Search

The possibilities of using high‐quality forages in incorporation with total mixed ration (TMR) during the fattening period of beef cattle have been investigated. A total of 30 Simmental bulls (438.94 ± 11.45 kg) were selected and randomly divided into two groups, TMR with single corn silage (SS) and TMR with various silage (MS). The whole experiment consisted of 15 days preparation period and 69 days experimental period. Rumen fluid and blood samples were taken from six beef cattle per treatment at the end of the experiment. The results showed that the average daily gain of the MS group (1.56 kg/day) was higher than (p, We investigated the effects of total mixed ration (TMR) with various silage on growth performance, serum parameters, ruminal fermentation, and microbial profiles of beef cattle. The results showed that the beef cattle fed TMR with various silage was a feasible strategy in the intensive feeding system. High‐quality forage can be used in beef cattle diets instead of concentrates, and no negative effect on growth performance and rumen fermentation of beef cattle.

Summary The objectives of this study were to investigate the adaptation and competition of Lactobacillus plantarum, Pediococcus pentosaceus and Enterococcus faecalis inoculated in alfalfa silage alone or in combination on the fermentation quality, dynamics of bacterial community, and their functional shifts using single‐molecule real‐time (SMRT) sequencing technology. Before ensiling, alfalfa was inoculated with L. plantarum (Lp), P. pentosaceus (Pp), E. faecalis (Ef) or their combinations (LpPp, LpEf, LpPpEf) and sampled at 1, 3, 7, 14 and 60 days. After 60‐days fermentation, the Lp‐, Pp‐ and LpPp‐inoculated silages had lower pH but greater concentrations of lactic acid were observed in Pp, LpEf and LpPpEf‐inoculated silages. The inoculants altered the keystone taxa and the bacterial community dynamics in different manners, where L. plantarum, Weissella cibaria and L. pentosaceus dominated the bacterial communities after 14 days‐fermentation in all treatments. The silages with better fermentation quality had simplified bacterial correlation structures. Moreover, different inoculants dramatically changed the carbohydrate, amino acid, energy, nucleotide and vitamin metabolism of bacterial communities during ensiling. Results of the current study indicate that effect of different inoculants on alfalfa silage fermentation was implemented by modulating the succession of bacterial community, their interactions and metabolic pathways as well during ensiling., This study were investigated the adaptation and competition of Lactobacillus plantarum, Pediococcus pentosaceus, and Enterococcus faecalis inoculated in alfalfa silage alone or in combination on the fermentation quality, dynamics of bacterial community, and their functional shifts of alfalfa silage. The inoculants altered the keystone taxa, dynamics of bacterial community and their functions in different manners, and the silages with better fermentation quality had simplified bacterial correlation structures.

Summary Multi‐omics approach was adopted to investigate the modulation of bacterial microbiota and metabolome as well as their interactions in whole crop corn ensiling systems by inoculating homofermentative Lactobacillus plantarum or heterofermentative Lactobacillus buchneri. Inoculations of the two different inoculants resulted in substantial differences in microbial community and metabolic composition as well as their dynamics in ensiled corn. Inoculants also altered the correlations of microbiota in different manners, and various keystone species were identified in corn silages with different treatments. Many metabolites with biofunctional activities like bacteriostatic, antioxidant, central nervous system inhibitory and anti‐inflammatory were found in the present silage. A constitutive difference in microbiota dynamics was found for several pathways, which were upregulated by specific taxa in middle stage of fermentation, and widespread associations between metabolites with biofunctions and the species of lactic acid bacteria dominated in silage were observed. Multiple microbial and metabolic structures and dynamics were correlated and affected the fermentation process of the corn ensiling systems. Results of the current study improve our understanding of the complicated biological process underlying silage fermentation and provide a framework to re‐evaluate silages with biofunctions, which may contribute to target‐based regulation methods to produce functional silage for animal production., Multi‐omics approach was adopted to investigate the modulation of bacterial microbiota and metabolome as well as their interactions in whole crop corn ensiling systems by inoculating homofermentative Lactobacillus plantarum or heterofermentative Lactobacillus buchneri. Results of the current study improve our understanding of the complicated biological process underlying silage fermentation, and provides a framework to re‐evaluate silages with biofunctions, which may contribute to target‐based reglation methods to produce functional silage for animal production.

Nonalcoholic fatty liver disease (NAFLD) is leading chronic liver syndrome worldwide. Gut microbiota dysbiosis significantly contributes to the pathogenesis and severity of NAFLD. However, its role is complex and even unclear. Treatment of NAFLD through chemotherapeutic agents have been questioned because of their side effects on health. In this review, we highlighted and discussed the current understanding on the importance of gut microbiota, its dysbiosis and its effects on the gut-liver axis and gut mucosa. Further, we discussed key mechanisms involved in gut dysbiosis to provide an outline of its role in progression to NAFLD and liver cirrhosis. In addition, we also explored the potential role of probiotics as a treatment approach for the prevention and treatment of NAFLD. Based on the latest findings, it is evident that microbiota targeted interventions mostly the use of probiotics have shown promising effects and can possibly alleviate the gut microbiota dysbiosis, regulate the metabolic pathways which in turn inhibit the progression of NAFLD through the gut-liver axis. However, very limited studies in humans are available on this issue and suggest further research work to identify a specific core microbiome association with NAFLD and to discover its mechanism of pathogenesis, which will help to enhance the therapeutic potential of probiotics to NAFLD.

Ru(ii)-based photoactivated chemotherapy (PACT) agents are promising; however, their short wavelength absorption (generally

L. plantarum LP3 isolated from traditinal fermented Tibetan yak milk has been identified as a potential probiotic candidate strain with high cholesterol-lowering activity. In this study, thirty Sprague-Dawley (SD) rats were randomly divided into three groups, including normal diet (NC), high-fat diet (HC), and high-fat diet + L. plantarum LP3 (HLp). The effects of L. plantarum LP3 on plasma lipid profile, gut bacterial microbiota, and metabolome induced by high-fat diet in rats were investigated. Results shown that L. plantarum LP3 administration was found to reduce the levels of total cholesterol, triglyceride, and low-density lipoprotein cholesterol (LDL-C) and atherogenic index in the serum of high-fat diet rats. It also controlled the decrease of Bacteroidetes and increase of Firmicutes at the phylum level in gut microbiota induced by high-fat diet in SD rats and increased the diversity and relative abundance of intestinal flora in obese rats. In particular, the LP3 strain controlled the changes induced by the high-fat diet in the abundance of for Lachnospiraceae and Erysipelotrichaceae. We also further observed the beneficial regulatory effects of L. plantarum LP3 on changes in the levels of obesity-related metabolites. The biosynthesis of fatty acids, steroids, and bile acids and metabolism of linoleic acid, linolenic acid, and arachidonic acid were the main metabolic pathways adjusted by L. plantarum LP3 in obese rats, and the metabolic rates were similar to those observed in normal diet rats levels. The findings of this study provided useful information on the mechanism underlying the hypocholesterolemic effects of L. plantarum LP3 in the high-fat induced SD rat model with the perspective of modulation of gut microbiota and metabolites.

The study was conducted to screen high 1,2-propanediol produced by Lactobacillus buchneri strains, isolated from baled silages stored for 1 or 2 years, and to evaluate their effects on fermentation quality and aerobic stability of whole-plant corn silage. In total, 31 L. buchneri strains were isolated from alfalfa, whole-plant corn and oat silages. Based on growth performance and 1,2-propanediol and acetic acid production, two strains, L. buchneri 9-2 and L. buchneri 10-1, from alfalfa silage, were further assessed in an ensiling trial on whole-plant corn. The corn silage inoculated with L. buchneri 9-2 or L. buchneri 10-1 had a higher concentration of 1,2-propanediol (34.7 or 34.6 g/kg dry matter (DM)) and acetic acid (47.2 or 45.9 g/kg DM) in comparison with L. buchneri 40788 (reference strain) treated silage (19.5 and 35.9 g/kg DM) after 90 d of fermentation. In addition, these two strains performed better in improving silage aerobic stability relative to control and L. buchneri 40788. The results above indicated that L. buchneri 9-2 and L. buchneri 10-1 could be candidate strains to increase 1,2-propanediol and acetic acid concentrations and improve the aerobic stability of whole-plant corn silage.

In this study, a novel beta-cypermethrin (beta-cyp)-degrading strain Lactobacillus pentosus 3–27 (LP3–27) was screened from beta-cyp-contaminated silage. The strain could degrade 96% of beta-cyp (50 mg/L) in MSM medium after 4 d of culture, while the strain lost its degradation ability when the beta-cyp concentration reached 250 mg/L. The effects of LP 3–27 on fermentation, bacterial community, and bioremediation of contaminated alfalfa silage at two dry matter (DM) contents were studied. The results showed that inoculation with LP3–27 not only degraded beta-cyp, but also improved the fermentation quality of alfalfa silage after 60 d of ensiling. Meanwhile, L. pentosus dominated the bacterial community during ensiling in LP3–27 inoculated silages, whereas Pediococcus acidilactici was the dominant species in the control silage. LP3–27 inoculation also simplified the bacterial interaction networks of ensiled alfalfa. Beta-cyp degradation was positively correlated with L. pentosus in LP- inoculated silages, which confirmed the function of beta-cyp degradation by L. pentosus. In addition, higher beta-cyp degradation was observed in silage with 35% versus 43% DM. In summary, strain LP3–27 could be used as a candidate inoculum for bioremediation of beta-cyp-contaminated silage and to produce safe silage for animal production.

Aims Ferulic acid esterase (FAE)-producing Lactobacillus species isolated from ensiled Elymus nutans growing on the Qinghai-Tibetan plateau were characterized, and effects of their application to the alfalfa ensiling process and the evidence to synergic effect between cellulase and FAE were investigated. Methods and results The results of 16S rRNA gene sequence and species-specific polymerase chain reaction amplification showed that two screened strains with high FAE activity were Lactobacillus plantarum A1 (LP) and L. brevis A3 (LBr). The optimum temperature and pH for the LP and LBr was 37°C and 6·4 respectively. The FAE exhibited a good stability at temperatures between 25 and 50°C and at pH values of 5·0-7·0. The two strains and a commercial cellulase (CE) were applied as additives to alfalfa silage. After 60 days of ensiling, the lactic acid in the control and CE groups were significantly lower than those of the other treatment groups. The neutral detergent fibre and acid detergent fibre contents in the LP group were significantly lower than those observed in the other groups. At the same time, the combination of CE and FAE-producing lactic acid bacteria synergistically improved the fermentation quality of the silage. Conclusions The addition of the FAE-producing strain of L. plantarum A1 to alfalfa silage improved its fermentation quality, and reduced the fibre content of the silage. Significance and impact of the study The screened homo-fermentative and FAE-producing strain of L. plantarum A1 could be a candidate strain in improving fermentation quality and fibre digestibility of ensiled forages.

The effects of Acremonium cellulase and L. plantarum A1 with ferulic acid esterase activity on corn stalk silage fermentation characteristics, carbohydrate composition and enzymatic saccharification were studied at 25 and 40 °C, respectively. Corn stalk was ensiled without additive (C), Acremonium cellulase (AC), L. plantarum A1 (Lp) and AC + Lp for 60 days. Pretreatment with Lp or AC + Lp promoted the better silage fermentation and the degradation of lignocellulose as indicated by high lactic acid and low pH and lignocellulose content compared to control silages at 25 °C. AC + Lp performed better in reducing lignocellulose and DM loss. In addition, Lp alone enhanced enzymatic saccharification of corn stalk silage. However, the influence of L. plantarum A1 on corn stalk silage was not obvious at 40 °C. Corn stalk ensiled with combined additive is a suitable pretreatment method for subsequent biofuel production at 25 °C, but addition of Acremonium cellulase alone at 40 °C may be a promising method.

Copper is one of the most ubiquitous environmental pollutants worldwide. Previous studies have focused on the toxicology of high copper exposure, while there has been comparatively less research on the biological effects of low copper exposure. Low concentrations of copper often exist in freshwater ecosystems, and its impact on the fish is unclear. Both Xenocypris microlepis and Xenocypris davidi are bottom-feeding fishes widely distributed in freshwater ecosystems of China, and they are more likely to be contaminated by low concentrations of copper. Low copper exposure may have effects on molecular regulation at the level of gene expression in the two Xenocypris species. To investigate gene expression differences involved in the response to low copper concentrations between X. microlepis and X. davidi, we established the responses to low copper exposure of 0.01 mg/L for 14 days at the transcriptional level, and RNA-Seq was used to perform a comparative transcriptomic analysis of the liver. A total of 74,135 and 60,894 unigenes from X. microlepis and X. davidi were assembled by transcriptome profiling, respectively. Among these, 84 genes of X. microlepis and 165 genes of X. davidi were identified as differentially expressed genes (DEGs). There were 60 and 135 up-regulated, 24 and 30 down-regulated genes in the two species, respectively. Comparative transcriptome analyses identified five differentially co-expressed genes (DCGs) related to low copper exposure from the DEGs of the two Xenocypris species. The five DCGs were related to the fishes' growth, antioxidant system, immune system and heavy metal tolerance. The results could help us to understand the molecular mechanisms of the response to low copper exposure, and the data should provide a valuable transcriptomic resource for the genus Xenocypris.

Feed deficiency during the long cold period of a year is one of the major problems that the traditional year-round animal grazing system has faced on the Qinghai-Tibetan plateau (QTP) since ancient time. Therefore, ensiling the grasses from grassland could be a desirable feeding regime to preserve high quality forage and to alleviate the seasonal unbalanced feed supply problem on this plateau. The present study was designed to investigate dynamics of bacterial community and natural fermentation quality of ensiled Elymus nutans collected from grasslands in four different areas with different elevations [Tianzhu County (TZ), 2965 m; Golog Prefecture (GL), 3763 m; Damxung County (DX), 4228 m, and Nagqu Prefecture (NQ), 4752 m] on the QTP. The bacterial community was characterized by using the PacBio single molecule with real-time sequencing technology (SMRT). The harvested fresh E. nutans grasses were ensiled in vacuum-sealed polyethylene bags for 14, 30, 60, and 90 days. Obvious differences in the epiphytic bacterial community of the fresh E. nutans samples from the four areas were observed, which resulted in various bacterial community dynamics and fermentation qualities of ensiled E. nutans. Higher fermentation quality was observed in silage samples from Nagqu than in those from the other areas (P < 0.05). Lactic acid bacteria (LAB) involved in fermentation of E. nutans from low altitude areas consisted of Pediococcus pentosaceus, Lactobacillus sp., Leuconostoc mesenteroides, and Lactobacillus coryniformis, whereas major LAB species involved in the fermentation of E. nutans silage from high altitudes included L. mesenteroides, Lactobacillus brevis, and Lactobacillus sp. Correlation analysis between bacterial composition and fermentation quality of E. nutans silages made from the four different areas in the QTP indicated that the LAB species responsible for silage fermentation in different areas were totally different, which was mainly due to the different epiphytic bacterial compositions in fresh E. nutans before ensiling. The present results provide important information on revealing the bacterial communities and fermentation quality of ensiled E. nutans, and on future screening of LAB isolates for making high quality silage in order to alleviate feed shortage of the traditional year-round grazing system on the QTP.

&lsquo, Red Globe&rsquo, table grapes are large, edible, seeded fruit with firm flesh that tastes good, but can have poor postharvest shelf-life. This study was conducted to explore the effects of products of Lactobacillus delbrueckii subsp. bulgaricus strain F17 and Leuconostoc lactis strain H52 on &lsquo, table grapes for the enhancement of shelf-life and improvement of grape quality characteristics during postharvest storage. Strains F17 and H52 were isolated from traditional fermented yak milk obtained in the Qinghai&ndash, Tibetan Plateau. Samples from untreated and treated grapes were analyzed for physicochemical, biochemical, and microbiological properties (weight loss, decay rate, pH, total soluble solids content, titratable acidity, total phenols, sensory evaluation, and microbial growth) for 20 days. The results demonstrated that supernatants from both strains significantly reduced weight loss, decay rate, aerobic mesophilic bacteria, and coliform bacteria counts, delayed maturity and senescence of table grapes, and reduced titratable acidity and total phenols. However, the supernatant of strain F17 was more effective and resulted in better sensory evaluations and had a significant inhibitory effect on yeast and molds by day 5. Meanwhile, the supernatant from strain H52 had a significant inhibitory effect on fungi over the whole storage period. In addition, the results of the Pearson correlation analysis suggested that weight loss, decay rate, total soluble solids content, and microorganisms were highly correlated with the sensory evaluation data and quality of postharvest grapes when treated with the products of strain F17. On the basis of these data and sensory organoleptic qualities, the supernatant containing products from strain F17 had the best potential as a biopreservative to improve the postharvest quality of &lsquo, table grapes.

The effects of feruloyl esterase-producing Lactobacillus plantarum A1, cellulase, or their combination on the fermentation characteristics, carbohydrate composition, and enzymatic hydrolysis of mixed corn stalk and potato pulp silage were investigated. Two mixture ratios were used: a weight ratio of rehydrated corn stalk to potato pulp of 35:1 (HD) and a weight ratio of dry corn stalk to potato pulp of 5:11 (LD). No advantage was observed with the addition of strain A1 alone for lignocellulosic degradation and cellulose conversion, while its combination with cellulase enhanced the lignocellulosic degradation and preserved more fermentable carbohydrates in co-ensiled corn stalk and potato pulp. The enzymatic hydrolysis results indicated a potential benefit of pretreatment for biogas production, as the co-ensiled HD ratio mixture without additive treatment showed high glucose yield after enzymatic hydrolysis following 60 d of fermentation.

Feeding ruminant animals with legume silage, rich in non-protein nitrogen, not only results in serious groundwater pollution but also induces a large amount of methane (CH4) releasing into atmospheric environment. Co-ensiling alfalfa with sainfoin containing condensed tannins in five ratios was investigated on silage fermentation, chemical and bacterial community composition, in vitro ruminal fermentation characteristics, CH4 emission and archaeal and protozoal community. Fresh alfalfa and sainfoin were wilted to dry matter concentrations of 381 and 390 g/kg wet weight, respectively, and chopped to 2–3 cm. Chopped alfalfa and sainfoin were combined in proportions of 1:0 (S0, Control), 0.75:0.25 (S25), 0.5:0.5 (S50), 0.25:0.75 (S75) and 0:1 (S100) on a wet weight basis, respectively. Each treatment was prepared in quadruplicate and fermented for 60 days. After 60 days of fermentation, incorporation of sainfoin into alfalfa before ensiling led to an improvement in silage fermentation and inhibited silage proteolysis in a proportion-dependent manner. Excellent fermentation profiles were observed in S50 and S75 silages, in which the non-protein nitrogen decreased by 11.33% and 13.01%, respectively, compared with S0 silage. As sainfoin proportion increased, the relative abundance of Pediococcus acidilactici linearly decreased (P

Background: Anaerobic digestion of agro-industrial residues that with rich lignocellulosics biomass is regarded as one of the cost-efficient and environmentally beneficial technologies for biofuels production. While, pretreatment is necessary to degrade cellulose and hemicellulose for enhancing the potential bio-digestibility process for biogas producing. Thus, the effects of co-ensiling of corn straw and potato pulp inoculated with ferulic acid esterase-producing Lactobacillus plantarum A1 or cellulases on lignocellulosic degradation, enzymatic hydrolysis and theoretical biochemical methane potential were investigated with two mixture ratios. Four treatments were applied: without additive (C), L. plantarum A1 (P), cellulases (E) and combination of L. plantarum A1 and cellulases (P+E). Two mixture ratios were used: weight ratio of wet corn straw (rehydrated to 460 g/kg fresh weight) and potato pulp of 4:1 (CP) and weight ratio of dry corn straw and potato pulp of 1:2 (PC).Results: The results revealed that silages treated with E and P+E performed better regarding lignocelluloses degradation by lowering the contents of lignocelluloses with prolonged fermentation time and preserved more available carbohydrates. The P and C resulted in greater enzymatic hydrolysis as indicated by higher glucose yield, cellulose convertibility and relative improvement ratio especially at 60 and 90 d of co-ensiling. For biofuels producing, the CP ratio of mixture had higher theoretical methane yield than PC ratio. Therefore, Co-ensiling CP ratio with additives E and P+E for 90 d might be considerable pretreatment of mixed corn stalk and potato pulp for biogas production. Conclusions: This work will helpful in investigating pretreatment of biomass that with rich lignocellulosics. In addition, the visualization results of the process of lignocellulosic degradation could be used for guidance to explore the lignocellulosic biomass using for large-scale biofuels production. Keywords: Co-ensiling, Theoretical methane yield, Silage additives, Solanum tuberosum , Zea mays

With the implementation of modern scientific protocols, the average human lifespan has significantly improved, but age-related problems remain a challenge. With the advent of ageing, there are alterations in gut microbiota and gut barrier functions, weak immune responses, increased oxidative stress, and other age-related disorders. This review has highlighted and discussed the current understanding on the significance of gut microbiota dysbiosis and ageing and its inherent effects against age-related oxidative stress as well as on the gut health and gut-brain axis. Further, we have discussed the key mechanism of action of Lactobacillus strains in the longevity of life, alleviating gut dysbiosis, and improving oxidative stress and inflammation to provide an outline of the role of Lactobacillus strains in restoration of gut microbiota dysbiosis and alleviating certain conditions during ageing. Microbiota-targeted interventions of some characterized strains of probiotic Lactobacillus for the restoration of gut microbial community are considered as a potential approach to improve several neurological conditions. However, very limited human studies are available on this alarmed issue and recommend further studies to identify the unique Lactobacillus strains with potential anti-ageing properties and to discover its novel core microbiome-association, which will help to increase the therapeutic potential of probiotic Lactobacillus strains to ageing.

We investigated the long-term effects of total mixed rations (TMR) containing various forage silages on the rumen community structure in beef cattle. Fifteen Simmental bulls (437.73 ± 4.01 kg) were fattened for 180 d, split into three trial stages (P1: 1–60 d, P2: 61–120 d, P3: 121–180 d). The diets were composed of corn silage, oat silage, alfalfa silage, wheat straw, and concentrates, formulated into a TMR. Rumen fluid was collected separately on the 60th, 120th, and 180th days among the three fattening stages. High-throughput 16S rRNA gene sequencing was used to analyse rumen bacterial composition and function, and the correlation between rumen bacteria and fermentation parameters was determined using redundant analysis. The results showed that rumen fermentation parameters were stable during long-term fattening. The alpha diversity index indicated that bacterial diversity was higher during the late fattening phase than in the early phase. The most abundant bacteria were Bacteroidetes, Firmicutes, and Prevotella_1 at the three fattening stages. The bacterial communities were clearly separated in the different stages, as indicated by the Box diagram. The thirteen bacterial taxa identified by LEfSe were significantly enriched in the rumen during the three stages. KEGG pathway fractions indicated that carbohydrate metabolism, amino acid metabolism, and energy metabolism pathways were enriched in the rumen during the three stages. In conclusion, we found that long-term feeding of beef cattle with high-quality forage + low levels of concentrate was a healthy and efficient feeding method, promoting a healthy and suitable long-term change in the rumen microbial environment.

Xenocypris argentea is a cyprinid fish species and widely distributed in rivers and lakes within China. The germplasm resources of X. argentea have recently been seriously degraded by human activities. Thus, the development of sufficient molecular markers to inform conservation efforts of X. argentea is urgently needed. In this study, we used Illumina HiSeq high-throughput sequencing of X. argentea transcriptomic data to identify single nucleotide polymorphism (SNP) markers for X. argentea. From 43,346 unigenes with functional annotations, 462,621 putative SNPs were identified. Among these, we validated 32 polymorphic loci of 40 function-related SNPs from a Poyang Lake population of X. argentea. Six of these SNP loci deviated significantly from Hardy–Weinberg equilibrium (P

Under traditional management on the Qinghai-Tibetan Plateau, yaks () graze only on natural pasture without supplements and are forced to cope with sparse forage of low N content, especially in winter. In contrast, indigenous Tibetan yellow cattle () require supplements during the cold season. We hypothesized that, in response to harsh conditions, yaks cope with low N intakes better than cattle. To test this hypothesis, a study of whole-body N retention and urea kinetics was conducted in 2 concurrent 4 × 4 Latin squares, with 1 square using yaks and 1 square using cattle. Four isocaloric forage-concentrate diets differing in N concentrations (10.3, 19.5, 28.5, and 37.6 g N/kg DM) were formulated, and by design, DMI were similar between species and across diets. Urea kinetics were determined with continuous intravenous infusion of NN urea for 104 h, and total urine and feces were concomitantly collected. Urea production, urea recycling to the gut, and ruminal microbial protein synthesis all linearly increased ( < 0.001) with increasing dietary N in both yaks and cattle. Urinary N excretion was less ( = 0.04) and N retention was greater ( = 0.01) in yaks than in cattle. Urea production was greater in yaks than in cattle at the 3 lowest N diets but greater in cattle than in yaks at the highest N diet (species × diet, < 0.02). Urea N recycled to the gut ( < 0.001), recycled urea N captured by ruminal bacteria ( < 0.001), and ruminal microbial protein production ( = 0.05) were greater in yaks than in cattle. No more than 12% of urea recycling was through saliva, with no difference between species ( = 0.61). Glomerular filtration rate was lower ( = 0.05) in yaks than in cattle. The higher urea recycling and greater capture of recycled urea by ruminal microbes in yaks than in cattle suggest that yaks use mechanisms to utilize dietary N more efficiently than cattle, which may partially explain the better survival of yaks than cattle when fed low-N diets.

This study investigated the antioxidant properties of lactic acid bacteria (LAB) isolated from spontaneously fermented yak milk collected on the Tibetan Plateau. Nine different species of LAB strains with high 2,2-diphenyl-1picrylhydrazyl radical-scavenging activity were screened from 403 isolates, and most of the selected LAB strains exhibited higher antioxidant activity than the reference strains from low-altitude areas. Among the 9 screened strains, L. delbrueckii subsp. bulgaricus F17 showed the greatest probiotic potential due to its high free radical scavenging activity (scavenging 59% OH and 54% O2−) and high survival rate (58%) within a simulated gastrointestinal tract. After administering the strain to ageing mice induced by d -galactose, the glutathione peroxidase activity in mouse livers and sera and the superoxide dismutase activities in mouse sera and brains increased significantly, while malondialdehyde levels in mouse livers and sera decreased significantly. This unique isolate could be considered a potential antioxidant strain for functional food production.

Urinary purine derivatives (PD) excretion, rumen bacterial purine bases and nitrogen (N) variations, estimated microbial N synthesis and the efficiency of utilization of recycled urea-N were determined in Tibetan and Gansu Alpine fine-wool sheep offered 4 diets with different N concentrations [11.0, 16.7, 23.1 and 29.2 g N/kg dry matter (DM)] in 2 concurrent 4 × 4 Latin square designs. Urine output increased linearly with increasing dietary N concentration ( P P P P > 0.10); however, the purine nitrogen index (PNI) decreased ( P 0.001). For the lowest N diet, allantoin, total PD and PNI were greater in Tibetan sheep than in fine-wool sheep (linear dietary N × breed, P 0.05). As dietary N increased, rumen bacterial purine bases [ribonucleic acid (RNA) equivalent] decreased linearly ( P 0.05), whereas total N content increased ( P 0.05). Compared to fine-wool sheep, rumen bacteria of Tibetan sheep contained higher RNA and lower N content ( P P > 0.05). As a proportion of total microbial N synthesis or hepatic urea-N production, recycled urea-N was utilized more efficiently in Tibetan than in fine-wool sheep ( P 0.05). These results suggest that Tibetan sheep are better able to cope with a low protein diet, which is characteristic of the Qinghai-Tibetan Plateau during the long-cold season, than are Gansu Alpine fine-wool sheep.

The objectives of the present study were to screen cholesterol-lowering lactic acid bacteria from traditional fermented Tibetan yak milk, and to evaluate their potential use as cholesterol-reducing probiotics in rats. A total of 115 isolates were evaluated for their cholesterol-lowering and probiotic profiles by in vitro assays, and a strain with good performance in in vitro test was selected to test its probiotic effects in rats fed a high cholesterol diet. Results showed that the strain of L. plantarum Lp3 had a high cholesterol-reducing rate (73.3%) and survival rate in simulated gastrointestinal fluids. Administration of Lp3 to rats fed a high-cholesterol diet promoted notable declines in serum and liver cholesterol and triglycerides levels, and reduced lipid deposition in the cytoplasm of rat’s liver tissue. These results suggest that the strain of L. plantarum Lp3 could be a potential probiotic to treat hyperlipidemia and to be used in functional food.

Strawberries are vulnerable to physical injuries and microbial invasion. To explore if beneficial lactic acid bacteria can improve the shelf life and edible quality of postharvest strawberry fruits, the effects of Lactobacillus delbrueckii subsp. bulgaricus (ital.) F17 (F17) and Leuconostoc lactis (ital.) H52 (H52) inoculation on the strawberry microbial community structure and saleable characteristics were examined by bacterial 16S rRNA and fungal ITS sequencing techniques. Lactobacillus (ital.) F17 and Leuconostoc lactis (ital.) H52 isolated from the traditional fermented yak milk in the Qinghai-Tibetan Plateau were used as the potential probiotic inocula. Samples from treated strawberries stored at 25 °C for 0, 12, 24, 48, and 72 hours were analyzed for their pH, weight loss percentage, decay percentage, total soluble solid content (SSC) and microbial counts, and for microbiome community diversity and canonical correspondence analysis. The results showed that F17 and H52 did not only significantly reduce the weight loss and decay percentage of strawberry fruits, but also delayed the decrease of the total SSC and pH (P < 0.05). In addition, F17 and H52 significantly inhibited the growth and colonization of aerobic mesophilic bacteria, yeast, mold and coliform bacteria. In particular, by comparing the microbiota composition of the samples, F17 significantly inhibited Pantoea, Mycospherella, unclassified_Pleosporales, Aureobasidium and Phoma at the genus level, whereas H52 inhibited Bacillus, Streptophyta, Mycospherella, Aureobasidium and Phoma. Moreover, analysis of alpha and beta diversity revealed that F17 and H52 had a significantly greater inhibitory effect on bacterial species compared to fungi. The results of canonical correspondence analysis revealed that the total SSC and pH were positively correlated with bacteria, whereas the decay percentage, weight loss percentage and total SSC were positively associated with fungi. Additionally, Podosphaera, Hanseniaspora, Botrytis and unclassified_Pleosporales were positively correlated with strawberry fruit decay and weight loss percentage. As a general result, Lactobacillus F17 and Leuconostoc lactis H52 have the potential to promote biological preservation, which is economically important to reduce the loss due to strawberry spoilage.

The present study investigated the species level based microbial community and metabolome in corn silage inoculated with or without homofermentative Lactobacillus plantarum and heterofermentative Lactobacillus buchneri using the PacBio SMRT Sequencing and time-of-flight mass spectrometry (GC-TOF/MS). Chopped whole crop corn was treated with (1) deionized water (control), (2) Lactobacillus plantarum, or (3) Lactobacillus buchneri. The chopped whole crop corn was ensiled in vacuum-sealed polyethylene bags containing 300 g of fresh forge for 90 days, with three replicates for each treatment. The results showed that a total of 979 substances were detected, and 316 different metabolites were identified. Some metabolites with antimicrobial activity were detected in whole crop corn silage, such as catechol, 3-phenyllactic acid, 4-hydroxybenzoic acid, azelaic acid, 3,4-dihydroxybenzoic acid and 4-hydroxycinnamic acid. Catechol, pyrogallol and ferulic acid with antioxidant property, 4-hydroxybutyrate with nervine activity, and linoleic acid with cholesterol lowering effects, were detected in present study. In addition, a flavoring agent of myristic acid and a depression mitigation substance of phenylethylamine were also found in this study. Samples treated with inoculants presented more biofunctional metabolites of organic acids, amino acids and phenolic acids than untreated samples. The Lactobacillus species covered over 98% after ensiling, and were mainly comprised by the L. acetotolerans, L. silagei, L. parafarraginis, L. buchneri and L. odoratitofui. As compared to the control silage, inoculation of L. plantarum increased the relative abundances of L. acetotolerans, L. buchneri and L. parafarraginis, and a considerable decline in the proportion of L. silagei was observed; whereas an obvious decrease in L. acetotolerans and increases in L. odoratitofui and L. farciminis were observed in the L. buchneri inoculated silage. Therefore, inoculation of L. plantarum and L. buchneri regulated the microbial composition and metabolome of the corn silage with different behaviors. The present results indicated that profiling of silage microbiome and metabolome might improve our current understanding of the biological process underlying silage formation.

The objective of this study was to evaluate the effects of a novel Lactobacillus plantarum strain with high-antioxidant activity on antioxidant status, chemical composition and fermentation profiles of alfalfa silage ensiled at two dry matter (DM) contents. Fresh chopped alfalfa was wilted to two targeted dry matter (DM) contents of approximately 300 (low DM) and 400 (high DM) g/kg fresh weight and treated without or with a strain of L. plantarum 24−7 with high antioxidant activity. Forages were ensiled in vacuum-sealed polyethylene bags containing ∼600 g wilted forage for 60 d, with 5 replicates for each treatment. Alfalfa silage ensiled at low DM had higher concentrations of acetic acid and non-protein nitrogen (NPN) and lower concentrations of lactic acid, propionic acid and water soluble carbohydrates (WSC) than silages with high DM. Inoculation of L. plantarum 24−7 led to lower silage pH and lower concentrations of NPN, neutral detergent fiber (aNDF), acid detergent fiber (ADF), and higher WSC compared to the control silage at two DM contents. Inoculation increased aerobic stability of the forage ensiled at low DM but decreased that ensiled at high DM. In control silages, almost half of the α-tocopherol and β-carotene was degraded during ensiling, whereas inoculation with L. plantarum 24−7 increased α-tocopherol and β-carotene concentrations as well as the proportion of polyunsaturated fatty acids (PUFA) in ensiled alfalfa at both DM contents. Greater concentrations of β-carotene were observed in L. plantarum 24−7 treated-silage at low DM compared to silage at high DM. The application of L. plantarum 24−7 strain also increased total antioxidant capacity (T-AOC), glutathione peroxidase (GSH-Px) and catalase (CAT) activities of the alfalfa silage but decreased superoxide dismutase (SOD) and lipoxygenase (LOX) activities. These results indicate that L. plantarum 24−7 improved the fermentation quality and antioxidant status of ensiled alfalfa forage relative to the control silage.

The present study investigated the bacterial community, metabolome and biotransformation of phenolic compounds in sainfoin silage inoculated either with or without Lactobacillus plantarum. Our results revealed that the epiphytic microbiota of wilted sainfoin mainly comprised Acinetobacter, Spingomonas, Pseudomonas, Lactobacillus, Delftia and Aquabacterium. After ensiling, L. acetotolerans, L. buchneri, L. plantarum, L. pentosus and Clostridium tyrobutricum were the dominant species. Compared to the control, the inoculant L. plantarum increased the relative abundance of L. buchneri while decreased that of the other dominant species. The ensiling process increased the concentrations of 21 flavones, 16 flavonols, 16 flavonoids, 14 flavanones and 9 isoflavones while decreased other 32 flavones and 11 anthocyanins, which mainly modulated by the "isoflavonoid biosynthesis" and "flavonoid biosynthesis" pathways. The inoculant L. plantarum mainly reduced the concentrations of 10 flavones. Compared with the control, the inoculant L. plantarum mainly affected the metabolism pathways related to carbohydrates and nitrogen.

This study assessed the effects of antibacterial peptide-producing Bacillus subtilis (BS), Lactobacillus buchneri (LB), or their combination on fermentation, proteolysis, aerobic stability, and microbial communities during ensiling and aerobic exposure phases of alfalfa silage. The results showed that the BS-treated silage displayed a higher lactic acid concentration, less proteolysis, and higher aerobic stability than those in the control silage. Both LB and BS treatments increased Lactobacillus and Ascochyta abundance, and decreased Enterococcus and Sporormiacea abundance after 60 d of fermentation. LB and BS also inhibited the growth of Enterococcus after 3 d of aerobic exposure but similar to the control silage, the fungal community of BS silage was dominated by Candida and Pichia after 9 d of aerobic exposure. Therefore, inoculation of BS improved silage fermentation quality, aerobic stability and bacterial community during ensiling and after 3 d of aerobic exposure.

The effects of inoculation of strain Pediococcus acidilactici J17 with high antioxidant activity and a widely used commercial inoculum of Lactobacillus plantarum MTD-1, on antioxidant status, concentrations of α‑tocopherol and β‑carotene, fatty acid composition and fermentation profiles of ensiled alfalfa prepared at two dry matter (DM) contents were investigated. Chopped fresh alfalfa was ensiled at two DM contents of approximately 300 (low DM) and 400 (high DM) g/kg fresh weight, and treated with distilled water (control), L. plantarumMTD-1 and P. acidilactici J17, respectively. Forages were ensiled in vacuum-sealed polyethylene bags containing 500 g wilted forage for 60 d, with 4 replicates for each treatment. All inoculants effectively improved fermentation profiles of silages and the silage with a high DM exhibited better effects on inhibiting proteolysis and lipid oxidation; however, the antioxidant strain P. acidilactici J17 had little influence on the fatty acid composition of alfalfa silage. Silages with a low DM had higher proportions of saturated fatty acid and monounsaturated fatty acid, and lower proportions of polyunsaturated fatty acid compared with the silages with a high DM. Extensive degradation of α-tocopherol and β-carotene in alfalfa occurred after ensiling. The concentration of α-tocopherol in control silage declined to almost half of its original concentration in fresh alfalfa. Concentrations of β-carotene in the control silages with the low and high DM were accounted for 1/3 and 1/2 of their original concentrations in fresh alfalfa, respectively. In comparison with control silage and silage treated with L. plantarum MTD-1, inoculation of P. acidilactici J17 with high-antioxidant activity markedly increased the total antioxidant capacity (T-AOC), catalase (CAT) activity and concentrations of α-tocopherol and β-carotene of alfalfa silage ensiled at both DM contents. On average, higher T-AOC was observed in silage with a high DM than silage with a low DM. However, both inoculants decreased superoxide dismutase (SOD) activity of ensiled alfalfa. These results indicated that the P. acidilactici J17 strain could be used as a candidate antioxidant inoculum to improve the antioxidant status of alfalfa silage.

The effects of two strains of class IIa bacteriocin-producing lactic acid bacteria, Lactobacillus delbrueckii F17 and Lactobacillus plantarum (BNCC 336943), or a non-bacteriocin Lactobacillus plantarum MTD/1 (NCIMB 40027), on fermentation quality, microbial counts, and aerobic stability of alfalfa silage were investigated. Alfalfa was harvested at the initial flowering stage, wilted to a dry matter concentration of approximately 32%, and chopped to 1 to 2 cm length. Chopped samples were treated with nothing (control, CON), Lactobacillus delbrueckii F17 (F17), Lactobacillus plantarum (BNCC 336943) (LPB), or Lactobacillus plantarum MTD/1 (NCIMB 40027) (LPN), each at an application rate of 1 &times, 106 colony-forming units/g of fresh weight. Each treatment was ensiled in quadruplicate in vacuum-sealed polyethylene bags packed with 500 g of fresh alfalfa per bag and ensiled at ambient temperature (25 &plusmn, 2 &deg, C) for 3, 7, 14, 30, and 60 days. The samples were then subjected to an aerobic stability test after 60 days of ensiling. Compared with the CON silage, the inoculants reduced the pH after 14 days of ensiling. After 60 days, pH was lowest in the LPB-treated silage, followed by the F17 and LPN-treated silages. Inoculation of F17 increased concentrations of lactic acid in silages fermented for 7, 14, 30, and 60 days relative to other treatments, except for the LPN-treated silages ensiled for 30 and 60 days, in which the lactic acid concentrations were similar to that of F17 silage. Application of F17 and LPB decreased the number of yeast and mold relative to CON and LPN-treated silages. Compared with the CON silage, inoculant-treated silages had greater aerobic stability, water-soluble carbohydrate, and crude protein concentrations, and lower neutral detergent fiber, amino acid nitrogen, and ammonia nitrogen concentrations. The LPB-treated silage had the greatest aerobic stability followed by the F17-treated silage. Both class IIa bacteriocin producing inoculants improved alfalfa silage fermentation quality, reduced the growth of yeasts and molds, and improved the aerobic stability of the ensiled forage to a greater extent than the proven LPN inoculant. However, higher crude protein concentration and lower ammonia nitrogen concentration were observed in LPN-treated silage relative to other treatments.

The objective of this study was to estimate cow variability that can be used to determine the optimal sample size for digestibility trials using lactating dairy cows. Experimental design was randomized complete block design having three blocks and three dietary treatments. Three similarly managed nearby intensive farms were considered as blocks, and three diets were formulated to have 0.7, 1.0, and 1.3 neutral detergent fiber (NDF): starch ratio. In each farm, 18 cows were assigned for each dietary treatment and five sample sizes per each treatment group were simulated by simple random sampling of data from 18, 15, 12, 9 and 6 cows respectively. Intake was not affected by diet or sample size (p &gt, 0.05). Estimated cow variability (as standard deviation) for digestibility of dry matter, NDF and starch were 3.8 g/kg, 5.1 g/kg and 3.3 g/kg, respectively. A major implication of this study is that cow variability is greatest for NDF digestibility and the use of a minimum of 12 cows per dietary treatment is adequate to reliably detect treatment effects on the digestibility of NDF, starch and dry matter using cows fed in groups with randomized block design under these experimental conditions.

Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis, responsible for killing millions of people throughout the world. This study was designed to evaluate the prevalence and antimicrobial susceptibility of pulmonary TB infections among the outdoor patients in Tertiary Care Hospitals of Quetta city. A total of 250 TB suspects were examined through Ziehl–Neelsen staining and culturing on Lowenstein–Jenson and modified Ogawa medium. Sociodemographical data of the patients were collected using prestructured questionnaire. Most of the suspects in this study were females (64%) with clinical signs and symptoms of TB. Furthermore, 35–50-year age group was most affected, with percentage prevalence of 51%, as compared with 15–35-year age group. Most patients were uneducated (78.4%) and with poor socioeconomic status (74.4%). Ten sputum smear samples were acid fast bacilli (AFB) positive 10/250 (4%) on Ziehl–Neelsen staining. All the sputum samples were inoculated (direct method) on solid Lowenstein–Jenson and modified Ogawa medium, and 9.2% and 8% of the samples, respectively, were positive. However, on drug susceptibility testing, no mycobacterium tuberculosis (MTB)-resistant strains were detected.

The impact of Lactobacillus plantarum A1 producing ferulic acid esterase and Acremonium cellulase on Pennisetum sinese silages was investigated at two dry matter contents by studying the ensiling characteristics, lignocellulosic degradation and enzymatic saccharification properties. The P. sinese was treated with nothing (control), Acremonium cellulase (AC), L. plantarum A1 (Lp) and AC + Lp and ensiled for 60 d. All additive treatments effectively preserved P. sinese and promoted the degradation of lignocellulose in comparison with control. Pretreatment with AC exhibited better effects in degradation of lignocellulose and enhancing enzymatic saccharification of P. sinese silage with low dry matter content (L-DM), while AC + Lp performed better in lignocellulose degradation in silages with high dry matter content (H-DM). Application of Lp exhibited a better performance in reducing the concentration of acid detergent lignin in treated silages. In addition, Lp enhanced enzymatic saccharification at 72 h in H-DM silage relative to other treatments.

The aim of this study was to evaluate the effect of two organic acids [malic acid (MA) and citric acid (CA)], Lactobacillus plantarum (LP) and their mixtures on the fermentation of alfalfa silage. The wilted and chopped alfalfa was ensiled in vacuum-sealed plastic bags (200-230 g per bag) with following additives: 0.5% distilled water (control), 0.5% DL-MA, 0.5% CA, LP (1 · 10

Using gas chromatography mass spectrometry and the PacBio single molecule with real-time sequencing technology (SMRT), we analyzed the detailed metabolomic profiles and microbial community dynamics involved in ensiled Medicago sativa (alfalfa) inoculated without or with the homofermenter Lactobacillus plantarum or heterofermenter Lactobacillus buchneri. Our results revealed that 280 substances and 102 different metabolites were present in ensiled alfalfa. Inoculation of L. buchneri led to remarkable up-accumulation in concentrations of 4-aminobutyric acid, some free amino acids, and polyols in ensiled alfalfa, whereas considerable down-accumulation in cadaverine and succinic acid were observed in L. plantarum-inoculated silages. Completely different microbial flora and their successions during ensiling were observed in the control and two types of inoculant-treated silages. Inoculation of the L. plantarum or L. buchneri alters the microbial composition dynamics of the ensiled forage in very different manners. Our study demonstrates that metabolomic profiling analysis provides a deep insight in metabolites in silage. Moreover, the PacBio SMRT method revealed the microbial composition and its succession during the ensiling process at the species level. This provides information regarding the microbial processes underlying silage formation and may contribute to target-based regulation methods to achieve high-quality silage production.

Yaks ( Bos grunniens ) are adapted to a harsh alpine environment above the altitude of 3000 m, and show strong compensatory growth ability. The objective of this study was to investigate the plasma hormonal status and metabolite levels of growing yak steers when either offered supplements (SP) or not supplemented (NS) during the annual season of severest pasture shortage in late April and early May. The experiment was conducted between 23 April (day 0) and 8 July 2013 (day 76). Twelve 3-year-old yak steers were allocated to one of two treatments, either to receive supplements for 25 days or to remain unsupplemented. The supplement, which was composed of ground maize (75%) and local rapeseed meal (25%), was offered at maintenance level of energy and protein to the group of yaks receiving supplements from 23 April to 18 May (day 25) at evening. All the yaks were released to pasture during the daytime. Rectal temperature was measured fortnightly using an electro thermometer. Heart rate was recorded over four 4-day periods using modified heart rate monitors. Live weights (LW) were weighed weekly in the morning. Afterward, blood samples were drawn before release to the pasture to measure blood glucose (GLU), blood urea nitrogen (BUN), nonesterified fatty acids (NEFA), β-hydroxybutyrate (BHBA), growth hormone (GH), cortisol, the thyroid hormones (triiodothyronine [T 3 ] and thyroxine [T 4 ]), insulin and insulin-like growth factor 1 (IGF-1). The supplemented yaks showed a higher growth rate and compensation ability compared with the unsupplemented yaks. The overall mean heart rates of the unsupplemented yaks were higher than those of the supplemented yaks, and were higher in both treatments in July than in June. There were significant treatment effects on the concentrations of IGF-1, insulin, NEFA and BUN. Whilst supplementation reduced the concentration of IGF-1, it increased the blood concentration of insulin. The differences of blood NEFA between treatments during feed restriction period disappeared in forage growing period. BUN concentrations of SP were significantly lower than NS from day 8 to day 28. Thereafter, BUN concentrations of yaks on the two treatments were similar. The results indicate that supplementary feeding to alleviate nutritional stress in yaks during the period of lowest herbage availability is critical for improving their ability to replace body tissue mobilized over the previous winter months.

We studied the effects on alfalfa preservation and chemical composition of the addition of different levels of malic acid and citric acid at ensiling as well as the utilization efficiency of these 2 organic acids after fermentation. Alfalfa was harvested at early bloom stage. After wilting to a dry matter content of approximately 40%, the alfalfa was chopped into 1- to 2-cm pieces for ensiling. Four levels (0, 0.1, 0.5, and 1% of fresh weight) of malic acid or citric acid were applied to chopped alfalfa at ensiling with 4 replicates for each treatment, and the treated alfalfa forages were ensiled for 60 d in vacuum-sealed polyethylene bags (dimensions: 200 mm × 300 mm) packed with 200 to 230 g of fresh alfalfa per mini silo and an initial density of 0.534 g/cm3. The application of malic or citric acids at ensiling for 60 d led to lower silage pH than was observed in the control silage (0% of malic or citric acids). Application of the 2 organic acids led to higher lactic acid concentration in alfalfa silage than in the control silage except with the application rate of 1% of fresh weight. Silages treated with both organic acids had lower nonprotein nitrogen concentrations than the control silages, and the nonprotein nitrogen concentrations in ensiled forages decreased with the increase in malic or citric acid application rates. The application of the 2 organic acid additives led to lower saturated fatty acid proportions and higher polyunsaturated fatty acid proportions in ensiled alfalfa than in the control silage. The amount of malic and citric acids degraded during ensiling of alfalfa was 1.45 and 0.63 g, respectively. At the application rate of 0.5% of fresh weight, residues of malic acid and citric acid in alfalfa silage were 11.1 and 13.6 g/kg of dry matter. These results indicate that including malic or citric acids at the ensiling of alfalfa effectively improved silage fermentation quality, limited proteolysis, improved fatty acid composition of the ensiled forage, and could provide animals with additional feed additives proven to promote animal performance. However, when the application rate of both organic acids reached 1%, the concentration of lactic acid in silages decreased notably. Additionally, 0.5 and 1% application rates also increased the yeast count in ensiled alfalfa.

Tibetan nomads have lived since ancient times in the unique and harsh environment of the Qinghai-Tibetan Plateau with average altitudes over 4000 m. These people have been able to live and multiply healthily over numerous generations under the extreme stress of high-altitude environment, including cold, hypoxia, and strong ultraviolet radiation, and with a simple diet devoid of vegetables and fruits for most of the year. Their survival depends heavily on yak milk, and its products comprise the main portion of their daily diet. In this review, yak milk and its derived products are examined in detail and compared with milk from other ruminant species. Yak milk products seem to be particularly rich in functional and bioactive components, which may play a role in maintaining the health status of Tibetan nomads. This includes particular profiles of amino acids and fatty acids, and high levels of antioxidant vitamins, specific enzymes, and bacteria with probiotic activity (yoghurt is the main food). Based on that, it is proposed that the Tibetan nomads have developed a nutritional mechanism adapted to cope with the specific challenges posed by the environment of the world's highest plateau. Systematic studies are required to demonstrate this in a more mechanistic way.

This experiment studied the contribution of plant enzymes and microbial activity on lipolysis and proteolysis in ensiled alfalfa. Before ensiling, the wilted alfalfa was treated with plant enzyme inactivation by autoclaving or with sterilization by γ-ray irradiation. The treated alfalfa was then inoculated with commercial lactic acid bacteria inoculants and ensiled for 40 d. Alfalfa without treatment was ensiled as the control. The content of total fatty acid (FA) after ensiling decreased 43% in the control silage and 28% in the γ-ray-treated silage, but did not change in the autoclave-treated silage. Among the major FA (C16:0, C18:2n-6, C18:3n-3), a considerable increase was observed in proportion of C16:0 in the control silage as compared with fresh alfalfa; conversely, decreases in proportions of C18:2n-6 and C18:3n-3 occurred during ensilage. Silage treated with γ-ray radiation at ensiling had a smaller proportion of C16:0 and greater proportions of C18:2n-6 and C18:3n-3 than control silage. Autoclave treatment further decreased proportions of C16:0 and most of the other FA, and increased C18:2n-6 and C18:3n-3 proportions in comparison with γ-ray treatment. Proportions of C16:0, C18:2n-6, C18:3n-3 and other detected FA (except for the proportion of C15:0) did not differ between fresh forage and autoclave-treated silage. Remarkably, smaller nonprotein nitrogen content was observed in the autoclave-treated silage compared with the γ ray-treated silage or the control silage. These results indicated that an extensive lipolysis occurred during ensiling of alfalfa, and plant enzymes played a major role in lipolysis and proteolysis.

The pH optimum and thermostability of both exopeptidases and endopeptidases were investigated in this study to elucidate the possible role of plant proteases in proteolysis during ensiling of alfalfa herbage. Proteolytic activities of 4 classes of endopeptidases (i.e., serine, metallo, aspartic, and cysteine peptidase) and 5 classes of exopeptidases (i.e., aminopeptidase, carboxypeptidase, dipeptidase, dipeptidyl-peptidase, and tripeptidyl-peptidase) were examined within pH values of 3 to 9, and within temperatures from 20 to 90°C. Serine and metalloproteases, the principal endopeptidases that hydrolyzed most of the protein to nonprotein nitrogen in alfalfa silage, had optimum activities at pH 4. Among the major exopeptidases contributing protein degradation in ensiled alfalfa, dipeptidase and tripeptidyl-peptidase had stable activities between pH 4 and 6, and carboxypeptidase activity was optimal at pH 5. The optimum temperature for most peptidase activities was 40°C. Proteolytic activities of both endo- and exopeptidases increased with the elevation of incubating temperature from 20 to 40°C. The pH value in well-preserved alfalfa silage is often above 4.0, and the temperatures in the ensiled mass range from 25 to 40°C. Therefore, high proteolytic activities between pH 4 and 6 and the temperature range of ensiled alfalfa suggest that plant peptidases play a role in hydrolyzing protein during prolonged storage.

The objective was to evaluate the effect of dietary coconut oil on methane (CH(4)) emissions and the microbial community in Tibetan sheep. Twelve animals were assigned to receive either a control diet (oaten hay) or a mixture diet containing concentrate (maize meal), in which coconut oil was supplemented at 12 g/day or not for a period of 4 weeks. CH(4) emissions were measured by using the 'tunnel' technique, and microbial communities were examined using quantitative real-time PCR. Daily CH(4) production for the control and forage-to-concentrate ratio of 6:4 was 17.8 and 15.3 g, respectively. Coconut oil was particularly effective at reducing CH(4) emissions from Tibetan sheep. The inclusion of coconut oil for the control decreased CH(4) production (in grams per day) by 61.2%. In addition, there was a positive correlation between the number of methanogens and the daily CH(4) production (R = 0.95, P0.001). Oaten hay diet containing maize meal (6:4) plus coconut oil supplemented at 12 g/day decreases the number of methanogens by 77% and a decreases in the ruminal fungal population (85-95%) and Fibrobacter succinogenes (50-98%) but an increase in Ruminococcus flavefaciens (25-70%). The results from our experiment suggest that adding coconut oil to the diet can reduce CH(4) emissions in Tibetan sheep and that these reductions persist for at least the 4-week feeding period.

Seedling performance may determine plant distribution, especially in water-limited environments. Plants of Caragana korshinskii commonly grow in arid and semiarid areas in northwestern China, and endure water shortage in various ways, but little is known about their performance when water shortage occurs at early growth stages. The water relations, photosynthetic activity, chlorophyll (Chl) content and proline accumulation were determined in 1-year-old seedlings growing in a 1:1 mixture of Loess soil and Perlite and subjected to (1) a water deficit for 20 days and (2) kept adequately watered throughout. The water deficit induced low (−6.1 MPa) predawn leaf water potentials (LWP), but did not induce any leaf abscission. Stomatal conductance (g s), leaf transpiration rate (E), and net photosynthetic rate (P N) decreased immediately following the imposition of the water deficit, while the maximal photochemical efficiency of photosystem II (PSII) (Fv/Fm) and the effective quantum yield of PSII (ΦPSII) decreased 15 days later. An early and rapid decrease in g s, reduced E, increased Chl (a+b) loss, increased the apparent rate of photochemical transport of electrons through PSII (ETR)/P N, as well as a gradual increase in non-photochemical quenching of fluorescence (NPQ) and proline may have contributed to preventing ΦPSII from photodamage. C. korshinskii seedlings used a stress-tolerance strategy, with leaf maintenance providing a clear selective advantage, considering the occasional rainfall events during the growing season.

The experiment was conducted to investigate the exopeptidase classes in alfalfa (Medicago sativa L.) leaves, and to determine their contribution to the formation of nonprotein nitrogen (NPN) components during ensiling. Six classes of inhibitors that included bestatin (aminopeptidase inhibitor), potato carboxypeptidase inhibitor (PCI, carboxypeptidase inhibitor), 1,10-phenanthroline (dipeptidase inhibitor), diprotin A (dipeptidyl-peptidase inhibitor), butabindide (tripeptidyl-peptidase inhibitor), and dipeptide Phe-Arg (peptidyl-dipeptidase inhibitor) were used. To determine the contribution of each exopeptidase to the formation of NPN products, aqueous extracts of fresh alfalfa were fermented to imitate the proteolytic process of ensiled alfalfa and to ensure that each class of exopeptidase inhibitor would have immediate contact with the proteases in the alfalfa extract. Five classes of exopeptidases; namely, aminopeptidase, carboxypeptidase, dipeptidase, dipeptidyl-peptidase, and tripeptidyl-peptidase, were shown to be present in alfalfa leaves, each playing a different role in alfalfa protein degradation. Aminopeptidase, carboxypeptidase, and dipeptidase were the main exopeptidases contributing to the formation of NH(3)-N. Among the 5 exopeptidases, tripeptidyl-peptidase appeared to be the principal exopeptidase in hydrolyzing forage protein into peptides, whereas carboxypeptidase and dipeptidase appeared to be more important in contributing to the formation of amino acid-N. Dipeptidyl-peptidase and tripeptidyl-peptidase did not play a role in the formation of NH(3)-N or amino acid-N. Dipeptidase, carboxypeptidase, and tripeptidyl-peptidase were the principal exopeptidases for hydrolyzing forage protein into NPN during ensilage, and treatment with a mixture of the 5 inhibitors reduced the total NPN concentration in the fermented alfalfa extract to about 45% of that in the control after 21 d of fermentation.

The objective of the present study was to examine whether yaks possess any adaptive mechanisms of nitrogen (N) metabolism to survive in the harsh foraging environment of the Qinghai-Tibetan Plateau. A grazing experiment on native alpine meadows was conducted to determine availability of herbage biomass and body weight (BW) change of yaks over the year, followed by two indoor feeding trials to investigate adaptation mechanisms of N metabolism in yaks fed at similar intake level to grazing conditions. Three castrated males of each of three genotypes; yak (Bos grunniens), indigenous cattle (Bos taurus) and their crossbred - cattleyak (Bos taurus maleBos grunniens female), were used in the housed trials. Results showed that: i) Monthly herbage biomass production and daily grazing intakes by yaks over the year ranged from 220 to 4,664 kg DM per ha, and 1.90 to 8.50 kg DM, respectively. For about seven months each year, yaks suffer from malnutrition as a result of inadequate pasture conditions; ii) Urinary N excretion and N retention by yaks were significantly affected by feeding level, and yaks had a lower (p) and a greater (p) than indigenous cattle (0.47 and -0.16 g/kg , respectively). Fasting daily urinary N excretion was greater (p). Purine derivative N excretion and purine derivative N index (PNI) increased with increasing feeding level, while the value of PNI was greater (p) and a greater (p) than indigenous cattle (0.47 and -0.16 g/kg , respectively). Fasting daily urinary N excretion was greater (p). Purine derivative N excretion and purine derivative N index (PNI) increased with increasing feeding level, while the value of PNI was greater (p

We investigated the macro-mineral status in free-grazing Tibetan sheep (Ovis aries) and their forage diets. The study was conducted in 4 counties in the northeast of the Qinghai–Tibetan Plateau. Forage samples and blood serum from 20 sheep in each county were collected in July (summer) and December (winter), and analyzed to determine the concentration of the main macro-minerals (Ca, K, Mg, Na and P). Macro-mineral concentrations varied with season, but values for forage were below the recommended levels for P and K in one or more counties in winter and for Na was low during both summer and winter for all counties. Similarly, serum samples were found to be within marginal range of P, with the exception of Tianzhu County (TC) in winter, and serum Na were all below the marginal level in both summer and winter in all counties. The results indicate that the winter forage in particular is insufficient in macro-minerals and that this may lead to the observed mineral deficiencies and marginal deficiencies in Tibetan sheep in these areas. Supplementary minerals may therefore play a role in balancing the minerals available from the forage in winter and lead to increases in animal production on the Tibetan Plateau.

Two experiments were conducted to determine the urinary purine derivative (PD) excretion rates and to analyze potential variations in PD excretions between yak, Tibetan indigenous cattle, and their crossbreds under similar ecological environment, and to develop prediction equations based on PD excretion for estimating rumen microbial protein supply. Three Tibetan castrated male yaks, and similar numbers of indigenous cattle and their crossbreds, were used in a fasting trial followed by a feeding trial, using three 3 x 3 Latin squares (1 for each breedtype), to measure responses of PD excretion to different feeding levels. The results showed that i) daily endogenous PD excretion for yak, indigenous cattle, and their crossbreds was 134, 163, and 138 micromol/kg of BW(0.75) (P = 0.38), respectively; and ii) crossbreds have greater PD excretion rate per unit digestible OM intake than indigenous cattle (P = 0.03). However, there were no significant differences between yaks and the crossbreds (P = 0.24) or between yaks and the indigenous cattle (P = 0.25). The proportion of allantoin to total PD in urine ranged from 0.83 to 0.88, with the crossbreds having greater values compared with the 2 parents (P = 0.03). Daily glomerular filtration rate, calculated using endogenous creatinine as an internal marker, for the above animals was 3.85, 4.23, and 3.61 L/kg of BW(0.75), respectively, in fasting trial (P = 0.59). The alpine animals may develop special regulating mechanisms in the kidney in terms of glomerular filtration rate and PD excretion, which would help the animals in adapting to the harsh environment of the Qinghai-Tibetan plateau.

This study evaluated the effects of Lactobacillus plantarum with or without Lactobacillus buchneri on the fermentation and aerobic stability of mixed tall fescue (Festuca arundinacea Schreb) and meadow fescue (Festuca pratensis Huds.) silage ensiled at different dry matter (DM) contents. The first cut was harvested at boot stage and second-cut grasses were harvested when 30- to 35-cm tall. Four DM content treatments of the first cut were 17.9, 24.9, 34.6, and 48.7%; and of the second cut were 29.1, 36.3, 44.1, and 49.2%. Chopped grasses at each DM content were treated with (1) deionized water (control), (2) Lb. plantarum MTD-1 (LP), or (3) a combination of Lb. plantarum MTD-1 and Lb. buchneri 40788 (LP+LB). The application amount of each inoculant to the fresh forage was 1 × 10(6) cfu/g. Grasses were ensiled in vacuum-sealed polyethylene bags containing 150 g of DM for 60 d, with 4 replicates for each treatment. Silages inoculated with LP+LB had greater pH compared with untreated or LP-treated silages. Lactate was greater in LP silage than control or LP+LB silages. As silage DM increased, lactate in untreated and LP-treated silages decreased, but increased in LP+LB-treated silage. Acetate concentration decreased with increased DM in all silages. The LP+LB-treated silage had the longest and control silage the shortest aerobic stability for both harvests. The greatest values in aerobic stability were observed in silages with highest DM content. In this study, aerobic stability of grass mixes ensiled between 18 and 44% DM content increased as the percentage of DM increased. The LP and LP+LB inoculants improved aerobic stability of silages harvested between 18 and 44% DM content.

The effects of different additives, including lactic acid bacteria inoculants, acremonium cellulase and mixtures of lactic acid bacteria inoculants and acremonium cellulase on changes of nutritive components and in vitro digestibility of Ceratoides arborescens during ensiling were investigated. The silages of each treatment were prepared in plastic film bags, kept in an incubator at 30°C and bags were opened after 1, 3, 5, 10, 30 and 45 days at room temperature. The results show that addition of additives and ensiling time did not affect acid detergent lignin content during ensiling (P>0.05). With ensiling time, pH value decreased (P

An experiment was conducted to characterise N use efficiency and quantify urea fluxes in yaks offered four levels of dietary N (1.43%, 1.97%, 2.45% and 2.90% of diet DM) in a 4 × 4 Latin square design. The incremental increase in N intake linearly increased N retention (P = 0.003) and the excretion of urinary N (P < 0.001), but no difference (P > 0.05) in faecal N excretion was observed in growing yaks fed any of the four diets. Microbial N production had quadratic (P < 0.001) responses to dietary N, characterised by the highest microbial N production occurring in the 1.97% N diet (P < 0.05). As the N content of the diet increased, the urinary excretion of urea increased from 13% to 27% of urea entry rate (quadratic, P < 0.001), whereas gastrointestinal entry urea returned to ornithine cycling decreased from 46% to 40% (linear, P < 0.001), and the gastrointestinal entry urea used for anabolism increased from 50% to 56% (linear, P < 0.001). Gastrointestinal entry urea incorporated into bacterial N decreased linearly (P < 0.001) with incremental increase in N intake, and the greatest concentration (23.5%) of bacterial N originating from plasma urea N was in yaks fed the 1.43% N diet. As much as 87% of the urea synthesised in the liver was returned to the gastrointestinal tract when the yaks were fed a diet with 1.43% N (1.1 times the maintenance N level). Moreover, constantly greater urea production than the intake of digestible N, and the gastrointestinal-urea clearance than the kidney-urea clearance were observed, respectively, in the growing yaks, regardless of the level of N intake. These results suggest that yaks might be more efficient at utilising N under harsh environment than are cattle.