Using behaviour to assess animal welfare
Rather than construct lists of many different welfare indicators and give each of them the same weight, I argue that the assessment of animal welfare should be directed at answering two key questions: 1) Are the animals healthy? 2) Do they have what they want? Behaviour has a major
role in answering both. Behaviour is currently used to help answer the first question through its use in the clinical and pre-clinical assessment of pain, injury and disease, and potentially could have an even greater role, particularly if used in conjunction with new technology. Behaviour
is also of crucial importance in gauging what animals want, most obviously in the use of choice and preference tests, but also through other methods that are particularly suitable for on-farm welfare assessment. These include quantitative observations of the spatial distribution of animals
and of behavioural 'indicators' of what animals want, such as vocalisations.