The first edition of this book, published in 1991, was based on a conference. However, this second edition consists of specially commissioned chapters to provide a more comprehensive and balanced review of the subject. Two additional editors, Stephen Bishop from the world-famous Roslin Institute, and Frank Nicholas, author of a widely respected textbook on veterinary genetics, have been brought in, as have several new contributors. As the subject of breeding for disease resistance rather than controlling diseases using expensive chemicals continues to be topical, this book will attract wide interest. The book gives full coverage of important areas of development, by those leading the field.