In developed and developing countries livestock are very important contributors to total agricultural output. Many breeds of different species have become either extinct or nearly so. With the spread of more advanced agricultural systems to many parts of the world, specialized strains of livestock, from a greatly reduced number of breeds within a species, have been bred for specific, but widely different, environmental conditions. This has led to a dilemma in the context of the balance to be effected between conservation of the present variety of genetic resources on the one hand and the need to concentrate increasingly on a narrow range of genotypes in the interests of improved efficiency on the other hand. The paper addresses this dilemma and discusses the FAO-instigated global programme—Animal Genetic Resources — which was designed to monitor changes in animal genetic resources on a global scale with the development of legal and regulatory instruments where necessary.