This book is the first in a set of four providing a series on controlled reproduction in farm animals. The aim of the series is to provide a general review of the literature dealing with the different ways in which reproduction in the major farm mammals can be controlled and manipulated. The four volumes are effectively an expanded and new edition of a previous work, Controlled Breeding in Farm Animals (Pergamon Press, 1983). However, the literature on this subject has expanded so rapidly since the time of the earlier volume, that it is now thought appropriate to published it in four separate volumes. Buffaloes, goats, deer and camelids have been added to the species covered by the series compared to the previous book. All volumes provide comprehensive reference lists and are fully up-to-date. This first volume focuses on cattle and buffaloes. It will appeal to reproductive physiologists and workers in animal production, animal breeding and veterinary medicine.