This text presents an overview of the basic aspects of protein metabolism and integration of these concepts with production responses. It is based on the main themes presented at the VIIIth International Symposium on Protein Metabolism and Nutrition, held in Aberdeen, Scotland, September 1999. Topics encompass mechanisms of protein turnover at the cellular level; the control of protein metabolism in individual tissues/organs; the co-ordination of inter-organ metabolism and the influence of protein metabolism on other processes such as appetite regulation and the immune system. Written by international authorities, this book contains both a summary of work on protein metabolism and future projections for research into the next millennium.