Technical papers cover specialised topics under the following themes:
Chairpersons: Ms Camille Richard, Drs Abdul Wahid Jasra and Zhang Degang
Session I addressed a broad range of considerations which impact pastoral production systems in yak rearing areas, including social, economic and environmental factors. Many of the papers recognised that these systems are concerned with more than just livestock production, and stressed the need for a more interdisciplinary approach to pastoral development. Participants emphasised that alternative livelihood strategies need to be considered as a means for improving the living standards of local people.
Socio-economic factors that specifically affect both human and yak demographics were discussed. In some areas, for example, external factors, such as increased government control over land resources in protected areas, and/or alternative livelihood options such as tourism, have caused new constraints on traditional systems resulting in declining human and yak populations in some areas. In other cases, collapsing local economies (e.g. in the Central Asian States) have led to a rise in yak numbers, mainly because yak (intrinsically a multi-purpose animal) are known by local people to provide a solid subsistence base.
Most of the papers illustrated how issues, which impede development in pastoral areas, are often social rather than technical in nature. In fact, technical interventions are usually not adopted unless and until the socio-cultural and economic situation is understood and appreciated. Some papers highlighted the rapid changes in political boundaries and policies that have led to restricted livestock mobility and the marginalisation of pastoral people, pointing out that such changes need to be understood in order to identify realistic strategies for livestock and rangeland development. It was also mentioned that mechanisms need to be considered which will ensure secure tenure, both within and across borders.
Other papers noted how land management policies in general are often not responsive to local conditions in yak rearing areas. One paper described the interactive effects of climate and grazing on alpine pastures, indicating that while livestock are often blamed for declining rangeland productivity, the situation is much more complex. Current policies may not adequately address this fact, however, which highlights the need to develop more appropriate policies based on accurate and up-to-date research. Greater stakeholder involvement (primarily of local herders and farmers) is also needed in the decision-making process.
Congress participants also raised the point that scientists themselves need to listen to herders, and stressed that more effective means of communicating research results to those most directly affected need to be devised. They also noted the need to recognise the aspirations of local people in efforts to maintain the integrity of mobile livestock systems.
Chairpersons: Dr Olivier Hanotte, Mr David Steane and Dr Han Jianlin
Session II focused on the biological factors which affect the conservation and management of yak populations, specifically in terms of their genetic potential and limitations. It was noted that studies addressing yak diversity using protein and DNA markers are now well under way, though unfortunately the usefulness of some of this work has been limited by less than adequate sample sizes and methodologies. There is a clear need for more research on all breeding populations if we are to develop optimal strategies for their management. Classical quantitative genetics will continue to be the major method for any genetic change made in the short to medium term (10–20 years), with molecular genetics complementing rather than replacing these efforts.
Chairpersons: Dr James Robinson, Mr Laurens Wester and Dr Zheng Yucai
This session focused on nutrition and forage management in yak rearing areas. More specifically, issues related to rangeland quality, the nutritive values of both native forages and supplementary feeds, and the importance and role of technology and indigenous knowledge were addressed.
Participants agreed that yak nutrition remains primarily dependent on natural forages in high mountain areas. Because of this, it was stressed that the carrying capacity of these rangelands must not be exceeded. Several papers highlighted the important role that shrubs can play in maintaining yak nutrition, particularly towards the end of summer when other natural feed varieties have been exhausted. Another stressed the fact that yak are fundamentally well adapted to their environment, pointing out that weight loss over the winter is a perfectly natural and acceptable phenomenon. The author questioned the necessity of supplemental feed sources given that most yak survive sufficiently on reserves built up over the summer on natural forage alone.
The practice of reseeding as a means of protecting rangeland resources was also discussed. One author stated that reseeding should be seen as a last resort, and should be considered only after other methods have been explored and tried first. He pointed out that appropriate technology for reseeding degraded rangeland is not available which herders themselves can apply. The technologies currently proposed require large machinery, and thus are out of reach of herders in Qinghai, for example, who often do not even have the money to buy seed. Another participant, noting that in Bangladesh at least, poor people have a high pay back rate, urged that microcredit schemes be considered to facilitate the introduction of appropriate technologies.
The importance of identifying and working with indigenous indicators of rangeland conditions was also mentioned. The person commented that outsiders are more likely to select erroneous indicators of rangeland conditions than are locals, which is why we should begin with indigenous indicators first. Another participant pointed out that science does not necessarily have all the solutions, and again stressed the importance of first learning what communities have been doing for centuries in these areas.
As in earlier sessions, participants also stressed the importance of sharing research results internationally. By way of example, one participant noted that protozoa are being discovered in other parts of the world that can detoxify plant poisons, a discovery which might prove useful for yak production in the future.
Chairpersons: Drs Ed Rege, Michael Goe and Zhao Xinbo
This session covered a broad area of topics related to reproduction, yak breeding and the yak production system, and included reports on yak evaluation studies and the status of yak populations as affected by changing economic and farming environments. Papers related to yak breeding covered phenotypic characterisation and aspects of genetic improvement—both within breed selection and crossbreeding involving different yak breeds, and hybridisation of yak and cattle. Papers on reproduction covered both male and female reproductive performance, including artificial insemination (AI), the effects of freezing and thawing semen, and aspects of semen sexing. A large number of published but not presented abstracts, some of which were referred to during the discussions, complemented the presented papers.
Both the papers and the ensuing discussions revealed that there is clearly an opportunity for crossing domestic yak with its wild relative. In fact, yak herders are already doing this routinely in some areas. However, the specific gains from such breeding systems have not yet been systematically quantified.
Crossbreeding among domestic yak populations was also discussed. However, the fact that this is happening in the absence of genetic and phenotypic characterisation data on the different yak populations involved highlighted the urgent need for yak populations to be characterised immediately.
The discussion also touched on possible gains to be had from cross-species hybridisation, specifically between yak and cattle. Two points were raised in this regard. First, there is a need to ensure that the practice does not deteriorate the traits of the breed—the situation now facing other species (e.g. cattle), where, because of a preference for crossbreeds, the less numerous indigenous populations have now become threatened. Second, it is important that the practice not be undertaken as a single path to genetic improvement, i.e. ignoring the characterisation and development of the yak resource itself.
Although the papers presented mainly focused on 'conventional' economic traits—reproductive traits, milk, meat (growth)— participants felt it was important to consider the aggregate genotype of yak in the development of yak breeding programmes. These should include the whole set of traits considered important by yak herders. Adaptive fitness in relation to the yak environment, transport (pack) function, fur yield and quality were some of the traits mentioned. It was noted that the future of yak would depend on their continued ability to survive in difficult—but increasingly changing—environments. Successful competition of yak products in a world of 'cheaper alternatives' will require the identification and promotion of an array of unique and exceptional high quality products, including a focus on 'niche' markets that will provide improved livelihoods to yak keepers. The issue concerning whether there is a real need to breed yak for increased body size—especially in view of the possibility of their becoming less adaptive in the process—was raised but not discussed conclusively.
Several papers raised the question of inbreeding as a possible problem for some yak populations in the region, but conflicting conclusions were suggested. Although there are differences between the various yak populations, none of the studies were of sufficient scope and design to provide compelling results in this regard. In view of the current belief that inbreeding is a problem for many yak populations in isolated areas, this issue needs to be addressed urgently by researchers. In the meantime, the practice of facilitating the exchange of bulls among herders should be promoted.
The yak is a seasonal breeder, and its peak-breeding season coincides with the time it resides in higher altitude areas—beyond the reach of extension agents. Consequently, attempts to use AI in yak have not been very successful. Thus, natural mating will remain the method of choice in yak breeding for the foreseeable future.
The need for an appropriate recording system for yak came out very strongly. A suggested set of measurements to be taken was presented. Although this was not discussed at length in the ensuing discussions, it presents a good starting point. One area that needs to be addressed is how such a recording system could be implemented (or simplified) given the mobility of the yak herds and the fact that most herders are illiterate. The benefits of recording, as pointed out, go beyond breeding and genetic improvement; improvement in herd management is probably the biggest and most immediate benefit of herd recording.
There is a big move towards high-tech molecular characterisation. Many countries, however, lamented that they do not have sufficient physical and human resources to undertake such characterisation on their own. The need for regional networking in this area became quite obvious and was emphasised. Additionally, some papers presented quite useful results from biochemical (principally protein polymorphism) analyses and phenotypic data-based on multivariate (principal component) analyses of linear and other body measurements. These techniques still have a role to play in breed characterisation, and should be applied in lieu of, or as a complement to, microsatellite or other DNA-based approaches.
One paper in the session presented some preliminary results on superovulation in yak. Another presented work on efficient production of transgenic bovine and cat embryos by microinjection and cloning—with implications for yak. Whereas these technologies, especially superovulation and embryo transfer, could possibly play an important role in ex-situ conservation of yak, they do not have an immediate application in commercial yak production. Unfortunately, because of time constraints, these two papers were among those not discussed in sufficient detail.
Chairpersons: Drs Eijin Han and Luo Xiaolin
This session focused on issues related to environmental physiology. Though it is well known that yak are well adapted to cold climates and high altitudes, and do not readily endure adverse environments such as those with high temperatures, one paper showed that at least some yak in North America are being raised in low elevation areas with warm climates for much of the year. These animals are said to be doing well.
Another paper described how adult yak at about 3000 metres above sea level displayed different physiological responses between seasons, namely the cold-humid (mean daily temperature 4.7 ± 2.3°C, and mean daily relative humidity of 74.5 ± 3.9%) and moderately cold-humid (mean daily temperature 18.1 ± 0.3°C, and mean daily relative humidity of 74.2 ± 2.5%). Using a Daily Search Index, it was found that yak lack thermoadaptability during the moderately cold season.
Another paper suggested that the crossbreeding of wild and domestic yak would be a useful tool for improving the productivity of yak in southern Qinghai Province.
Chairpersons: Drs Peter J. Waller, Lham Tshering and Hu Songhua
This session looked at health-related issues, such as diseases, which afflict yak and health services available to them. Specifically, the papers presented covered parasitic infections, bacterial infections, drug susceptibility testing, serological surveys, bovine mastitis and community animal health workers.
Chairpersons: Drs Kulsina Kachkynbaeva and Han Jianlin
This session focused on the processing and marketing of yak products. Participants underlined the importance of developing raw material and different yak products processing for market. In particular, great attention was paid to meat, milk and butter processing and marketing, as well as leather and hair. Studies indicated that the processing and wide marketing of yak products could serve to improve the health of people and help to realise the sustainable development of the yak rearing regions of the world.