Book excerpt: Whilst it can mean enhanced biosecurity, more intensive and globalised pig production (based on a narrowing genetic base) also potentially increases the risk of disease and its spread. It has been estimated that production diseases can lower pig production efficiency by 10-15%, though financial losses can be much greater. The sector must allocate more resources to the creation and development of preventative measures that can be used to tackle the threat of disease. Optimising pig herd health and production provides a comprehensive review of the wealth of research on optimising pig health to prevent the development and consequent spread of diseases that can devastate the industry, such as African Swine Fever (ASF) and Porcine Reproductive and Respiratory Syndrome (PRRS). Chapters in this volume consider the methods used to prevent disease outbreaks, ranging from on-farm strategies, such as managing feed, housing and stocking density to optimise health, to the development and use of vaccines.