Science-based management of livestock welfare in intensive systems: looking to the future.

As welfare is a multidimensional concept, its assessment should be a multidisciplinary process, providing a comprehensive assessment of animal welfare in any given system. The different measurable aspects of welfare may be turned into welfare indicators and assessed in a scientific manner. Assessment of welfare may combine different approaches that include the assessment of the production system and measurement of animal-based welfare indicators. With both approaches, however, risk managers face difficulties related to the availability of resources for implementing regulations and training staff. Most animal-based welfare indicators have the advantage that they can be measured whatever the production system; they relate to the animal's experience of its own state. It is essential to confirm the reliability of the measures and their robustness to ensure valid welfare assessment, especially for a science-based management approach. Many welfare indicators, even those measured at the individual level, are expressed at group level, as a proportion of the animals. This allows benchmarking and following of trends over time. The decision on what is or is not acceptable from a welfare point of view is an ethical or managerial one. The advantage of a graded welfare indicator is that it allows different thresholds to be set by different people, countries or organisations, depending on the purpose of the assessment. The development of a set of harmonised international welfare indicators for global trade is also discussed.