The wise management of the world’s agricultural biodiversity is becoming an ever greater challenge for the international community. The livestock sector in particular is undergoing dramatic changes as large-scale production expands in response to surging demand for meat, milk and eggs. A wide portfolio of animal genetic resources is crucial to adapting and developing our agricultural production systems. Climate change and the emergence of new and virulent animal diseases underline the need to retain this adaptive capacity. For hundreds of millions of poor rural households, livestock remain a key asset, often meeting multiple needs, and enabling livelihoods to be built in some of the world’s harshest environments. Livestock production makes a vital contribution to food and livelihood security, and to meeting the United Nations Millennium Development Goals. It will be of increasing significance in the coming decades. And yet, genetic diversity is under threat. The reported rate of breed extinctions is of great concern, but it is even more worrying that unrecorded genetic resources are being lost before their characteristics can be studied and their potential evaluated. Strenuous efforts to understand, prioritize and protect the world’s animal genetic resources for food and agriculture are required. Sustainable patterns of utilization must be established. Traditional livestock keepers – often poor and in marginal environments – have been the stewards of much of our animal genetic diversity. We should not ignore their role or neglect their needs. Equitable arrangements for benefit- sharing are needed, and broad access to genetic resources must be ensured. An agreed international framework for the management of these resources is crucial. This report is the first global assessment of the status and trends of animal genetic resources, and of the state of institutional and technological capacity to manage these resources.