This publication describes the roles of smallholder farmers and pastoralists in the development, use and conservation of animal genetic resources and of wild biodiversity and cultural landscapes. It highlights the fact that as well as supplying many products and services directly used by humans, livestock often play important roles in the provision of agro-ecosystem services. The creation of mosaic landscapes and wildlife habitats, seed dispersal, fire prevention and nutrient cycling are among the contributions described. The importance of livestock-keeping communities in the creation and development of livestock breeds is outlined, with emphasis being given to social breeding mechanisms, indigenous knowledge, traditional breeding institutions and livestock keepers' breeding goals, breeding management and experimentation. The future prospects for livestock keepers as custodians of livestock diversity are reviewed by considering the reasons why livestock keepers give up their breeds and, conversely, the motivations and incentives that promote ongoing use. Finally, attention is given to means by which the participation of small-scale livestock keepers in the implementation of the Global Plan of Action for Animal Genetic Resources can be improved.