A user's guide to animal welfare science

Here, I provide a guide for those new to the burgeoning field of animal welfare science as to what this comprehensive, relatively young discipline is all about. Drawing on all branches of biology, including behavioural ecology and neuroscience, the science of animal welfare asks three big questions: Are animals conscious? How can we assess good and bad welfare in animals? How can we use science to improve animal welfare in practice? I also provide guidelines for an evidence-based approach to welfare issues for policy makers and other users of animal welfare research.     

The Science of Animal Suffering

Can suffering in non‐human animals be studied scientifically? Apart from verbal reports of subjective feelings, which are uniquely human, I argue that it is possible to study the negative emotions we refer to as suffering by the same methods we use in ourselves. In particular, by asking animals what they find positively and negatively reinforcing (what they want and do not want), we can define positive and negative emotional states. Such emotional states may or may not be accompanied by subjective feelings but fortunately it is not necessary to solve the problem of consciousness to construct a scientific study of suffering and welfare. Improvements in animal welfare can be based on the answers to two questions: Q1: Will it improve animal health? and Q2: Will it give the animals something they want? This apparently simple formulation has the advantage of capturing what most people mean by ‘improving welfare’ and so halting a potentially dangerous split between scientific and non‐scientific definitions of welfare. It can also be used to validate other controversial approaches to welfare such as naturalness, stereotypies, physiological and biochemical measures. Health and what animals want are thus not just two of many measures of welfare. They provide the definition of welfare against which others can be validated. They also tell us what research we have to do and how we can judge whether welfare of animals has been genuinely improved. What is important, however, is for this research to be done in situ so that it is directly applicable to the real world of farming, the sea or an animal’s wild habitat. It is here that ethology can make major contributions.     

Friends with benefits: Social support and its relevance for farm animal welfare

Despite growing interest in promoting positive welfare, rather than just alleviating poor welfare, potential measures of good welfare, and means to provide it, have remained elusive. In humans social support improves stress-coping abilities, health, and promotes positive psychological welfare. Therefore, social support may be a key approach to promote positive physical and psychological welfare in farm animals. However, the roles of positive social behaviors and social support have been overlooked in comparison to negative social behaviors such as agonistic interactions. The benefits of social partners on an animal's stress coping abilities and welfare are yet poorly understood.The purpose of this paper is to review the protective or buffering effects of social support against stressful challenges and its potential implications for farm animal welfare. The biology of social support is first presented with its behavior, endocrine, autonomic and immune components. The major factors modulating the social support process are then synthesized. Research and implications for animal welfare in different farm species are discussed. Lastly, this review identifies research areas that especially deserve further attention in our effort to understand and implement social support in farm animal welfare.Social support could constitute one of the foundations for welfare researchers to leap from the absence of negative welfare to the provision of positive welfare and emotional experiences.     

Cumulative stress in research animals: Telomere attrition as a biomarker in a welfare context?

Progress in improving animal welfare is currently limited by the lack of objective methods for assessing lifetime experience. I propose that telomere attrition, a cellular biomarker of biological age, provides a molecular measure of cumulative experience that could be used to assess the welfare impact of husbandry regimes and/or experimental procedures on non‐human animals. I review evidence from humans that telomere attrition is accelerated by negative experiences in a cumulative and dose‐dependent manner, but that this attrition can be mitigated or even reversed by positive life‐style interventions. Evidence from non‐human animals suggests that despite some specific differences in telomere biology, stress‐induced telomere attrition is a robust phenomenon, occurring in a range of species including mice and chickens. I conclude that telomere attrition apparently integrates positive and negative experience in an accessible common currency that translates readily to novel species – the Holy Grail of a cumulative welfare indicator.     

A concept of welfare based on reward evaluating mechanisms in the brain: anticipatory behaviour as an indicator for the state of reward systems

In this review we attempt to link the efficiency by which animals behave (economy of animal behaviour) to a neuronal substrate and subjective states to arrive at a definition of animal welfare which broadens the scope of its study. Welfare is defined as the balance between positive (reward, satisfaction) and negative (stress) experiences or affective states. The state of this balance may range from positive (good welfare) to negative (poor welfare). These affective states are momentary or transient states which occur against the background of and are integrated with the state of this balancing system. As will be argued the efficiency in behaviour requires that, for instance, satisfaction is like a moving target: reward provides the necessary feedback to guide behaviour; it is a not steady-state which can be maintained for long. This balancing system is reflected in the brain by the concerted action of opioid and mesolimbic dopaminergic systems. The state of this system reflects the coping capacity of the animal and is determined by previous events. In other words, this integrative approach of behavioural biology and neurobiology aims at understanding how the coping capacity of animals may be affected and measured. We argue that this balancing system underlies the economy of behaviour. Furthermore we argue that among other techniques anticipation in Pavlovian conditioning is an easy and useful tool to assess the state of this balancing system: for estimating the state of an animal in terms of welfare we focus on the conditions when an animal is facing a challenge.     

Reflecting on ethical and legal issues in wildlife disease

Disease in wildlife raises a number of issues that have not been widely considered in the bioethical literature. However, wildlife disease has major implications for human welfare. The majority of emerging human infectious diseases are zoonotic: that is, they occur in humans by cross‐species transmission from animal hosts. Managing these diseases often involves balancing concerns with human health against animal welfare and conservation concerns. Many infectious diseases of domestic animals are shared with wild animals, although it is often unclear whether the infection spills over from wild animals to domestic animals or vice versa. Culling is the standard means of managing such diseases, bringing economic considerations, animal welfare and conservation into conflict. Infectious diseases are also major threatening processes in conservation biology and their appropriate management by culling, vaccination or treatment raises substantial animal ethics issues. One particular issue of great significance in Australia is an ongoing research program to develop genetically modified pathogens to control vertebrate pests including rabbits, foxes and house mice. Release of any self‐replicating GMO vertebrate pathogen gives rise to a whole series of ethical questions. We briefly review current Australian legal responses to these problems. Finally, we present two unresolved problems of general importance that are exemplified by wildlife disease. First, to what extent can or should ‘bioethics’ be broadened beyond direct concerns with human welfare to animal welfare and environmental welfare? Second, how should the irreducible uncertainty of ecological systems be accounted for in ethical decision making?     

Welfare of sheep: Providing for welfare in an extensive environment

As a species traditionally managed extensively, at least for some of the year, sheep have received relatively little attention from a welfare perspective. Although extensively managed animals have greater behavioural freedom than those managed intensively, they are still vulnerable to other welfare challenges. Welfare can be considered from the perspective of the animals biological functioning, the naturalness of the way in which they are kept, or their feelings (negative or positive). These different domains can be integrated by considering the animal (and the adaptations it possesses) and the environment (made up of the challenges the animal experiences). In this schema, the extensively managed animal may experience poor welfare if the environmental challenges overwhelm its evolved coping strategies (for example, in high temperatures if behavioural and physiological adaptations cannot dissipate heat sufficiently) or if it has adaptations (such as behavioural anti-predator responses) that are no longer required. To assess welfare of sheep, therefore, we need to know when the animal may begin to suffer if its adaptations do not meet the challenges presented by the environment or when the cost of meeting those challenges is too great. In addition, the adaptations the sheep possess will affect how well it copes, e.g. breed differences in maternal behaviour and responses to predators will influence lamb survival and predation risk in extensive environments, respectively. How well the extensive environment can meet the behavioural needs of sheep has never been tested. However, consideration of the behaviour and habitat of wild sheep suggests that some preferred environmental features, such as escape terrain or specific birth sites, may not be present in farmed environments. How this affects sheep welfare is still to be determined. Sheep welfare is also affected by the quality of the stockperson caring for them. Interactions with people for extensively managed sheep are infrequent, but nearly always aversive, and whether the nature of interactions can be affected by stockperson attitude and behaviour, as seen in intensively managed species, remains to be seen. There is evidence, however, that farmers may under-estimate the negative impact that themselves and their sheepdogs can have on their sheep. Farmer attitude can also affect management decisions which may have an indirect impact on the welfare of their sheep. For example, farmer attitudes towards lameness are related to treatment decisions. The extensive environment thus provides particular challenges to welfare that differ markedly from those in intensive systems, and still need further investigation.     

Thirty years after Brambell: whither animal welfare science?

It has been just over 30 years since the Brambell Committee issued its clarion call for research on the welfare of animals used in agriculture. What progress has farm animal welfare science made in those 30 years, and what challenges will it face in the next 30? In this article, I discuss the ways in which the Brambell report, with its emphasis on behavioral needs and suffering, both propelled and constrained the development of animal welfare science. The role that economic factors play and the ways in which they have imposed other kinds of constraints on scientists working with farm animals are also mentioned. Despite these constraints, animal welfare science has contributed to a number of significant improvements in the welfare of farm animals. There is, however, a growing sense that animal welfare science has reached an impasse and that ethical and scientific questions about animal welfare have become hopelessly entangled. In this context, I address what I view to be the principal challenge facing farm animal welfare science, namely to move the issue of beyond suffering to an evaluation of broader quality-of-life questions and their application to improvements in welfare.     

Exploring Children’s Perspectives on the Welfare Needs of Pet Animals

Children are increasingly viewed as important recipients of educational interventions to improve animal welfare, yet research examining their perspectives is lacking, particularly within the UK. Helping children to care appropriately for animals depends, not least, on an ability to understand the needs of different species and correctly identify cues given by the animal that indicate its welfare state. This study began to explore: (a) children’s perceptions of welfare needs, focusing on four common pet animals; (b) influences on the development of knowledge; (c) beliefs about whether or not (all) animals are sentient, and (d) their confidence in identifying when their own pets are in need. Fourteen focus groups were carried out with 53 children aged 7 to 13 years. Findings highlighted an affirmative response that animals have feelings (dogs especially), albeit with doubts about this applying universally. There was wide variation in children’s knowledge of welfare needs, even among owners of the animal in question. Conversely, some children lacked confidence in spite of the extensive knowledge they had developed through direct experience. An important finding was a perceived difficulty in identifying the needs of particular species or specific types of need in their own pets. Fitting well with a recent emphasis on “positive welfare,” children felt that many animals need demonstrative love and attention, especially cats and dogs. While there is clearly scope for educating children about common needs and cues that indicate animals’ welfare state, other areas pose a greater challenge. Emotional connection seems important in the development of extensive knowledge and concern for welfare. Accordingly, animals that do not possess the kind of behavioral repertoire that is easy to interpret or allows for a perceived sense of reciprocity are possibly at risk of negative welfare experiences.     

Phylogenetic comparative methods: Harnessing the power of species diversity to investigate welfare issues in captive wild animals

This paper reviews a way of investigating health and welfare problems in captive wild animals (e.g., those in zoos, aviaries, aquaria, or aquaculture systems) that has great potential, but to date has been little used: systematically comparing species with few or no health and welfare issues to those more prone to problems. Doing so empirically pinpoints species‐typical welfare risk and protective factors (such as aspects of their natural behavioral biology): information which can then be used to help prevent or remedy problems by suggesting new ways to improve housing and husbandry, and by identifying species intrinsically best suited to captivity. We provide a detailed, step‐by‐step “how to” guide for researchers interested in using these techniques, including guidance on how to statistically control for the inherent similarities shared by related species: an important concern because simple, cross‐species comparisons that do not do this may well fail to meet statistical assumptions of non‐independence. The few relevant studies that have investigated captive wild animals’ welfare problems using this method are described. Overall, such approaches reap value from the great number and diversity of species held in captivity (e.g., the many thousands of species held in zoos); can yield new insights from existing data and published results; render previously intractable welfare questions (such as “do birds need to fly?” or “do Carnivora need to hunt?”) amenable to study; and generate evidence‐based principles for integrating animal welfare into collection planning.     

Advances in Applied Zoo Animal Welfare Science

ABSTRACT

Nonhuman animal welfare science is the scientific study of the welfare state of animals that attempts to make inferences about how animals feel from their behavior, endocrine function, and/or signs of physical health. These welfare measurements are applicable within zoos yet inherently more complex than in farms and laboratories. This complexity is due to the vast number of species housed, lack of fundamental biological information, and relatively lower sample sizes and levels of experimental control. This article summarizes the invited presentations on the topic of “Advances in Applied Animal Welfare Science,” given at the Fourth Global Animal Welfare Congress held jointly by the Detroit Zoological Society and the World Association of Zoos and Aquariums in 2017. The article focuses on current trends in research on zoo animal welfare under the following themes: (a) human–animal interactions and relationships, (b) anticipatory behavior, (c) cognitive enrichment, (d) behavioral biology, and (e) reproductive and population management. It highlights areas in which further advancements in zoo animal welfare science are needed and the challenges that may be faced in doing so.     

Road transport of farm animals: effects of journey duration on animal welfare

Transport of farm animals gives rise to concern about their welfare. Specific attention has been given to the duration of animal transport, and maximum journey durations are used in legislation that seek to minimise any negative impact of transport on animal welfare. This paper reviews the relatively few scientific investigations into effects of transport duration on animal welfare in cattle, sheep, horses, pigs and poultry. From the available literature, we attempt to distinguish between aspects, which will impair welfare on journeys of any duration, such as those associated with loading, and those aspects that may be exacerbated by journey time. We identify four aspects of animal transport, which have increasing impact on welfare as transport duration increases. These relate to (i) the physiological and clinical state of the animal before transport; and - during transport - to (ii) feeding and watering; (iii) rest and (iv) thermal environment. It is thus not journey duration per se but these associated negative aspects that are the cause of compromised welfare. We suggest that with a few exceptions, transport of long duration is possible in terms of animal welfare provided that these four issues can be dealt with for the species and the age group of the animals that are transported.     

A guide to defining and implementing protocols for the welfare assessment of laboratory animals: eleventh report of the BVAAWF/FRAME/RSPCA/UFAW Joint Working Group on Refinement

The refinement of husbandry and procedures to reduce animal suffering and improve welfare is an essential component of humane science. Successful refinement depends upon the ability to assess animal welfare effectively, and detect any signs of pain or distress as rapidly as possible, so that any suffering can be alleviated. This document provides practical guidance on setting up and operating effective protocols for the welfare assessment of animals used in research and testing. It sets out general principles for more objective observation of animals, recognizing and assessing indicators of pain or distress and tailoring these to individual projects. Systems for recording indicators, including score sheets, are reviewed and guidance is set out on determining practical monitoring regimes that are more likely to detect any signs of suffering. This guidance is intended for all staff required to assess or monitor animal welfare, including animal technologists and care staff, veterinarians and scientists. It will also be of use to members of ethics or animal care and use committees. A longer version of this document, with further background information and extra topics including training and information sharing, is available on the Laboratory Animals website.     

Sensitivity to reward loss as an indicator of animal emotion and welfare

The scientific study of animal emotion is an important emerging discipline in subjects ranging from neuroscience to animal welfare research. In the absence of direct measures of conscious emotion, indirect behavioural and physiological measures are used. However, these may have significant limitations (e.g. indicating emotional arousal but not valence (positivity versus negativity)). A new approach, taking its impetus from human studies, proposes that biases in information processing, and underlying mechanisms relating to the evaluation of reward gains and losses, may reliably reflect emotional valence in animals. In general, people are more sensitive to reward losses than gains, but people in a negative affective state (e.g. depression) are particularly sensitive to losses. This may underlie broader findings such as an enhanced attention to, and memory of, negative events in depressed individuals. Here we show that rats in unenriched housing, who typically exhibit indicators of poorer welfare and a more negative affective state than those in enriched housing, display a prolonged response to a decrease in anticipated food reward, indicating enhanced sensitivity to reward loss. Sensitivity to reward reduction may thus be a valuable new indicator of animal emotion and welfare.     

Infrared thermal imaging associated with pain in laboratory animals

The science of animal welfare has evolved over the years, and recent scientific advances have enhanced our comprehension of the neurological, physiological, and ethological mechanisms of diverse animal species. Currently, the study of the affective states (emotions) of nonhuman animals is attracting great scientific interest focused primarily on negative experiences such as pain, fear, and suffering, which animals experience in different stages of their lives or during scientific research. Studies underway today seek to establish methods of evaluation that can accurately measure pain and then develop effective treatments for it, because the techniques available up to now are not sufficiently precise. One innovative technology that has recently been incorporated into veterinary medicine for the specific purpose of studying pain in animals is called infrared thermography (IRT), a technique that works by detecting and measuring levels of thermal radiation at different points on the body’s surface with high sensitivity. Changes in IRT images are associated mainly with blood perfusion, which is modulated by the mechanisms of vasodilatation and vasoconstriction. IRT is an efficient, noninvasive method for evaluating and controlling pain, two critical aspects of animal welfare in biomedical research. The aim of the present review is to compile and analyze studies of infrared thermographic changes associated with pain in laboratory research involving animals.     

Impacts of natural history and exhibit factors on carnivore welfare

To improve the welfare of nonhuman animals under professional care, zoological institutions are continuously utilizing new methods to identify factors that lead to optimal welfare. Comparative methods have historically been used in the field of evolutionary biology but are increasingly being applied in the field of animal welfare. In the current study, data were obtained from direct behavioral observation and institutional records representing 80 individual animals from 34 different species of the order Carnivora. Data were examined to determine if a variety of natural history and animal management factors impacted the welfare of animals in zoological institutions. Output variables indicating welfare status included behavioral diversity, pacing, offspring production, and infant mortality. Results suggested that generalist species have higher behavioral diversity and offspring production in zoos compared with their specialist counterparts. In addition, increased minimum distance from the public decreased pacing and increased offspring production, while increased maximum distance from the public and large enclosure size decreased infant mortality. These results have implications for future exhibit design or renovation, as well as management practices and priorities for future research.     

Animal Welfare in Relation to Standards in Organic Farming

The new EU-regulations on organic farming (1804/1999) are also influencing the animal welfare. A lot of positive regulations is to find, but also regulations that seen to mind more about the general public and customer and their view on organic farming, than the health and welfare of the animals.The paper specially focus on the impact of the regulations and the recommendations that phytotherapeutic essences and homeopathic products take precedence over the so called chemically-synthesised allopatic veterinary medical products, and that the use of the same is prohibited for preventive treatments. Key questions here are the lack of scientific evidence concerning homeopathy in animals, and that Swedish veterinarians are not allowed to work with homeopathy.Differences in interpretation of the regulations between animal owners and veterinarians will also be discussed. What is a disease that needs treatment? Who is to decide about the treatment? Parasitic infections are discussed as an illustrative example.Other consequences of the regulations concerning the animal welfare are problems in certain geographical zones, for instance subarctic areas where necessary crops are impossible to grow.Animal transports and splitting mother-offspring are briefly discussed as future problems to be handled in the regulations, and the paper ends by presenting the need of regulated herd health control programs in organic husbandry, which can detect and focus on welfare and production problems. The organic movement is not static, and must not be so.     

How is animal welfare addressed in Canada's emergency response plans?

In 2005, Hurricanes Katrina and Rita clearly revealed that even in the United States the welfare of companion animals and nonhuman animals in the wild, zoo, or aquarium was not considered within the evacuation plans for their human caretakers (owners). The lack of proper planning and trained individuals resulted in a huge loss of animal life as well as suffering and trauma to both animals and their owners. The present Canadian Federal Emergency Response Plan does not have adequate procedures for the evacuation of animals together with their owners, nor do Canada or the provinces and territories have a plan in place that consists of properly trained and equipped individuals to respond to this aspect of disaster management. The Canadian Veterinary Reserve (CVR) was thus organized at a national level to respond properly to disasters or emergencies of all types and thereby reduce animal suffering and loss of life. This article describes the formation of the CVR and its anticipated national role in addressing animal welfare during times of catastrophic need.     

Blood cells of Fundulus heteroclitus (L.)

Much of the parenchyma of the normal pronephros of the adult Fundulus heterodilus , a euryhaline teleost, is haematopoietic tissue which was examined in cytocentrifuge preparations and plastic embedded thick sections. As we have not characterized many of the blood cells functionally, the terminology used is based on their morphological resemblance to similarly named cells in higher vertebrates. Approximately 80% of the non-erythroid elements observed in the pronephros are mature eosinophilic granulocytes (48%), immature eosinophilic granulocytes (25%), or cells likely to be their precursors [e.g. small blast cells (6%) and large blast cells (2%)]. Although there are macrophages in the pronephros that are capable of endocytotic activity, the mature and immature granulocytes are not. The granulocytes are non-specific esterase positive, PAS positive, acid phosphatase negative, and are capable of being mobilized by a RES activating agent, Ecteinascidia turbinata .     

Current available strategies to mitigate greenhouse gas emissions in livestock systems: an animal welfare perspective

Livestock production is a major contributor to greenhouse gas (GHG) emissions, so will play a significant role in the mitigation effort. Recent literature highlights different strategies to mitigate GHG emissions in the livestock sector. Animal welfare is a criterion of sustainability and any strategy designed to reduce the carbon footprint of livestock production should consider animal welfare amongst other sustainability metrics. We discuss and tabulate the likely relationships and trade-offs between the GHG mitigation potential of mitigation strategies and their welfare consequences, focusing on ruminant species and on cattle in particular. The major livestock GHG mitigation strategies were classified according to their mitigation approach as reducing total emissions (inhibiting methane production in the rumen), or reducing emissions intensity (Ei; reducing CH₄ per output unit without directly targeting methanogenesis). Strategies classified as antimethanogenic included chemical inhibitors, electron acceptors (i.e. nitrates), ionophores (i.e. Monensin) and dietary lipids. Increasing diet digestibility, intensive housing, improving health and welfare, increasing reproductive efficiency and breeding for higher productivity were categorized as strategies that reduce Ei. Strategies that increase productivity are very promising ways to reduce the livestock carbon footprint, though in intensive systems this is likely to be achieved at the cost of welfare. Other strategies can effectively reduce GHG emissions whilst simultaneously improving animal welfare (e.g. feed supplementation or improving health). These win–win strategies should be strongly supported as they address both environmental and ethical sustainability. In order to identify the most cost-effective measures for improving environmental sustainability of livestock production, the consequences of current and future strategies for animal welfare must be scrutinized and contrasted against their effectiveness in mitigating climate change.