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Executive Summary Livestock animals meet a variety of human needs. They are important sources of transport, draft power, fiber, hides, fertil- izer, fuel, and nutritional protein in the form of meat, milk, eggs, and processed products, such as cheese. More than half of all protein consumed by humans comes from livestock and fish, which are a more complete source of essential amino acids than are plants. As nations struggle to improve nutrition and to feed their growing populations, demands for the food, fiber, and other products derived from livestock will increase. As with crop plants, the purpose of livestock genetic resource management is to maintain a reservoir of potentially useful genetic variation culled from the multitude of livestock breeds and varieties within species. Even though there is little danger that the major domestic animal species, such as Bos Taurus (cattle) or Callus domesticus (chickens), will become extinct, genes from preserved livestock germplasm can be used for developing new types and breeds, adapting existing types and breeds to new conditions, or meeting changing consumer preferences or production requirements. The application of the science of genetics in this century to breed- ing and improvement has substantially increased agricultural pro- duction, but it could have deleterious effects in the future. Basic to developing new and more productive animals with better nutritional qualities has been the availability of diverse breeding populations that possess genes useful for livestock improvement. As new breeds develop and spread, however, they may displace indigenous breed 1
2 / Livestock ing populations. Furthermore, as the efficiency of selection within commercial breeds increases, the capacity within a breed for genetic change could become limited. Preserving society's capacity to im- prove and develop modern livestock requires that actions are taken to prevent the loss of potentially valuable genetic resources. Because future needs cannot be reliably predicted, a broad array of genetic diversity must be conserved. T\X!O VIEWS ON LIVESTOCK CONSERVATION - Although a consensus within the livestock community exists on the need to develop national and international efforts to preserve and manage livestock genetic resources, the approaches to conservation differ widely. They hinge on differences in opinion about the impor- tance of traditional livestock breeds, including indigenous breeds, for long-term genetic improvement programs. In general terms, these approaches can be divided into two broad categories: utilization and preservation. The utilizationist's primary concern is the immediate usefulness of available genetic resources to improve livestock populations. De- scendants of animals with documentable, unique biological charac- teristics are to be maintained for future use. The loss of breeds as distinct identities is not generally a concern, as long as the genes that make these breeds potentially useful are retained in commercial stocks. The preservationist's primary objective is long-term conservation of genetic resources for future use. This view emphasizes the value of preserving the widest possible spectrum of genetic diversity to be prepared for unpredictable changes or future needs. The greatest possible number of breeds are to be preserved as purebreds. Differences between the preservationist and utilizationist views largely pertain to perspective and emphasis, but they strongly influ- ence the practices that are favored for managing genetic resources. The committee bases its conclusions and recommendations on the common goal held by proponents of both views the goal of sus- tained improvement of livestock for use by an expanding global popu- lation. Setting national or global priorities for sustained livestock improvement will depend on a variety of factors, including available funding and technical expertise, national and international needs, and genetic similarity among available breeds and populations. How- ever, the committee believes that at a minimum, conservation should focus on breeds that are (1) of potential economic value, or (2) are both endangered and represent types with unique biological charac- teristics.
Executive Summary / 3 What scientists have come to understand thus far about livestock is impressive. This basic knowledge has been swiftly carried forward by application. With such rapid advances in science and application, it is imperative that policymakers and researchers seize the opportu- nity now to put into place priorities for the improved preservation and management of livestock genetic resources. GENETIC DIVERSITY OF LIVESTOCK Genetic diversity within a livestock species is reflected in the range of types and breeds that exist and in the variation present within each. Examples of types include milk or beef cattle, milk, meat, or wool sheep, and layer hens or broiler chickens. In dairy cattle, examples of breeds include Holstein-Friesian, Jersey, and the Swedish Red-and-White. For growth and maternal traits in cattle, Cundiff et al. (1986) has shown that differences among breeds substantially exceed those within breeds. This conclusion can probably be extended to other traits and species, and it suggests that genetic variation among breeds is a ma- jor component of the readily accessible livestock diversity. Thus losses of unique types and breeds compromise access to their unique genes and gene combinations. For example, in sheep raised for meat, intensification of produc- tion in the early 1970s led to a desire to increase lambing rates in commercial stock. Selection within existing North American breeds could increase the lambing rate by perhaps .02 lambs per ewe annu- ally. Thus achievement of 0.50 in lambs per year (from 1.50 to 2.00 lambs/ewe/year) would have taken 25 years. Yet through utilization of the prolific Finnish Landrace, a breed that was, at the time, little more than a novel indigenous type of Northern Europe with a mean lambing rate in excess of 2.5, a single generation of crossing to cur- rent commercial breeds led to a ewe with a lambing rate of about 2.0. This example illustrates the point that within-breed selection can lead to great genetic change, but only over a long period of intense selec- tion. The presence of a breed with the desired characteristics already in place and with the controlling genes already at high frequency greatly enhances the efficiency of the improvement process. At times, however, within-breed selection will be required to go beyond the limits of existing breeds. The genetic variation within commercial stocks is the ultimate raw material that allows continued improvements or, if necessary, redirection of selection to achieve new results. The recombination and concentration of favorable genes within major commercial stocks under intensive selection have allowed de
4 / Livestock velopment of animals with productive capacities that greatly exceed those of their ancestors. Likewise, the store of genetic diversity within commercial breeds has permitted relatively prompt responses to changes in societal demands. The change from the relatively fat pigs of the 1950s to the extremely lean pigs of today was achieved largely through within-breed selection. Historically, the preservation of genetic diversity within commer- cial breeds has not been an issue. Accurate identification of superior individuals and their intensive propagation have justifiably received much greater emphasis in order to increase production (more milk from a cow, for example). It can be argued that if genetic diversity were declining, the selection of stocks for commercially desired traits would be less productive for developing improved breeds. However, a decreasing rate of response to selection cannot be documented. Yet technological advances in animal breeding and reproductive control have the potential to change this situation. Embryo transfer and cloning, molecular aids to selection, and greater control of reproduc- tive processes can produce rapid and considerable increases in both the accuracy of selection and in the ability to propagate selected indi- viduals. Through the use of follicle maturation techniques, in vitro fertilization, and embryo cloning, a pair of parents could produce hundreds, or even thousands, of progeny. Given this prospect, con- sideration of the maintenance of genetic diversity must become part of livestock improvement programs. Origins of Traditional Breeds Hoofed animals, specifically cattle, goats, pigs, and sheep, first began to be domesticated about 11,000 years ago. They quickly be- came essential to the establishment and spread of agriculture. A wide array of subpopulations evolved through adaptation to differ- ent environments, as humans migrated, over several thousand years and through breeding efforts during the past 200 years. These sub- populations are generally recognized as breeds, that is, groups of individuals that are similar in their appearance and characteristics. Their genetic diversity has been shaped by the need to adapt to tem- perature extremes, humidity, variations in quality and availability of feed supplies, diseases and parasites, and other factors that are re- gionally and globally divergent. They represent easily recognizable genetic resources that can serve as a convenient and reliable source of genes associated with particular physiological or morphological characteristics. For example, Criollo cattle in South America are descended from Iberian stock brought to the Americas during the 1500s. Over the
Executive Summary / 5 past 500 years they have developed traits, through natural selection, that enable them to live on poor nutritional levels and to withstand climatic extremes. Genetic diversity has allowed for their survival, and they are now a source of genes that may contribute to adapting other breeds for production in comparable environments around the world. One of the challenges in conserving genetic resources is to pre- vent excessive losses of unique, adapted breeds. They need to be maintained, and their potential contribution to future commercial stocks should be carefully assessed. Displacement of Traditional Breeds The traditional indigenous breeds, particularly in developing coun- tries, are generally considered to be at greatest risk of genetic loss. In the tropics, temperate breeds usually cannot be introduced as pure- bred animals without also introducing high levels of feeding, special management, investments, and risks. Small farmers often cannot af- ford the cost of the high-maintenance breeds that are being intro- duced. However, these breeds are commonly crossbred with local animals to combine adaptation and disease resistance with higher production. Although the traditional indigenous breeds are needed initially to produce crossbreeds, and perhaps over the longer term to create a stable self-perpetuating subpopulation, their critical role in maintaining self-perpetuating breeding programs is often not recog- nized. Farmers may be reluctant to keep the indigenous breeds if they are less profitable than crossbreeds. As a result, indigenous breeds lose their genetic identity or disappear. Although the extent and usefulness of genetic variation among most traditional breeds have not yet been fully characterized, the differentiation clearly reflects a wealth of genetic diversity within the species diversity that permits further selection and improvement. In particular, these populations hold genetic combinations that may prove valuable in meeting future environmental, production, or mar- keting conditions. In many temperate regions, a number of local breeds have al- ready been replaced by high-performance and more economically vi- able breeds. For example, in Great Britain, the English Longhorn was the dominant cattle breed during the nineteenth century. It was prized for its size and fat, because draft work and tallow for candles were the important products of the time. Beginning only about 200 years ago, when the horse became the preferred draft animal, the enclosure of common land made controlled breeding possible (Mason, 1984~. Cattle feeding practices also im
6 / Livestock proved (Mason, 1984~. By the turn of the century, selection for milk and beef production became paramount and the Longhorn's position gave way to the Shorthorn, a dual-purpose, milk and beef breed. By the mid-twentieth century, the Holstein-Friesian, a specialized dairy breed, was on the rise in the United Kingdom, and large continental breeds, such as the Charolais, were being used as sire lines for beef production. The flexibility to change genotype relatively quickly to meet changing market requirements results from the genetic varia- tion between breeds. This same flexibility will likely be required under future, unforeseen production conditions. The Impact of Technology Recent biotechnological advances can further alter genetic struc- ture and limit the diversity of livestock species. Cryopreservation of semen and embryos (storage typically in liquid nitrogen at a tempera- ture of -196°C) is now feasible for many livestock species. Germplasm can be stored indefinitely and shipped worldwide. Health concerns, traditionally a barrier to international transport of livestock, may soon be resolved by special handling techniques for embryos that provide better control against the spread of pathogenic organisms. The inter- national transport of germplasm can be expected to increase. Con- currently, technology advances for storing and transporting semen and embryos have allowed the trend toward widespread use of germ- plasm from a small number of individuals, which could cause overall genetic diversity to decline. Regardless of geographic location, when production and market- ing systems become more uniform or when the influx of foreign germplasm of one breed is allowed to dominate the population, the danger of narrowing the genetic base of livestock species exists. The application of new technology for germplasm propagation and dis- semination may contribute to the erosion of diversity. Unique germplasm is threatened by replacement of breeds with more productive or popular stocks, dilution of breeds through crossbreeding programs, and de- creased diversity within highly selected breeds or lines that have a small number of breeding individuals. The committee believes that it is now time, scientifically and socially, to address these concerns in the design of programs for livestock improvement. LIVESTOCK PRODUCTION SYSTEMS Production and management systems for domestic livestock can be broadly classified as either intensive or extensive. Intensive sys
Executive Summary / 7 A_ A_ _ _ _ A young female commune worker in the People's Republic of China collects eggs from chickens kept in cages, a common intensive production approach used for poultry. Credit: Dean Conger, O1992 National Geographic Society. tems were developed in the latter half of the twentieth century and involve high levels of inputs, such as supplemental feed and disease prevention efforts, and require more capital investment, such as housing construction and equipment. Chickens, for example, are now com- monly raised in confined, environmentally controlled housing with sophisticated disease control programs. This type of system is more frequently found in developed countries, which have the capital to invest, plentiful grain supplies for animal feed, and supportive tech- nologies such as veterinary care and modern production facilities. The stocks of chickens, dairy cattle, pigs, and turkeys that now predominate in developed countries have been selected for high pro- duction under intensive management and optimal environmental con- ditions. The genetic base of these specialized stocks may become more narrow because of intensification of selection and smaller effec- tive population sizes (the number of reproducing individuals in a population). Examples of specialized stocks are Leghorn chickens, which are superior for egg production, and the familiar black and white Holstein-Friesian cattle, which dominate other dairy cattle breeds because of higher milk production. The term extensive describes the more traditional systems used to raise livestock. Fewer purchased inputs, such as high-quality feed or
8 / Livestock pharmaceuticals, are provided. For ruminants, this approach involves maintaining animals, such as cattle, goats, and sheep, under range conditions. Backyard poultry and swine production is another ex- ample of extensive systems. Nutritional supplementation and veteri- nary care are minimal or nonexistent. In extensive systems, animals are generally less protected from a variety of environmental and nutritional stresses, and they can be- come adapted to local conditions over long periods of time (several generations). The N'Dama cattle of West Africa, for example, are genetically tolerant of the effects of trypanosome infection and, thus, can survive in an area that is inhospitable to susceptible breeds. In Africa, about 30 percent of the 147 million cattle in countries inhab- ited by the tsetse fly, which transmits trypanosomiasis, are exposed to the disease. The disease can cause poor growth, weight loss, low milk yield, reduced capacity for work, infertility, abortion, and early death. Annual losses in the value of meat production alone are esti- mated at $5 billion. Additional costs come from losses in milk yields, tractive power, waste products that provide natural fuel and fertil- izer, and secondary products, such as hides (International Laboratory for Research on Animal Diseases, 1991~. Animals in extensive production systems, like this flock of sheep in Tunisia, usually forage and water on open pasture. Credit: Food and Agriculture Organization of the United Nations.
Executive Summary / 9 WHY CONSERVE THE GENETIC DIVERSITY OF LIVESTOCK? Extinction is not a concern for the major domestic species, which benefit from society's protective custody. Large total population sizes are maintained to ensure adequate product supplies, and the species' basic needs are usually met. Total population sizes are generally in the hundreds of millions, even though the effective population size may be much smaller. The compelling need for conserving domestic species is to pre- vent the loss of the many differentiated populations that, because of geographic or reproductive isolation, have evolved distinct charac- teristics and now occupy different environmental niches. A further need exists to guard against depleting diversity due to current breed- ing technologies, worldwide movement of germplasm, the prolifera- tion of highly selected industrialized breeds, and commercial stocks founded on a relatively small number of breeding individuals. The range of genetic diversity in livestock species must be saved as a foundation for future improvements and adjustments to changing production conditions. Because the ultimate effects of diminished genetic diversity are hard to estimate, given the unpredictability of future needs, the con- servation of livestock genetic diversity can best be considered as a form of insurance. Preserved stocks will possess potential economic, scientific, and sociocultural benefits. Economic Benefits Genetic variation provides the foundation to continue improve- ments in production efficiency and to accommodate, relatively rap- idly, unpredicted changes in the methods for producing animals and marketing their products, or in the demand for animal products. An example of the need to respond to changing demands is seen in the pork industry where several decades ago animals that possessed large amounts of fat for lard were desired. With the advent of consumer concerns about animal fats, and the ready availability of vegetable shortenings, the demand for lard declined. Consequently, breeders produced the leaner, meat-producing animals prevalent today. Scientific Benefits Studies of genetic variation and gene variants provide insight into physiological and biochemical functions, gene structure and con- trol, and evolutionary processes in animals. Miniature pigs (a geno- type commonly used in studies of growth, obesity, and diabetes) il
10 / Livestock lustrate the use of a domestic stock to further scientific investiga- tions. Such studies are beneficial to both animal and human health. Sociocultural Benefits Genetic diversity may be of social or cultural value. Some animals are used for recreation, and animal breed exhibits and fairs are attrac- tions for many people. Genuine cultural benefits can be realized through the use of animals to visually chart important historical developments- certain breeds are living evidence of a nation's agricultural heritage. In Hungary and France, for example, traditional indigenous breeds are maintained in national park settings and serve as tourist attractions. Traditional livestock breeds are essential components of living his- torical farms in Europe and North America. In addition, specific livestock breeds characterize the way of life and provide specific products for many villages and regions around the world. TECHNOLOGIES FOR CONSERVING AND USING GERMPLASM Recent technological developments may, in some instances, have a negative impact on genetic diversity by reducing the number of parents required to propagate a population. However, they also open important avenues for expanding the scope and assessing the poten- tial value of conservation efforts. Improved reproductive technolo- gies enhance the feasibility of preserving germplasm through better reproduction rates and disease control. Molecular technologies pro- ~ride more understanding and control at the level of the gene, and should vastly improve opportunities to use preserved stocks. Molecular Technologies New molecular genetic technologies will improve the use of pre- served stocks and aid in assessing genetic distance and variation. For example, individual animals could be selected for breeding and preservation based on specific knowledge of their genotypes. Mo- lecular studies may provide greatly enhanced understanding of the genetic basis of important livestock production traits. These tech- nologies also promise the capacity to move routinely important genes between unrelated animal species. Characterization of Genomes Methods to characterize the genomes of individual animals and the gene pools of breeds are becoming a reality. A variety of tech
Executive Summary / 11 niques is available to quantify genetic variation at the levels of the gene product and of the gene itself. Numerous studies have exam- ined variation in the protein products of the genes, but as molecular technologies become more sophisticated, the focus is shifting to the genes and the DNA (deoxyribonucleic acid) to quantify differences among individuals, breeds, and species. Genetic distances, indexes of the relative genetic differences between two or more breeds, can be estimated. This information can be used to aid decisions regard- ing preservation that are based on the genetic uniqueness of a germ- plasm source. Gene Transfer and Mapping Technologies The expansion of research on the effects of specific genes, and on their transfer between individuals of the same or different species, has major implications for the potential value of preserved germplasm. It should be possible to screen preserved stocks and, if desired, to extract and use a beneficial gene or genes that may be located in an otherwise undesirable background. For example, the International Livestock Center for Africa, in Ethiopia, and the International Labo- ratory for Research on Animal Diseases, in Kenya, are cooperatively conducting research to identify the genetic basis of tolerance to try- panosome infection. This knowledge (and perhaps the genes them- selves) may expand the tolerance to trypanosomiasis of livestock across breeds and even species. Efforts to map livestock genomes are progressing. Advances in sequencing and mapping techniques that emerge during this effort will enhance, and be enhanced by, identification and use of human genes. Genomic Libraries Today's technology permits the formation of genomic libraries theoretically containing the full set of genes from any given indi- vidual. However, a tremendous amount of research must still be done to identify genes of importance. Regeneration of living animals from DNA stores in genomic libraries is not yet possible, and ge- nomic libraries should only be considered as an adjunct means of germplasm storage at this time. Their potential value as a preserva- tion tool, however, can be likened to a form of insurance. It is antici- pated that methods will improve for isolating and manipulating spe- cific DNA segments.
12 / Livestock Animal Reproduction Technologies Animal reproduction technologies include multiple ovulation, in vitro fertilization, embryo transfer, embryo splitting, cloning, sexing, and cryopreservation. The cryopreservation of gametes and embryos is a well-established technology in livestock production, although suc- cessful application to a wider array of livestock species and to oo- cytes and embryos requires more research and development. Nota- bly, methods to cryopreserve pig embryos have been unreliable. Although widespread use of these technologies can narrow the breeding popu- lation and thereby have negative impacts on genetic diversity, these technologies can also, if properly used, become tools for support of genetic resource management. An important development in embryo research has been the use of hormones that induce multiple ovulations in a donor female and lead to a greater number of embryos. This capacity is especially important in species that normally produce only one offspring per pregnancy. Further, embryos can be cloned to produce genetically identical animals, providing much greater flexibility in distribution and research efforts. One of the main limitations to the movement and use of genetic resources has been concern about the health status of the germplasm. If, in the course of importing livestock, exotic diseases are inadver- tently introduced into a region, the effects on indigenous stocks could be devastating. Most nations have not been willing to take the risks involved in importing livestock. However, methods for the screen- ing, diagnosis, and control of diseases are improving, and new em- bryo-washing techniques offer promise for eliminating disease agents. The international movement of animal breeding stock as frozen se- men and embryos is thus becoming more feasible. METHODS OF PRESERVING ANIMAL GERMPLASM Three basic approaches can be identified for preserving genetic diversity: maintaining living herds or flocks, cryopreserving gametes or embryos, and establishing genomic libraries. The vast majority of livestock genetic resources will continue to be maintained in living herds and flocks, many of which are privately owned. If the size of the breeding population is sufficiently large and the population is not decreasing in number, directed conservation efforts will not be required. Periodic inventories of animal populations can provide early warnings of any changing patterns in production or use that may alter the diversity within breeds. A major advantage of preserv
Executive Summary /13 ing live herds and flocks is the opportunity for selection, thereby allowing the breed to adapt to shifting environmental conditions. Frozen storage of gametes and embryos offers a cost-effective method to preserve the genetic material of a breed for an indefinite period of time. Collection and freezing of semen is relatively simple and, if samples are collected from a sufficient number of males, allows the preservation of essentially all the genetic variation in a stock. The costs of collection are not excessive, although in remote areas where accessibility to equipment and facilities may be problematic, they can be higher. The cost of maintaining the samples in frozen storage is low. Methods for collecting, handling, and freezing embryos, although more complex than those for semen, also offer efficient means of preservation. Embryo storage has not been used for conservation, in part because of the cost of sampling, but research on collecting and handling oocytes and embryos is advancing rapidly. Cryopreservation can complement efforts to preserve live populations, and it should be used as a safeguard when population numbers are dangerously low or when certain breeds or lines are likely to be replaced with other populations. As noted earlier, genomic libraries are of little use for breed pres- ervation. As technologies develop, however, they may provide an important mechanism not only for conserving diversity, but also for accessing particular genes. Their value will be enhanced with con- tinuing advances in molecular genetics research. Criteria and priorities must be established to identify which ge- netic resources merit conservation. Considerable attention has been given to determining the basis for classifying a breed as endangered, and guidelines for various species are available to aid in evaluating preservation needs (Maijala et al., 1984~. However, the status of each breed must be evaluated on a case-by-case basis. In general, an en- dangered breed is defined as having a small and decreasing number of breeding individuals. Unfortunately, in developing countries, fre- quently little or no information is available on certain breeds, and information cannot be quickly gathered. At times, extemporaneous judgments must be made about which individuals constitute a breed- ing population. Once a decision is made to preserve a breed, a sampling strategy must be developed. Factors such as geographic distribution and popu- lation structure, if known, should be taken into consideration. A stratified system of sampling (that is, identifying breeds and taking samples of unrelated individuals and at random) will in most situa- tions be appropriate. The effective preservation and management of livestock genetic
14 / Livestock resources will require organization and accessibility of basic informa- tion on animal breeds in a data base. Although some descriptive and analytic information exists for many livestock breeds, it still may be insufficient for making management decisions. Studies to inventory, characterize, and compare livestock populations are badly needed, particularly in developing countries. The cataloging of information so it can be readily retrieved will be critical. Information accruing from research on gene mapping, gene transfer, and related technolo- gies must also be cataloged in an accessible format. EFFORTS TO IMPLEMENT LIVESTOCK CONSERVATION The issues surrounding the conservation of animal genetic re- sources have been discussed and debated for more than 30 years. Conclusions generally have been similar: · Diversity in livestock breeds is increasingly at risk, · Valid reasons exist to conserve diversity, and · Organized preservation and management activities are highly desirable. Nevertheless, active programs to inventory and preserve genetic diversity are the exception rather than the rule. This situation ap- pears to be changing as more developed and several developing countries implement preservation and management programs for animal ge- netic resources. The lead on discussions of genetic resource management has largely been taken by the Food and Agriculture Organization (FAO) of the United Nations, with support from the United Nations Environment Program (UNEP). The FAO has contributed through its comprehen- sive publications on characterization and management techniques of animal genetic resources. It has also recognized the need for collat- ing information contained in central data bases, and has supported studies to determine how best to establish and organize such data bases. In 1989, the Commission on Plant Genetic Resources of the FAO voted to address conservation of animal genetic resources in addition to plants, thereby demonstrating its recognition of the importance of livestock genetic resources in global agricultural production. In 1992, FAO announced the initiation of a program to conserve and develop the livestock and poultry genetic resources of develop- ing nations (Henson, 1992; Ruane, 1992~. Its five elements are a glo- bal inventory, breed preservation, indigenous breed development and conservation, gene technologies, and a legal and international frame- work. The Global Data Bank for Domestic Livestock, based in Rome, Hi,
Executive Summary / 15 Italy, covers all areas of the world with the exception of Europe, but including the Commonwealth of Independent States (the former So- viet Union). This data base will document arid characterize the dif- ferent populations of domestic livestock. The loss of local minor breeds has been a concern in Europe for many decades. The European Association for Animal Production (EAAP), based in Italy, formed a group to coordinate activities relating to livestock resources of Europe. National conservation programs have been established both in Europe and In several developing countries. The FAO and EAAP have promoted establishment of a regional data base for Europe. The Animal Genetic Data Bank at the Hanover School of Veterinary Medicine in Germany records census data on populations of breeds arid genetic characterization data. The data bank will be valuable to educational institutions, governments, com- mercial interests, and others who are concerned with the conserva- tion of animal genetic resources. RECOMMENDATIONS Livestock genetic diversity is an essential component of livestock improvement programs, especially to meet the future needs of hu- man society. There is a paucity of quantitative evidence to support arguments for He need to conserve livestock genetic resources. However, when examining the use made of landraces in plant improvement in both developed and developing nations, the committee concluded that it is prudent to preserve unique sources of germplasm in ani- mals as well. Ensuring that livestock resources will be preserved and properly used will require expansion and coordination of existing efforts and implementation of new ones. Technologies that emerge from scien- tific research will enhance the present capacities to preserve and use animal genetic diversity. Ultimately, conservation of livestock ge- netic resources will require cooperation at the national and global levels. The following are the committee's major recommendations for addressing the management and use of livestock genetic resources. Additional recommendations and further detail are presented in the main text. Expanded Programs ant! Activities Mechanisms must be put in place to ensure that genetic diversity of the major livestock species is maintained to support improvements in produc- tion efficiency and to Accommodate future changes in selection goals.
16 / Livestock The issues surrounding the need to conserve livestock resources have been discussed for many years in a variety of forums. For example, FAO forums have provided a wealth of guidelines for es- tablishing programs, and the FAO and UNEP have worked together to supply training and to organize regional meetings on animal ge- netic resources. Additional activities have been ongoing in Africa, Asia, Europe, and Latin America. All of these efforts recognize the urgent need to integrate conservation and livestock improvement ef- forts. If action is not taken soon, potentially valuable livestock ge- netic resources could be lost. Documentation of Breeds Increased efforts are needed to inventory and characterize unique and endangered populations and breeds, particularly in developing countries. Decisions about needs and priorities in livestock conservation pro- grams must be based on knowledge of the animal populations. For populations found in developing regions, the need for documenta- tion is particularly acute, because industrialization and the importa- tion of improved breeds can threaten indigenous breeds. An essen- tial component of this process is establishing national and international data bases that maintain information in a readily accessible form. The Animal Genetic Data Bank at the Hanover School of Veterinary Medicine and FAO's world inventory of native livestock breeds and strains constitute a good beginning, but much greater effort is needed to collect information, particularly from developing countries. Increased Cooperation aged. Private efforts to preserve animals in breeding herds should be encour Private farm parks, such as those associated with the Rare Breeds Survival Trust in England, have proved successful in preserving se- lected rare or historic breeds. In some cases, governments have sub- sidized or otherwise assisted farmers who elected to maintain ani- mals of particular breeds. In Canada, for example, farmers in the Province of Quebec are paid for rearing purebred Canadienne cattle. Cooperation also could take the form of exchanging information about the breeds preserved or of providing technical assistance on breeding programs to control inbreeding or ensure breed purity. Although the many herds and flocks held by private individuals and groups may not originally have been assembled for conservation
Executive Summary / 17 motives, these populations can supplement public activities. The ef- forts of these groups enable a broader diversity of breeds and popu- lations to be preserved than would otherwise be possible with na- tional resources that are frequently limited. Responsible private efforts to preserve livestock germplasm should be encouraged and offered public support. Research and Technology Development Research on technologies that could benefit preservation and use of animal genetic resources should be continued and expanded. Research in new technologies, such as genome mapping and gene transfer, is moving at a rapid pace. Future breakthroughs are likely to have significant effects on the efficiency of animal production and on the ability and need to preserve germplasm. Major research ef- forts are under way on the human genome, and complementary work is progressing on the genomes of cattle, pigs, and sheep. Preliminary results suggest that much of the genomic information from one spe- cies will be applicable to others. To maximize the efficiency of basic and applied research, geneticists working in different areas and on different species must take the initiative to cooperate and share infor- mation. A number of research areas have potential to enhance the preservation, management, and use of animal genetic resources. Cryopreservation as a Supplement to Breeding Populations The preservation and management of endangered and unique popula- tions as breeding herds orflocks should be supplemented by cryopreservation of their germplasm. Cryopreservation of semen and embryos complements preserva- tion of live populations and provides a safeguard when population numbers are dangerously low or when breeds or lines are likely to be replaced or lost. It offers the potential to store large numbers of genotypes for indefinite periods of time. In general, the costs of collecting and processing samples for cryopreservation are not exces- sive for domestic animals, particularly in regard to semen. At present, semen from the major livestock species can be cryopreserved, but the process is only reliable enough to be routine and commercial for species such as cattle and, increasingly, sheep. For pigs, goats, horses, and poultry, cryopreservation methods, al- though available, need further refinement. The effectiveness of cryopreservation for preserving species and breeds of minor live
18 / Livestock stock is less well established. With semen storage, it is not possible to derive purebreeding stock from stored germplasm unless suitable female recipients are available. However, the most common future use of cryopreserved germplasm is expected to involve crosses with commercial populations to introduce new genetic traits and develop new breeds. Frozen semen is ideal for such use. Mouse embryos were reported to be successfully cryopreserved, thawed, and implanted in 1972. Since then, the procedures have become routine in several mammalian species, including cattle, sheep, rabbits, and mice. Notably, efforts to cryopreserve pig embryos have been unsuccessful. Cryopreservation of male and female embryos preserves the entire genome of a breed and is particularly appropri- ate when regeneration of purebred animals is desired. National Initiatives National programs for preserving, managing, and using livestock ge- netic resources must be established in developed and developing countries and suited to different needs. Before global efforts can be effective, conservation of animal ge- netic resources must be a national initiative. Given the substantial differences in needs and appropriate approaches in individual coun- tries, the organization of national conservation programs will vary widely. It is important that private and public interests within each country cooperate in developing a strategy to ensure an effective, coordinated national program. The support of a strong network of national programs is essential to the success of international conser- vation efforts. Mechanisms for providing bilateral and multilateral support to enable developing nations to preserve, manage, and use their livestock genetic re- sources must be developed. Multilateral and bilateral aid programs will be required in many cases to help establish national preservation and utilization efforts in developing countries. Technical expertise from the developed coun- tries should also be readily available. Conservation of genetic diver- sity is a global concern, and given the greater threat to uncharacterized, unimproved livestock populations in developing countries, support from conservation programs by developed nations is essential. Ulti- mately, livestock production and improvement programs of both de- veloped and developing countries will benefit from international support and assistance and from enhanced international movement of germplasm resources.
Executive Summary / 19 A Global Organization A global mechanism should be established to provide leadership and support to nations to ensure the adequate conservation of livestock genetic resources. International leadership is needed to coordinate and facilitate na- tional and regional efforts, and to foster cooperation among national efforts. An organization with leadership responsibilities could as- semble experienced specialists to develop priorities and guidelines for global cooperation. This organization must have the confidence of financial donors in its ability to succeed, scientific capability, ad- ministrative expertise, and a consultative mechanism. The committee examined three potential options for achieving the necessary global leadership and coordination: · Establishing an institute within the Consultative Group on In- ternational Agricultural Research (CGIAR); · Expanding the efforts of the FAO; and · Expanding support to an existing institution, such as the World Conservation Union (IUCN), formerly the International Union for Conservation of Nature and Natural Resources. Organizing a new program within the CGIAR or expanding the existing International Board for Plant Genetic Resources (IBPGR) would require new financial resources and considerable study. The FAO's work in this area spans more than 4 decades, and it has an experi- enced administration in place that could manage a conservation pro- gram. However, it has certain limitations. For example, although FAO has a clear mandate to fully develop many of the actions recom- mended by its advisory panels, its funding is inadequate. Most conservation-related organizations are not structured to deal with agricultural germplasm preservation. Some reorientation of pro- grams, funding, philosophy, and purpose may be required. An orga- nization that might undertake responsibility for animal genetic re- sources is IUCN, which has been involved in conservation activities for more than 40 years. It has experience in developing data bases for supporting conservation activities with wildlife, monitoring natu- ral areas, and fostering international cooperation for conservation (Office of Technology Assessment, 1987~. Expansion of its mandate would be needed to include livestock genetic resources, and philosophical conflicts between the needs of agriculture and the organization's en- vironmental priorities are likely. Given the need to establish global leadership in guiding, coordi- nating, promoting, and instituting animal genetic resource conserva
20 / Livestock lion efforts, the committee considers the FAO to be an appropriate institution for these efforts. However, FAO should call on the exper- tise of other national and international institutions to achieve its goals. In conclusion, a broad base of genetic diversity in domestic ani- mal species must be maintained to provide flexibility to improve livestock for today's production conditions and to meet unforeseen future pro- cluction requirements. Technological advances in identifying and propa- gating superior types may allow for substantial losses in genetic di- versity. These situations suggest that designers of livestock improvement programs must begin conscientiously to consider their potential im- pact on genetic diversity.
