Since the third edition was published in 1992 there have been many more developments in the poultry industry, which have made a new edition necessary. These include new systems which are environmentally and welfare 'friendly'; much more emphasis on hygiene and vaccines in disease control and the role of molecular biology and cloning; further advances in management with special reference to feeding, drinking, lighting and egg collection; advances in genetics; developments in housing; nutritional advances; and increasingly restrictive legislation concerning the safety to the public of poultry products (particularly zoonotic diseases and drug residues) and welfare.

Dr David Sainsbury is a veterinarian that was formerly lectured in Animal Health at the University of Cambridge. He is well known and respected by the poultry industry as a writer, lectured and adviser, and has traveled extensively as a specialist adviser throughout the world, including USA, Russia, Scandinavia, Germany, Italy, South Africa, Angola, Iran, Cyprus, Iraq, Greece, Holland, Belgium, and France. He is also examiner in Animal Health at the several universities, and in a number of overseas countries.