In this second edition several chapters have been extensively revised or re-written. The introduction develops the theme of the role of animals (especially the dairy cow) in sustained agricultural systems. New material is included on buffer feeding, wholecrop cereals and feeding by-products as straights, along with a complete explanation of the new Metabolisable Protein System adopted as the UK standard in 1992. New problems associated with BST and BSE (bovine spongiform encephalopathy) are explained and a new chapter on breeding critically examines the practice, principles and limits of genetic improvement by multiple ovulation, embryo transfer and cloning. The book ends with a review of future developments in dairy cow husbandry ranging from the use of robotics to allow cows almost complete control of their own environment to the use of intermediate technology to roll back the major constraints on dairy production in the tropics.