Figure 1.

The Five Domains Model (modified from [12]): The examples provided for the physical/functional Domains 1 to 3, labelled “Nutrition”, “Environment” and “Health”, are intended to direct attention towards mainly internal survival-related factors, and those provided for Domain 4, labelled “Behaviour”, focus attention largely on external situation-related factors. For each of Domains 1 to 4, examples of negative and positive factors are provided and are aligned with inferred negative or positive affective experiences, assigned to Domain 5, labelled “Mental State”. The overall affective experience in the mental domain equates to the welfare status of the animals, as explained in the text. Note that an animal exercises “agency” (Domain 4: “Behaviour”) when it engages in voluntary, self-generated and goal-directed behaviours [44,45].