This is a book concerned with a strategic area of science. All topics on animal production and comparative physiology are very important to aid in the better understanding of areas related to pet companionship, health sciences and food production. Nowadays, humanity is facing breakthroughs in new technologies, genetics and environmental challenges. This book is an attempt at fulfilling the need for information about the scientific and, most importantly, applied aspects of animal reproduction. Considering the importance of many species that need assisted reproductive technologies, the authors covered the most studied models, including cattle, horses, sheep and others. The authors also exposed the main biotechnologies used in animal assisted reproduction, discussing their indications according to each species to which they are applicable. This book covers topics such as the reproductive physiology of males and females; production of embryo (in vivo and in vitro); cryopreservation of embryos; artificial insemination; control of estrous cycle; hormonal treatments; semen analysis; reproductive ultrasonography; in vitro culture of ovarian follicles; animal cloning; advances on biotechnology of small ruminants; epigenetics in animal reproduction; equine reproduction and ovum pick-up. Over twenty leading scientists from several universities and countries have contributed research to create the first single-source reference on reproductive techniques. It is hoped that this book will be convenient to all categories of people dedicated to animal reproduction, whether they are undergraduate and graduate students, teachers, scientists or practitioners.