This overview analyses the key drivers of change in the global livestock sector and assesses how they are influencing current trends and future prospects in the world's diverse livestock production systems and market chains; and what are their consequent impacts on the management of animal genetic resources for food and agriculture. The trends are occurring in both developing and industrialized countries, but the responses are different. In the developing world, the trends are affecting the ability of livestock to contribute to improving livelihoods and reducing poverty as well as the use of natural resources. In the industrialized world, the narrowing animal genetic resource base in industrial livestock production systems raises the need to maintain a broader range of animal genetic resources to be able to deal with future uncertainties, such as climate change and zoonotic diseases.

This chapter discusses:

• What are the global drivers of change for livestock systems? Economic development and globalization; changing market demands and the “livestock revolution”; environmental impacts including climate change; and science and technology trends.

• How are the livestock production systems responding to the global drivers of change? Trends in the three main livestock production systems (industrial, crop-livestock and pastoral systems); the range and rate of changes occurring in different systems and how these affect animal genetic resources. The implications are that breeds cannot adapt in time to meet new circumstances. Hence new strategies and interventions are necessary to improve the management of animal genetic resources in situations where these genetic resources are most at risk.

• What are the implications for animal genetic resources diversity and for future prospects of their use? - Industrial livestock production systems are expected to have a limited demand for biodiversity, while crop-livestock and pastoral systems will rely on biodiversity to produce genotypes of improved productivity under changing environmental and socio-economic conditions. All systems will rely on biodiversity, albeit to varying degrees, to cope with expected climate change.

• What immediate steps are possible to improve animal genetic resources characterization, use and conservation? Appropriate institutional and policy frameworks are required to improve animal genetic resources management and these issues are being addressed at national and intergovernmental levels, in a process led by FAO to promote greater international collaboration on animal genetic resources. Based on an analysis of the current situation, the continuing loss of indigenous breeds and new developments in science and technology, there are several complementary actions that can begin to improve the management of animal genetic resources and maintain future options in an uncertain world.

These are summarized here as:

a. “Keep it on the hoof” - Encouraging the continuing sustainable use of traditional breeds and in situ conservation by providing market-driven incentives, public policy and This paper has benefited from inputs from several reviewers and other contributors, and we thank all for their thoughtful insights. We acknowledge the contributions of our colleagues at FAO, particularly Irene Hoffmann, Dafydd Pilling and Henning Steinfeld, and at the International Livestock Research Institute (ILRI): Ade Freeman, Mario Herrero, Olivier Hanotte, Steve Kemp, Sandy McClintock, Sara McClintock, Margaret MacDonald-Levy, Susan MacMillan, Grace Ndungu, An Notenbaert, Mwai Okeyo and Robin Reid. other support to enable livestock keepers to maintain genetic diversity in their livestock populations.

b. “Move it or lose it” - Enabling access to and the safe movement of animal genetic resources within and between countries, regions and continents is a key factor in use, development and conservation of animal genetic resources globally.

c. “Match breeds to environments” - Understanding the match between livestock populations, breeds and genes with the physical, biological and economic landscape. This “landscape livestock genomics” approach offers the means to predict the genotypes most appropriate to a given environment and, in the longer term, to understand the genetic basis of adaptation of the genotype to the environment.

d. “Put some in the bank” — New technologies make ex situ, in vitro conservation of animal genetic resources feasible for critical situations and are a way to provide long-term insurance against future shocks.

The multiple values, functions and consequences of livestock production systems and their rapid rate of change lead to divergent interests within and between countries. Conversely, the uncertainty about the implications of rapid, multifaceted global change for each livestock production system and the resulting future changes in the required genetic make-up of animal genetic resources make collective action to tackle conservation of animal genetic resources a long-term, global public good. Conserving animal genetic resources will not by itself solve these problems, but it is an important first step towards maintaining future options.

Advances in science and the technology, in areas such as reproductive technology, genomics and spatial analysis, as well as progress in conceptualization of global public good production for the future management of animal genetic resources, should enable the international community to address both the short- and long-term challenges in innovative ways.

Inventory of species and breeds, their population sizes, geographic distribution and possibly their genetic diversity is generally undertaken as a first step in any national programme for the management of animal genetic resources for food and agriculture. The primary purpose of such an assessment is to document the current state of knowledge in terms of a population's ability to survive, reproduce, produce and provide services to farmers. Starting an inventory requires some knowledge of the inventory items and their characteristic attributes. Inventory and characterization are, therefore, complementary processes, in which the characterization step provides the baseline information as well as the criteria that will be used to establish and update the inventory. Characterization provides data on present and potential future uses of the animal genetic resources under consideration, and establishes their current state as distinct breed populations and their risk status. As use and management of animal genetic resources are dynamic processes, monitoring the status of a population has to be done on a regular basis. Thus, risk status indicators for use during the monitoring process need to be defined following the inventory and characterization steps.

This paper discusses methods and criteria currently available, from research and past experience, for inventory, characterization and monitoring of animal genetic resources, with the view to assist in the development of a more comprehensive framework. Particular consideration is given to emerging tools and technologies. The scope of the review includes all livestock species and their wild ancestors and wild related species. Examples focus on cattle, sheep, goats, pigs and chickens.

Sustainable use of animal genetic resources for agriculture and food production is proposed as the best strategy for maintaining their diversity. Achievement of sustainable use would continue to support livelihoods and minimize the long-term risk for survival of animal populations. The concept of sustainable use has economic, environmental and socio-cultural dimensions. Sustainable use of animal genetic resources also contributes to food security, rural development, increasing employment opportunities and improving standards of living of keepers of breeds. Supporting the rearing of breeds through better infrastructure, services, animal health care, marketing opportunities and other interventions would make a significant contribution to the sustainable use of animal genetic resources.

Sustainable use envisages the use and improvement of breeds that possess high levels of adaptive fitness to the prevailing environment. It also encompasses the deployment of sound genetic principles for sustainable development of the breeds and the sustainable intensification of the production systems themselves. Sustainable use and genetic improvement rely on access to a wide pool of genetic resources.

Genetic improvement programmes need to be considered in terms of national agriculture and livestock development objectives, suitability to local conditions and livelihood security as well as environmental sustainability. Genetic improvement can involve choice of appropriate breeds, choice of a suitable pure breeding or crossbreeding system and application of within-breed genetic improvement. The choice of appropriate breeds and crossbreeding systems in developed countries has been a major contributor to the large increases in productivity, and has benefited greatly from the fact that developed country animal genetic resources are well characterized and relatively freely exchanged. Where proper steps have been followed by careful assessment of demand, execution, delivery, impact and cost-benefit analyses, successful within-breed improvement has been realized within indigenous populations in developing countries. Breeding objectives and programmes for subsistence oriented and pastoralist systems are likely to be entirely different from conventional programmes. Crossbreeding has been most successful where it is followed by a rigorous selection programme involving livestock owners' participation and substantial public sector investment in the form of technical support. In any genetic improvement programme, inbreeding needs to be monitored and controlled.

Within-breed genetic improvement is normal practice in the developed world, and has become a highly technical enterprise, involving a range of reproduction, recording, computing and genomic technologies. Emerging genomic technologies promise the ability to identify better, use and improve developing world animal genetic resources in the foreseeable future. Useful systems can, however, be established without the need for application of advanced technology or processes.

Livestock production faces major challenges through the coincidence of major drivers of change, some with conflicting directions. These are:

1. An unprecedented global change in demands for traditional livestock products such as meat, milk and eggs.

2. Large changes in the demographic and regional distribution of these demands.

3. The need to reduce poverty in rural communities by providing sustainable livelihoods.

4. The possible emergence of new agricultural outputs such as bio-fuels making a significant impact upon traditional production systems.

5. A growing awareness of the need to reduce the environmental impact of livestock production.

6. The uncertainty in the scale and impact of climate change. This paper explores these challenges from a scientific perspective in the face of the large-scale and selective erosion of our animal genetic resources, and concludes thai there is a stronger and more urgent need than ever before to secure the livestock genetic resources available to humankind through a comprehensive global conservation programme.