Animal sentience and animal welfare: What is it to them and what is it to us?

This special issue contains 14 papers addressing the nature of animal sentience and suffering as experienced by the animals themselves and how practitioners in the field can incorporate this understanding to ensure the proper treatment of animals. The simplest definition of animal sentience is "feelings that matter". Therefore sentient animals are those that experience emotions associated with pleasure and suffering and are motivated to promote their evolutionary fitness, not as part of a well-planned, long-term strategy to ensure the well-being of future generations, but through the simpler, but no less intense, need to feel good about themselves. Most of the papers in this issue are comprehensive, fully referenced scientific reviews. However, it also includes a number of short. The papers in this special issue may be categorized under four headings. Section 1 addresses the nature of sentience. Section 2 deals with the study of sentience. Section 3 deals with cognition, communication and higher emotions and presents convincing evidence to illustrate that advanced features of cognition and affect (or emotion) are not unique to humans but widely shared within the animal kingdom. The fourth and last section is on the respect of sentience in farm and working animals, consisting of two comprehensive reviews and two short communications that consider how our scientific understanding of animal sentience may be incorporated into the practice of good animal husbandry.