exemplified by a longitudinal study of two polar bears. We designed an animal tracking framework to localise and identify individual animals in the enclosure. After determining their position on the enclosure map via homographic transformation, we refined the resulting trajectories using a particle filter. Finally, we classified the trajectory patterns as SB or normal behaviour using a lightweight random forest approach with an accuracy of 94.9 %. The system not only allows for continuous, objective monitoring of animal behaviours but also provides insights into seasonal variations in SB, illustrating its potential for improving animal welfare in zoological settings. Ultimately, we analysed 607 days for the occurrence of SB, allowing us to discuss seasonal patterns of SB in both the male and female polar bear monitored. This work advances the field of animal welfare research by introducing a scalable, efficient method for the long-term, automated detection and monitoring of stereotypical behaviour, paving the way for its application across various settings and species that can be continuously monitored with cameras. We made the code publicly available at https://github.com/team-vera/stereotypy-detector.

Longitudinal Study of Changes in Ammonia, Carbon Dioxide, Humidity and Temperature in Individually Ventilated Cages Housing Female and Male C57BL/6N Mice during Consecutive Cycles of Weekly and Bi-Weekly Cage Changes.

Housing conditions are essential for ensuring animal welfare and high-quality research outcomes. In this study, we continuously monitored air quality-specifically ammonia, carbon dioxide, relative humidity, and temperature-in Individually Ventilated Cages (IVCs) housing five female or male C57BL/6N mice. The cages were cleaned either weekly or bi-weekly, and the data were collected as the mice aged from 100 to 348 days. The survival rate remained above 96%, with body weight increasing by 35-52% during the study period. The ammonia levels rose throughout the cleaning cycle, but averaged below 25 ppm. However, in the older, heavier mice with bi-weekly cage cleaning, the ammonia levels reached between 25 and 75 ppm, particularly in the males. While circadian rhythms influenced the ammonia concentration only to a small extent, the carbon dioxide levels varied between 800 and 3000 ppm, increasing by 30-50% at night and by 1000 ppm with body weight. Humidity also correlated primarily with the circadian rhythms (10% higher at night) and, to a lesser extent, with body weight, reaching ≥70% in the middle-aged mice. The temperature variations remained minimal, within a 1 °C range. We conclude that air quality assessments in IVCs should be conducted during animals' active periods, and both housing density and biomass must be considered to optimise welfare.

Opinion: Promoting the Welfare of Research Animals: The Need to Expand the Roles and Views of Laboratory Animal Veterinarians.

Opinion: Promoting the Welfare of Research Animals: The Need to Expand the Roles and Views of Laboratory Animal Veterinarians.

Enhancing stress assessment in sledge reindeer (Rangifer tarandus): a pilot study on infrared thermal imaging and its opportunities for advancement as a welfare assessment tool

Measuring immediate physiological stress responses in animals can be challenging; saliva and blood sampling, while invasive, may also generate confounding stress responses, and equipping animals with heart rate sensors is not always feasible. Nevertheless, emerging technologies offer a non-invasive and contactless method to measure additional body surface temperature changes induced by acute stress, using infrared thermal measurement of the eye caruncle region. Contactless temperature measurement has the potential to assess the emotional state of animals affected by human physical contact. Reindeer, being highly sensitive to touch and naturally avoiding physical contact, exemplify this case. With growing interest in safari tours involving sledging reindeer, there is a need to investigate how these animals are affected by human interactions and how they adapt to daily close contact. In this pilot experiment, we evaluated the efficacy of thermal imaging in measuring medial canthus temperature fluctuations in non-habituated sledging reindeer while being petted by unfamiliar humans. Our findings support the hypothesis that medial canthus temperature significantly decreases during petting and increases once the interaction ceases, aligning with established stress response patterns found in the literature. This pilot experiment underscores the potential of infrared thermal imaging for non-invasively monitoring physiological responses to stress in tamed reindeer. Moreover, it sets the foundation for refining methodologies and experimental designs using infrared thermal imaging in animal welfare research.

The Royal Zoological Society of Scotland's Approach to Assessing and Promoting Animal Welfare in Collaboration with Universities.

Good zoos have four aims-to conserve species, educate the public, engage in research, and provide recreation-all of which can only be achieved when underpinned by high animal welfare standards. In this paper, we share the approach that The Royal Zoological Society of Scotland's (RZSS) Edinburgh Zoo and Highland Wildlife Park take to animal welfare. We highlight the role that animal welfare research, in collaboration with universities, has had in enabling the zoo to take an evidence-based approach to welfare and to put findings into practice. We share the collaborative process through which we developed and piloted the current animal welfare assessment tools, how they were validated, and how they were tested for reliability as part of a long-term collaboration between the Royal Zoological Society of Scotland and the University of Stirling: (1) the RZSS Welfare Assessment Tool, a 50-question animal welfare assessment adapted from the British and Irish Association of Zoos and Aquariums (BIAZA) Toolkit; and (2) the Stirling Toolkit, a package of evidence-based resources for behavioural-data collection. Our aim is to facilitate standardised, evidence-based approaches to assessing animal welfare which, when finalised, can be used collaboratively across zoos.

Exploring pet rat care: A comprehensive survey of husbandry, health, behavior, and the associations between caretaker attitudes, attachment, and husbandry practices

Pet rats are still understudied in terms of animal welfare and human-animal interaction research. An extensive online survey targeting German-speaking rat caretakers was conducted (n = 978). One of the study's goals was to investigate husbandry practices, health indicators, rat behaviors that suggest either good or compromised welfare, as well as elements of the human-animal relationship, including interactions between humans and animals, caretaker attitudes, and attachment. The second aim was to explore the associations between caretaker attitudes and attachment, and caretaker behavior, encompassing routine health checks, interactions between humans and animals, as well as the activities and enrichment provided to rats. In some instances, welfare issues were identified: insufficient space (evident in 10.6% of rats), provision of unhealthy snacks (14.6%). The vast majority of rats enjoyed a variety of enrichment objects, e.g., huts/houses (98.4%), nesting material (92.7%), hammocks (91.7%), and tunnels/tubes (83.7%). The average amount of space and time provided for roaming in case of no permanent roaming possibility (13.9 m2 and 2.5 h per day) was positive in terms of welfare. About 79.0% of rats did not suffer from a disease diagnosed by a veterinarian. Repetitive behaviors, which may represent stereotypies, were uncommon (plucking out own fur and cage bar chewing occurred “never” in 99.1% and 81.5%). Indicators of good welfare (e.g., self-grooming, rearing, eye-boggling) were observed several times/day in 89.6%, 46.7%, and 11.6% respectively. Caretakers who formed strong bonds with their rats tended to express positive general attitudes (such as finding rats ‘‘lovable’’ and ‘‘fun’’), while showing little agreement with statements reflecting negative attitudes (like considering rats ‘‘dirty’’). About 84.4% reported stroking their rat, 94.9% reported talking to it, and 70.9% mentioned hand-feeding their rat several times per day. Caretaker attitudes and attachment and human-animal interactions and caretaker behaviors correlated weakly but consistently (P < 0.01): respondents who felt more comfortable during positive interactions, stroked, hand-fed their rats, offered rat-friendly enrichment and performed health checks more often. In contrast, higher agreement to rats being ‘‘dirty’’ related to less frequent health checks and less frequent positive human-animal interactions. The identified relationships between caretaker attitudes and behaviors can help design interventions to promote caretaker behavior that is beneficial for rat welfare.

Contactless vital signs monitoring in macaques using a mm-wave FMCW radar

Heart rate (HR) and respiration rate (RR) play an important role in the study of complex behaviors and their physiological correlations in non-human primates (NHPs). However, collecting HR and RR information is often challenging, involving either invasive implants or tedious behavioral training, and there are currently few established simple and non-invasive techniques for HR and RR measurement in NHPs owing to their stress response or indocility. In this study, we employed a frequency-modulated continuous wave (FMCW) radar to design a novel contactless HR and RR monitoring system. The designed system can estimate HR and RR in real time by placing the FMCW radar on the cage and facing the chest of both awake and anesthetized macaques, the NHP investigated in this study. Experimental results show that the proposed method outperforms existing methods, with averaged absolute errors between the reference monitor and radar estimates of 0.77 beats per minute (bpm) and 1.29 respirations per minute (rpm) for HR and RR, respectively. In summary, we believe that the proposed non-invasive and contactless estimation method could be generalized as a HR and RR monitoring tool for NHPs. Furthermore, after modifying the radar signal-processing algorithms, it also shows promise for applications in other experimental animals for animal welfare, behavioral, neurological, and ethological research.

Assessing the Current Landscape of Reptile Pet Ownership in Hong Kong: A Foundation for Improved Animal Welfare and Future Research Directions.

We investigated the evolving landscape of reptile pet ownership in Hong Kong. Employing a quantitative approach, a self-administered survey was distributed and over 200 reptile pet owners residing in Hong Kong responded. The survey instrument captured demographic data on pet ownership history, species preferences, husbandry practices, and veterinary care utilization. The findings revealed a strong interest in pet reptiles, with lizards being particularly popular (67%) among new owners. Turtles remain common (35%), likely due to cultural factors and perceived ease of care. However, a gap was noted between the awareness and the implementation of proper husbandry practices, with 51% of respondents expressing concerns about enrichment and 21% uncertain about appropriate enclosure size. Veterinary care utilization also showed a disconnect, with 50% of the respondents reporting no regular check-ups were performed, despite acknowledging its importance. Reptile behavior served as a well-being indicator. Over 90% of the respondents observed normal behaviors like locomotion and breathing. Interestingly, a positive correlation emerged between reptile behavior scores and duration of ownership (r = 0.200, p < 0.01), suggesting improved well-being for reptiles that were in long-term care. These findings emphasize the need for educational initiatives promoting responsible pet ownership practices and fostering collaboration between reptile owners, veterinarians, and animal welfare organizations. By addressing these knowledge gaps and promoting a collaborative approach, our results aim to contribute to enhanced reptile welfare in the context of Hong Kong's evolving pet ownership trends.

An Interactive Feeder to Induce and Assess Emotions from Vocalisations of Chickens.

Understanding the emotional states of animals is a long-standing research endeavour that has clear applications in animal welfare. Vocalisations are emerging as a promising way to assess both positive and negative emotional states. However, the vocal expression of emotions in birds is a relatively unexplored research area. The goal of this study was to develop an interactive feeding system that would elicit positive and negative emotional states, and collect recordings of the vocal expression of these emotions without human interference. In this paper, the mechatronic design and development of the feeder is described. Design choices were motivated by the desire for the hens to voluntarily interact with the feeder and experience the different stimuli that were designed to induce (1) positive low-arousal, (2) positive high-arousal, (3) negative low-arousal, and (4) negative high-arousal states. The results showed that hens were motivated to engage with the feeder despite the risk of receiving negative stimuli and that this motivation was sustained for at least 1 week. The potential of using the interactive feeder to analyse chicken vocalisations related to emotional valence and arousal is being explored, offering a novel proof of concept in animal welfare research. Preliminary findings suggest that hens vocalised in response to all four stimulus types, with the number of vocalisations, but not the probability of vocalising, distinguishing between low- and high-arousal states. Thus, the proposed animal-computer interaction design has potential to be used as an enrichment device and for future experiments on vocal emotions in birds.

Rethinking core affect: the role of dominance in animal behaviour and welfare research

This paper critically examines the philosophical underpinnings of current experimental investigation into animal affect-related decision-making. Animals’ affective states are standardly operationalised by linking positively valenced states with “approach” behaviours and negatively valenced states with “avoidance” behaviours. While this operationalisation has provided a helpful starting point to investigate the ecological role of animals’ internal states, there is extensive evidence that valenced and motivational states do not always neatly align, namely, instances where “liking” does not entail “wanting” (and vice versa). To address this limitation, this paper proposes the (re-)integration of dominance as a dimension of affect. In particular, I argue that dominance, construed as a measure of organisms’ self-assessed behavioural control, can provide the necessary nuance to understand animal affect-related decision-making. Thus, after addressing the theoretical and methodological challenges related to incorporating dominance into a definition of “core affect”, this paper introduces the “Valence-Arousal-Dominance” model of animal affect. This model is explored for its potential applications in two domains. Firstly, in the study of animal affect-related decision-making under predation risk, and secondly, in the study of animal wellbeing. Through these applications, this model aims to bring experimental paradigms of animal affect-related behaviour closer to ecologically relevant scenarios.

Animal behaviour and welfare research: A One Health perspective

Animal behaviour and welfare research are part of a wider endeavour to optimize the health and wellbeing of humans, animals and ecosystems. As such, it is part of the One Health research agenda. This article applies ethical principles described by the One Health High Level Expert Panel to animal behaviour and welfare research. These principles entail that animal behaviour and welfare research should be valued equitably alongside other research in transdisciplinary and multisectoral collaboration. It should include and promote a multiplicity of marginalized voices, including those of animals, and it should apply and describe a harmonious balance between human—animal-environment interactions. Lastly, it should describe how humans need to change behaviour, adopt sustainable solutions and recognize the importance of animal welfare and the integrity of the whole ecosystem.

Validation of Fecal Glucocorticoid Metabolites as Non-Invasive Markers for Monitoring Stress in Common Buzzards (Buteo buteo).

For wild animals, being in captivity in wildlife centers can cause considerable stress. Therefore, it is necessary to establish and validate non-invasive tools to measure chronic stress during rehabilitation. Eight Common Buzzards which lived in permanent husbandry were placed individually into prepared aviaries and their feces were collected before, during and after a stress event for biological validation over a period of seven days. The extracted fecal glucocorticoid metabolites (fGCMs) were analyzed with three different enzyme immune assays (EIA) to find the most suitable one. Additionally, we aimed to investigate the stability of fGCM levels after defecation because further metabolization by bacterial enzymes can lead to changed results. The Cortisone-EIA performed best in males and females and showed that the stress event led to an fGCM increase of 629% (557% in females and 702% in males) in relation to basal values. We found no significant differences between the sexes, but observed significant differences between different times of day. FGCM concentration significantly changed after eight hours at room temperature. Our study successfully validated the non-invasive measurement of fGCM as a stress indicator in Common Buzzards and could therefore lay the foundation for future studies providing new insights for animal welfare research in Buzzards.

Automated Observations of Dogs' Resting Behaviour Patterns Using Artificial Intelligence and Their Similarity to Behavioural Observations.

Although direct behavioural observations are widely used, they are time-consuming, prone to error, require knowledge of the observed species, and depend on intra/inter-observer consistency. As a result, they pose challenges to the reliability and repeatability of studies. Automated video analysis is becoming popular for behavioural observations. Sleep is a biological metric that has the potential to become a reliable broad-spectrum metric that can indicate the quality of life and understanding sleep patterns can contribute to identifying and addressing potential welfare concerns, such as stress, discomfort, or health issues, thus promoting the overall welfare of animals; however, due to the laborious process of quantifying sleep patterns, it has been overlooked in animal welfare research. This study presents a system comparing convolutional neural networks (CNNs) with direct behavioural observation methods for the same data to detect and quantify dogs' sleeping patterns. A total of 13,688 videos were used to develop and train the model to quantify sleep duration and sleep fragmentation in dogs. To evaluate its similarity to the direct behavioural observations made by a single human observer, 6000 previously unseen frames were used. The system successfully classified 5430 frames, scoring a similarity rate of 89% when compared to the manually recorded observations. There was no significant difference in the percentage of time observed between the system and the human observer (p > 0.05). However, a significant difference was found in total sleep time recorded, where the automated system captured more hours than the observer (p < 0.05). This highlights the potential of using a CNN-based system to study animal welfare and behaviour research.

After a wealth of welfare experience I landed my dream job at The Donkey Sanctuary.

From an early age Jo Hockenhull was acutely aware of the plight of equids and how animals' behaviour reveals a huge amount about their wellbeing, leading to a distinguished career in animal welfare research.

Methods of Alleviating Working Dog’s Anxiety

As our society evolved swiftly, working dogs are becoming more predominant in assisting people in diverse fields. It's easier to see our loyal friends working hard in places like battlefields, rescuing people, or in airfields, detecting drugs. At the same time, researchers proposed a deeper understanding of animal welfare and people are more concerned about how to enhance the standard of living of working dogs. This report aimed to use the scientific studies of working dogs from the last decade to list both methods of preventing and alleviating working dogs' anxiety. These methods encompass both physical supplements and mental support. We will go through these methods through three main categories: methods to prevent their anxiety, physical items, and measures and reminders for their trainers in their everyday training and life. Utilizing this framework, we were able to assist these dogs who were having anxiety because of us. We benefit from their hard work and, subsequently, are responsible for their trauma. On the other hand, just like the inextricable link between living organisms, these methods may not only serve working dogs but also other animals around us, including your pet. Lastly, prioritizing animal welfare in research and practice will be pivotal to ensure the ongoing relationship between dogs and people as co-workers.

Deep learning strategies with CReToNeXt-YOLOv5 for advanced pig face emotion detection.

This study underscores the paramount importance of facial expressions in pigs, serving as a sophisticated mode of communication to gauge their emotions, physical well-being, and intentions. Given the inherent challenges in deciphering such expressions due to pigs' rudimentary facial muscle structure, we introduced an avant-garde pig facial expression recognition model named CReToNeXt-YOLOv5. The proposed model encompasses several refinements tailored for heightened accuracy and adeptness in detection. Primarily, the transition from the CIOU to the EIOU loss function optimized the training dynamics, leading to precision-driven regression outcomes. Furthermore, the incorporation of the Coordinate Attention mechanism accentuated the model's sensitivity to intricate expression features. A significant innovation was the integration of the CReToNeXt module, fortifying the model's prowess in discerning nuanced expressions. Efficacy trials revealed that CReToNeXt-YOLOv5 clinched a mean average precision (mAP) of 89.4%, marking a substantial enhancement by 6.7% relative to the foundational YOLOv5. Crucially, this advancement holds profound implications for animal welfare monitoring and research, as our findings underscore the model's capacity to revolutionize the accuracy of pig facial expression recognition, paving the way for more humane and informed livestock management practices.

The impact of induced pluripotent stem cells in animal conservation.

It is widely acknowledged that we are currently facing a critical tipping point with regards to global extinction, with human activities driving us perilously close to the brink of a devastating sixth mass extinction. As a promising option for safeguarding endangered species, induced pluripotent stem cells (iPSCs) hold great potential to aid in the preservation of threatened animal populations. For endangered species, such as the northern white rhinoceros (Ceratotherium simum cottoni), supply of embryos is often limited. After the death of the last male in 2019, only two females remained in the world. IPSC technology offers novel approaches and techniques for obtaining pluripotent stem cells (PSCs) from rare and endangered animal species. Successful generation of iPSCs circumvents several bottlenecks that impede the development of PSCs, including the challenges associated with establishing embryonic stem cells, limited embryo sources and immune rejection following embryo transfer. To provide more opportunities and room for growth in our work on animal welfare, in this paper we will focus on the progress made with iPSC lines derived from endangered and extinct species, exploring their potential applications and limitations in animal welfare research.

Between animal research and animal welfare: Analysing the openness practices of UK Named Veterinary Surgeons.

The use of animals as scientific models is argued to be crucial for producing new scientific and medical knowledge and clinical treatments. However, animal research continues to raise socio-ethical concerns. In recent years, there has been a push for openness amongst the life science community, with the aim of increasing the transparency of animal research to wider publics. Yet, how this push for openness is experienced by those responsible for the care and welfare of research animals requires further study. This paper draws upon qualitative interviews with Named Veterinary Surgeons (NVS) in the UK and explores how they practise openness, avoid openness, and, at times, challenge the way their role is represented within openness agendas. Overall, this social scientific analysis reveals that the current openness agenda has the potential to create tensions for professionals, as they seek to manage regulatory and public imaginaries of the veterinary identity alongside the animal research controversy. The paper concludes by arguing for a culture of dialogue, where openness includes allowing those with responsibilities for animal welfare to express ambivalence or concern about their own role. Finally, the paper calls for sustained academic work on relations between the veterinary profession and wider society, particularly areas that involve contested practices in which care and harm may coincide.

Human-animal interactions and machine-animal interactions in animals under human care: A summary of stakeholder and researcher perceptions and future directions

Abstract Animals under human care are exposed to a potentially large range of both familiar and unfamiliar humans. Human-animal interactions vary across settings, and individuals, with the nature of the interaction being affected by a suite of different intrinsic and extrinsic factors. These interactions can be described as positive, negative or neutral. Across some industries, there has been a move towards the development of technologies to support or replace human interactions with animals. Whilst this has many benefits, there can also be challenges associated with increased technology use. A day-long Animal Welfare Research Network workshop was hosted at Harper Adams University, UK, with the aim of bringing together stakeholders and researchers (n = 38) from the companion, farm and zoo animal fields, to discuss benefits, challenges and limitations of human-animal interactions and machine-animal interactions for animals under human care and create a list of future research priorities. The workshop consisted of four talks from experts within these areas, followed by break-out room discussions. This work is the outcome of that workshop. The key recommendations are that approaches to advancing the scientific discipline of machine-animal interactions in animals under human care should focus on: (1) interdisciplinary collaboration; (2) development of validated methods; (3) incorporation of an animal-centred perspective; (4) a focus on promotion of positive animal welfare states (not just avoidance of negative states); and (5) an exploration of ways that machines can support a reduction in the exposure of animals to negative human-animal interactions to reduce negative, and increase positive, experiences for animals.

Study on the current research trends and future agenda in animal products: an Asian perspective.

This study aimed to analyze the leading research materials and research trends related to livestock food in Asia in recent years and propose future research agendas to ultimately contribute to the development of related livestock species. On analyzing more than 200 relevant articles, a high frequency of studies on livestock species and products with large breeding scales and vast markets was observed. Asia possesses the largest pig population and most extensive pork market, followed by that of beef, chicken, and milk; moreover, blood and egg markets have also been studied. Regarding research keywords, "meat quality" and "probiotics" were the most common, followed by "antioxidants", which have been extensively studied in the past, and "cultured meat", which has recently gained traction. The future research agenda for meat products is expected to be dominated by alternative livestock products, such as cultured and plant-derived meats; improved meat product functionality and safety; the environmental impacts of livestock farming; and animal welfare research. The future research agenda for dairy products is anticipated to include animal welfare, dairy production, probiotic-based development of high-quality functional dairy products, the development of alternative dairy products, and the advancement of lactose-free or personalized dairy products. However, determining the extent to which the various research articles' findings have been applied in real-world industry proved challenging, and research related to animal food laws and policies and consumer surveys was lacking. In addition, studies on alternatives for sustainable livestock development could not be identified. Therefore, future research may augment industrial application, and multidisciplinary research related to animal food laws and policies as well as eco-friendly livestock production should be strengthened.