Neurophysiology and assessment of welfare

Concern for animal welfare is a major consideration in meal production and is barred upon the belief that animals can suffer. Welfare may be considered in terms of the subjective experiences of animals; preference testing is often used in this approach. Neurophysiology has provided insight into the biological basis of emotions and into the mechanisms of learning and memory, which are important to interpret the results of preference tests. Welfare may also be defined in terms of the biological functioning of the animals; physiological measures of stress such as plasma levels of glucocorticoids, catecholamines, prolactin and endorphins, as well as heart rate and brain levels of neurotransmitters are then used to assess welfare. Individual differences in the stress response are important in welfare issues. Slaughter poses particular problems and neurophysiology has provided objective criteria to assess the effectiveness of electrical stunning. It is concluded that neurophysiology has made important contributions to assess and improve animal welfare. (C) 1998 Elsevier Science Ltd. All rights reserved.