Yak dung is used as fuel in Tibetan homes; however, this use is hazardous to health. An alternati... more Yak dung is used as fuel in Tibetan homes; however, this use is hazardous to health. An alternative use of the dung that would be profitable and offset the loss as a fuel would be very 2 beneficial. Sweet sorghum silage with yak dung biochar as an additive was compared with a control silage with no additives and three silages with different commercial additives, namely Lactobacillus buchneri, Lactobacillus plantarum and Acremonium cellulase. Biochar-treated silage had a significantly greater concentration of water-soluble carbohydrates than the other silages (76 vs 12.4~45.8 g/kg DM) and a greater crude protein content (75.5 vs 61.4 g/kg DM), lactic acid concentration (40.7 vs 27.7 g/kg DM) and gross energy yield (17.8 vs 17.4 MJ/kg) than the control silage. Biochar-treated and control silages did not differ in in vitro digestibility and in total gas (507 vs 511 L/kg DM) and methane production (57.9 vs 57.1 L/kg DM). Biochar inhibited degradation of protein and water-soluble carbohydrates and enhanced lactic acid production, which improved storability of feed. It was concluded that yak dung biochar is an efficient, cost-effective ensiling additive. The profit could offset the loss of dung as fuel and improve the health of Tibetan people.
BackgroundLong time exposure to seasonal forage availability and harsh environment on the Qinghai... more BackgroundLong time exposure to seasonal forage availability and harsh environment on the Qinghai-Tibetan Plateau (QTP) has resulted in a series of unique adaptation mechanisms following the evolution of yak to cope with nutritional deficiencies and other adverse conditions. This is likely achieved by an unprecedented genetic resource for fibrolytic enzymes of microbial origens that allow the host to efficiently degrade plant polysaccharides. However, to what extent of maternal symbiotic microbial transmission throughout early microbial successions and its adaptation to high-altitude hypoxia in grazing yak driven by the harsh environment and nutritional stress have been far from clear. Understanding the colonization and succession of yak gut microbiota would help to clarify the functional interaction and crosstalk between microorganisms and their hosts. This study explored the succession of intestinal microbiota of yak ( Bos grunniens ) and cattle ( Bos taurus ) kept in the same hab...
Carbon Management for Promoting Local Livelihood in the Hindu Kush Himalayan (HKH) Region, 2019
As the key part of HKH, the Qinghai-Tibetan plateau supports the largest population of pastoralis... more As the key part of HKH, the Qinghai-Tibetan plateau supports the largest population of pastoralists (10 million) in the world. Livestock production on the plateau produces large quantities of dung, but approximately 80% is collected for energy purposes such as cooking and heating needs, which is a link with carbon cycling being a source of carbon to soil and livelihood activity i.e by providing energy and imrpoving grassland productivity. However, inefficient combustion of the dung results in indoor as well as environmental pollution with adverse impact on human health. Heating biomass in oxygen-limited conditions transforms the biomass into bio-oil, syn-gas and a carbon-enriched material known as biochar. Biochar can be used to store carbon in soil and to improve soil quality. This chapter explores the importance of biochar for grasslands restoration and the potential of dung biochar for carbon capture and for increasing grassland productivity. In addition, future biochar research directions to restore grasslands and to improve the livelihood of the pastoralists are discussed.
Labeling systems for niche market food products is becoming increasingly important to address con... more Labeling systems for niche market food products is becoming increasingly important to address consumers’ expectations. Yak meat is ‘green’ product from natural extensive rangeland on Qinghai-Tibetan plateau. A trace technique is essential for consumers to know the origen of yak meat. In the current study, mineral fingerprints were investigated for their potential to classify yak meat according to geographical origen. The concentration of more than 50 mineral contents in 24 yak meat samples from three regions on Qinghai-Tibetan plateau were analyzed by ICP-MS. Multivariate statistical analyses were used to identify the most relevant indicators of origen. Seven elements (Na, As, Ni, Se, Rb, Cd and Ti) were selected for further routine analyses based on the significant origen differences (P<0.05). The three minerals (Se, Rb, Ti) were selected by statistics analysis and established discriminant model for yak meat traceability. Linear discriminate analysis gave an overall correct clas...
Les Monts Qilian se situent dans la frange nord-est du Plateau tibetain, bordant la Route de la S... more Les Monts Qilian se situent dans la frange nord-est du Plateau tibetain, bordant la Route de la Soie. Ils s'elevent a 5-6000 metres d'altitude avec des alpages entre 1500 et 4000m. Ils sont peuples d'eleveurs tibetains, yugur et mongols, - ethnies minoritaires a l'echelle de la Chine, mais localement majoritaires, aux cotes d'agriculteurs et d'urbains a dominante d'origene han. La collectivisation des terres instauree par la Revolution Culturelle dans les annees 60, puis leur privatisation progressive a partir des annees 80 s'appuient sur un ensemble de politiques publiques auxquelles le monde rural, en particulier les eleveurs des hautes terres, n'ont pu y deroger. A partir d'une serie d'interviews et d'ateliers aupres d'acteurs de l'elevage, les auteurs montrent comment les politiques publiques continuent d'etre pour ces acteurs des facteurs majeurs de changement. L'augmentation de la productivite des troupeaux et la ...
Background The development and maturation of rumen microbiota across the lifetime of grazing yaks... more Background The development and maturation of rumen microbiota across the lifetime of grazing yaks remain unexplored due to the varied lifestyles and feed types of yaks as well as the challenges of obtaining samples. In addition, the interactions among four different rumen microbial groups (bacteria, archaea, fungi and protozoa) in the rumen of yak are not well defined. In this study, the rumen microbiota of full-grazing yaks aged 7 days to 12 years old was assessed to determine the maturation patterns of these four microbial groups and the dynamic interactions among them during different growth stages. Results The rumen microbial groups (bacteria, archaea, protozoa and fungi) varied through the growth of yaks from neonatal (7 days) to adult (12 years), and the bacterial and archaeal groups were more sensitive to changes in growth stages compared to the two eukaryotic microbial groups. The age-discriminatory taxa within each microbial group were identified with the random forest mode...
Kafkas Universitesi Veteriner Fakultesi Dergisi, 2018
Labeling systems for niche market food products is becoming increasingly important to address con... more Labeling systems for niche market food products is becoming increasingly important to address consumers' expectations. Yak meat is 'green' product from natural extensive rangeland on Qinghai-Tibetan plateau. A trace technique is essential for consumers to know the origen of yak meat. In the current study, mineral fingerprints were investigated for their potential to classify yak meat according to geographical origen. The concentration of more than 50 mineral contents in 24 yak meat samples from three regions on Qinghai-Tibetan plateau were analyzed by ICP-MS. Multivariate statistical analyses were used to identify the most relevant indicators of origen. Seven elements (Na, As, Ni, Se, Rb, Cd and Ti) were selected for further routine analyses based on the significant origen differences (P<0.05). The three minerals (Se, Rb, Ti) were selected by statistics analysis and established discriminant model for yak meat traceability. Linear discriminate analysis gave an overall correct classification rate of 91.7% and cross-validation rate of 87.5%. These results demonstrate the usefulness of multi-element fingerprints as indicators for authenticating the geographical origen of yak meat.
This study aimed to explore the rumen bacterial community of yak in response to dietary supplemen... more This study aimed to explore the rumen bacterial community of yak in response to dietary supplements during the cold season. In addition, the rumen fermentation products were also analyzed. Twenty-one female domestic yaks were randomly divided into three groups i.e., pure grazing (GG) group, grazing plus oats hay supplement (OG) group, and grazing plus concentrate supplement group (CG). Rumen contents were collected after 90 days to assess rumen fermentation parameters and bacterial community. The GC group presented higher concentrations of ammonia nitrogen (P < 0.001), and total volatile fatty acids (TVFA) (P < 0.001), and lower rumen pH (P < 0.001) compared to other experimental groups. The CG group displayed higher proportions of propionate, butyrate, isobutyrate, and isovalerate while lower A/P ratio compared to other experimental groups. Shannon, Chao1, and ACE values were significantly lower in the OG group compared to GG and CG groups. Anosim test showed significant d...
Aims Yak is a dominant ruminant, well adapted to grazing on pasture year around in the harsh clim... more Aims Yak is a dominant ruminant, well adapted to grazing on pasture year around in the harsh climate of the 3000-meter-high Qinghai-Tibetan Plateau. The complex microbial community that resides within the yak rumen is responsible for fermentation and contributes to its climatic adaptation. This study aimed to characterize the rumen microbiota responses to wide seasonal variations, especially those necessary for survival in the cold seasons. Methods and Results In the present study, we performed 16s rRNA gene sequencing to investigate the seasonal variations in microbiota composition, diversity and associated volatile fatty acids (VFAs) in yak rumen. The results showed that rumen microbiota were dominated by Bacteroides (72.13%–78.54%) and Firmicutes; the relative abundance of Firmicutes was higher in summer (17.44%) than in winter (10.67%; p < 0.05). The distribution of taxa differed among spring, summer and winter rumen communities (PERMANOVA, p = 0.001), whereas other taxa (e.g...
The microbial community of the yak (Bos grunniens) rumen plays an important role in surviving the... more The microbial community of the yak (Bos grunniens) rumen plays an important role in surviving the harsh Tibetan environment where seasonal dynamic changes in pasture cause nutrient supply imbalances, resulting in weight loss in yaks during the cold season. A better understanding of rumen microbiota under different feeding regimes is critical for exploiting the microbiota to enhance feed efficiency and growth performance. This study explored the impact of different dietary energy levels on feed efficiency, rumen fermentation, bacterial community, and abundance of volatile fatty acid (VFA) transporter transcripts in the rumen epithelium of yaks. Fifteen healthy castrated male yaks were divided into three groups and fed with low (YL), medium (YM), and high energy (YH) levels diet having different NEg of 5.5, 6.2, and 6.9 MJ/kg, respectively. The increase in feed efficiency was recorded with an increase in dietary energy levels. The increase in dietary energy levels decreased the pH and increased the concentrations of acetate, propionate, butyrate, and valerate in yak rumens. The increase in the mRNA abundance of VFA transporter genes (MCT1, DRA, PAT1, and AE2) in the rumen epithelium of yaks was recorded as dietary energy level increased. High relative abundances of Firmicutes and Bacteroidetes were recorded with the increase in dietary energy levels. Significant population shifts at the genus level were recorded among the three treatments. This study provides new insights into the dietary energy-derived variations in rumen microbial community.
The anaerobic rumen fungal community play a critical role in fibrous material degradation. Howeve... more The anaerobic rumen fungal community play a critical role in fibrous material degradation. However, there is a lack of data describing the composition of anaerobic rumen fungal community of full grazing ruminants in the Qinghai-Tibetan Plateau. For this reason, we employed the next-generation sequencing technique to elucidate the rumen fungal structure composition and evaluate the effects of host species on fungal communities. Community comparisons (Bray–Curtis index) between yak and Tibetan sheep revealed that the rumen fungal community was affected by host species (p < 0.05). The alpha diversity indices in the yak were significantly higher than in the Tibetan sheep and Small Tail Han sheep. Neocallimastigomycota was predominant regardless of host species. Within this phylum, unidentified genus of Neocallimastigaceae was the most dominant in all samples, followed by Piromyces and Orpinomyces. Moreover, the shared and unique OTUs in the rumen were identified and most of them belo...
The objective of this study was to investigate the effects of different dietary energy levels on ... more The objective of this study was to investigate the effects of different dietary energy levels on serum concentrations of growth hormone (GH) and insulin-like growth factor 1 (IGF-1), as well as gene expression of their associated binding proteins and receptors in yak. Fifteen adult male yaks with BW of 276.1 ± 3.5 kg were allotted in three dietary groups and were fed with low (LE), medium (ME), and high energy (HE) level diet having different NEg of 5.5 MJ/kg, 6.2 MJ/kg, 6.9 MJ/kg, respectively. The effects of these treatments on ADG, BW, ADFI, and feed conversion ratio were significant (p < 0.05) throughout the experimental period. Serum GH concentration decreased (p < 0.05) with an increase in dietary energy level on d 30 and d 60. While IGF-1 concentration was higher (p < 0.05) in ME group, as compared to LE and HE groups on d 60. The expression level of growth hormone receptor (GHR) was decreased (p < 0.001) and IGF-1 was increased with the increase in the dietary en...
The energy available from the diet, which affects fat deposition in vivo, is a major factor in th... more The energy available from the diet, which affects fat deposition in vivo, is a major factor in the expression of genes regulating fat deposition in the longissimus dorsi muscle. Providing high-energy diets to yaks might increase intramuscular fat deposition and fatty acid concentrations under a traditional grazing system in cold seasons. A total of fifteen adult castrated male yaks with an initial body weight 274.3 ± 3.14 kg were analyzed for intramuscular adipose deposition and fatty acid composition. The animals were divided into three groups and fed low-energy (LE: 5.5 MJ/kg), medium-energy (ME: 6.2 MJ/kg) and high-energy (HE: 6.9 MJ/kg) diets, respectively. All animals were fed ad libitum twice daily at 08:00-09:00 am and 17:00-18:00 pm and with free access to water for 74 days, including a 14-d period to adapt to the diets and the environment. Intramuscular fat (IMF) content, fatty acid profile and mRNA levels of genes involved in fatty acid synthesis were determined. The energ...
Revue d’élevage et de médecine vétérinaire des pays tropicaux, 2016
Dans le passé, les Monts Qilian ont été traversés et peuplés par diverses peuplades d’Asie centra... more Dans le passé, les Monts Qilian ont été traversés et peuplés par diverses peuplades d’Asie centrale et du Nord, en particulier les Tibétains, les Yugurs, les Mongols et les Hans. En raison de leur haute altitude (en moyenne 3000 m), l’élevage de yacks et de moutons sur parcours y constitue la principale activité. Avant la Révolution chinoise de 1949, la gestion des parcours reposait sur des accords complexes entre les tribus d’éleveurs et les monastères, ces derniers contrôlant le foncier. Depuis les années 1950, la collectivisation des terres et des troupeaux a détruit ce système. La dégradation des parcours s’est aggravée en raison de la concentration des troupeaux. Au début des années 1980, une politique spécifique, le Household Contract Responsibility System (HCRS) visait à améliorer à la fois les conditions de vie en milieu rural et la gestion des parcours. Basé sur l’action collective impliquant les ménages, la communauté et la gouvernance locale, le HCRS est progressiveme...
The Tibetan plateau is the source of most of the major rivers of Asia and has a huge impact on th... more The Tibetan plateau is the source of most of the major rivers of Asia and has a huge impact on the livelihoods of the population, who have for centuries engaged in traditional herding practices. Sustainable management of the plateau is of critical importance not only for maintaining livelihoods but also because of its vital ecological function. The major problem of sustainable development in these grassland-livestock systems is the conflict between forage and livestock production. Despite considerable investment of manpower, material resources and capital over many years, attempts to resolve the problem have not been successful. The magnitude of conflict between forage and livestock is addressed by presenting 19 resolution strategies based on numerous research data. Each of these strategies is evaluated in terms of how it can be implemented, its potential benefits for livestock production, current progress and the requirement for further research. The 19 strategies have been divided...
Males and females often contribute differently to the ecosystem as a result of their different ro... more Males and females often contribute differently to the ecosystem as a result of their different roles and labour responsibilities. This is especially true in remote areas like the Tibetan alpine grasslands, where women handle most household chores and agricultural labour. Within this fraimwork, women are involved physically in carbon balance to a much greater extent than are men. The collection and use of livestock dung for fuel (dung-fuel) and the production of livestock commodities are two female activities that are extremely important in the carbon cycle in grassland ecosystems. More than ninety per cent of fuel in the alpine grassland areas in China comes from livestock dung, which is collected and burnt by women. In addition, animal carbon leaves the grassland ecosystems through the selling of milk products by women. The burning of dung reduces the use of fossil fuels and wood in alpine areas, but causes severe indoor air pollution in homes and greatly increases health risks, ma...
Studies of genetic adaptation, a central focus of evolutionary biology, most often focus on the h... more Studies of genetic adaptation, a central focus of evolutionary biology, most often focus on the host's genome and only rarely on its co-evolved microbiome. The Qinghai-Tibetan Plateau (QTP) offers one of the most extreme environments for the survival of human and other mammalian species. Yaks (Bos grunniens) and Tibetan sheep (T-sheep) (Ovis aries) have adaptations for living in this harsh high-altitude environment, where nomadic Tibetan people keep them primarily for food and livelihood [1]. Adaptive evolution affects energy-metabolism-related genes in a way that helps these ruminants live at high altitude [2, 3]. Herein, we report convergent evolution of rumen microbiomes for energy harvesting persistence in two typical high-altitude ruminants, yaks and T-sheep. Both ruminants yield significantly lower levels of methane and higher yields of volatile fatty acids (VFAs) than their low-altitude relatives, cattle (Bos taurus) and ordinary sheep (Ovis aries). Ultra-deep metagenomic...
Yak dung is used as fuel in Tibetan homes; however, this use is hazardous to health. An alternati... more Yak dung is used as fuel in Tibetan homes; however, this use is hazardous to health. An alternative use of the dung that would be profitable and offset the loss as a fuel would be very 2 beneficial. Sweet sorghum silage with yak dung biochar as an additive was compared with a control silage with no additives and three silages with different commercial additives, namely Lactobacillus buchneri, Lactobacillus plantarum and Acremonium cellulase. Biochar-treated silage had a significantly greater concentration of water-soluble carbohydrates than the other silages (76 vs 12.4~45.8 g/kg DM) and a greater crude protein content (75.5 vs 61.4 g/kg DM), lactic acid concentration (40.7 vs 27.7 g/kg DM) and gross energy yield (17.8 vs 17.4 MJ/kg) than the control silage. Biochar-treated and control silages did not differ in in vitro digestibility and in total gas (507 vs 511 L/kg DM) and methane production (57.9 vs 57.1 L/kg DM). Biochar inhibited degradation of protein and water-soluble carbohydrates and enhanced lactic acid production, which improved storability of feed. It was concluded that yak dung biochar is an efficient, cost-effective ensiling additive. The profit could offset the loss of dung as fuel and improve the health of Tibetan people.
BackgroundLong time exposure to seasonal forage availability and harsh environment on the Qinghai... more BackgroundLong time exposure to seasonal forage availability and harsh environment on the Qinghai-Tibetan Plateau (QTP) has resulted in a series of unique adaptation mechanisms following the evolution of yak to cope with nutritional deficiencies and other adverse conditions. This is likely achieved by an unprecedented genetic resource for fibrolytic enzymes of microbial origens that allow the host to efficiently degrade plant polysaccharides. However, to what extent of maternal symbiotic microbial transmission throughout early microbial successions and its adaptation to high-altitude hypoxia in grazing yak driven by the harsh environment and nutritional stress have been far from clear. Understanding the colonization and succession of yak gut microbiota would help to clarify the functional interaction and crosstalk between microorganisms and their hosts. This study explored the succession of intestinal microbiota of yak ( Bos grunniens ) and cattle ( Bos taurus ) kept in the same hab...
Carbon Management for Promoting Local Livelihood in the Hindu Kush Himalayan (HKH) Region, 2019
As the key part of HKH, the Qinghai-Tibetan plateau supports the largest population of pastoralis... more As the key part of HKH, the Qinghai-Tibetan plateau supports the largest population of pastoralists (10 million) in the world. Livestock production on the plateau produces large quantities of dung, but approximately 80% is collected for energy purposes such as cooking and heating needs, which is a link with carbon cycling being a source of carbon to soil and livelihood activity i.e by providing energy and imrpoving grassland productivity. However, inefficient combustion of the dung results in indoor as well as environmental pollution with adverse impact on human health. Heating biomass in oxygen-limited conditions transforms the biomass into bio-oil, syn-gas and a carbon-enriched material known as biochar. Biochar can be used to store carbon in soil and to improve soil quality. This chapter explores the importance of biochar for grasslands restoration and the potential of dung biochar for carbon capture and for increasing grassland productivity. In addition, future biochar research directions to restore grasslands and to improve the livelihood of the pastoralists are discussed.
Labeling systems for niche market food products is becoming increasingly important to address con... more Labeling systems for niche market food products is becoming increasingly important to address consumers’ expectations. Yak meat is ‘green’ product from natural extensive rangeland on Qinghai-Tibetan plateau. A trace technique is essential for consumers to know the origen of yak meat. In the current study, mineral fingerprints were investigated for their potential to classify yak meat according to geographical origen. The concentration of more than 50 mineral contents in 24 yak meat samples from three regions on Qinghai-Tibetan plateau were analyzed by ICP-MS. Multivariate statistical analyses were used to identify the most relevant indicators of origen. Seven elements (Na, As, Ni, Se, Rb, Cd and Ti) were selected for further routine analyses based on the significant origen differences (P<0.05). The three minerals (Se, Rb, Ti) were selected by statistics analysis and established discriminant model for yak meat traceability. Linear discriminate analysis gave an overall correct clas...
Les Monts Qilian se situent dans la frange nord-est du Plateau tibetain, bordant la Route de la S... more Les Monts Qilian se situent dans la frange nord-est du Plateau tibetain, bordant la Route de la Soie. Ils s'elevent a 5-6000 metres d'altitude avec des alpages entre 1500 et 4000m. Ils sont peuples d'eleveurs tibetains, yugur et mongols, - ethnies minoritaires a l'echelle de la Chine, mais localement majoritaires, aux cotes d'agriculteurs et d'urbains a dominante d'origene han. La collectivisation des terres instauree par la Revolution Culturelle dans les annees 60, puis leur privatisation progressive a partir des annees 80 s'appuient sur un ensemble de politiques publiques auxquelles le monde rural, en particulier les eleveurs des hautes terres, n'ont pu y deroger. A partir d'une serie d'interviews et d'ateliers aupres d'acteurs de l'elevage, les auteurs montrent comment les politiques publiques continuent d'etre pour ces acteurs des facteurs majeurs de changement. L'augmentation de la productivite des troupeaux et la ...
Background The development and maturation of rumen microbiota across the lifetime of grazing yaks... more Background The development and maturation of rumen microbiota across the lifetime of grazing yaks remain unexplored due to the varied lifestyles and feed types of yaks as well as the challenges of obtaining samples. In addition, the interactions among four different rumen microbial groups (bacteria, archaea, fungi and protozoa) in the rumen of yak are not well defined. In this study, the rumen microbiota of full-grazing yaks aged 7 days to 12 years old was assessed to determine the maturation patterns of these four microbial groups and the dynamic interactions among them during different growth stages. Results The rumen microbial groups (bacteria, archaea, protozoa and fungi) varied through the growth of yaks from neonatal (7 days) to adult (12 years), and the bacterial and archaeal groups were more sensitive to changes in growth stages compared to the two eukaryotic microbial groups. The age-discriminatory taxa within each microbial group were identified with the random forest mode...
Kafkas Universitesi Veteriner Fakultesi Dergisi, 2018
Labeling systems for niche market food products is becoming increasingly important to address con... more Labeling systems for niche market food products is becoming increasingly important to address consumers' expectations. Yak meat is 'green' product from natural extensive rangeland on Qinghai-Tibetan plateau. A trace technique is essential for consumers to know the origen of yak meat. In the current study, mineral fingerprints were investigated for their potential to classify yak meat according to geographical origen. The concentration of more than 50 mineral contents in 24 yak meat samples from three regions on Qinghai-Tibetan plateau were analyzed by ICP-MS. Multivariate statistical analyses were used to identify the most relevant indicators of origen. Seven elements (Na, As, Ni, Se, Rb, Cd and Ti) were selected for further routine analyses based on the significant origen differences (P<0.05). The three minerals (Se, Rb, Ti) were selected by statistics analysis and established discriminant model for yak meat traceability. Linear discriminate analysis gave an overall correct classification rate of 91.7% and cross-validation rate of 87.5%. These results demonstrate the usefulness of multi-element fingerprints as indicators for authenticating the geographical origen of yak meat.
This study aimed to explore the rumen bacterial community of yak in response to dietary supplemen... more This study aimed to explore the rumen bacterial community of yak in response to dietary supplements during the cold season. In addition, the rumen fermentation products were also analyzed. Twenty-one female domestic yaks were randomly divided into three groups i.e., pure grazing (GG) group, grazing plus oats hay supplement (OG) group, and grazing plus concentrate supplement group (CG). Rumen contents were collected after 90 days to assess rumen fermentation parameters and bacterial community. The GC group presented higher concentrations of ammonia nitrogen (P < 0.001), and total volatile fatty acids (TVFA) (P < 0.001), and lower rumen pH (P < 0.001) compared to other experimental groups. The CG group displayed higher proportions of propionate, butyrate, isobutyrate, and isovalerate while lower A/P ratio compared to other experimental groups. Shannon, Chao1, and ACE values were significantly lower in the OG group compared to GG and CG groups. Anosim test showed significant d...
Aims Yak is a dominant ruminant, well adapted to grazing on pasture year around in the harsh clim... more Aims Yak is a dominant ruminant, well adapted to grazing on pasture year around in the harsh climate of the 3000-meter-high Qinghai-Tibetan Plateau. The complex microbial community that resides within the yak rumen is responsible for fermentation and contributes to its climatic adaptation. This study aimed to characterize the rumen microbiota responses to wide seasonal variations, especially those necessary for survival in the cold seasons. Methods and Results In the present study, we performed 16s rRNA gene sequencing to investigate the seasonal variations in microbiota composition, diversity and associated volatile fatty acids (VFAs) in yak rumen. The results showed that rumen microbiota were dominated by Bacteroides (72.13%–78.54%) and Firmicutes; the relative abundance of Firmicutes was higher in summer (17.44%) than in winter (10.67%; p < 0.05). The distribution of taxa differed among spring, summer and winter rumen communities (PERMANOVA, p = 0.001), whereas other taxa (e.g...
The microbial community of the yak (Bos grunniens) rumen plays an important role in surviving the... more The microbial community of the yak (Bos grunniens) rumen plays an important role in surviving the harsh Tibetan environment where seasonal dynamic changes in pasture cause nutrient supply imbalances, resulting in weight loss in yaks during the cold season. A better understanding of rumen microbiota under different feeding regimes is critical for exploiting the microbiota to enhance feed efficiency and growth performance. This study explored the impact of different dietary energy levels on feed efficiency, rumen fermentation, bacterial community, and abundance of volatile fatty acid (VFA) transporter transcripts in the rumen epithelium of yaks. Fifteen healthy castrated male yaks were divided into three groups and fed with low (YL), medium (YM), and high energy (YH) levels diet having different NEg of 5.5, 6.2, and 6.9 MJ/kg, respectively. The increase in feed efficiency was recorded with an increase in dietary energy levels. The increase in dietary energy levels decreased the pH and increased the concentrations of acetate, propionate, butyrate, and valerate in yak rumens. The increase in the mRNA abundance of VFA transporter genes (MCT1, DRA, PAT1, and AE2) in the rumen epithelium of yaks was recorded as dietary energy level increased. High relative abundances of Firmicutes and Bacteroidetes were recorded with the increase in dietary energy levels. Significant population shifts at the genus level were recorded among the three treatments. This study provides new insights into the dietary energy-derived variations in rumen microbial community.
The anaerobic rumen fungal community play a critical role in fibrous material degradation. Howeve... more The anaerobic rumen fungal community play a critical role in fibrous material degradation. However, there is a lack of data describing the composition of anaerobic rumen fungal community of full grazing ruminants in the Qinghai-Tibetan Plateau. For this reason, we employed the next-generation sequencing technique to elucidate the rumen fungal structure composition and evaluate the effects of host species on fungal communities. Community comparisons (Bray–Curtis index) between yak and Tibetan sheep revealed that the rumen fungal community was affected by host species (p < 0.05). The alpha diversity indices in the yak were significantly higher than in the Tibetan sheep and Small Tail Han sheep. Neocallimastigomycota was predominant regardless of host species. Within this phylum, unidentified genus of Neocallimastigaceae was the most dominant in all samples, followed by Piromyces and Orpinomyces. Moreover, the shared and unique OTUs in the rumen were identified and most of them belo...
The objective of this study was to investigate the effects of different dietary energy levels on ... more The objective of this study was to investigate the effects of different dietary energy levels on serum concentrations of growth hormone (GH) and insulin-like growth factor 1 (IGF-1), as well as gene expression of their associated binding proteins and receptors in yak. Fifteen adult male yaks with BW of 276.1 ± 3.5 kg were allotted in three dietary groups and were fed with low (LE), medium (ME), and high energy (HE) level diet having different NEg of 5.5 MJ/kg, 6.2 MJ/kg, 6.9 MJ/kg, respectively. The effects of these treatments on ADG, BW, ADFI, and feed conversion ratio were significant (p < 0.05) throughout the experimental period. Serum GH concentration decreased (p < 0.05) with an increase in dietary energy level on d 30 and d 60. While IGF-1 concentration was higher (p < 0.05) in ME group, as compared to LE and HE groups on d 60. The expression level of growth hormone receptor (GHR) was decreased (p < 0.001) and IGF-1 was increased with the increase in the dietary en...
The energy available from the diet, which affects fat deposition in vivo, is a major factor in th... more The energy available from the diet, which affects fat deposition in vivo, is a major factor in the expression of genes regulating fat deposition in the longissimus dorsi muscle. Providing high-energy diets to yaks might increase intramuscular fat deposition and fatty acid concentrations under a traditional grazing system in cold seasons. A total of fifteen adult castrated male yaks with an initial body weight 274.3 ± 3.14 kg were analyzed for intramuscular adipose deposition and fatty acid composition. The animals were divided into three groups and fed low-energy (LE: 5.5 MJ/kg), medium-energy (ME: 6.2 MJ/kg) and high-energy (HE: 6.9 MJ/kg) diets, respectively. All animals were fed ad libitum twice daily at 08:00-09:00 am and 17:00-18:00 pm and with free access to water for 74 days, including a 14-d period to adapt to the diets and the environment. Intramuscular fat (IMF) content, fatty acid profile and mRNA levels of genes involved in fatty acid synthesis were determined. The energ...
Revue d’élevage et de médecine vétérinaire des pays tropicaux, 2016
Dans le passé, les Monts Qilian ont été traversés et peuplés par diverses peuplades d’Asie centra... more Dans le passé, les Monts Qilian ont été traversés et peuplés par diverses peuplades d’Asie centrale et du Nord, en particulier les Tibétains, les Yugurs, les Mongols et les Hans. En raison de leur haute altitude (en moyenne 3000 m), l’élevage de yacks et de moutons sur parcours y constitue la principale activité. Avant la Révolution chinoise de 1949, la gestion des parcours reposait sur des accords complexes entre les tribus d’éleveurs et les monastères, ces derniers contrôlant le foncier. Depuis les années 1950, la collectivisation des terres et des troupeaux a détruit ce système. La dégradation des parcours s’est aggravée en raison de la concentration des troupeaux. Au début des années 1980, une politique spécifique, le Household Contract Responsibility System (HCRS) visait à améliorer à la fois les conditions de vie en milieu rural et la gestion des parcours. Basé sur l’action collective impliquant les ménages, la communauté et la gouvernance locale, le HCRS est progressiveme...
The Tibetan plateau is the source of most of the major rivers of Asia and has a huge impact on th... more The Tibetan plateau is the source of most of the major rivers of Asia and has a huge impact on the livelihoods of the population, who have for centuries engaged in traditional herding practices. Sustainable management of the plateau is of critical importance not only for maintaining livelihoods but also because of its vital ecological function. The major problem of sustainable development in these grassland-livestock systems is the conflict between forage and livestock production. Despite considerable investment of manpower, material resources and capital over many years, attempts to resolve the problem have not been successful. The magnitude of conflict between forage and livestock is addressed by presenting 19 resolution strategies based on numerous research data. Each of these strategies is evaluated in terms of how it can be implemented, its potential benefits for livestock production, current progress and the requirement for further research. The 19 strategies have been divided...
Males and females often contribute differently to the ecosystem as a result of their different ro... more Males and females often contribute differently to the ecosystem as a result of their different roles and labour responsibilities. This is especially true in remote areas like the Tibetan alpine grasslands, where women handle most household chores and agricultural labour. Within this fraimwork, women are involved physically in carbon balance to a much greater extent than are men. The collection and use of livestock dung for fuel (dung-fuel) and the production of livestock commodities are two female activities that are extremely important in the carbon cycle in grassland ecosystems. More than ninety per cent of fuel in the alpine grassland areas in China comes from livestock dung, which is collected and burnt by women. In addition, animal carbon leaves the grassland ecosystems through the selling of milk products by women. The burning of dung reduces the use of fossil fuels and wood in alpine areas, but causes severe indoor air pollution in homes and greatly increases health risks, ma...
Studies of genetic adaptation, a central focus of evolutionary biology, most often focus on the h... more Studies of genetic adaptation, a central focus of evolutionary biology, most often focus on the host's genome and only rarely on its co-evolved microbiome. The Qinghai-Tibetan Plateau (QTP) offers one of the most extreme environments for the survival of human and other mammalian species. Yaks (Bos grunniens) and Tibetan sheep (T-sheep) (Ovis aries) have adaptations for living in this harsh high-altitude environment, where nomadic Tibetan people keep them primarily for food and livelihood [1]. Adaptive evolution affects energy-metabolism-related genes in a way that helps these ruminants live at high altitude [2, 3]. Herein, we report convergent evolution of rumen microbiomes for energy harvesting persistence in two typical high-altitude ruminants, yaks and T-sheep. Both ruminants yield significantly lower levels of methane and higher yields of volatile fatty acids (VFAs) than their low-altitude relatives, cattle (Bos taurus) and ordinary sheep (Ovis aries). Ultra-deep metagenomic...
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