If the aim of a welfare assessment is to describe the welfare on-farm, not only here and now but for a longer time period, then the measures to be used have to be chosen with this in mind. It is by choosing relevant but common indicators that the assessment is representative of the farm over time. There are two types of animal welfare protocols, those that require the farms to comply with a set of criteria and those that attempt to assess the welfare of the animals on the farm. The advantage of the first approach is that it is transparent and easy to understand, the advantage of the second that it is more flexible and can give a better understanding of what is happening on the farm.