Animal welfare.

The concept of animal welfare includes three elements: The animal’s normal biological functioning (which, among other things, means ensuring that the animal is healthy and well-nourished), its emotional state (including the absence of negative emotions, such as pain and chronic fear), and its ability to express certain normal behaviours (Fraser et al., 1997). This notwithstanding, not all behaviours are equally important in terms of animal welfare. From a practical standpoint, the clearest indication that a given behaviour is important is whether the animal shows a stress response or exhibits abnormal behaviour when prevented from performing it. A sow’s prepartum nesting behaviour or the foraging behaviour of pigs are examples of such important behaviours. These three principles do not necessarily contradict one another; indeed, they are often complementary (Mendl, 2001).