This book recounts the history and achievements of research at the International Livestock Research Institute (ILRI), including work at its predecessors the International Livestock Centre for Africa (ILCA; 1974-1994) and the International Laboratory for Research on Animal Diseases (ILRAD; 1974-1994). The scientific and economic impacts of tropical livestock research reveal valuable lessons, in this work charting the research of these three institutions. Describing mixed crop and livestock systems' impact on the global environment, it also covers animal genetics, production, health and disease control, land management, public policy, and economics. Providing global estimates of the impact of livestock research and with useful pointers for future research, this book provides an important reference for animal scientists and veterinarians working in the global south.