Objective:To evaluate the antimicrobial efficacy of berberine,a plant alkaloid.Methods:Five multi-drug resistant(MDR) STEC/EPEC and five MDR ETEC isolates from yaks with haemorrhagic diarrhoea were selected for the ...Objective:To evaluate the antimicrobial efficacy of berberine,a plant alkaloid.Methods:Five multi-drug resistant(MDR) STEC/EPEC and five MDR ETEC isolates from yaks with haemorrhagic diarrhoea were selected for the study.Antibacterial activity of berberine was evaluated by broth dilution and disc diffusion methods.The binding kinetics of berberine to DNA and protein was also enumerated.Results:For both categories of enterovirulent Escherichia coli(E.roli) isolates, berberine displayed the antibaclerial effect in a dose dependent manner.The MIC<sub>50</sub> of berberine chloride for STEC/EPEC isolates varied from 2.07μM to 3.6μM with a mean of(2.95±0.33)μM where as for ETEC strains it varied from 1.75 to 1.96μM with a mean of(1.87±0.03)μM. Berberine bind more tightly with double helix DNA with Bmax and Kd of(24.68±2.62) and(357.8±57.8),respectively.Berberine reacted with protein in comparatively loose manner with Bmax and Kd of(18.9±3.83) and 【286.2±113.6),respectively.Conclusions:The results indicate clearly that berberine may serve as a good antibacterial against multi drug resistant E.coli.展开更多
Primers based upon the mitochondrial genome sequences of Bos taurus were used to amplify and sequence the complete mitochondrial D-loop region of Jiulong yak(Poephagus grunniens).The results showed that the length of ...Primers based upon the mitochondrial genome sequences of Bos taurus were used to amplify and sequence the complete mitochondrial D-loop region of Jiulong yak(Poephagus grunniens).The results showed that the length of D-loop was 893 bp,with 87.4%homology to the Bos taurus D-loop sequence;there were 17 bp deletion.Using Ovis aries as an outgroup,the phylogeny of representative species of Bovinae(P.grunniens,P.mutus,Bos taurus,Bos indicus,Bison bison,Bison bonasus,and Bubalus bubalis)was analyzed.Among Bovinae,the sequence divergence between P.grunniens,P.mutus and American bison(Bison bison)was 6.2%-6.8%,which was less than that of Bos taurus and Bos indicus within Bos(10.0%-11.3%).Phylogenetic analysis found that P.grunniens,P.mutus and Bison bison clustered first of all,indicating there was higher genetic comparability among them than to that of Bos.Combining data from paleontology,morphology,and molecular biology,the present analysis supports the argument that Poephagus grunniens and Poephagus mutus should be classified as a distinct genus in Bovinae,that is Poephagus.展开更多
Camels and yaks milks are rich in numerous bioactive substances that function beyond their nutritive value. Milk Camel milk is more similar to goat milk and contains less short-chain fatty acids than cow, sheep and bu...Camels and yaks milks are rich in numerous bioactive substances that function beyond their nutritive value. Milk Camel milk is more similar to goat milk and contains less short-chain fatty acids than cow, sheep and buffalo milks, and about 3 times greater vitamin-C than cow milk. One kg of camel milk meets 100% of daily human requirements for calcium and phosphorus, 57.6% for potassium, 40% for iron, copper, zinc and magnesium, and 24% for sodium. Camel milk helps treat liver problems, lowers bilirubin output, lightens vitamin inadequacy and nutrient deficiency, and boosts immunity. Camel milk reduces allergies caused by cow dairy products. Camel milk has low milk fat made mainly from polyunsaturated fatty acids. It lacks ?-lactoglobulin and is rich in immunoglobulins, compatible with human milk. Yak milk has 16.9 - 17.7% solids, 4.9 - 5.3% protein, 5.5 - 7.2% fat, 4.5 - 5.0% lactose, and 0.8 - 0.9% minerals. Yak milk fat is richer in polyunsaturated fatty acids, protein, casein and fat than cow milk. Yak milk casein is used to produce antihypertensive peptides with capacities for producing value-added functional foods and proteins. Continual system-atic education of milk science especially for non-cow species will be an obligation for health implications to be optimally perceived by human populations worldwide.展开更多
To understand the exact changes in body size and body weight of Jinchuan female yaks within one year,the body size and body weight of 30 Jinchuan female yaks were measured from July 2015 to July 2016. The results show...To understand the exact changes in body size and body weight of Jinchuan female yaks within one year,the body size and body weight of 30 Jinchuan female yaks were measured from July 2015 to July 2016. The results showed that the body weight of Jinchuan female yak declined continuously since October 2015,and the weight loss in November 2015 was the largest. The body weight started to increase in May 2016,and the body weight increased significantly in June and July of 2016.展开更多
[Objective] The aim was to explore radical metabolism and mechanism of energy metabolism in mitochondria of yak calves. [Method] Activities of T-AOC, GSH-Px, SOD and LDH and contents of MDA and NO were measured of mit...[Objective] The aim was to explore radical metabolism and mechanism of energy metabolism in mitochondria of yak calves. [Method] Activities of T-AOC, GSH-Px, SOD and LDH and contents of MDA and NO were measured of mitochondria in cardiac and skeletal muscles of yak calves with 1/4 wild bloods at six-month old. [ Result] T-AOC, GSH-Px and SOD activities and NO content were all a little higher in mitochoodria of yaks with wild bloods than those in skeletal muscles (P 〉0.05) and MDA content in mitochondria in cardiac muscles was significantly higher than that in skeletal muscles (P 〈0.05). [ Conclude] The research provides theoretical references for hypoxia-adaptability of yak calves with 1/4 wild bloods.展开更多
In order to clarify the interactive mechanism between grazing yak and alpine meadow on the Qinghai-Tibetan Plateau,our study assessed seed density(by species) in the topsoil of alpine meadow with different grazing i...In order to clarify the interactive mechanism between grazing yak and alpine meadow on the Qinghai-Tibetan Plateau,our study assessed seed density(by species) in the topsoil of alpine meadow with different grazing intensities in the Tianzhu area,north-eastern margins of the Qinghai-Tibetan Plateau and their rates of occurrence in yak dung.Seed density in the topsoil of the lightly grazed,moderately grazed,heavily grazed and extremely grazed alpine meadows in November,2010 were 1 551,1 692,2 660 and 1 830 grains m-2,while in the same meadows in April,2011 densities were 1 530,2 404,2 530 and 2 692 grains m-2,respectively.In the cold season pasture,mean seed density in yak dung from November to April in the lightly grazed,moderately grazed,heavily grazed and extremely grazed sites were 121,127,187,and 120 grains kg-1of dry yak dung.The proportion of total seed numbers in yak dung to soil seed bank in lightly grazed,moderately grazed,heavily grazed and extremely grazed alpine meadow was 1.40,2.62,0.69,and 0.90%.12 species out of the 47 were not found in topsoil but were found in yak dung,10 species out of 45 were not found in yak dung but were found in the topsoil.Endozoochorous dispersal by yaks is therefore very important for soil seed bank and plant biodiversity and population dynamics in alpine meadows.展开更多
Melanin granules were isolated from fine yak hair by means of protein enzyme and hydrochloric acid.Resultsof SEM investigation and amino acid analysis were usedto study the physical and chemical properties of melaning...Melanin granules were isolated from fine yak hair by means of protein enzyme and hydrochloric acid.Resultsof SEM investigation and amino acid analysis were usedto study the physical and chemical properties of melaningranules.The solubility of melanin granules in differentchemical solutions was also studied.展开更多
Yaks live in Qinghai-Tibet Plateau (4 km above sea level), and the nutrient components of their placenta were determined, including 17 kinds of amino acids and 11 kinds of trace elements. The results showed that the...Yaks live in Qinghai-Tibet Plateau (4 km above sea level), and the nutrient components of their placenta were determined, including 17 kinds of amino acids and 11 kinds of trace elements. The results showed that there are abundant amino acids and trace elements in the placenta of yak, equal to that of human and deer, indicating some medical and nutritional value of yak placenta.展开更多
This study was conducted to investigate the phylogenetic diversity of archaea in the rumen of adult and elderly yaks. Six domesticated female yaks, 3 adult yaks ((5.3±0.6) years old), and 3 elderly yaks ((1...This study was conducted to investigate the phylogenetic diversity of archaea in the rumen of adult and elderly yaks. Six domesticated female yaks, 3 adult yaks ((5.3±0.6) years old), and 3 elderly yaks ((10.7±0.6) years old), were used for the rumen contents collection. Illumina MiSeq high-throughput sequencing technology was applied to examine the archaeal composition of rumen contents. A total of 92 901 high-quality archaeal sequences were analyzed, and these were assigned to 2 033 operational taxonomic units (OTUs). Among these, 974 OTUs were unique to adult yaks while 846 OTUs were unique to elderly yaks; 213 OTUs were shared by both groups. At the phylum level, more than 99% of the obtained OTUs belonged to the Euryarchaeota phylum. At the genus level, the archaea could be divided into 7 archaeal genera. The 7 genera (i.e., Methanobrevibacter, Methanobacterium, Methanosphaera, Thermogymnomonas, Methanomicrobiu, Meth- animicrococcus and the unclassified genus) were shared by all yaks, and their total abundance accounted for 99% of the rumen archaea. The most abundant archaea in elderly and adult yaks were Methanobrevibacterand Thermogymnomonas, respectively. The abundance of Methanobacteria (class), Methanobacteriales (order), Methanobacteriaceae (family), and Methanobrevibacter (genus) in elderly yaks was significantly higher than in adult yaks. In contrast, the abundance of Ther-mogymnomonas in elderly yaks was 34% lower than in adult yaks, though the difference was not statistically significant. The difference in abundance of other archaea was not significant between the two groups. These results suggested that the structure of archaea in the rumen of yaks changed with age. This is the first study to compare the phytogenetic differences of rumen archaeal structure and composition using the yak model.展开更多
Nine Chinese yak breeds (Maiwa, Tianzhu White, Qinghai Plateau, Sibu, Zhongdian, Pali, Tibetan High Mountain, Jiulong, and Xinjiang) and Gayal were analyzed by means of 16 microsatellite markers to determine the lev...Nine Chinese yak breeds (Maiwa, Tianzhu White, Qinghai Plateau, Sibu, Zhongdian, Pali, Tibetan High Mountain, Jiulong, and Xinjiang) and Gayal were analyzed by means of 16 microsatellite markers to determine the level of genetic variation within populations, genetic relationship between populations, and population structure for each breed. A total of 206 microsatellite alleles were observed. Mean F-statistics (0.056) for 9 yak breeds indicated that 94.4% of the genetic variation was observed within yak breeds and 5.6% of the genetic variation existed amongst breeds. The Neighbor-Joining phylogenetic tree was constructed based on Nei's standard genetic distances and two clusters were obtained. The Gayal separated from the yaks far away and formed one cluster and 9 yak breeds were grouped together. The analysis of population structure for 9 yak breeds and the Gayal showed that they resulted in four clusters; one cluster includes yaks from Tibet Autonomous Region and Qinghai Province, one cluster combines Zhongdian, Maiwa, and Tianzhu White, and Jiulong and Xinjiang come into the third cluster. Pali was mainly in the first cluster (90%), Jiulong was mainly in the second cluster (87.1%), Zhongdian was primarily in the third cluster (83%), and the other yak breeds were distributed in two to three clusters. The Gayal was positively left in the fourth cluster (99.3%).展开更多
Endothelial PAS domain protein 1 gene (EPAS1) is a key transcription factor that activates the expression of oxygen-regu- lated genes. In this study, in order to better understand the effects of EPAS1 gene on hemato...Endothelial PAS domain protein 1 gene (EPAS1) is a key transcription factor that activates the expression of oxygen-regu- lated genes. In this study, in order to better understand the effects of EPAS1 gene on hematologic parameters in yak, we firstly quantified the tissue expression patterns for EPASl mRNA of yak, identified polymorphism in this gene and evaluated its association with hematologic parameters. Expression of EPAS1 mRNA was detected in all eight tissues (heart, liver, lung, spleen, pancreas, kidney, muscles and ovary). The expressions of EPAS1 in lung and pancreas were extremely higher than other tissues examined. Three novel single nucleotide polymorphisms (SNPs) (g.83052 C〉T, g.83065 G〉A and g.83067 C〉A) within the EPAS1 were identified and genotyped in Pali (PL), Gannan (GN) and Tianzhu White (TZW) yak breeds. Significant higher frequencies of the AA and GA genotypes and A allele of the g.83065 G〉A were observed in the PL and GN breeds than that in the TZW breed (P〈0.01). Association analysis of the PL breed indicated that the g.83065 G〉A polymorphism was significantly associated with hemoglobin (HGB) concentration in yaks (P〈0.05). Individuals with genotype AA had significantly higher HGB concentration (P〈0.05) than those with genotype GA and GG. All these results will help our further understanding of biological functional of yak EPAS1 gene in responding to hypoxia and also indicate EPAS1 might contribute to the hypoxia adaptation of the yak.展开更多
Yaks of two lactating types, the half-Iactating yak and the total lactating yak, were investigated in their milk compositions, milk coagulation properties, and contents of three kinds of hormones, glucose, and protein...Yaks of two lactating types, the half-Iactating yak and the total lactating yak, were investigated in their milk compositions, milk coagulation properties, and contents of three kinds of hormones, glucose, and protein in plasma. The half-lactating Maiwa yak and Jiulong yak contained significantly higher contents of protein, fat, and activities of alkaline phosphatase and Y-glutamyl transpeptidase in milk than that of the corresponding total-lactating yak breeds, with reduced milk yield and similar lactose level and relative percentages of main milk protein components. The half-lactatin yak resembled yaks in a late stage of lactation in their biochemical composition of milk; however, significant differences were also observed, which indicated that the former was in a special stage of lactation quite different from dairy cows. Milk of the total-lactating or half-lactating yaks could be coagulated normally by adding chymosin, with a similar coagulation time. No significant difference was observed between prolactin and progesterone concentrations in plasma of the half-lactating yaks and total-lactating yaks; however, half-lactating yaks had significantly lower level of oestradiol-17 β in plasma than total-lactating yaks.展开更多
To assess the impact of N fertilization on contents of mineral elements in herbage and the effect of increased forage S on the copper metabolism of grazing yaks, study was conducted during the summer grazing season (...To assess the impact of N fertilization on contents of mineral elements in herbage and the effect of increased forage S on the copper metabolism of grazing yaks, study was conducted during the summer grazing season (2005, 2006, and 2007). Pasture replicates (20 ha; n=3 per treatment) received the same fertilizer treatment in each growing season, consisting of i) 90 kg N ha^-1 from quickly available nitrogen, ii) 90 kg N ha^-1 from ammonium nitrate, iii) 90 kg N ha^-1 from ammonium sulfate, and iv) control (no fertilizer). Forage sampling was collected at 60 days intervals following fertilization (10 samples per pasture) for Cu, Mo, Mn, Se, Fe, Zn, Ca, and P. To determine the effect of fertilizer treatment on mineral metabolism in grazing yaks, liver and blood samples were collected at the start and end of the study period in 2005, 2006, and 2007. Ammonium sulfate fertilization increased (P 〈 0.01) forage S concentration. Plant tissue N concentrations were increased by N fertilization, regardless of source in 2005, 2006, and 2007. Yaks grazing S fertilization pastures had lower (P〈0.05) liver and blood Cu concentrations at the end of the study period in 2005, 2006, and 2007, compared with urea, ammonium nitrate, and control. Nominal increases in forage in vitro organic matter digestibility were realized by fertilization, regardless of N source in each year.展开更多
Since the 1990s, yak in the Haizi area in China has been affected by an ailment characterized by pica, emaciation, dyskinesia, and anemia. To determine the cause of disease, the mineral composition of soil and forages...Since the 1990s, yak in the Haizi area in China has been affected by an ailment characterized by pica, emaciation, dyskinesia, and anemia. To determine the cause of disease, the mineral composition of soil and forages, and samples of blood, hair, and liver of yaks from the Haizi area in China were determined. The concentrations of copper in soil and forage from affected ranches and unaffected areas are within the normal ranges. The mean concentration of copper in blood and liver from the affected yaks was (0.31±0.03) and (13.7±3.1)μg·g^-1 respectively, compared with (0.98±0.16) and (95.6±11.2)μg·g^-1 for unaffected yaks. The concentrations of sulfur in soil and forage from affected ranches were (1.91±0.26) and (1.37±0.17)%, respectively, compared with (1.11±0.31) and (0.52±0.18)% (dry matter) for normal areas. The contents of sulfur in blood and liver affected animals were (7.32±1.8) and (2.54±3.1)%, respectively, compared with (4.22±0.73) and (1.31±0.33)% (in fresh and soft tissues) for healthy animals, respectively. Oral administration of tribasic copper chloride prevented and cured the disease. Thus it is reasonable to conclude that ailments of yaks in the Haizi area are probably caused by a secondary copper deficiency, mainly due to high sulfur content in soil and forage.展开更多
The change in lactation of Maiwa yak was studied based on the data of locating Maiwa yak in warm seasons during 2003- 2009. The results showed that the milk yield was increasing gradually during days 30- 70 after calv...The change in lactation of Maiwa yak was studied based on the data of locating Maiwa yak in warm seasons during 2003- 2009. The results showed that the milk yield was increasing gradually during days 30- 70 after calving,reached the peak at days 70- 110,and decreased gradually to no milking whenafter. The milk yield of Maiwa yak was greatly influenced by lactation age rather than the yearly effect.展开更多
[ Objective ] To analyze the hair and villus production performance of Tianzhu white yak and thus provide conditions for the genetic breed ing and product development. [Method] The hair and villus yield as well as vil...[ Objective ] To analyze the hair and villus production performance of Tianzhu white yak and thus provide conditions for the genetic breed ing and product development. [Method] The hair and villus yield as well as villus rate of male and female Tianzhu white yaks from one year to six years old was detected and the villus yield was also determined. And these indexes of hair and villus were analyzed to evaluate the production per formance. [ Result] In Tianzhu white yaks from one year to two years old, the hair and villus yield was lower, but the villus rate and yield were high er. The hair and villus yield, villus rate, and villus yield were all higher in Tianzhu white yaks from three years to six years old but significantly de creased in 7yearold Tianzhu white yaks. In addition, the hair and villus yield was significantly ( P 〈 0.05) or very significantly ( P 〈 0.01 ) higher in male yaks than in female yaks. The villus rate was very significantly ( P 〈0.01 ) higher than in female yaks from five years to seven years old than in male yaks at the same age. [ Conclusion] Tianzhu white yaks from one year to two years old have the best hair and villus production perform ance; Tianzhu white yaks from three years to six years old are in the main phase of hair and villus production; Tianzhu white yaks older than seven years old should not be used for hair and villus production.展开更多
The milk protein polymorphisms were typed by polyacrylamide gel electrophoresis (PAGE)from 109 Maiwa and 100 Jiulong yaks, and the relationships among milk protein polymorphisms,milking traits and milk protein composi...The milk protein polymorphisms were typed by polyacrylamide gel electrophoresis (PAGE)from 109 Maiwa and 100 Jiulong yaks, and the relationships among milk protein polymorphisms,milking traits and milk protein compositions were studied. The results showed thatβ-CN,κ-CN andα-La were monomorphic,αs1-CN andβ-Lg were polymorphic, the dominantgenes were αs1-CN D and β-Lg E,respectively. The frequencies of αs1-CN D were 0.8073and 0.6000 and β-Lg E were 0.9770 and 0.9700 in two populations respectively.The meanheterozygosities were 0.1021 and 0.1867 in two populations. No significant effects onmilking traits and milk protein compositions were observed except for αs1-CN locus onfat percentage in Jiulong yak.展开更多
文摘Objective:To evaluate the antimicrobial efficacy of berberine,a plant alkaloid.Methods:Five multi-drug resistant(MDR) STEC/EPEC and five MDR ETEC isolates from yaks with haemorrhagic diarrhoea were selected for the study.Antibacterial activity of berberine was evaluated by broth dilution and disc diffusion methods.The binding kinetics of berberine to DNA and protein was also enumerated.Results:For both categories of enterovirulent Escherichia coli(E.roli) isolates, berberine displayed the antibaclerial effect in a dose dependent manner.The MIC<sub>50</sub> of berberine chloride for STEC/EPEC isolates varied from 2.07μM to 3.6μM with a mean of(2.95±0.33)μM where as for ETEC strains it varied from 1.75 to 1.96μM with a mean of(1.87±0.03)μM. Berberine bind more tightly with double helix DNA with Bmax and Kd of(24.68±2.62) and(357.8±57.8),respectively.Berberine reacted with protein in comparatively loose manner with Bmax and Kd of(18.9±3.83) and 【286.2±113.6),respectively.Conclusions:The results indicate clearly that berberine may serve as a good antibacterial against multi drug resistant E.coli.
文摘Primers based upon the mitochondrial genome sequences of Bos taurus were used to amplify and sequence the complete mitochondrial D-loop region of Jiulong yak(Poephagus grunniens).The results showed that the length of D-loop was 893 bp,with 87.4%homology to the Bos taurus D-loop sequence;there were 17 bp deletion.Using Ovis aries as an outgroup,the phylogeny of representative species of Bovinae(P.grunniens,P.mutus,Bos taurus,Bos indicus,Bison bison,Bison bonasus,and Bubalus bubalis)was analyzed.Among Bovinae,the sequence divergence between P.grunniens,P.mutus and American bison(Bison bison)was 6.2%-6.8%,which was less than that of Bos taurus and Bos indicus within Bos(10.0%-11.3%).Phylogenetic analysis found that P.grunniens,P.mutus and Bison bison clustered first of all,indicating there was higher genetic comparability among them than to that of Bos.Combining data from paleontology,morphology,and molecular biology,the present analysis supports the argument that Poephagus grunniens and Poephagus mutus should be classified as a distinct genus in Bovinae,that is Poephagus.
文摘Camels and yaks milks are rich in numerous bioactive substances that function beyond their nutritive value. Milk Camel milk is more similar to goat milk and contains less short-chain fatty acids than cow, sheep and buffalo milks, and about 3 times greater vitamin-C than cow milk. One kg of camel milk meets 100% of daily human requirements for calcium and phosphorus, 57.6% for potassium, 40% for iron, copper, zinc and magnesium, and 24% for sodium. Camel milk helps treat liver problems, lowers bilirubin output, lightens vitamin inadequacy and nutrient deficiency, and boosts immunity. Camel milk reduces allergies caused by cow dairy products. Camel milk has low milk fat made mainly from polyunsaturated fatty acids. It lacks ?-lactoglobulin and is rich in immunoglobulins, compatible with human milk. Yak milk has 16.9 - 17.7% solids, 4.9 - 5.3% protein, 5.5 - 7.2% fat, 4.5 - 5.0% lactose, and 0.8 - 0.9% minerals. Yak milk fat is richer in polyunsaturated fatty acids, protein, casein and fat than cow milk. Yak milk casein is used to produce antihypertensive peptides with capacities for producing value-added functional foods and proteins. Continual system-atic education of milk science especially for non-cow species will be an obligation for health implications to be optimally perceived by human populations worldwide.
基金Supported by Key Technology R&D Program of Sichuan Department of Science and Technology "Germplasm Characteristics Studies of Multi-rib Yak"(2014NZ0094)National Beef Cattle Yak Industrial Technology System(CARS-38)
文摘To understand the exact changes in body size and body weight of Jinchuan female yaks within one year,the body size and body weight of 30 Jinchuan female yaks were measured from July 2015 to July 2016. The results showed that the body weight of Jinchuan female yak declined continuously since October 2015,and the weight loss in November 2015 was the largest. The body weight started to increase in May 2016,and the body weight increased significantly in June and July of 2016.
基金Supported by Qinghai Science and Technology Department(2010-Z-745)National Natural Science Foundation of China(31160489)
文摘[Objective] The aim was to explore radical metabolism and mechanism of energy metabolism in mitochondria of yak calves. [Method] Activities of T-AOC, GSH-Px, SOD and LDH and contents of MDA and NO were measured of mitochondria in cardiac and skeletal muscles of yak calves with 1/4 wild bloods at six-month old. [ Result] T-AOC, GSH-Px and SOD activities and NO content were all a little higher in mitochoodria of yaks with wild bloods than those in skeletal muscles (P 〉0.05) and MDA content in mitochondria in cardiac muscles was significantly higher than that in skeletal muscles (P 〈0.05). [ Conclude] The research provides theoretical references for hypoxia-adaptability of yak calves with 1/4 wild bloods.
基金supported by the National Natural Science Foundation of China(31001029)
文摘In order to clarify the interactive mechanism between grazing yak and alpine meadow on the Qinghai-Tibetan Plateau,our study assessed seed density(by species) in the topsoil of alpine meadow with different grazing intensities in the Tianzhu area,north-eastern margins of the Qinghai-Tibetan Plateau and their rates of occurrence in yak dung.Seed density in the topsoil of the lightly grazed,moderately grazed,heavily grazed and extremely grazed alpine meadows in November,2010 were 1 551,1 692,2 660 and 1 830 grains m-2,while in the same meadows in April,2011 densities were 1 530,2 404,2 530 and 2 692 grains m-2,respectively.In the cold season pasture,mean seed density in yak dung from November to April in the lightly grazed,moderately grazed,heavily grazed and extremely grazed sites were 121,127,187,and 120 grains kg-1of dry yak dung.The proportion of total seed numbers in yak dung to soil seed bank in lightly grazed,moderately grazed,heavily grazed and extremely grazed alpine meadow was 1.40,2.62,0.69,and 0.90%.12 species out of the 47 were not found in topsoil but were found in yak dung,10 species out of 45 were not found in yak dung but were found in the topsoil.Endozoochorous dispersal by yaks is therefore very important for soil seed bank and plant biodiversity and population dynamics in alpine meadows.
文摘Melanin granules were isolated from fine yak hair by means of protein enzyme and hydrochloric acid.Resultsof SEM investigation and amino acid analysis were usedto study the physical and chemical properties of melaningranules.The solubility of melanin granules in differentchemical solutions was also studied.
文摘Yaks live in Qinghai-Tibet Plateau (4 km above sea level), and the nutrient components of their placenta were determined, including 17 kinds of amino acids and 11 kinds of trace elements. The results showed that there are abundant amino acids and trace elements in the placenta of yak, equal to that of human and deer, indicating some medical and nutritional value of yak placenta.
基金the International Cooperation Project of the Ministry of Sciences and Technology of China(2014DFA32860)the National Natural Science Foundation of China(31402104)for their financial support
文摘This study was conducted to investigate the phylogenetic diversity of archaea in the rumen of adult and elderly yaks. Six domesticated female yaks, 3 adult yaks ((5.3±0.6) years old), and 3 elderly yaks ((10.7±0.6) years old), were used for the rumen contents collection. Illumina MiSeq high-throughput sequencing technology was applied to examine the archaeal composition of rumen contents. A total of 92 901 high-quality archaeal sequences were analyzed, and these were assigned to 2 033 operational taxonomic units (OTUs). Among these, 974 OTUs were unique to adult yaks while 846 OTUs were unique to elderly yaks; 213 OTUs were shared by both groups. At the phylum level, more than 99% of the obtained OTUs belonged to the Euryarchaeota phylum. At the genus level, the archaea could be divided into 7 archaeal genera. The 7 genera (i.e., Methanobrevibacter, Methanobacterium, Methanosphaera, Thermogymnomonas, Methanomicrobiu, Meth- animicrococcus and the unclassified genus) were shared by all yaks, and their total abundance accounted for 99% of the rumen archaea. The most abundant archaea in elderly and adult yaks were Methanobrevibacterand Thermogymnomonas, respectively. The abundance of Methanobacteria (class), Methanobacteriales (order), Methanobacteriaceae (family), and Methanobrevibacter (genus) in elderly yaks was significantly higher than in adult yaks. In contrast, the abundance of Ther-mogymnomonas in elderly yaks was 34% lower than in adult yaks, though the difference was not statistically significant. The difference in abundance of other archaea was not significant between the two groups. These results suggested that the structure of archaea in the rumen of yaks changed with age. This is the first study to compare the phytogenetic differences of rumen archaeal structure and composition using the yak model.
文摘Nine Chinese yak breeds (Maiwa, Tianzhu White, Qinghai Plateau, Sibu, Zhongdian, Pali, Tibetan High Mountain, Jiulong, and Xinjiang) and Gayal were analyzed by means of 16 microsatellite markers to determine the level of genetic variation within populations, genetic relationship between populations, and population structure for each breed. A total of 206 microsatellite alleles were observed. Mean F-statistics (0.056) for 9 yak breeds indicated that 94.4% of the genetic variation was observed within yak breeds and 5.6% of the genetic variation existed amongst breeds. The Neighbor-Joining phylogenetic tree was constructed based on Nei's standard genetic distances and two clusters were obtained. The Gayal separated from the yaks far away and formed one cluster and 9 yak breeds were grouped together. The analysis of population structure for 9 yak breeds and the Gayal showed that they resulted in four clusters; one cluster includes yaks from Tibet Autonomous Region and Qinghai Province, one cluster combines Zhongdian, Maiwa, and Tianzhu White, and Jiulong and Xinjiang come into the third cluster. Pali was mainly in the first cluster (90%), Jiulong was mainly in the second cluster (87.1%), Zhongdian was primarily in the third cluster (83%), and the other yak breeds were distributed in two to three clusters. The Gayal was positively left in the fourth cluster (99.3%).
基金supported by the Special Fund for Agro-scientific Research in the Public Interest,China (201003061)the Key Technologies R&D Program of China during the 12thFive-Year Plan period (2012BAD13B05)+1 种基金the Great Project of Science and Technology of Gansu Province in China (1102NKDA027)the National Natural Science Foundation of China (31101702)
文摘Endothelial PAS domain protein 1 gene (EPAS1) is a key transcription factor that activates the expression of oxygen-regu- lated genes. In this study, in order to better understand the effects of EPAS1 gene on hematologic parameters in yak, we firstly quantified the tissue expression patterns for EPASl mRNA of yak, identified polymorphism in this gene and evaluated its association with hematologic parameters. Expression of EPAS1 mRNA was detected in all eight tissues (heart, liver, lung, spleen, pancreas, kidney, muscles and ovary). The expressions of EPAS1 in lung and pancreas were extremely higher than other tissues examined. Three novel single nucleotide polymorphisms (SNPs) (g.83052 C〉T, g.83065 G〉A and g.83067 C〉A) within the EPAS1 were identified and genotyped in Pali (PL), Gannan (GN) and Tianzhu White (TZW) yak breeds. Significant higher frequencies of the AA and GA genotypes and A allele of the g.83065 G〉A were observed in the PL and GN breeds than that in the TZW breed (P〈0.01). Association analysis of the PL breed indicated that the g.83065 G〉A polymorphism was significantly associated with hemoglobin (HGB) concentration in yaks (P〈0.05). Individuals with genotype AA had significantly higher HGB concentration (P〈0.05) than those with genotype GA and GG. All these results will help our further understanding of biological functional of yak EPAS1 gene in responding to hypoxia and also indicate EPAS1 might contribute to the hypoxia adaptation of the yak.
基金supported by the Chinese Natural Science Foundation(No.39870607)the key.lab of the Chinese Agricultural Ministry in Nanjing Agricultural University.
文摘Yaks of two lactating types, the half-Iactating yak and the total lactating yak, were investigated in their milk compositions, milk coagulation properties, and contents of three kinds of hormones, glucose, and protein in plasma. The half-lactating Maiwa yak and Jiulong yak contained significantly higher contents of protein, fat, and activities of alkaline phosphatase and Y-glutamyl transpeptidase in milk than that of the corresponding total-lactating yak breeds, with reduced milk yield and similar lactose level and relative percentages of main milk protein components. The half-lactatin yak resembled yaks in a late stage of lactation in their biochemical composition of milk; however, significant differences were also observed, which indicated that the former was in a special stage of lactation quite different from dairy cows. Milk of the total-lactating or half-lactating yaks could be coagulated normally by adding chymosin, with a similar coagulation time. No significant difference was observed between prolactin and progesterone concentrations in plasma of the half-lactating yaks and total-lactating yaks; however, half-lactating yaks had significantly lower level of oestradiol-17 β in plasma than total-lactating yaks.
基金the National Natural Science Foundation of China (90202009) for financial support
文摘To assess the impact of N fertilization on contents of mineral elements in herbage and the effect of increased forage S on the copper metabolism of grazing yaks, study was conducted during the summer grazing season (2005, 2006, and 2007). Pasture replicates (20 ha; n=3 per treatment) received the same fertilizer treatment in each growing season, consisting of i) 90 kg N ha^-1 from quickly available nitrogen, ii) 90 kg N ha^-1 from ammonium nitrate, iii) 90 kg N ha^-1 from ammonium sulfate, and iv) control (no fertilizer). Forage sampling was collected at 60 days intervals following fertilization (10 samples per pasture) for Cu, Mo, Mn, Se, Fe, Zn, Ca, and P. To determine the effect of fertilizer treatment on mineral metabolism in grazing yaks, liver and blood samples were collected at the start and end of the study period in 2005, 2006, and 2007. Ammonium sulfate fertilization increased (P 〈 0.01) forage S concentration. Plant tissue N concentrations were increased by N fertilization, regardless of source in 2005, 2006, and 2007. Yaks grazing S fertilization pastures had lower (P〈0.05) liver and blood Cu concentrations at the end of the study period in 2005, 2006, and 2007, compared with urea, ammonium nitrate, and control. Nominal increases in forage in vitro organic matter digestibility were realized by fertilization, regardless of N source in each year.
基金supported financially by the National Natural Science Foundation of China(90202009)
文摘Since the 1990s, yak in the Haizi area in China has been affected by an ailment characterized by pica, emaciation, dyskinesia, and anemia. To determine the cause of disease, the mineral composition of soil and forages, and samples of blood, hair, and liver of yaks from the Haizi area in China were determined. The concentrations of copper in soil and forage from affected ranches and unaffected areas are within the normal ranges. The mean concentration of copper in blood and liver from the affected yaks was (0.31±0.03) and (13.7±3.1)μg·g^-1 respectively, compared with (0.98±0.16) and (95.6±11.2)μg·g^-1 for unaffected yaks. The concentrations of sulfur in soil and forage from affected ranches were (1.91±0.26) and (1.37±0.17)%, respectively, compared with (1.11±0.31) and (0.52±0.18)% (dry matter) for normal areas. The contents of sulfur in blood and liver affected animals were (7.32±1.8) and (2.54±3.1)%, respectively, compared with (4.22±0.73) and (1.31±0.33)% (in fresh and soft tissues) for healthy animals, respectively. Oral administration of tribasic copper chloride prevented and cured the disease. Thus it is reasonable to conclude that ailments of yaks in the Haizi area are probably caused by a secondary copper deficiency, mainly due to high sulfur content in soil and forage.
基金Supported by Special Fund from National Modern Agriculture Sci-tech System(CARS-38)National Science and Technology Program(2012BAD13B06)
文摘The change in lactation of Maiwa yak was studied based on the data of locating Maiwa yak in warm seasons during 2003- 2009. The results showed that the milk yield was increasing gradually during days 30- 70 after calving,reached the peak at days 70- 110,and decreased gradually to no milking whenafter. The milk yield of Maiwa yak was greatly influenced by lactation age rather than the yearly effect.
文摘[ Objective ] To analyze the hair and villus production performance of Tianzhu white yak and thus provide conditions for the genetic breed ing and product development. [Method] The hair and villus yield as well as villus rate of male and female Tianzhu white yaks from one year to six years old was detected and the villus yield was also determined. And these indexes of hair and villus were analyzed to evaluate the production per formance. [ Result] In Tianzhu white yaks from one year to two years old, the hair and villus yield was lower, but the villus rate and yield were high er. The hair and villus yield, villus rate, and villus yield were all higher in Tianzhu white yaks from three years to six years old but significantly de creased in 7yearold Tianzhu white yaks. In addition, the hair and villus yield was significantly ( P 〈 0.05) or very significantly ( P 〈 0.01 ) higher in male yaks than in female yaks. The villus rate was very significantly ( P 〈0.01 ) higher than in female yaks from five years to seven years old than in male yaks at the same age. [ Conclusion] Tianzhu white yaks from one year to two years old have the best hair and villus production perform ance; Tianzhu white yaks from three years to six years old are in the main phase of hair and villus production; Tianzhu white yaks older than seven years old should not be used for hair and villus production.
基金supported by the Nationa1 Natura1 Science Foundation of China(39870607).
文摘The milk protein polymorphisms were typed by polyacrylamide gel electrophoresis (PAGE)from 109 Maiwa and 100 Jiulong yaks, and the relationships among milk protein polymorphisms,milking traits and milk protein compositions were studied. The results showed thatβ-CN,κ-CN andα-La were monomorphic,αs1-CN andβ-Lg were polymorphic, the dominantgenes were αs1-CN D and β-Lg E,respectively. The frequencies of αs1-CN D were 0.8073and 0.6000 and β-Lg E were 0.9770 and 0.9700 in two populations respectively.The meanheterozygosities were 0.1021 and 0.1867 in two populations. No significant effects onmilking traits and milk protein compositions were observed except for αs1-CN locus onfat percentage in Jiulong yak.