igs in Pain – Causes, Mechanisms and Possibilities for Future Development

Despite a long history of debate about negative affective states in animals, it was only in the last decades of the 20^th century, that the state of pain was mentioned in definitions of animal welfare, included in veterinary education, and became target of scientific interest. Pain is a perceptional phenomenon built from information gathered by specialized sensory receptors for tissue damage and integrated into a discrete experience with a negative emotional valence in the brain. Based on knowledge about porcine neuroanatomy, physiology and studies focusing on pig behaviour and pathology, we review evidence for causes of pain in pigs, underlying biological mechanisms as well as the possibility to quantify different types of indicators of pain states relevant to the welfare of the animals under production conditions. The presentation will primarily focus on pigs because of the dual purpose of this species as a meat producing as well as research animal species (the latter driven by the anatomical and physiological homologies with humans) making pigs unique among livestock. We will present methodologies and results from current research projects across Europe and North-America targeting typical industry-related injuries (e.g. tail docking, lameness and shoulder lesions) and aiming to understand the welfare consequences for the pigs.Throughout the talk the emphasis will be put on future opportunities to link research outcomes with industry initiatives towards the improvement of animal welfare and production. In addition, possible future research efforts to help face current methodological limitations and favor a more comprehensive evaluation of animal pain as an overall experience will be discussed. This seeks to facilitate common future targeted research and enable us to overcome the paradoxical low level of knowledge about porcine pain and its alleviation under production conditions.