I talked in one of my Instagram posts recently about animal welfare being less about what we, as animal keepers, pet owners, trainers, and veterinarians, actively provide animals with, in terms of husbandry and care and more regarding the effective state the care has over an animal’s life. I also mentioned how this can be measured objectively, leaving out opinions of what we as humans morally consider right and wrong.
But what is welfare? How can we scientifically measure it? What are the methods used? Why is a more subjective approach sometimes considered alongside more objective based methods of research? And why is all of this so important?
So what is welfare?
Some people emphasise it’s the physical well-being of animals, some more about providing a natural lifestyle, and others focusing more on an animal’s psychological state. In order to properly assess welfare, we need to be able to agree on what it actually is. Most agree that welfare is a state or condition that changes depending on an animal’s experiences, and its ability to deal with the challenges it may face at any given time, both mentally and physically.
Welfare consists of a multitude of aspects, and all must be taken into consideration when judging the overall welfare of an individual animal. When assessments are made, using only one dimension of an animal’s welfare, there is the risk that not all their needs are being considered or catered for. There is also the problem that there are differences in opinion to what is and isn’t considered acceptable. This is why it is critical to design a language, so to speak, that is internationally recognised so that we are all on the same page.
Using a scientific approach, we can take out some of the subjectiveness that occurs when we base decisions based on animals and their welfare our own beliefs and opinions. Using an evidence-based approach, allows us to make meaningful use of measurements that have been developed to enable a much more objective assessment of an animal’s response to any situation it finds itself in.
How is this done?
Firstly, a hypothesis or explanation is formulated based on observations of animals. The measurements used to test this hypothesis will need to be robust and the results subjected to statistical analysis before a decision is made about whether there is good enough evidence for or against a possible explanation. This process of experiment needs to be repeated a number of times to check that the results are similar, at which point a conclusion can be drawn. Scientists believe that this process allows us to make more accurate judgements about how an animal is coping with its environment or its situation and move us much closer to understanding the individual animal’s experience and enabling us to make more animal centric decisions.
So, what are these aspects that need to be taken into consideration and measured?
There are several methods used for measuring animal responses that are based upon the notion that an animal’s emotional response to a situation it finds itself in is expressed in its physiology and behaviour. These are called welfare indicators.
Scientists are extremely good at measuring behavioural, physiological, and even immunological responses to negative experiences such as pain, fear, or stress. For example, we can measure heart rate, blood pressure and chemicals in the brain and blood, that will tell us more about short-term changing in emotion. Whereas, behavioural changes give us an idea of more long-term emotional responses, including the development of stereotypic behaviours. Of course, behavioural changes can lead to more physical side effects too, including limiting disease resistance and health and growth problems, if animals are kept in these negative situations for prolonged periods. However, more recently there has been an appreciation of the importance of discovering measures indicative of positive emotional states, including social behaviour such as play and other comfort behaviours.
Why is measuring welfare in this way so important?
Through measuring changes in behaviour and physiology in a structured way, scientists are able to work out the relationships between different types of housing, different handling conditions, and transport, and look at the way that animals normally experience this and how their responses will allow them to adapt to cope with the challenges that this may impose upon them. By measuring welfare through these indicators, we are in a better position to properly manage animal needs, helping us decipher what is positive or negative from the animal’s point of view, which can be applied in improving their environment, handling, and ensuring highest standards of welfare through their life.
Using objective measures of animal responses can provide us with a universal language, one that transcends culture, religion and language and ensures the truth about animals and their welfare cannot be disputed. We all, as individuals, companies and even countries, have our own beliefs of what ‘good welfare’ looks like, so this allows for us to provide reliable evidence of what good welfare actively entails on a worldwide basis – regardless of if the animal is a pet, zoo animal, livestock, in a sanctuary, or even the wild. But the key thing to remember, is that if you are responsible for an animal in any scenario, you have a duty of care to ensure their welfare needs are provided for to the best of your ability.
WELFARE INDICATORS
As I stated, there are several indicators used to measure welfare and the main focus is on behaviour, physiological, immunological and more subjective measurements. So, let’s take a deeper look into each.
PHYSIOLOGY MEASURES
One way is to measure stress levels in animals. Now, it is a common misconception that we should completely rid captive animals of any stressful situation. However, it is very important to remember that stress is natural and there is a level of stress considered healthy and does not pose as a welfare concern. Animals encounter may encounter stress in new situations, during breeding, and when learning, making this a more positive emotional experience. Stress only becomes a concern for welfare when the animal is being continually challenged and exposed to situations where they are stressed beyond capacity to emotionally and physically cope. This level of stress causes changes within the immune system, leading to increased disease susceptibility, reduced production, and poor growth – resulting in poor animal welfare.
An animal’s behavioural response to a situation is usually easier to observe and more accessible. However, we can also use physiological measures of welfare, which provide an indirect measure of an animal's experience.
There is a sequence that makes up an animal's overall experience. Firstly, animals get sensory input from their environment and the brain evaluates this information in relation to several factors, including their previous experiences. This process then leads to the brain responding either positively, negatively, or neutrally. The body’s response to these emotions allows them to adapt to its environment, enabling it to return to a state of homeostasis.
Stressful situations can lead to more complicated internal and physiological responses, in which animals may experience a ‘fight or flight’ response to escape from or attack whatever may be the cause of the stress. The body’s response caters for the longer-term requirements to maintain it, and then ensures the animal's body function returns to normal. This also ensures the animal isn’t wasting critical energy reserves by not being constantly on alter.
Activation of the stress response can occur when an animal perceives a stimulus as being of significance, whether that is something that causes pain, is a threat to their wellbeing or something frightening. Coping mechanisms are then stimulated and the body immediately goes into protective mode.
In more 'sciency' terms:
The amygdala is an area of the brain where an animal's emotional centres are. Any threat to an animal will cause a chain of brain chemical responses as a result of activation of the Sympathetic-Adrenal-Medullary Axis (SAM axis). Immediately, blood hormones, called adrenaline, will rise, which will provide the energy required to respond effectively.
The hippocampus will simultaneously provide a longer acting and slower response, with the Hypothalamic Pituitary Adrenal axis (HPA axis) controlling the body’s reaction to stress and regulating bodily processes, including digestion, immune function, and emotion.
Animal welfare studies record and compare the immediate responses of changes in these two axes to situation changes within an animal's environment. Activation of the HPA axis is associated with increases in hormones such as cortisol, which can be measured in an animal's blood, saliva, urine, and faeces. Measurements of the heart rate and heart rate variation can be made to see if the SAM axis has been activated, as well as adrenaline measurements. It is a useful way to look at immediate consequences of painful situations, but it does require multiple quick succession sampling and is limited because of the short-term nature of the response.
This is where measuring the HPA axis becomes useful, as its easier to measure and responds more slowly – around two to ten minutes for a rise in the levels of cortisol in blood to be measurable. This helps work out recovery from stress over time. There is a cascade of chemical responses in different parts of an animal’s body and brain when the HPA axis is activated, leading the pituitary gland to release a hormone called Adrenal Corticotropic hormone (ACTH). The adrenal glands are in turn stimulated to release Glucocorticoids, which are circulating hormones. Cortisol levels are most commonly measured in mammals, and corticosterone in birds. Again, these measurements can be made by looking at levels in the blood, urine, faeces, saliva and milk or an animal, identifying situations that cause negative stress responses. It is important to limit the stress on an animal when collecting these measurements though, as you want to minimise stress levels that could influence the measurements.
However, we cannot rely only on one measure to tell us everything we need to know about the animal and its feelings, and behavioural measurements should be taken alongside these physiological measures for more accurate representation. Cross validating these two methods are critical to build a better understanding of what animals are actively experiencing and assess situations using the best evidence.
BEHAVIOURAL MEASUREMENTS
The most obvious animal responses to challenges in their life are behavioural. This can be very useful because it allows scientists to have a non-invasive way for measuring welfare. However, it can also lead to problems because it is too accessible and therefore easy for us to interpret what we see as if this were the same as human responses. This is called anthropomorphism. Being anthropomorphic can become an issue when ascribing human qualities to animals because it can lead to misinterpretation of what is really going on for that animal.
Scientists have developed a variety of more objective methods for measuring animal behaviour from simply recording what they observe in a standardised way, to more elaborate psychological tests designed to ‘ask’ animals how they feel about their life experiences. Examples of these methods include behavioural observations using ethograms – a detailed list of all natural and stereotypic behaviours we might observe. But do these sorts of studies provide us with enough information about the animal’s needs? One of the limitations with just using observation method is that it only tells us what animals do in different environments, and how often they exhibit certain behaviours, without helping us to understand what these mean to the animal?
Without digging deeper all we know is that the behaviour is different depending on environment and different environments will provide different behavioural opportunities. If we are to be able to make accurate assessments about animal welfare, we need to explore much further into an animal’s mind.
Animal based measures involve giving the animals the opportunity to make choices that enable us to work out what they prefer and actively avoid. The idea behind choice or preference tests is that animals are faced with a choice between different situations or resources, and we monitor which the animal chooses more frequently or stays with/in for longer. The assumption is that an animal will actively approach and stay with things they desire and will actively avoid choices that are undesirable or unpleasant.
Aversion tests are used to work out what an animals find unpleasant once it has had experience of different types of handling or management. Their choices and behavioural responses during these tests are measured and used to infer how they may feel about their previous experiences based on what they actively choose.
Examples of these tests include giving livestock the option of how they choose to be handled or how long it takes them to be moved into an environment they’ve experienced more negative experiences. In a study on done on sheep, by Professor Jeff Rushen and his colleagues, they discovered that the sheep were more likely to become stressed and take longer to walk through a passageway if they had previously experienced shearing on the other side. Sheep who had never experienced this before or had only been handled prior were less likely to take as much time to walk through the passageway and remained calm in demeanour.
Choice testing has also been explored on other types of animal preference, including with laying hens to see which aspects of their caged housing systems they preferred. This has in turn led to the development of modified cages with perches and laying boxes, as well as dust baths as it was clear the hens would pick these aspects of their environment, given the choice.
The issue with choice testing is that animals are still limited in what they can choose, as it’s dependant on what we, as humans, provide them with. We still can’t measure if not being provided with their preferable options results in an animal suffering. The only thing we can guarantee is that the responses of animals will vary according to developmental experiences, environmental factors, and internal factors.
This is where motivational testing comes in, and this refers to if an animal is willing to ‘pay’ for access to certain choices and aspects of its environment. Animals can learn to operate certain devices or complete tasks in order to access parts of their enclosure or gain a resource. The work an animal is willing to dedicate towards a resource they wish to acquire is measured in various ways and allows researchers to determine what is important to the animals involved. This can then be used by organisations, facilities, and policy makers to help them include resources and environments animals have been proven to favour, even though it’s required them to actively work for it.
Scientists have been able to understand better how strongly animals feel about given situations through the various methods developed for measuring their behavioural responses to different experimental testing protocols. Along with the information gained from measures made of the animal’s physiological responses, it can provide us with a more holistic view of the way animals view the world and their situations.
ANIMALS EMOTIONS
Animal emotions and feelings have recently become a hot topic because we are starting to realise that they should be considered when we discuss welfare. How does an animal feel about its situation? How can we prove this? This could be considered the most important aspect of measuring welfare.
Scientists have begun to understand how an animal’s sentience makes them capable of feeling both positive and negative feelings, such as pain and fear, as well as happiness and pleasure. They have needs and feelings of their own, and if these are not satisfied, animals are likely to suffer.
Professor John Webster once said, “it’s not what we think or say that matters - it’s what we do.”
Professor Francoise Wemelsfelder, an animal behaviour and welfare scientist, has been studying more subjective means of measuring animal welfare through animal emotional and behavioural states, proving that there is evidence-based correlation between the descriptions of what animal care specialists believe their animals are experiencing and more objective measures of welfare, such as cortisol levels.
She uses an approach called qualitative behaviour assessments, which focuses on how an animal dynamically moves around its environment, their expressive qualities, and body language. This gives scientists and people working with animals information about an animal’s perceptive of its environment, it’s effective state, and in turn welfare.
Animal handlers, pet owners, zookeepers, farmers, veterinarians, and anyone working closely with animals use qualitative descriptors to try and understand how their animals are feeling on a daily basis. Animals can appear to show their emotional states through their behaviour – if they are relaxed and friendly, tense, curious and lively, hesitant and anxious, and lethargic etc. Francoise’s work is aiming to scientifically validate this approach through developing methodology to accurately measure these qualitative expressions, without it being classified as anthropomorphism.
When asked, people usually agree on what they observe in their animals and are able to repeat species specific observations, also correlating well to other physiological and behavioural scientific measures. This has led to innovative studies of animal facial expression, and the development of pain scoring systems called grimace scales. This is based on the idea that animals will show characteristic changes in ear, nose, whisker and eye shape and movements, that can be related to different painful experiences.
The next challenge for scientists is to develop practical methods for assessing positive emotions, such as happiness, which is currently being studied by researchers with horses in New Zealand.
CONCLUSION
Animal welfare is complex and challenging, and at times can be a difficult and distressing topic to manage. There is still so much work that needs to be done in order to fully understand every aspect of animal welfare and ensure high standards are being enforced globally, in all industries.
For me and many others, it is one of the most rewarding areas to study and work in; being able to provide both direct and indirect evidence of what good welfare means to animals. It is the job of everyone who works with animals to improve and ensure a high quality of life experience. Not just for the benefit of animals everywhere but for our own benefit as well.
Written by Sophie Pogmore (12/12/2024)
References:
· Coursera. (2023). How Do We Assess Animal Welfare? - What We Can Measure We Can Manage | Coursera. [online] Available at: https://www.coursera.org/learn/animal-welfare/lecture/kS0Cg/how-do-we-assess-animal-welfare [Accessed 12 Dec. 2024].
· Coursera. (2023). Using An Animal’s Behaviour to Assess Welfare - What We Can Measure We Can Manage | Coursera. [online] Available at: https://www.coursera.org/learn/animal-welfare/lecture/GTzQo/using-an-animals-behaviour-to-assess-welfare [Accessed 12 Dec. 2024].
· Coursera. (2023). Physiological Measures of Animal Welfare - What We Can Measure We Can Manage | Coursera. [online] Available at: https://www.coursera.org/learn/animal-welfare/lecture/HcfY9/physiological-measures-of-animal-welfare [Accessed 12 Dec. 2024].
· Fraser, D. (2009). Understanding animal welfare: the science in its cultural context. Oxford; Ames, Iowa: Wiley-Blackwell.
· Mellor et al (2009) The Sciences of Animal Welfare, published by the Universities Federation for Animal Welfare. Available at: https://www.ufaw.org.uk/ufaw-wiley-blackwell-animal-welfare-series/the-sciences-of-animal-welfare.
· Wemelsfelder, P.F. (n.d.). New Developments In Animal Welfare. [online] Available at: https://www.coursera.org/learn/animal-welfare/lecture/m0cFL/new-developments-in-animal-welfare [Accessed Dec. 2024].
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