The final chapter of the first edition of this book reviewed briefly the current situation and aims of yak keeping. It considered the impact of research on yak production and attempted to suggest gaps in knowledge. It ended, perhaps rashly, with thoughts about the future.
A similar approach seems appropriate here but with the need to add some thoughts on how the situation appears to have changed in the eight-year interval since the first edition was published by FAO.
Clearly, what has not changed are the principal territories with their harsh and demanding climate and environment where yak are still of great importance to the livelihood of the people and the economy of the region. What has also not yet changed to a major extent is the generally nomadic system of exploiting the vast rangelands of "the roof of the world" and the mountainous territories of western China and adjacent countries. Changes are, however, in the process of taking place. Over important parts of the yak territories of China, the policy of "Household Responsibility" has now moved on from the individual ownership of the animals to individual responsibility for land through a system of land allocation to families. The move towards settlement in place of a mainly nomadic lifestyle has progressed further. Thus, a traditional system of yak-keeping and rangeland utilization that had not altered fundamentally perhaps in centuries is now in the process of change (see Chapter 13 dealing with the management of the ecosystem and Chapter 12 for the social implications).
These changes are likely to have far-reaching consequences for yak production and for a way of life. Settlement of families, fencing of land, more roads and greater access to markets inevitably steer a subsistence animal husbandry towards a market driven one where the products from yak may need to compete with animal products from elsewhere. The enhanced opportunities of herders to purchase goods they want, require in turn a need to sell the products from yak rather than retain them largely for home consumption. Monetary costs and returns from yak production and concepts of cost-effectiveness of different methods of production - as well as the idea of efficiency of production - could well become more important considerations for yak keeping in the future. Thus, a change in the economics of yak-keeping may bring a consequent change in objectives and in the concepts of what constitutes "improvement" as far as the yak is concerned.
However, there are other factors that may not only put a brake on a headlong dash into a purely market-oriented future for yak production but should also be made part of any process of change. It was pointed out more than once in the first edition of this book that yak-keeping in the past has not been just an economic activity, but that it has been inextricably linked with the culture, religion, social customs and life experience of the people. This is still true now. Hence any technological changes, based on scientific knowledge, should be integrated with, rather than imposed upon, the traditions and experiences of the herdsmen. The fuller attention given to these matters in Chapter 12 makes it unnecessary to elaborate this point further.
It is as well to be aware that tensions can arise between those who advocate husbandry practices based on traditional experience and the scientists, technologists and legislators who may sometimes be impatient to advance new practices based on a better understanding of physiology, nutritional biochemistry and genetic principles.
The authors and editors of this book belong, of course, to the tribe of the scientists. This does not mean that they hold uncritically to the view that science and technology should be the main, less still the only, driving force or consideration for change in yak husbandry practices. That would be foolish and counter-productive. Every change interacts with many other components of the yak production system and the interactions are among the least studied of the factors. Technological changes also impinge on the social fabric of the people who keep yak for their living. But what each of the authors and not least the late Professor Cai Li whose name is perpetuated in this book would claim is that knowledge itself is of fundamental importance. It is the basis for the understanding of the complex system that is yak production and hence for the opportunities to improve the living standards of the people who depend on yak. The contribution to knowledge and understanding of yak and yak keeping remains the sole purpose of this book.
What is needed is mutual understanding and dialogue. But part of that dialogue should also be recognition that it is easy to romanticize a traditional "way of life" and its cohabitation with raw nature - especially when sitting snugly in a town dwelling (or conference chamber!). Ultimately, it is for the herders and their families alone to decide whether to retain their way of life and the traditions and practices that support it. If alternatives were available, would they wish to escape from the undoubted harshness and periodic cruelty of nature, which is part of the life of these regions and abandon their system of yak keeping - and perhaps even life in these regions. Might yak ranching become an alternative to relatively small-scale yak keeping, with a change of emphasis from milk products to meat? Would less dramatic changes, with improvements in output from the present system and amelioration of its harshest features, meet the aspirations of yak herders and their families and of the younger generation in particular? Answers to questions such as these will determine the role and direction that science and technology can or should play in yak husbandry and range management.
In the study of yak and the yak environment there has been one notable change over the past decade or so. It is symbolized by the passing of Professor Cai Li who dedicated his life to the study of yak to the exclusion of almost everything else. He was one of a small group of notable men in China, the former Soviet Union and some of the other "yak" countries who were recognized as the unchallenged "experts" in their field.
The number from that generation has declined with the passage of time and in its place has grown up a new, young generation of scientists who may be better trained in their own, more specialized subjects, but who are, inevitably, less by way of all-rounders, or "yak experts" - though a few would still claim that honour. It remains to be seen whether the new generation of scholars is, by virtue of specialization, less in tune with the needs of the people, the herders and their families, whom their studies, experiments and surveys are ultimately intended to serve. The integration of new knowledge with tradition and practical needs may therefore have become just that bit more difficult.
Yak numbers are still increasing in China where most of the world's yak are kept; but of great interest in the context of yak numbers is the recent evidence of a reduction in the size of the yak population in Qinghai, until recently the foremost of the yak-keeping provinces. The speculation is (see Chapter 11, part 1) that this reduction is in response to overgrazing and a loss of herds during natural snow disasters. It underlines the fact that the rangelands on which yak, sheep, goats and wild animals depend are a finite resource and, as documented in Chapter 13, rangeland degradation is an increasingly serious problem. More mouths and less feed is a recipe for problems and potential disasters. From a technological point of view, it seems that the most pressing need is to bridge this deficit - whatever the size of herds or the allocation of land resources. There are a number of different ways of achieving this end. Selective reductions in stock numbers may appear obvious, but represents a difficult choice when animal numbers are still widely regarded as signs of status and wealth for the families owning them and as insurance against exceptional losses. Changes in grazing management are made both easier and more difficult, at the same time, by the subdivision and fencing of rangeland intended also to accommodate social and political aims. The use of supplementary feed, especially over late winter and early spring, is equally obvious in theory, but the provision of such feed on the scale required is still an unsolved problem although new plant varieties and opportunities for limited cropping hold out good prospects. Changes in the plant communities of the grazing lands and the introduction of legumes and limited areas of sown swards still seem far off - but the work of the plant breeders is of importance here.
In countries other than China but with the probable exception of Mongolia, yak numbers have continued to decline, and changes in patterns of yak keeping are noted. Different reasons are attributed for these trends, some of which were discussed in the first edition of this book. In some areas, these reasons include the provision of alternative employment, for example from tourism. In other areas, market forces and the attractions of a less demanding lifestyle have driven changes. For example, breeding hybrid stock for sale to other herders, rather than keeping yak directly for the sale of milk, has been a consequence of the development of the cheese factories in Nepal. These factories have greatly increased the demand for milk in their vicinity and have provided those with herds distant from the factories with the opportunity for a new enterprise of breeding stock for sale to the milk producers - an enterprise which is not as demanding of time and attention as direct milk production. In some countries, yak production has always been more peripheral and lacking the mutual support which is provided when entire communities, and the neighbours of those communities, all share a similar lifestyle engaged in the business of yak production - as over the vast areas of the Qinghai-Tibetan Plateau. Following the break-up of the Soviet Union and the establishment of independent republics, the decline in the yak population in these countries has been attributed to social and economic problems during the transitional period into new political and economic frameworks. Whether there will be a recovery in yak numbers as economic and social balance is achieved remains to be seen.
The thoughts here will focus on nutrition, breeding (genetics), reproduction and the interactions in the production system.
Over the past decade there has been a significant increase in research on nutritional biochemistry and physiology in relation to the yak and in the development of potential supplementary feeding regimes to overcome, or at least to lessen, the problems of late winter and early spring starvation in yak. Much of this work is reviewed in Chapter 14. At the same time, a more fundamental understanding has arisen, as a result of investigational work and plant trials, into the management and potential improvement - or at least the conservation - of the grazing lands. This work is discussed in some detail in Chapter 13. Clearly, these various investigations have led to a significant advance in the body of knowledge. Subject to finding economically viable strategies for application of this new knowledge into practice, this work is a cause for optimism.
In terms of breeding and reproduction of the yak, the success of research and development in providing a potentially significant advance over traditional practice is still in question. As pointed out in Chapter 3, the interest in crosses of domestic yak with wild yak has taken a step forward (since this matter was noted in the first edition of this book) with the development, at the Datong Yak Farm, of a "new breed" that is based on this crossbred (see Chapter 2). The extent of the recording of pedigrees and performance undertaken for purposes of selection in the development of this new breed is highly commendable and provides a good example for other breeding schemes to follow. Though the jury is still out on the ultimate performance and uptake of this new breed.
In terms of new genetic studies, as shown in Chapter 15, studies of yak DNA, mostly mitochondrial DNA, are being undertaken by several groups. This work is providing new evidence of relationships - or distances - between different types of yak and other bovines and thus provides some help in setting priorities as to which populations of yak should be conserved among those at risk. This work is, however, still a long way from providing associations with performance traits of yak, through the identification of quantitative trait loci (QTL). In fact, the value of the molecular genetics as an aid to "improving" yak is hampered by the absence of any widespread recording of performance, whether in relation to growth, milk production, reproduction, fibre production or disease. Whether the corresponding work on other cattle in different parts of the world will provide pointers for yak has still to be verified.
The DNA work does, however, provide some potential information, at least in theory, for the avoidance of inbreeding - a subject now more widely accepted to be of practical relevance by yak academics and, by all accounts by herders, than it was formerly. But the brief treatise on inbreeding in Chapter 3 is still appropriate, as the harm done by inbreeding to animal performance is substantial, and avoidance measures are relatively simple to apply (without the need for DNA typing!).
The big unknowns in yak breeding are still, as they were ten years ago, the absence of information on 1) the extent of differences in performance among the various yak breeds and 2) the extent to which heterosis might arise from crossing of breeds (as, for example, in crossing domestic yak with wild yak) and in the production of hybrids.
There are certainly claims that some breeds are better, in some respects, than others, and a few limited comparisons support this view. However, the main problem is still that, in general, different breeds are found in different localities often very far apart. In nearly all cases, the breed type is therefore confounded with the environment in which the breed is kept. It is not enough for this purpose to claim that all yak environments are similar. There is sufficient local variation in climate, management and grazing patterns to make a comparison of the performance of breeds across areas invalid. Even for the same breed, published estimates of performance can vary from each other in different studies, as the estimates may relate to different conditions (not only different times) under which the animals were observed - and the precise conditions are not always specified. In general, therefore, it is safest to regard records of performance as guidelines only or as "orders of magnitude".
In order to estimate hybrid vigour (heterosis), a potential but not universal benefit from crossing breeds, strict genetic principles have to be applied, as discussed in Chapter 7. However, the conditions for applying these principles are difficult to meet in practice, and accordingly, even the claims for hybrid vigour in crosses of domestic and wild yak have to be regarded very cautiously. Similar problems arise, as also discussed in Chapter 7, over claims for hybrid vigour from hybrids of yak with other cattle. The necessary contemporary comparisons of the parental breeds and the hybrids are rare (and would occur at best only when local cattle are involved and never with high-producing exotic cattle breeds). Only a couple of instances have been found in the literature where valid comparisons are claimed for estimating the extent of heterosis. Thus in respect of the results from hybridization, the extent of hybrid vigour also remains in question.
The best that can be said is that crosses (wild yak crossed with domestic) are to some extent better than the contemporary domestic yak with which they are compared - and for practical purposes that may be good enough reason to use the crosses or any new breed developed for them. And in respect of hybrids, questions of heterosis apart, there is clearly a useful place for them in some environments and yak production systems where they are a supplement to, but not a replacement for, pure yak. In relation to fundamental knowledge, there is still a large gap to be filled to discover the genetic components of differences between breeds and of the effects of crossbreeding and hybridization - knowledge that when obtained can lead to improved design of breeding schemes.
Still in relation to genetics, it is of interest to note that there continues to be a virtual absence for yak of estimates of heritability of performance traits, genetic correlations among traits, economic values, construction of selection indices and the rest. These have been the stocks-in-trade in the application of quantitative genetics to animal breeding in most parts of the world for well over half a century. As the chapter on Molecular Genetics (Chapter 15) illustrates, the genetics of yak has taken a straight leap from the nineteenth to the twenty-first century, leaving out all that has transformed the livestock of most other species in most countries into high-producing stock. The absence of this information for yak is almost entirely due to the absence of records of performance and of parentage on any significant scale. Clearly the application of such information, even if it were available, would have obstacles to overcome in the yak territories that are unheard of, for example, in the realm of Holstein dairy cows.
Studies on yak reproduction appear to have advanced relatively little, and there still appears to be a preoccupation with the improvement of A.I. techniques. How widely A.I. might be successfully applied in practice and turn out to be cost-effective are still open questions. The use of A.I. in remote areas and the need to time inseminations fairly precisely face massive obstacles at present. From the point of view of genetic improvement, an assurance that the A.I. bulls are in fact genetically better than the females for which they are the mates is a prerequisite for a worthwhile use of A.I. As already said, because of the absence of widespread performance recording the necessary information for this purpose is not generally available or adequate. To set up a performance-recording scheme in order to sustain genetic selection of potential AI bulls would be expensive and in present circumstances perhaps not cost effective - but market forces may change.
In the production of hybrids, particularly through the use of "improved" breeds of cattle mated to yak, A.I. provides the main method of creating the hybrids. And to this end, the continuing studies of insemination procedures and the attempts to induce and synchronize oestrus are welcome.
For the majority of yak herders, however, hybrid animals can at best provide only an adjunct to their herds and not the mainstay of production. Although some argue differently, the view here is still that hybrid production is only a partial answer to increased output from yak-producing areas. The main thrust to increased production, if it is economically desirable, must come from improving the pure yak itself and the feed supply, in part through improved grazing management.
The importance of the feed supply is given support by the performance of yak in North America. Although the population of domestic yak in North America is small (around 2 000 animals) by Chinese standards, they are distributed in relatively small herds over a fairly wide area. The performance information from them, and the reproductive pattern of these yak in particular, shows that most, perhaps all, of the reputation of the yak as reproductively poor in its native areas is due to environment and is not a genetic feature. Although, as noted in Chapter 11, part 3, a proportion of the North American yak show mitochondrial cattle DNA (which has passed through the maternal line but could have been introduced many generations back) this fact is unlikely to account for the differences in reproductive performance or growth rate. The fact is that yak in North America are fed over winter and spring and suffer none of the weight loss of yak in their traditional environment. The yak females respond by growing well, breeding at a relatively young age and thereafter annually. No need for complex physiological explanations here.
In the first edition of this book, the concluding chapter promoted the idea that one of the gaps in yak research and development was the absence of a systems approach. In the light of what has been written in this book and the new chapters that have been added to it, it should be apparent that in yak production there are a host of interacting factors. This is true at the level of a trait (the example was given previously of meat production, which is the end result and interrelationship of several contributory traits). However, interaction is also a highly relevant concept to the production system as a whole where biology interacts with social, cultural and economic forces. We know of no studies in yak that embrace the systems approach - but the resources needed are perhaps too great to make this a realistic expectation, especially as replication would be demanded for different regions and different breeds and environments.
Crystal gazing is neither science nor art. Often-times it is practised to deceive. So, why tempt fate (again) by trying to look into the future?
One reason is the strong feeling that yak are, in many respects, a unique genetic resource with an amazing ability to survive, reproduce and provide marketable products under incredibly harsh conditions and with sparse, poor quality feed for long periods. These are attributes to be cherished. Over-production of human food in some parts of the world (more than matched by the human food deficit in others) and of animal produce in particular, makes it unlikely that those with money to invest will populate remote cold and mountainous areas with yak or yak hybrids - though that was the original concept for the projects in Canada and Alaska in the early part of the twentieth century (see Chapter 11, part 3). Today, parts of Northern Canada and Alaska, parts of the Andes, Greenland and further extensions into Siberia are all areas that must spring to mind as underexploited and where the yak or yak hybrids could play a role. Perhaps in a more rational world the day may yet come when meat production from otherwise barren areas will find favour and make economic sense.
Interestingly, the recent proposal put forward by Jack Rutledge (personal communication, 2002), referred to in Chapter 3, extends this idea to milk production from hybrids of yak and cattle for those harsh environments where there are currently no equally good alternative livestock. The proposal, as outlined in Chapter 3, involves the use of relatively new, technology-based procedures to produce the hybrids from a large potential pool of the cattle eggs. Such ideas could well lead to a future extension of some of the adaptive characteristics of the yak to hostile environments, without the more traditional need for importing the pure-bred animals.
Coming back to the present, it is important to ensure that the yak genotype is conserved (perhaps in several forms if the DNA work so suggests) and that the wild yak in particular is not endangered further. This is not just a matter of sentiment but a sound biological need to conserve genetic resources - and especially where, as in the case of the yak, there is good reason to believe there are special, perhaps unique, genes involved.
Changes in yak production systems are on the speculative list of prospects. If indeed social change were to bring about a degree of rural depopulation, as in many rural parts of the world, then the vast rangelands of the Qinghai-Tibetan Plateau and beyond would still be potentially the home for yak. However, with fewer people to tend them, a change to a more ranching-style production system with meat as the principal product (and perhaps fibre) may be foreseen. Large herds managed by few people would call for something different from the traditional systems - and an edition of this book in the more distant future might then have to mourn the passing of a way of life. It is fortunate that this edition of the book is free of that burden.
 Honorary Professor,
Gansu Agricultural University, China; Centre for Tropical Veterinary Medicine,
University of Edinburgh and Roslin Institute, Edinburgh, UK.Deputy director of
former Agricultural and Food Research Council's Animal Breeding Research