Chapter 1: Quantifying animal welfare preslaughter using behavioural, physiological and carcass and meat quality measures

Abstract

Animal welfare and stress refer to the subjective experience of the animal, which depends on its emotional and cognitive capacities to evaluate the situation it is in, to know its body state in terms of needs, and the higher-order, conscious, processing of the information. The origin of stress-inducing factors may be psychological, such as fear, or physical, such as food deprivation. In both cases, they influence the emotional status of the animal. Due to its subjective, therefore unmeasurable, character, the assessment of animal welfare is indirect. During the preslaughter period, this assessment relies on the physiological and behavioural stress reactions and environmental context. Physiological reactions are not specific to stress; they allow any adaptive response potentially requiring increased physical activity and vigilance. Combining physiological measurements and behavioural observations in relation to the environmental context allow interpreting these different types of information in terms of stress. Physiological and behavioural reactions further influence meat quality traits, such as post-mortem temperature and pH decline, which influence other traits, such as colour and tenderness, and carcass quality characteristics, such as bruising. Individuals show a degree of consistency in their responses to stress factors. The determination of the animal’s stress reactivity using standardised tests before slaughter facilitates the interpretation of the physiological and behavioural observations made in the slaughter setting. Stress reactivity determined before slaughter may predict stress reactions at slaughter, and future meat quality. Summarising, the assessment of animal welfare and stress involves the interpretation of a range of measurements on the physiology and behaviour of the animal, the environmental context, post-mortem meat and carcass quality traits, and the characteristics of the animal itself, in terms of stress reactivity and rearing and genetic background.