Ethnic and Cultural Diversity amongst Yak Herding Communities in the Asian Highlands

A one health approach to improve the safety of traditional yak blood drinking in Nepal

We discuss the potential risk of zoonotic pathogen transmission and negative health impact associated with fresh yak blood drinking ceremony in Nepal. We recommend applying One Health approach involving local government, public health officials and community organisers to enable continuation of the tradition in a safe manner.

The effects of ethnic sentiment and social differentiation on pastoralists' willingness to turn out of pasture

The pastures in China's pastoral areas have a "small and scattered" distribution, which results in overloading and overgrazing, ecological degradation, and other problems. These problems have constrained the sustainable development of grassland animal husbandry. Governments at all levels have implemented measures to promote the transfer of pastureland for herders, which has become a meaningful way to optimize the allocation of pastureland resources and improve the ecological environment in the second instance. In order to deeply explore the influence of pasture turn-out on herders' traditional lifestyle and to promote the rational utilization of pastureland in pastoral areas, the study is based on 437 interview data of herders in Inner Mongolia and Xinjiang. It adopts the Binary Logit model to analyze the influence and mechanism of herders' willingness to turn out of pastureland in terms of ethnic sentiment and social differentiation. The results show that (1) Nomadic and mutual aid sentiments significantly and negatively affect herders' willingness to transfer pasture. The stronger the national sentiment, the lower the willingness to transfer pasture and the more cautious the behaviour of transferring pasture. (2) The proportion of pasture income and the proportion of pasture labour significantly and negatively affect the herders' willingness to transfer pasture. Specifically, the increase in herders's family pasture income and the proportion of pasture labour will reduce the willingness to transfer pasture. The conclusion still holds after further robustness checks by introducing instrumental variables, changing the regression model, and replacing the sample size. (3) At the macro level, the government needs to take advantage of the situation and tap the positive role of national sentiment in rural revitalization; at the micro level of herders, it needs to enhance their employability, enrich income channels, stimulate the endogenous dynamics of social differentiation in the development of herders' livelihoods, and realize the effective matching of pasture resources.

Distribution characteristics and morphological comparison of telocytes in the aortic bulb and myocardium of yak heart

BACKGROUND

Telocytes (TCs) are small interstitial cells that extend into multiple bead-like protrusions called telopodes (TPs). TCs are widely found in many tissues and organs, form connections with almost all types of cardiomyocytes, and participate in regulating cardiac microenvironment homeostasis.

METHODS

In this study, transmission electron microscopy combined with special staining techniques (Gomori's, Masson's trichrome, and toluidine blue staining) were used to analyse the ultrastructure, distribution, and cytochemical characteristics of TCs in yak hearts. Immunohistochemistry and immunofluorescence double staining techniques were combined to identify the immunophenotypic characteristics of TCs functional markers (CD34, CD117, PDGFR-α and α-SMA) and further reveal their potential functions.

RESULTS

The results showed that the TCs in the aortic bulb of yak hearts had prominent nuclei, and thin, long TPs with abundant secretory vesicles. TCs in the myocardial tissue exhibited irregularly shaped nuclei, shorter TPs, and connections with myocardial fibres and adjacent capillaries, forming a complex TC network. Immunohistochemical results demonstrated the positive expression of functional markers CD34, CD117, α-SMA and PDGFR-α in both the aortic bulb and myocardium. Immunofluorescence double staining results indicated co-expression of CD34/CD117, CD34/α-SMA, and CD117/PDGFR-α in TCs.

CONCLUSION

This is the first study to report the presence of TCs in the aortic bulb and myocardium of yak hearts and that it may form TC networks that mainly participate in mechanical support and cell communication in the heart. The presence and distribution characteristics of TCs in the heart of yaks provide important clues for further research on the role of TC networks in the adaptability of plateau animals to the environment.

Feeding systems change yak meat quality and flavor in cold season

Yak meat is in high demand due to its unique flavor. Thus this research utilized GC × GC-ToF-MS to discover important flavor compounds in yak meat raised during the cold season under different feeding systems: traditional grazing (TG), grazing-based supplementation (GS), and stall-feeding (SF). Meat quality results showed that SF significantly improved meat's lightness and tenderness (P < 0.05), as compared to TG. Intramuscular fat (2.7 g/100 g) was highest in the SF, followed by the GS (2.46 g/100 g) and the TG (1.57 g/100 g), whereas protein content was similar in the GS and TG, but again higher in the SF. β-carotene and Vitamin E were highest in the GS and TG groups (P < 0.05), respectively. Essential, fresh, and total amino acids were richer in the SF and TG than in the GS group (P < 0.05). TG exhibited a significantly elevated level of n-3 PUFA compared to the SF and GS systems (P < 0.05). Flavoromics analysis identified 736, 721, and 869 flavor substances in the TG, GS, and SF groups, respectively with six as key flavor compounds (ROAV ≥ 1) in all belonging to aldehydes, ketones, and heterocyclic compounds. The pyruvate, glycolysis/gluconeogenesis, and phenylalanine metabolic pathways significantly contributed to the yak meat flavor. Network analysis showed a complex significant positive correlation between amino acids in meat and Vitamin A in fodder (P < 0.05). Altogether, this study provides a basis for selecting a suitable meat production system that benefits producers and consumers by ensuring an annual supply of fresh meat.

Identifying low-density, ancestry-informative SNP markers through whole genome resequencing in Indian, Chinese, and wild yak

The current investigation was undertaken to elucidate the population-stratifying and ancestry-informative markers in Indian, Chinese, and wild yak populations using whole genome resequencing (WGS) analysis while employing various selection strategies (Delta, Pairwise Wright's Fixation Index-FST, and Informativeness of Assignment) and marker densities (5-25 thousand). The study used WGS data on 105 individuals from three separate yak cohorts i.e., Indian yak (n = 29), Chinese yak (n = 61), and wild yak (n = 15). Variant calling in the GATK program with strict quality control resulted in 1,002,970 high-quality and independent (LD-pruned) SNP markers across the yak autosomes. Analysis was undertaken in toolbox for ranking and evaluation of SNPs (TRES) program wherein three different criteria i.e., Delta, Pairwise Wright's Fixation Index-FST, and Informativeness of Assignment were employed to identify population-stratifying and ancestry-informative markers across various datasets. The top-ranked 5,000 (5K), 10,000 (10K), 15,000 (15K), 20,000 (20K), and 25,000 (25K) SNPs were identified from each dataset while their composition and performance was assessed using different criteria. The average genomic breed clustering of Indian, Chinese, and wild yak cohorts with full density dataset (105 individuals with 1,002,970 markers) was 81.74%, 80.02%, and 83.62%, respectively. Informativeness of Assignment criterion with 10K density emerged as the best combination for three yak cohorts with 86.94%, 96.46%, and 98.20% clustering for Indian, Chinese, and wild yak, respectively. There was an average increase of 7.56%, 22.72%, and 30.35% in genomic breed clustering scores of Indian, Chinese, and wild yak cohorts over the estimates of the original dataset. The selected markers showed overlap multiple protein-coding genes within a 10 kb window including ADGRB3, ANK1, CACNG7, CALN1, CHCHD2, CREBBP, GLI3, KHDRBS2, and OSBPL10. This is the first report ever on elucidating low-density SNP marker sets with population-stratifying and ancestry-informative properties in three yak groups using WGS data. The results gain significance for application of genomic selection using cost-effective low-density SNP panels in global yak species.

Fatty Acids Composition of Pasture Grass, Yak Milk and Yak Ghee from the Four Altitudes of Qinghai-Tibet Plateau: A Predictive Modelling Approach to Evaluate the Correlation among Altitude, Pasture Grass, Yak Milk and Yak Ghee

This study investigates the effect of altitude on the fatty acid composition of pasture grass, yak milk, and yak ghee on the Qinghai-Tibet Plateau, aiming to understand how environmental factors influence the nutritional quality of these products. Samples were collected from four different altitudes and analyzed for fatty acid profiles using gas chromatography. The analysis reveals that higher altitudes are associated with an increased prevalence of beneficial unsaturated fatty acids, such as oleic acid (C18:1) and linoleic acid (C18:2n6c). These findings highlight the significant influence of altitude on yak lipid metabolism, ultimately enhancing the nutritional value of dairy products. This adaptation not only supports the health and resilience of yaks, but also provides vital nutritional benefits to residents in high-altitude regions. The research underscores the importance of further investigations to optimize dairy production practices, ensuring improved food security and health outcomes for residents of the plateau.

Alterations in the diversity and composition of the fecal microbiota of domestic yaks (Bos grunniens) with pasture alteration-induced diarrhea

Diarrhea is a common issue in domestic yaks (Bos grunniens) that can occur with pasture alterations and significantly impacts growth performance. Previous research has examined the microbiota of diarrhetic yaks; however, the structural changes in gut bacterial community and microbial interactions in yaks with grassland alteration-induced diarrhea remain poorly understood. To explore variations in gut microbiota homeostasis among yaks suffering from diarrhea, fecal microbiota diversity and composition were analyzed using 16 S rRNA amplicon sequencing. Gut fecal microbiota diversity was lower in diarrhetic yaks than in non-diarrhetic yaks. Furthermore, the bacterial community composition (including that of Proteobacteria and Actinobacteria) in the feces of diarrhetic yaks displayed significant alterations. Co-occurrence network analysis further underscored the compromised intestinal flora stability in yaks with diarrhea relative to that in non-diarrhetic yaks. Interestingly, the abundance of beneficial bacteria, such as Lachnospiraceae_AC2044_group and Lachnospiraceae_NK4A136_group, were decreased in yaks with diarrhea, and the reductions were negatively correlated with the fecal water content. Collectively, these findings indicate that diminished microbial stability and increased abundance of certain bacteria in the gut may contribute to diarrhea occurrence in yaks.

Temporal-spatial variability of grazing behaviors of yaks and the drivers of their intake on the eastern Qinghai-Tibetan Plateau

Introduction

Grassland-livestock balance is an important principle of sustainable development of grassland livestock production and grassland ecosystem health. Grassland degradation becomes more serious at global scales and especially at the area that is sensitive to climate change and human activities. Decreases in pasture biomass and shifts in plant community composition in degraded grasslands can largely affect grazing behaviors of livestock. Up to date, however, it is unclear that whether livestock behaviors change across spatial and temporal scales and what key factors are to shape observed behavioral patterns of livestock.

Methods

Here, yak behaviors including grazing, rumination and walking on the eastern Qinghai-Tibetan Plateau (QTP) were monitored by a continuous visual observation, to investigate temporal and spatial variations of grazing behavior of yaks (Bos grunniens); based on the data from public database in the past 18 years, a meta-analysis was conducted to examine the main factors that affect grazing behaviors and intake of yaks.

Results

We showed that grazing behaviors of yaks differed significantly within hours, among hours of each day and among days as well as across different observation sites. Intake rate of yaks was higher in the morning than in the afternoon, but walking speed showed an inverse trend compared with intake rate. Resting, altitude, the mean annual precipitation (MAP), the mean annual temperature (MAT), forage ash, yak age and season were the main predictors for yak intake, and forage and yak individual characteristics had direct effects on grazing behaviors and intake of yaks.

Discussion

The findings confirm that grazing behaviors of yaks can vary even at small temporal scales and regional scales, which is closely related to the shift in forage quality and biomass caused by environmental changes. The study suggests that multiple factors can be responsible for the variation in livestock behaviors and shifts in behavioral patterns may consequently lead to positive or negative feedback to grassland ecosystems through plant-animal interactions.

THE FIRST SURVEY OF BOVINE BABESIA SPECIES INFECTING YAKS (BOS GRUNNIENS) IN MONGOLIA

Yak (Bos grunniens) farming is an important part of Mongolia's livestock industry. Yaks survive in harsh mountain environments; provide meat, milk, and wool; and serve as a mode of transportation. In Mongolia, yaks are frequently raised alongside other livestock animals such as cattle, Bactrian camels, sheep, goats, and horses. Recently, we demonstrated that Babesia bovis, Babesia bigemina, and Babesia naoakii-parasites with the potential to cause clinical bovine babesiosis-infect not only cattle but also Bactrian camels in Mongolia. However, yaks have never been surveyed for Babesia infections in this country. In the present study, we surveyed yaks in 8 Mongolian provinces: Bayankhongor, Bayan-Ulgii, Khovd, Khovsgol, Omnogovi, Ovorkhangai, Uvs, and Zavkhan. Blood samples were taken and deoxyribonucleic acid (DNA) was extracted from 375 yaks. Furthermore, Giemsa-stained thin smears were prepared from 315 of the 375 blood samples and then examined for the microscopic detection of Babesia parasites. Microscopy revealed that 34 (10.8%) of 315 blood smears were positive for Babesia parasites. All 375 DNA samples were then tested for B. bovis, B. bigemina, and B. naoakii infection using specific polymerase chain reaction assays. We observed that 238 (63.5%) yaks in all surveyed provinces and 8 (2.1%) yaks in 3 provinces (Bayankhongor, Bayan-Ulgii, and Omnogovi) were positive for B. bovis and B. bigemina, respectively. However, all yaks tested were negative for B. naoakii. This epidemiological survey, the first to report Babesia infection in Mongolian yaks, suggests that disease management strategies for yaks in this country should further address bovine babesiosis.

Effects of sources and levels of dietary supplementary manganese on growing yak's in vitro rumen fermentation

Introduction

Manganese (Mn) is an essential trace element for livestock, but little is known about the optimal Mn source and level for yak.

Methods

To improve yak's feeding standards, a 48-h in vitro study was designed to examine the effect of supplementary Mn sources including Mn sulfate (MnSO₄), Mn chloride (MnCl₂), and Mn methionine (Met-Mn) at five Mn levels, namely 35 mg/kg, 40 mg/kg, 50 mg/kg, 60 mg/kg, and 70 mg/kg dry matter (includes Mn in substrates), on yak's rumen fermentation.

Results

Results showed that Met-Mn groups showed higher acetate (p < 0.05), propionate, total volatile fatty acids (p < 0.05) levels, ammonia nitrogen concentration (p < 0.05), dry matter digestibility (DMD), and amylase activities (p < 0.05) compared to MnSO4 and MnCl2 groups. DMD (p < 0.05), amylase activities, and trypsin activities (p < 0.05) all increased firstly and then decreased with the increase of Mn level and reached high values at 40-50 mg/kg Mn levels. Cellulase activities showed high values (p < 0.05) at 50-70 mg/kg Mn levels. Microbial protein contents (p < 0.05) and lipase activities of Mn-Met groups were higher than those of MnSO4 and MnCl2 groups at 40-50 mg/kg Mn levels.

Discussion

Therefore, Mn-met was the best Mn source, and 40 to 50 mg/kg was the best Mn level for rumen fermentation of yaks.

Permafrost preservation reveals proteomic evidence for yak milk consumption in the 13th century

Domesticated yaks endure as iconic symbols of high-altitude frozen landscapes, where herding communities depend on their high-fat milk, transport, dung, and natural fibers. While there is established proteomic evidence for ancient consumption of ruminant and horse milk in the mountains and steppes of northern Eurasia, yak dairy products have yet to be detected. Yak domestication and the species' dispersal from Tibet into the mountainous zones to the north are also poorly resolved due to a paucity of zooarchaeological data. To examine the potential of paleoproteomics to shed light on domesticated yak in Mongolia, we analyzed human dental calculus from Mongol era elite individuals recovered from permafrost burials in Khovsgol province, where people continue to herd yak to this day. We report the first evidence for yak dairy consumption, linked to local resource control. In addition, we confirm a large diversity of recovered whey, curd, tissue, and blood proteins, likely reflecting the excellent preservation conditions found at permafrost sites.

"The Yak"-A remarkable animal living in a harsh environment: An overview of its feeding, growth, production performance, and contribution to food security

Yaks play an important role in the livelihood of the people of the Qinghai-Tibet Plateau (QTP) and contribute significantly to the economy of the different countries in the region. Yaks are commonly raised at high altitudes of ~ 3,000-5,400 m above sea level. They provide many important products, namely, milk, meat, fur, and manure, as well as social status, etc. Yaks were domesticated from wild yaks and are present in the remote mountains of the QTP region. In the summer season, when a higher quantity of pasture is available in the mountain region, yaks use their long tongues to graze the pasture and spend ~ 30-80% of their daytime grazing. The remaining time is spent walking, resting, and doing other activities. In the winter season, due to heavy snowfall in the mountains, pasture is scarce, and yaks face feeding issues due to pasture scarcity. Hence, the normal body weight of yaks is affected and growth retardation occurs, which consequently affects their production performance. In this review article, we have discussed the domestication of yaks, the feeding pattern of yaks, the difference between the normal and growth-retarded yaks, and also their microbial community and their influences. In addition, blood biochemistry, the compositions of the yaks' milk and meat, and reproduction are reported herein. Evidence suggested that yaks play an important role in the daily life of the people living on the QTP, who consume milk, meat, fur, use manure for fuel and land fertilizer purposes, and use the animals for transportation. Yaks' close association with the people's well-being and livelihood has been significant.

Management of Social Behaviour of Domestic Yaks in Manang, Nepal: An Etho-Ethnographic Study

Herdsmen use different techniques, as per varying geographies and cultures, to keep the cohesion within herds and avoid animals getting lost or predated. However, there is no study on the social behaviour of yaks and herdsmen management practices. Therefore, this ethology study was initiated by ethnographic inquiries. In Manang, the success of the shepherd is dictated by his personal attribute of 'Khula man' or open-heartedness. This attribute refers to good intentions and emotions such as empathy, which allow the shepherd to focus more on others than on himself. This cultural way of assessing the skills required to become a successful and knowledgeable shepherd guided us to study the effect of cultural values on the herd's social behaviour. We collected data from two herds living at the same settlement (Yak kharka, 4100 m altitude, Nepal) by equipping them with loggers. One of the herdsmen used the tether rope while the other one did not. Moreover, the Thaku herd had a more proactive shepherd than the Phurba one. In each herd, 17 animals were equipped with one Actigraph wgt3x-BT to measure activity using an accelerometer and spatial associations using a proximity recorder. One of the herds was equipped with GPS (N = 11) as well. Using GPS locations and activity, we showed that the two herds were cohesive and synchronised their activities but the Thaku herd (tether rope herd) was more cohesive than the Phurba herd based on the Actigraph signals. The shepherds also have personal knowledge of the social relationships of individual animals in their herds and use these relationships to keep the group cohesive and to manage cattle well.

Effects of Maize Varieties on Biomass Yield and Silage Quality of Maize–Soybean Intercropping in the Qinghai–Tibet Plateau

Forage deficiency is the bottleneck that restricts the development of plateau animal husbandry. Maize (Zea mays L.)–soybean (Glycine max L.) intercropping can improve the forage biomass yield and silage quality. This experiment was conducted in Ganzi Tibetan Autonomous Prefecture to explore the effects of four maize varieties (M1, Rongyu Silage No. 1; M2, Yayu 04889; M3, Demeiya No. 1; M4, Zhenghong 505) on biomass yield, nutritional composition, and silage quality in maize–soybean intercropping. The results showed that M1S had the highest total dry matter yield (18.03 t ha−1), M3S had the highest crude protein (CP) content (8.46% DM), and soybeans had the highest water-soluble carbohydrate (WSC) content (8.55% DM). After silage, the CP content (13.44% DM) of mixed silage in M3S was higher, and the contents of neutral detergent fiber (39.42% DM) and acid detergent fiber (25.42% DM) were lower than those in maize silage alone. The WSC content (4.45% DM) of mixed silage in M3S was higher and the pH value (4.46) and ammonia–nitrogen to total nitrogen (3.97%) were lower than those of soybean silage alone. The results of membership function analysis showed that M3S was the best in fresh feeding and silage utilization, followed by M1S. Therefore, M3S (Demeiya No 1. intercropped with soybeans) is recommended in high-altitude areas.

Rumen microbiota of indigenous and introduced ruminants and their adaptation to the Qinghai-Tibetan plateau

The grassland in the Qinghai-Tibetan plateau provide habitat for many indigenous and introduced ruminants which perform important ecological functions that impact the whole Qinghai-Tibetan plateau ecosystem. These indigenous Tibetan ruminants have evolved several adaptive traits to withstand the severe environmental conditions, especially cold, low oxygen partial pressure, high altitude, strong UV radiation, and poor forage availability on the alpine rangelands. Despite the challenges to husbandry associated with the need for enhanced adaptation, several domesticated ruminants have also been successfully introduced to the alpine pasture regions to survive in the harsh environment. For ruminants, these challenging conditions affect not only the host, but also their commensal microbiota, especially the diversity and composition of the rumen microbiota; multiple studies have described tripartite interactions among host-environment-rumen microbiota. Thus, there are significant benefits to understanding the role of rumen microbiota in the indigenous and introduced ruminants of the Qinghai-Tibetan plateau, which has co-evolved with the host to ensure the availability of specific metabolic functions required for host survival, health, growth, and development. In this report, we systemically reviewed the dynamics of rumen microbiota in both indigenous and introduced ruminants (including gut microbiota of wild ruminants) as well as their structure, functions, and interactions with changing environmental conditions, especially low food availability, that enable survival at high altitudes. We summarized that three predominant driving factors including increased VFA production, enhanced fiber degradation, and lower methane production as indicators of higher efficiency energy harvest and nutrient utilization by microbiota that can sustain the host during nutrient deficit. These cumulative studies suggested alteration of rumen microbiota structure and functional taxa with genes that encode cellulolytic enzymes to potentially enhance nutrient and energy harvesting in response to low quality and quantity forage and cold environment. Future progress toward understanding ruminant adaptation to high altitudes will require the integration of phenotypic data with multi-omics analyses to identify host-microbiota co-evolutionary adaptations enabling survival on the Qinghai-Tibetan plateau.

Effect of the ratio of dietary metabolizable energy to nitrogen content on production performance, serum metabolites, rumen fermentation parameters, and bacterial diversity in yaks

This study examined the effect of the ratio of dietary metabolizable energy (MJ) to nitrogen (g) content (ME:N) on average daily gain (ADG), blood biochemical indices, rumen fermentation parameters, and rumen bacterial community in yaks. Thirty-six male yaks, aged 2–3 years, were divided into three groups and received a ME:N ratio of 0.42 (HY), 0.36 (MY,) or 0.32 (LY) MJ/g. Dry matter intake ranged between 3.16 and 3.63 kg/d and was lesser (p < 0.001) in the LY group than the other two groups. ME intake increased (p < 0.001) with an increase in the ME:N ratio, while N intake did not differ among groups. The ADG was 660 g/day for the MY group, which was higher (p < 0.005) than the 430 g/day in the LY group, while the HY group gained 560 g/day and did not differ from the other two groups. Feed intake to ADG ratio ranged between 5.95 and 7.95, and numerically was highest in the LY group and lowest in the MY group. In general, the concentration of ruminal total volatile fatty acids (p < 0.03) and molar proportions of propionate (p < 0.04), increased, while the molar proportion of acetate (p < 0.005) and the acetate:propionate ratio decreased (p < 0.001) with a decrease in the ME:N ratio. The molar proportion of butyrate did not differ among groups (p = 0.112). Group MY had higher ruminal NH₃-N content than group HY and had a higher serum glucose content but lower urea content, lactate dehydrogenase, and creatine kinase content than group LY. In ruminal bacteria at the phylum level, the relative abundance of Firmicutes (F) was greater and of Bacteroidetes (B) was lesser, while the F:B ratio was greater in group MY than in groups HY an LY. We concluded that the yaks consuming the diet containing a ME:N ratio of 0.36 MJ/g had the best performance of the three groups.

Trajectory of livestock genomics in South Asia: A comprehensive review

Livestock plays a central role in sustaining human livelihood in South Asia. There are numerous and distinct livestock species in South Asian countries. Several of them have experienced genetic development in recent years due to the application of genomic technologies and effective breeding programs. This review discusses genomic studies on cattle, buffalo, sheep, goat, pig, horse, camel, yak, mithun, and poultry. The frontiers covered in this review are genetic diversity, admixture studies, selection signature research, QTL discovery, genome-wide association studies (GWAS), and genomic selection. The review concludes with recommendations for South Asian livestock systems to increasingly leverage genomic technologies, based on the lessons learned from the numerous case studies. This paper aims to present a comprehensive analysis of the dichotomy in the South Asian livestock sector and argues that a realistic approach to genomics in livestock can ensure long-term genetic advancements.

The adaptive strategies of yaks to live in the Asian highlands

The yak (Bos grunniens), an indigenous herbivore raised at altitudes between 3,000 and 5,000 m above sea level, is closely linked to more than 40 ethnic communities and plays a vital role in the ecological stability, livelihood security, socio-economic development, and ethnic cultural traditions in the Asian highlands. They provide the highlanders with meat, milk, fibres, leather and dung (fuel). They are also used as pack animals to transport goods, for travel and ploughing, and are important in many religious and traditional ceremonies. The Asian highlands are known for an extremely, harsh environment, namely low air temperature and oxygen content and high ultraviolet light and winds. Pasture availability fluctuates greatly, with sparse pasture of poor quality over the long seven-month cold winter. After long-term natural and artificial selections, yaks have adapted excellently to the harsh conditions: 1) by genomics, with positively selected genes involved in hypoxia response and energy metabolism; 2) anatomically, including a short tongue with a weak sense of taste, and large lung and heart; 3) physiologically, by insensitivity to hypoxic pulmonary vasoconstriction, maintaining foetal haemoglobin throughout life, and low heart rate and heat production in the cold season; 4) behaviourlly, by efficient grazing and selecting forbs with high nutritional contents; 5) by low nitrogen and energy requirements for maintenance and low methane emission and nitrogen excretion, namely, 'Low-Carbon' and 'Nitrogen-Saving' traits; 6) by harboring unique rumen microbiota with a distinct maturation pattern, that has co-evolved with host metabolism. This review aims to provide an overview of the comprehensive adaptive strategies of the yak to the severe conditions of the highlands. A better understanding of these strategies that yaks employ to adapt to the harsh environment could be used in improving their production, breeding and management, and gaining benefits in ecosystem service and a more resilient livelihood to climate change in the Asian highlands.

Diversity of beneficial microorganisms and their functionalities in community-specific ethnic fermented foods of the Eastern Himalayas

The Eastern Himalayan regions of India, Nepal and Bhutan have more than 200 varieties of unsurpassed ethnic fermented foods and alcoholic beverages, which are lesser known outside the world. However, these ethnic foods are region- and community-specific, unique and some are exotic and rare, which include fermented vegetables, bamboo shoots, soybeans, cereals, milk (cow and yak), meats, fishes, and cereal-based alcoholic beverages and drinks. Ethnic communities living in the Eastern Himalayas have invented the indigenous knowledge of utilization of unseen microorganisms present in and around the environment for preservation and fermentation of perishable plant or animal substrates to obtain organoleptically desirable and culturally acceptable ethnic fermented food and alcoholic beverages. Some ethnic fermented products and traditionally prepared dry starters for production of alcoholic beverages of North Eastern states of India and Nepal were scientifically studied and reported till date, and however, limited publications are available on microbiological and nutritional aspects of ethnic fermented foods of Bhutan except on few products. Most of the beneficial microorganisms isolated from some ethnic fermented foods of the EH are listed in microbial food cultures (MFC) safe inventory. This study is aimed to review the updates on the beneficial importance of abundant microbiota and health-promoting benefits and functionalities of some ethnic fermented foods of the Eastern Himalayan regions of North East India, Nepal and Bhutan.

Rumen Bacterial Community of Grazing Lactating Yaks (Poephagus grunniens) Supplemented with Concentrate Feed and/or Rumen-Protected Lysine and Methionine

Simple Summary

Ruminal microorganisms, especially bacteria, play a vital role in utilizing fibrous material in ruminants. The yak is a bovid on the Qinghai-Tibet Plateau that traditionally only grazes natural pasture all year. During lactation, energy intake of yaks is often well below requirements, and yaks lose body weight. Today, to mitigate body weight losses during lactation, suckling yaks are often offered supplementary feed. This study examined the effect of dietary supplements on rumen bacteria in lactating yak. The yaks were offered supplementary concentrate feed (C), rumen-protected Lys and Met (RPA), or both (RPA+C). The ratio of the relative abundance of Firmicutes to Bacteroidetes in RPA+C was greater than in the RPA group, while there was no difference between C and RPA+C. The intakes of supplements resulted in a number of alterations in the abundances of bacteria at the genus level. When supplemented with C, yaks increased the concentration of ruminal total volatile fatty acids (VFAs), acetate, and butyrate. These results demonstrate that supplementary feed: (1) alters the composition of rumen microbiota and VFAs of lactating yaks; and (2) can be used to manipulate the composition of rumen microbiota.

Abstract

Traditionally, yaks graze only natural pasture all year round without supplements. Forage intake of lactating yaks is below energy and protein requirements, even in the summer, and suckling yaks lose a substantial amount of significant body weight. Today, to mitigate the loss in body weight, supplementary feed is being offered to lactating yaks. However, the effects of supplementary feed on ruminal bacterial communities in lactating yaks is unknown. In the current study, we examined the effect of supplementary feed on ruminal microbiota, using 16S rRNA sequencing, and on volatile fatty acids (VFAs). Twenty-four lactating yaks of similar body weight (218 ± 19.5 kg) and grazing natural pasture were divided randomly into four groups and received different supplements: (1) rumen-protected amino acids (RPA); (2) concentrate feed (C); (3) RPA plus C (RPA+C); and (4) no supplements (control-CON). The concentrations of total VFAs, acetate, and butyrate were greater (p < 0.05) when supplemented with concentrate feed (C and RPA+C) than without concentrate feed (CON and RPA). Bacteroidetes (B) and Firmicutes (F) were the dominant ruminal bacterial phyla in all groups. The ratio of relative abundance of F:B in RPA+C was greater than in the RPA group, while there was no difference between CON and RPC (interaction, p = 0.026). At the genus level, the relative abundances of Absconditabacteriales_SR1, Bacteroidales-RF16-group, Bacteroidales_BS11_gut_group, Prevotellaceae, and Rikenellaceae_RC9_gut_group were lesser (p < 0.05) with supplementary concentrate feed (C and RPA+C) than without concentrate feed (CON and RPA), whereas Butyrivibrio_2 and Pseudobutyrivibrio were greater (p < 0.05) with supplementary rumen-protected amino acids (RPA and RPA+C) than without rumen-protected amino acids (CON and C). These results demonstrate that supplementary feed: (1) alters the composition of rumen microbiota and concentrations of ruminal VFAs in lactating yaks; and (2) can be used to manipulate the composition of rumen microbiota.

Pastoralism in the highest peaks: Role of the traditional grazing systems in maintaining biodiversity and ecosystem function in the alpine Himalaya

Rangelands cover around half of the planet’s land mass and provide vital ecosystem services to over a quarter of humanity. The Himalayan rangelands, part of a global biodiversity hotspot is among the most threatened regions in the world. In rangelands of many developing nations policies banning grazing in protected areas is common practice. In 1998, the Indian state of Sikkim, in the Eastern Himalaya, enacted a grazing ban in response to growing anthropogenic pressure in pastures and forests that was presumably leading to degradation of biodiversity. Studies from the region demonstrate the grazing ban has had some beneficial results in the form of increased carbon stocks and regeneration of some species of conservation value but the ban also resulted in negative outcomes such as reduced household incomes, increase in monocultures in lowlands, decreased manure production in a state that exclusively practices organic farming, spread of gregarious species, and a perceived increase in human wildlife conflict. This paper explores the impact of the traditional pastoral system on high elevation plant species in Lachen valley, one of the few regions of Sikkim where the grazing ban was not implemented. Experimental plots were laid in along an elevation gradient in grazed and ungrazed areas. Ungrazed areas are part of pastures that have been fenced off (preventing grazing) for over a decade and used by the locals for hay formation. I quantified plant species diversity (Species richness, Shannon index, Simpson diversity index, and Pielou evenness index) and ecosystem function (above ground net primary productivity ANPP). The difference method using movable exlosure cages was used in grazing areas to account for plant ANPP eaten and regrowth between grazing periods). The results demonstrate that grazing significantly contributes to greater plant species diversity (Species richness, Shannon index, Simpson diversity index, and Pielou evenness index) and ecosystem function (using above ground net primary productivity as an indicator). The multidimensional scaling and ANOSIM (Analysis of Similarities) pointed to significant differences in plant species assemblages in grazed and ungrazed areas. Further, ecosystem function is controlled by grazing, rainfall and elevation. Thus, the traditional transhumant pastoral system may enhance biodiversity and ecosystem function. I argue that a complete restriction of open grazing meet neither conservation nor socioeconomic goals. Evidence based policies are required to conserve the rich and vulnerable biodiversity of the region.

The Future of Yak Farming from the Perspective of Yak Herders and Livestock Professionals

The declining number of yak farming families is perceived as a socio-political and economic concern in Bhutan. However, there is limited understanding of what influences herders’ plans and decisions on yak farming. We studied factors determining future perspectives of yak farming by interviewing yak herders and livestock professionals. We analysed relationships between herders’ characteristics and level of concerns, and future plans related to yak farming. Furthermore, relationships between level of concern and future plans were analysed. Most of the herder characteristics did not influence their future plans with yak farming. Age and level of perceived concern of the herders was associated with their wish for their children to continue yak farming in the future. Nevertheless, they expect that the number of yak farming families will decline in the next ten years. Additionally, most of the livestock professionals believe that the number of yak farming families will decline in the future. No differences were observed between the aggregated score of concern of herders and livestock professionals. The most important factors threatening the future of yak farming in Bhutan according to herders and livestock professionals are forage shortage, predation and no successor to take up yak farming.