The most obvious animal responses to challenges in their life are behavioral. This can be very useful because it allows scientists to have a non-invasive way for measuring welfare. But it can also lead to problems because it's 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, and it's a problem because ascribing human qualities to animals can lead to misinterpretation of what is really going on for that animal. For example, many people believe their pets can feel guilty because they react as a human would if they were caught doing something they shouldn't be. And some people believe their animals know what they're thinking. In reality there really is no evidence that animals think and react as we do. And since they have their own species specific responses, it is far better if we do not impose our beliefs and feelings on them. We must strive to try to understand the world from their perspective. Scientists have developed a variety of more objective methods for measuring animal behavior from simply recording what they observe in a standardized way, to more elaborate psychological tests designed to ask animals about how they feel about their life experiences. A relatively simple approach used in animal welfare assessment is to watch the animals in their home environment, and then make a list of the behaviors that they perform. This behavioral list called an ethogram provides a detailed description of each behavior. Building an ethogram ensures that the distinctive appearance of each behavior when performed can be easily recognized by any person observing that species. By standardizing the list of behaviors we're interested in observing, we can be sure that they're clearly described, and can be accurately recorded in a way that can be repeated by anyone in future studies. Behaviors listed in the ethogram can then be observed, and the number of times and how long the animal performs them can be recorded during a set period. And this behavioral record can be compared across treatments or environments. Using this methodology, researchers have been able to measure differences in the frequencies of specific activities in animals in different living conditions. For example, we know that horses spend around 16 hours a day moving around and grazing, when they're kept out in a paddock, as compared with a fraction of that time when kept in more restricted stables or stalls. Observations of animals in natural environments can provide us with a lot of good information about key behaviors different species perform when provided with the right environmental stimulation. Around 30 years ago, here in the hills south of Edinburgh, the late Professor David Wood-Gush and his students released domesticated white pigs into a natural reserve, where they lived and bred for a number of years. Through intensive field observations, Professor Wood-Gush was able to convince the pig industry of the essential behaviors pigs needed to perform, such as rooting using their sensitive snouts, and being able to build nests for sleeping in, and for giving birth. It's hard to believe that most pig producers then had only ever seen pigs being kept inside. And the pictures of sows carrying grass to build nests gave them an insight into the secret life of pigs and the fact that they had lost none of their important species specific behavior as a result of domestication. But do these sorts of studies provide us with enough information about the animals' needs? One of the limitations with just using the observation method is that it only tells us what animals do in different environments without helping us to understand what these mean to the animal. Without digging deeper, all we know is that the behavior is different, depending on environment, and different environments will provide different behavioral opportunities. If we are to be able to make accurate assessments about animal welfare, we need to go much further into the 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 what they actively avoid. The idea behind choice or preference test is simple, when faced with a choice between two or more situations or resources, which one will an animal move towards most frequently,or spend the most time with. The assumption behind the test is that the animals will actively approach and stay with things they want or like, and will avoid those things they find unpleasant or undesirable. The choice testing approach can be used for looking at what animals actively avoid. Aversion tests are used to work out what an animal finds unpleasant, once it has had experience of two different types of handling or management. Animals will be placed in a start box and then released, so they can move down a race or a passageway, to where a specific type of handling or treatment was carried out previously. Their behavioral responses as they move along the passageway are measured and used to infer how they might be feeling about their previous experiences. A nice example of this approach is in some work carried out by Professor Jeff Rushen and his colleagues in Canada, who measured how much time was needed to push or drive sheep along a passageway to where they had previously experienced shearing. They then compared this with the time needed to push or drive those sheep after they had experienced nothing, or had just been restrained. As can be seen here, sheep were far more reluctant to go back towards a place where shearing had been experienced, and this was measurable. Choice testing has been used to explore many examples of animal preferences. It has been used extensively for examining the choices made by hens in relation to aspects of the caged housing systems where hens laying eggs are intensively managed. For example, researchers have looked at whether hens will choose to be in a pen or a run with bedding, or one with a concrete or bare floor. In addition, researchers have investigated where the hens prefer to have a nesting box for laying their eggs, or an open cage with a wire floor. It was research such as this that led to the development of modified caging with perches and laying boxes as well as dust baths since it was clear that hens, when given the chance to choose, would pick these as preferred parts of their environment. However, this is only part of the story. Since although hens and other animals will make choices, they are limited by the options that are offered by the experimenter. We really do not know whether these are exactly what the animal wants, nor whether the animal suffers if it cannot have the preferred option. And we know that the animals responses will vary according to developmental experiences, environmental factors such as temperature, and internal factors such as age, sex or even in hens, whether an egg needs to be laid. This is where motivational testing comes in. The consumer demand approach to assessing animal welfare was derived from economic studies where human motivation for different resources is used to help understand how willing a person is to pay for a particular commodity. In studies of animal welfare, animals are placed in an enclosure where there is some sort of device they need to learn to operate to be able to make active choices. Willingness to pay is assessed through setting the animal tasks that will require certain set of behaviors or a behavior response to be carried out in order to get a resource. The work the animal is prepared to do to acquire resource is measured in various ways. For example, hens have been trained to push through swing doors that are weighted so that if the hen wants to get to resources such as more space, a dust bath, or a nest box, it has to push through increasingly heavy weights, to get to them. In other studies, the animal is trained that it has to push a panel with its nose multiple times to get what it wants. The weight pushed through, or the number of panel pushes is described as the price the animal is willing to pay to buy access to the commodity. These studies have allowed researchers to determine what is really important to animals, enabling them to provide robust information that can be used by policy makers, animal industries and animal organizations. The various methods developed for measuring animal behavioral responses to different experimental testing protocols, have enabled scientists to move much closer to being able to understand how strongly an animal feels about a given situation. And this information, along with that gained from measures made of the animal's physiological responses, can provide a much, much more holistic view of the world from the animal's point of view.
