Background:Ruminants rely upon a complex community of microbes in their rumen to convert host-indigestible feed into nutrients.However,little is known about the association between the rumen microbiota and feed effici...Background:Ruminants rely upon a complex community of microbes in their rumen to convert host-indigestible feed into nutrients.However,little is known about the association between the rumen microbiota and feed efficiency traits in Nellore(Bos indicus)cattle,a breed of major economic importance to the global beef market.Here,we compare the composition of the bacterial,archaeal and fungal communities in the rumen of Nellore steers with high and low feed efficiency(FE)phenotypes,as measured by residual feed intake(RFI).Results:The Firmicutes to Bacteroidetes ratio was significantly higher(P<0.05)in positive-RFI steers(p-RFI,low feed efficiency)than in negative-RFI(n-RFI,high feed efficiency)steers.The differences in bacterial composition from steers with high and low FE were mainly associated with members of the families Lachnospiraceae,Ruminococcaceae and Christensenellaceae,as well as the genus Prevotella.Archaeal community richness was lower(P<0.05)in p-RFI than in n-RFI steers and the genus Methanobrevibacter was either increased or exclusive of p-RFI steers.The fungal genus Buwchfawromyces was more abundant in the rumen solid fraction of n-RFI steers(P<0.05)and a highly abundant OTU belonging to the genus Piromyces was also increased in the rumen microbiota of highefficiency steers.However,analysis of rumen fermentation variables and functional predictions indicated similar metabolic outputs for the microbiota of distinct FE groups.Conclusions:Our results demonstrate that differences in the ruminal microbiota of high and low FE Nellore steers comprise specific taxa from the bacterial,archaeal and fungal communities.Biomarker OTUs belonging to the genus Piromyces were identified in animals showing high feed efficiency,whereas among archaea,Methanobrevibacter was associated with steers classified as p-RFI.The identification of specific RFI-associated microorganisms in Nellore steers could guide further studies targeting the isolation and functional characterization of rumen microbes potentially important for the energy-harvesting efficiency of ruminants.展开更多
Background:Endolysins,the bacteriophage-originated peptidoglycan hydrolases,are a promising replacement for antibiotics due to immediate lytic activity and no antibiotic resistance.The objectives of this study were to...Background:Endolysins,the bacteriophage-originated peptidoglycan hydrolases,are a promising replacement for antibiotics due to immediate lytic activity and no antibiotic resistance.The objectives of this study were to investigate the lytic activity of endolysin LyJH307 against S.bovis and to explore changes in rumen fermentation and microbiota in an in vitro system.Two treatments were used:1)control,corn grain without LyJH307;and 2)LyJH307,corn grain with LyJH307(4 U/mL).An in vitro fermentation experiment was performed using mixture of rumen fluid collected from two cannulated Holstein steers(450±30 kg)and artificial saliva buffer mixed as 1:3 ratio for 12 h incubation time.In vitro dry matter digestibility,pH,volatile fatty acids,and lactate concentration were estimated at 12 h,and the gas production was measured at 6,9,and 12 h.The rumen bacterial community was analyzed using 16S rRNA amplicon sequencing.Results:LyJH307 supplementation at 6 h incubation markedly decreased the absolute abundance of S.bovis(approximately 70% compared to control,P=0.0289)and increased ruminal pH(P=0.0335)at the 12 h incubation.The acetate proportion(P=0.0362)was significantly increased after LyJH307 addition,whereas propionate(P=0.0379)was decreased.LyJH307 supplementation increased D-lactate(P=0.0340)without any change in L-lactate concentration(P>0.10).There were no significant differences in Shannon’s index,Simpson’s index,Chao1 estimates,and evenness(P>0.10).Based on Bray-Curtis dissimilarity matrices,the LyJH307 affected the overall shift in microbiota(P=0.097).LyJH307 supplementation induced an increase of 11 genera containing Lachnoclostridium,WCHB1-41,unclassified genus Selenomonadaceae,Paraprevotella,vadinBE97,Ruminococcus gauvreauii group,Lactobacillus,Anaerorhabdus furcosa group,Victivallaceae,Desulfuromonadaceae,and Sediminispirochaeta.The predicted functional features represented by the Kyoto Encyclopedia of Genes and Genomes pathways were changed by LyJH307 toward a decrease of carbohydrate metabolism.Conclusions:LyJH307 caused a reduction of S.bovis and an increase of pH with shifts in minor microbiota and its metabolic pathways related to carbohydrate metabolism.This study provides the first insight into the availability of endolysin as a specific modulator for rumen and shows the possibility of endolysin degradation by rumen microbiota.展开更多
The aim of this experiment was to determine the effects of beta-acids, prenylated phenolic compounds from the hops plant, on fermentation of individual carbohydrates by rumen microorganisms. Mixed, uncultivated rumen ...The aim of this experiment was to determine the effects of beta-acids, prenylated phenolic compounds from the hops plant, on fermentation of individual carbohydrates by rumen microorganisms. Mixed, uncultivated rumen microbiota was harvested from rumen fistulated steers and washed to make cell suspensions. The suspensions were used to inoculate media with a glucan, fructan or constituent sugar, and fermentation was evaluated by production of short-chain fatty acids (SCFA). Hops beta-acid (30 ppm) was not universally inhibitory, but each of the SCFA (acetate, propionate or butyrate) was decreased (P < 0.05) in one or more of each cellulose or starch tested. The fermentation of sugars and fructans (short- or long-chain inulins) was not impacted by the phytochemicals. Previous results have shown that hops and hops extracts had the beneficial effects of reducing rumen ammonia and methane. The current results indicate that both starch and cellulose fermentation could be impacted. Because cellulose fermentation is nutritionally important on forage-based diets, hops phytochemicals might have more utility in cereal grain-based rations.展开更多
Background The enteric methane inhibitor 3-nitrooxypropanol(3-NOP)inhibits the key enzyme in ruminal methanogenesis,but whether short-term(ST)and long-term(LT)dietary supplementation has similar effects on rumen micro...Background The enteric methane inhibitor 3-nitrooxypropanol(3-NOP)inhibits the key enzyme in ruminal methanogenesis,but whether short-term(ST)and long-term(LT)dietary supplementation has similar effects on rumen microbiota in beef cattle and how microbes change after 3-NOP withdrawal have not been studied.This study investigated changes in rumen bacteria,archaea,and protozoa after ST and LT dietary supplementation and removal of 3-NOP using metataxonomic analysis.Results A total of 143 rumen samples were collected from two beef cattle studies with 3-NOP supplementation.The ST study(95 samples)used eight ruminally cannulated beef cattle in a 4×4 Latin square design with four 28-d of 3-NOP treatments[mg/kg of dry matter(DM)]:control:0,low:53,med:161,and high:345.The LT study(48 samples)was a completely randomized design with two 3-NOP treatments[control:0,and high:280 mg/kg of DM)fed for 112-d followed by a 16-d withdrawal(without 3-NOP).Bacterial and archaeal communities were significantly affected by 3-NOP supplementation but limited effects on protozoal communities were observed.Under ST supplementation,the relative abundances of Prevotella,Methanobrevibacter(Mbb.)ruminantium,Methanosphaera sp.ISO3-F5,and Entodinium were increased(Q<0.05),whereas those of Mbb.gottschalkii and Epidinium were decreased(Q<0.05)with 3-NOP supplementation.In LT study,relative abundances of Mbb.ruminantium,and Methanosphaera sp.Group5 were increased(Q<0.05),while those of Saccharofermentans and Mbb.gottschalkii were decreased(Q<0.05)with 3-NOP supplementation.Comparison between 3-NOP supplementation and the withdrawal revealed increased relative abundances of Clostridia UCG-014 and Oscillospiraceae NK4A214 group and decreased those of Eubacterium nodatum group and Methanosphaera sp.Group5(P<0.05)after 3-NOP withdrawal.Further comparison of rumen microbiota between control and 3-NOP withdrawal showed significantly higher(P=0.029)relative abundances of Eggerthellaceae DNF00809,p-1088-a5 gut group,and Family XII UCG-001 in control group while no significant differences were detected for archaea and protozoa.Microbial network analysis revealed that microbial interactions differed by both 3-NOP dose and durations.Conclusions Both ST and LT supplementation affected overall rumen microbial profile,with individual microbial groups responded to 3-NOP supplementation differently.After 3-NOP withdrawal,not all microbes showed recovery,indicating that the 3-NOP driven shifts were only partially reversible.These findings provide an understanding of the effects of 3-NOP on rumen microbial communities and their adaptability to methane mitigation strategies.展开更多
Gut-brain communication via the peripheral neural network is vital for regulating local digestive function and systemic physiology.Gut microbiota,which produces a wide array of neuroactive compounds,is a critical modu...Gut-brain communication via the peripheral neural network is vital for regulating local digestive function and systemic physiology.Gut microbiota,which produces a wide array of neuroactive compounds,is a critical modulator in this bidirectional dialog.Perturbations in the gut microbiota have been implicated in neurological disorders such as depression and stress.Distinct from humans and other monogastric animals,ruminants possess a unique,microbially dense gastrointestinal compartment,the rumen,that facilitates the digestion of fibrous plant materials.These ruminal microbes are likely key contributors to rumen-brain crosstalk.Unlike certain microbe-derived neuroactive compounds produced in the hindgut that are minimally absorbed and primarily excreted in feces,those generated in rumen can reach the small intestine,where they are largely absorbed and affect central nervous system through systemic regulation in addition to the vagal pathway.Notably,emerging evidence suggests that rumen microbiota dysbiosis under stress is associated with abnormal behavior,altered hormonal and neurotransmitter levels.In this review,we introduce the concept of the rumen-microbiome-brain axis by comparing the anatomical structures and microbial characteristics of the intestine and the rumen,emphasizing the neuroactive potential of rumen microbiome and underlying mechanisms.Advances in this frontier hold tremendous promise to reveal a novel dimension of the gut-microbiome-brain axis,providing transformative opportunities to improve ruminant welfare,productivity,and agricultural sustainability.展开更多
Background Methane(CH_(4))emissions from ruminants significantly contribute to greenhouse gas effects and energy loss in livestock production.Methyl-coenzyme M reductase(MCR)is the key enzyme in methanogenesis,making ...Background Methane(CH_(4))emissions from ruminants significantly contribute to greenhouse gas effects and energy loss in livestock production.Methyl-coenzyme M reductase(MCR)is the key enzyme in methanogenesis,making it a promising target for CH_(4) mitigation.This study aimed to identify and validate plant-derived inhibitors by using molecular docking to screen compounds with strong binding affinity to the F430 active site of MCR and assessing their efficacy in reducing CH_(4) emissions.Results Molecular docking analysis identified salvianolic acid C(SAC)as a potent inhibitor of MCR,showing a strong binding affinity to the F430 active site(binding energy:-8.2 kcal/mol).Enzymatic inhibition assays confirmed its inhibitory effect,with a half-maximal inhibitory concentration(IC50)of 692.3μmol/L.In vitro rumen fermentation experiments demonstrated that SAC supplementation(1.5 mg/g DM)significantly reduced CH_(4)production(P<0.01)without negatively affecting major fermentation parameters.Microbial community analysis using 16S rRNA sequencing and metagenomics revealed that SAC selectively altered the rumen microbiota,increasing the relative abundance of Bacteroidota while significantly reducing Methanobrevibacter(P=0.04).Moreover,metagenomic analysis showed the downregulation of key methanogenesis-related genes(mcrA and rnfC),suggesting a dual mechanism involving direct enzymatic inhibition and microbial community modulation.Conclusions These findings indicate that SAC effectively reduces CH_(4)production by inhibiting MCR activity and reshaping the rumen microbial community.As a plant-derived compound with strong inhibitory effects on methanogenesis,SAC presents a promising and sustainable alternative to synthetic CH_(4) inhibitors,offering potential applications for mitigating CH_(4)emissions in livestock production.展开更多
Background: Dietary energy source and level in lactation diets can profoundly affect milk yield and composition.Such dietary effects on lactation performance are underpinned by alteration of the rumen microbiota, of w...Background: Dietary energy source and level in lactation diets can profoundly affect milk yield and composition.Such dietary effects on lactation performance are underpinned by alteration of the rumen microbiota, of which bacteria, archaea, fungi, and protozoa may vary differently. However, few studies have examined all the four groups of rumen microbes. This study investigated the effect of both the level and source of dietary energy on rumen bacteria, archaea, fungi, and protozoa in the rumen of lactating dairy cows. A 2 × 2 factorial design resulted in four dietary treatments: low and high dietary energy levels(LE: 1.52–1.53;and HE: 1.71–1.72 Mcal/kg dry matter) and two dietary energy sources(GC: finely ground corn;and SFC: steam-flaked corn). We used a replicated 4 × 4 Latin square design using eight primiparous Chinese Holstein cows with each period lasting for 21 d. The rumen microbiota was analyzed using metataxonomics based on kingdom-specific phylogenetic markers [16 S r RNA gene for bacteria and archaea, 18 S r RNA gene for protozoa, and internally transcribed spacer 1(ITS1) for fungi] followed with subsequent functional prediction using PICRUSt2.Results: The GC resulted in a higher prokaryotic(bacterial and archaeal) species richness and Faith's phylogenetic diversity than SFC. For the eukaryotic(fungi and protozoa) microbiota, the LE diets led to significantly higher values of the above measurements than the HE diets. Among the major classified taxa, 23 genera across all the kingdoms differed in relative abundance between the two dietary energy levels, while only six genera(none being protozoal)were differentially abundant between the two energy sources. Based on prokaryotic amplicon sequence variants(ASVs) from all the samples, overall functional profiles predicted using PICRUSt2 differed significantly between LE and HE but not between the two energy sources. Fish Taco analysis identified Ruminococcus and Coprococcus as the taxa potentially contributing to the enriched KEGG pathways for biosynthesis of amino acids and to the metabolisms of pyruvate, glycerophospholipid, and nicotinate and nicotinamide in the rumen of HE-fed cows. The co-occurrence networks were also affected by the dietary treatments, especially the LE and GC diets, resulting in distinct co-occurrence networks. Several microbial genera appeared to be strongly correlated with one or more lactation traits.Conclusions: Dietary energy level affected the overall rumen multi-kingdom microbiota while little difference was noted between ground corn and steam-flaked corn. Some genera were also affected differently by the four dietary treatments, including genera that had been shown to be correlated with lactation performance or feed efficiency.The co-occurrence patterns among the genera exclusively found for each dietary treatment may suggest possible metabolic interactions specifically affected by the dietary treatment. Some of the major taxa were positively correlated to milk properties and may potentially serve as biomarkers of one or more lactation traits.展开更多
Background Subacute ruminal acidosis(SARA)is a common metabolic disorder of high yielding dairy cows,and it is associated with dysbiosis of the rumen and gut microbiome and host inflammation.This study evaluated the i...Background Subacute ruminal acidosis(SARA)is a common metabolic disorder of high yielding dairy cows,and it is associated with dysbiosis of the rumen and gut microbiome and host inflammation.This study evaluated the impact of two postbiotics from Saccharomyces cerevisiae fermentation products(SCFP)on rumen liquid associated microbiota of lactating dairy cows subjected to repeated grain-based SARA challenges.A total of 32 rumen cannulated cows were randomly assigned to 4 treatments from 4 weeks before until 12 weeks after parturition.Treatment groups included a Control diet or diets supplemented with postbiotics(SCFPa,14 g/d Original XPC;SCFPb-1X,19 g/d Nutri Tek;SCFPb-2X,38 g/d Nutri Tek,Diamond V,Cedar Rapids,IA,USA).Grain-based SARA challenges were conducted during week 5(SARA1)and week 8(SARA2)after parturition by replacing 20%DM of the base total mixed ration(TMR)with pellets containing 50%ground barley and 50%ground wheat.Total DNA from rumen liquid samples was subjected to V3–V416S r RNA gene amplicon sequencing.Characteristics of rumen microbiota were compared among treatments and SARA stages.Results Both SARA challenges reduced the diversity and richness of rumen liquid microbiota,altered the overall composition(β-diversity),and its predicted functionality including carbohydrates and amino acids metabolic pathways.The SARA challenges also reduced the number of significant associations among different taxa,number of hub taxa and their composition in the microbial co-occurrence networks.Supplementation with SCFP postbiotics,in particular SCFPb-2X,enhanced the robustness of the rumen microbiota.The SCFP supplemented cows had less fluctuation in relative abundances of community members when exposed to SARA challenges.The SCFP supplementation promoted the populations of lactate utilizing and fibrolytic bacteria,including members of Ruminococcaceae and Lachnospiraceae,and also increased the numbers of hub taxa during non-SARA and SARA stages.Supplementation with SCFPb-2X prevented the fluctuations in the abundances of hub taxa that were positively correlated with the acetate concentration,andα-andβ-diversity metrics in rumen liquid digesta.Conclusions Induction of SARA challenges reduced microbiota richness and diversity and caused fluctuations in major bacterial phyla in rumen liquid microbiota in lactating dairy cows.Supplementation of SCFP postbiotics could attenuate adverse effects of SARA on rumen liquid microbiota.展开更多
Background： A possible option to meet the increased demand of forage for dairy industry is to use the agricultural byproducts, such as corn stover. However, nutritional value of crop residues is low and we have been ...Background： A possible option to meet the increased demand of forage for dairy industry is to use the agricultural byproducts, such as corn stover. However, nutritional value of crop residues is low and we have been seeking technologies to improve the value. A feeding trial was performed to evaluate the effects of four levels of Saccharomyces cerevisiae fermentation product（SCFP; Original XP; Diamond V） on lactation performance and rumen fermentation in mid-lactation Holstein dairy cows fed a diet containing low-quality forage. Eighty dairy cows were randomly assigned into one of four treatments： basal diet supplemented with 0, 60, 120, or 180 g/d of SCFP per head mixed with 180, 120, 60, or 0 g of corn meal, respectively. The experiment lasted for 10 wks, with the first 2 weeks for adaptation.Results： Dry matter intake was found to be similar（P 〉 0.05） among the treatments. There was an increasing trend in milk production（linear, P ≤ 0.10） with the increasing level of SCFP supplementation, with no effects on contents of milk components（P 〉 0.05）. Supplementation of SCFP linearly increased（P 〈 0.05） the N conversion, without affecting rumen pH and ammonia-N（P 〉 0.05）. Increasing level of SCFP linearly increased（P 〈 0.05） concentrations of ruminal total volatile fatty acids, acetate, propionate, and butyrate, with no difference in molar proportion of individual acids（P 〉 0.05）. The population of fungi and certain cel ulolytic bacteria（Ruminococcus albus, R. flavefaciens and Fibrobacter succinogenes）increased linearly（P 〈 0.05） but those of lactate-utilizing（Selenomonas ruminantium and Megasphaera elsdeni） and lactate-producing bacteria（Streptococcus bovis） decreased linearly（P ≤ 0.01） with increasing level of SCFP. The urinary purine derivatives increased linearly（P 〈 0.05） in response to SCFP supplementation, indicating that SCFP supplementation may benefit for microbial protein synthesis in the rumen.Conclusions： The SCFP supplementation was effective in maintaining milk persistency of mid-lactation cows receiving diets containing low-quality forage. The beneficial effect of SCFP could be attributed to improved rumen function; 1）microbial population shift toward greater rumen fermentation efficiency indicated by higher rumen fungi and cel ulolytic bacteria and lower lactate producing bacteria, and 2） rumen microbial fermentation toward greater supply of energy and protein indicated by greater ruminal VFA concentration and increased N conversion. Effects of SCFP were dose-depended and greater effects being observed with higher levels of supplementation and the effect was more noticeable during the high THI environment.展开更多
The transition period for dairy cows usually refers to the 3 weeks pre-calving to the 3 weeks post-calving.During this period,dairy cows undergo metabolic and physiological adaptations because of their susceptibility ...The transition period for dairy cows usually refers to the 3 weeks pre-calving to the 3 weeks post-calving.During this period,dairy cows undergo metabolic and physiological adaptations because of their susceptibility to metabolic and infectious diseases.Poor feeding management under these circumstances may adversely affect the health and subsequent production performance of the cows.Owing to long-term adaptation and evolution,the rumen has become a unique ecosystem inhabited by a complex microbial community closely associated with its natural host.Dietary components are metabolized by the rumen microbiota,and volatile fatty acids and microbial protein products can be used as precursor substances for synthesizing meat and milk components.The successful transition of perinatal dairy cows includes changes in diet,physiology,and the rumen microbiota.Rumen microbial profiles have been confirmed to be heritable and repairable;however,adverse circumstances affect rumen microbial composition,host digestion and metabolism,as well as postpartum production traits of dairy cows for a certain period.Preliminary evidence indicates a close relationship between the rumen microbiota and animal performance.Therefore,changes in rumen microbes during the transition period and the intrinsic links between the microbiota and host postpartum phenotypic traits need to be better understood to optimize production performance in ruminants.展开更多
Developing alternatives to antibiotics for prevention of gastrointestinal dysbiosis in early-weaning farmed animals is urgently needed.This study was to explore the potential effects of trans-10,cis-12 conjugated lino...Developing alternatives to antibiotics for prevention of gastrointestinal dysbiosis in early-weaning farmed animals is urgently needed.This study was to explore the potential effects of trans-10,cis-12 conjugated linoleic acid(CLA)on maintaining ruminal homeostasis of young ruminants during the weaning transition period.Thirty neonatal lambs were selected(6 lambs per group)and euthanized for rumen microbial and epithelial analysis.The lambs were weaned at 28 d and experienced the following 5 treatments:euthanized on d 28 as the pre-weaning control(CON0),fed starter feed for 5(CON5)or 21(CON21)d,fed starter feed with 1%of CLA supplemented for 5(CLA5)or 21(CLA21)d.Results showed that the average daily weight gain and dry matter intake were significantly higher in CLA5 than CON5 group.As compared with the CON5 and CON21 group,the relative abundances of volatile fatty acid(VFA)producing bacteria including Bacteroides,Treponema,Parabacteroides and Anaerovibrio,as well as the concentrations of acetate,butyrate and total VFA were significantly increased in CLA5 and CLA21 group,respectively.Integrating microbial profiling and epithelial transcriptome results showed that 7 downregulated inflammatory signaling-related host genes IL2RA,CXCL9,CD4,CCR4,LTB,SPP1,and BCL2A1 with CLA supplementation were significantly negatively correlated with both VFA concentration and VFA producing bacteria,while 3(GPX2,SLC27A2 and ALDH3A1)and 2(GSTM3 and GSTA1)upregulated metabolism-related genes,significantly positively correlated with either VFA concentration or VFA producing bacteria,respectively.To confirm the effects of CLA on epithelial signal transduction,in vitro experiment was further conducted by treating rumen epithelial cells without or with IL-17A+TNF-αfor 12 h after pretreatment of 100μM CLA or not(6 replicates per treatment).The results demonstrated the anti-inflammatory effect of CLA via suppressing the protein expression of NF-кB p-p65/p65 with the activation of peroxisome proliferator-activated receptor gamma(PPARγ).In conclusion,CLA supplementation enhanced the ruminal microbiota-driven transcriptional regulation in healthy rumen epithelial development via rumen VFA production,and CLA may therefore serve as an alternative way to alleviate early-weaning stress and improve physiological and metabolic conditions of young ruminants.展开更多
Background During the transition period,excessive negative energy balance(NEB)lead to metabolic disorders and reduced milk yield.Rumen microbes are responsible for resolving plant material and producing volatile fatty...Background During the transition period,excessive negative energy balance(NEB)lead to metabolic disorders and reduced milk yield.Rumen microbes are responsible for resolving plant material and producing volatile fatty acids(VFA),which are the primary energy source for cows.In this study,we aimed to investigate the effect of citrus peel extract(CPE)supplementation on rumen microbiota composition,energy metabolism and milk performance of peri-partum dairy cows.Methods Dairy cows were fed either a basal diet(CON group)or the same basal diet supplemented with CPE via intragastric administration(4 g/d,CPE group)for 6 weeks(3 weeks before and 3 weeks after calving;n=15 per group).Samples of serum,milk,rumen fluid,adipose tissue,and liver were collected to assess the effects of CPE on rumen microbiota composition,rumen fermentation parameters,milk performance,and energy metabolic status of dairy cows.Results CPE supplementation led to an increase in milk yield,milk protein and lactose contents,and serum glucose levels,while reduced serum concentrations of non-esterified fatty acid,β-hydroxybutyric acid,insulin,aspartate aminotransferase,alanine aminotransferase,and haptoglobin during the first month of lactation.CPE supplemen-tation also increased the content of ruminal VFA.Compared to the CON group,the abundance of Prevotellaceae,Methanobacteriaceae,Bacteroidales_RF16_group,and Selenomonadaceae was found increased,while the abun-dance of Oscillospiraceae,F082,Ruminococcaceae,Christensenellaceae,Muribaculaceae UCG-011,Saccharimona-daceae,Hungateiclostridiaceae,and Spirochaetaceae in the CPE group was found decreased.In adipose tissue,CPE supplementation decreased lipolysis,and inflammatory response,while increased insulin sensitivity.In the liver,CPE supplementation decreased lipid accumulation,increased insulin sensitivity,and upregulated expression of genes involved in gluconeogenesis.Conclusions Our findings suggest that CPE supplementation during the peripartum period altered rumen micro-biota composition and increased ruminal VFA contents,which further improved NEB and lactation performance,alleviated lipolysis and inflammatory response in adipose tissue,reduced lipid accumulation and promoted gluconeo-genesis in liver.Thus,CPE might contribute to improve energy metabolism and consequently lactation performance of dairy cows during the transition period.展开更多
Background An imbalance in the rumen microbiota caused by high-concentrate diets(HCD)is a significant endogenous trigger of mastitis.However,the underlying mechanisms remain largely unknown.Microbial extracellular ves...Background An imbalance in the rumen microbiota caused by high-concentrate diets(HCD)is a significant endogenous trigger of mastitis.However,the underlying mechanisms remain largely unknown.Microbial extracellular vesicles(mEVs)are critical mediators of microbe-host communication.However,the role of mEVs in rumen microbiota-mediated mastitis has not yet been reported.In this study,we used an HCD-induced rumen microbiota dysbiosis model to investigate the role of mEVs-derived from rumen microbiota in the pathogenesis of mastitis.Results Our results indicate that HCD leads to mastitis and systemic inflammation.Meanwhile,HCD-fed goats exhibited substantial rumen microbiota dysbiosis and the disruption of the rumen barrier.Transplanting rumen microbiota from HCD goats into mice induced both mastitis and systemic inflammation in the recipients.Specifically,HCD increases the production of mEVs carrying microbial DNA,which can translocate across the compromised rumen barrier to the mammary gland,triggering a mammary inflammatory response via activation of the cGAS-STING-NF-κB/NLRP3 pathway.Furthermore,treating mice with mEVs isolated from the rumen fluid of HCD goats directly induced mastitis,whereas depletion of microbial DNA attenuated mEVs-induced mastitis.Conclusion Our findings suggest that HCD induces rumen microbiota dysbiosis and impairs rumen barrier function.This dysfunction leads to an increase in microbial DNA-containing mEVs,which subsequently leak into the mammary gland.Once there,these mEVs activate the cGAS-STING-NF-κB/NLRP3 signaling pathway,ultimately inducing mastitis.This study provides a new perspective on the“rumen microbiota-mammary gland axis”and enhances the understanding of the pathogenesis of mastitis.展开更多
基金supported by Fundação de AmparoàPesquisa do Estado de Minas Gerais-FAPEMIG[grant number APQ-02171-15]Conselho Nacional de Desenvolvimento Científico e Tecnológico-CNPq[grant number PVE 313792/2014-3]+3 种基金Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-CAPES/Proex PPGMBA/UFV[grant number 0001]the Instituto Nacional de Ciência e Tecnologia de Ciência Animal-INCT-CAThis work was also supported by a traineeship from the National Institute of AllergyInfectious Diseases of the National Institutes of Health[grant number T32AI55397]to ALR.
文摘Background:Ruminants rely upon a complex community of microbes in their rumen to convert host-indigestible feed into nutrients.However,little is known about the association between the rumen microbiota and feed efficiency traits in Nellore(Bos indicus)cattle,a breed of major economic importance to the global beef market.Here,we compare the composition of the bacterial,archaeal and fungal communities in the rumen of Nellore steers with high and low feed efficiency(FE)phenotypes,as measured by residual feed intake(RFI).Results:The Firmicutes to Bacteroidetes ratio was significantly higher(P<0.05)in positive-RFI steers(p-RFI,low feed efficiency)than in negative-RFI(n-RFI,high feed efficiency)steers.The differences in bacterial composition from steers with high and low FE were mainly associated with members of the families Lachnospiraceae,Ruminococcaceae and Christensenellaceae,as well as the genus Prevotella.Archaeal community richness was lower(P<0.05)in p-RFI than in n-RFI steers and the genus Methanobrevibacter was either increased or exclusive of p-RFI steers.The fungal genus Buwchfawromyces was more abundant in the rumen solid fraction of n-RFI steers(P<0.05)and a highly abundant OTU belonging to the genus Piromyces was also increased in the rumen microbiota of highefficiency steers.However,analysis of rumen fermentation variables and functional predictions indicated similar metabolic outputs for the microbiota of distinct FE groups.Conclusions:Our results demonstrate that differences in the ruminal microbiota of high and low FE Nellore steers comprise specific taxa from the bacterial,archaeal and fungal communities.Biomarker OTUs belonging to the genus Piromyces were identified in animals showing high feed efficiency,whereas among archaea,Methanobrevibacter was associated with steers classified as p-RFI.The identification of specific RFI-associated microorganisms in Nellore steers could guide further studies targeting the isolation and functional characterization of rumen microbes potentially important for the energy-harvesting efficiency of ruminants.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.2019R1F1A1056904).
文摘Background:Endolysins,the bacteriophage-originated peptidoglycan hydrolases,are a promising replacement for antibiotics due to immediate lytic activity and no antibiotic resistance.The objectives of this study were to investigate the lytic activity of endolysin LyJH307 against S.bovis and to explore changes in rumen fermentation and microbiota in an in vitro system.Two treatments were used:1)control,corn grain without LyJH307;and 2)LyJH307,corn grain with LyJH307(4 U/mL).An in vitro fermentation experiment was performed using mixture of rumen fluid collected from two cannulated Holstein steers(450±30 kg)and artificial saliva buffer mixed as 1:3 ratio for 12 h incubation time.In vitro dry matter digestibility,pH,volatile fatty acids,and lactate concentration were estimated at 12 h,and the gas production was measured at 6,9,and 12 h.The rumen bacterial community was analyzed using 16S rRNA amplicon sequencing.Results:LyJH307 supplementation at 6 h incubation markedly decreased the absolute abundance of S.bovis(approximately 70% compared to control,P=0.0289)and increased ruminal pH(P=0.0335)at the 12 h incubation.The acetate proportion(P=0.0362)was significantly increased after LyJH307 addition,whereas propionate(P=0.0379)was decreased.LyJH307 supplementation increased D-lactate(P=0.0340)without any change in L-lactate concentration(P>0.10).There were no significant differences in Shannon’s index,Simpson’s index,Chao1 estimates,and evenness(P>0.10).Based on Bray-Curtis dissimilarity matrices,the LyJH307 affected the overall shift in microbiota(P=0.097).LyJH307 supplementation induced an increase of 11 genera containing Lachnoclostridium,WCHB1-41,unclassified genus Selenomonadaceae,Paraprevotella,vadinBE97,Ruminococcus gauvreauii group,Lactobacillus,Anaerorhabdus furcosa group,Victivallaceae,Desulfuromonadaceae,and Sediminispirochaeta.The predicted functional features represented by the Kyoto Encyclopedia of Genes and Genomes pathways were changed by LyJH307 toward a decrease of carbohydrate metabolism.Conclusions:LyJH307 caused a reduction of S.bovis and an increase of pH with shifts in minor microbiota and its metabolic pathways related to carbohydrate metabolism.This study provides the first insight into the availability of endolysin as a specific modulator for rumen and shows the possibility of endolysin degradation by rumen microbiota.
文摘The aim of this experiment was to determine the effects of beta-acids, prenylated phenolic compounds from the hops plant, on fermentation of individual carbohydrates by rumen microorganisms. Mixed, uncultivated rumen microbiota was harvested from rumen fistulated steers and washed to make cell suspensions. The suspensions were used to inoculate media with a glucan, fructan or constituent sugar, and fermentation was evaluated by production of short-chain fatty acids (SCFA). Hops beta-acid (30 ppm) was not universally inhibitory, but each of the SCFA (acetate, propionate or butyrate) was decreased (P < 0.05) in one or more of each cellulose or starch tested. The fermentation of sugars and fructans (short- or long-chain inulins) was not impacted by the phytochemicals. Previous results have shown that hops and hops extracts had the beneficial effects of reducing rumen ammonia and methane. The current results indicate that both starch and cellulose fermentation could be impacted. Because cellulose fermentation is nutritionally important on forage-based diets, hops phytochemicals might have more utility in cereal grain-based rations.
基金funded by the Beef Cattle Research Council Cluster(FDE.18.21C)Natural Sciences and Engineering Research Council of Canada(NSERC)Discovery,NSERC Canadian Research Chair(Tier 1)program+2 种基金NSERC Alliance program(ALLRP 588541‐23)Foundation for Food&Agriculture Research Greener Cattle Initiative(Award ID 22‐000373)DSM Nutritional Products,Kaiseraugst,Switzerland。
文摘Background The enteric methane inhibitor 3-nitrooxypropanol(3-NOP)inhibits the key enzyme in ruminal methanogenesis,but whether short-term(ST)and long-term(LT)dietary supplementation has similar effects on rumen microbiota in beef cattle and how microbes change after 3-NOP withdrawal have not been studied.This study investigated changes in rumen bacteria,archaea,and protozoa after ST and LT dietary supplementation and removal of 3-NOP using metataxonomic analysis.Results A total of 143 rumen samples were collected from two beef cattle studies with 3-NOP supplementation.The ST study(95 samples)used eight ruminally cannulated beef cattle in a 4×4 Latin square design with four 28-d of 3-NOP treatments[mg/kg of dry matter(DM)]:control:0,low:53,med:161,and high:345.The LT study(48 samples)was a completely randomized design with two 3-NOP treatments[control:0,and high:280 mg/kg of DM)fed for 112-d followed by a 16-d withdrawal(without 3-NOP).Bacterial and archaeal communities were significantly affected by 3-NOP supplementation but limited effects on protozoal communities were observed.Under ST supplementation,the relative abundances of Prevotella,Methanobrevibacter(Mbb.)ruminantium,Methanosphaera sp.ISO3-F5,and Entodinium were increased(Q<0.05),whereas those of Mbb.gottschalkii and Epidinium were decreased(Q<0.05)with 3-NOP supplementation.In LT study,relative abundances of Mbb.ruminantium,and Methanosphaera sp.Group5 were increased(Q<0.05),while those of Saccharofermentans and Mbb.gottschalkii were decreased(Q<0.05)with 3-NOP supplementation.Comparison between 3-NOP supplementation and the withdrawal revealed increased relative abundances of Clostridia UCG-014 and Oscillospiraceae NK4A214 group and decreased those of Eubacterium nodatum group and Methanosphaera sp.Group5(P<0.05)after 3-NOP withdrawal.Further comparison of rumen microbiota between control and 3-NOP withdrawal showed significantly higher(P=0.029)relative abundances of Eggerthellaceae DNF00809,p-1088-a5 gut group,and Family XII UCG-001 in control group while no significant differences were detected for archaea and protozoa.Microbial network analysis revealed that microbial interactions differed by both 3-NOP dose and durations.Conclusions Both ST and LT supplementation affected overall rumen microbial profile,with individual microbial groups responded to 3-NOP supplementation differently.After 3-NOP withdrawal,not all microbes showed recovery,indicating that the 3-NOP driven shifts were only partially reversible.These findings provide an understanding of the effects of 3-NOP on rumen microbial communities and their adaptability to methane mitigation strategies.
基金supported by National Institute of Food and Agriculture,U.S.Department of Agriculture,under the award number 2024-67015-42622 to PFMississippi State Agricultural and Forestry Experiment Station(MAFES)Strategic Research Initiative Programsupported by the Mississippi State University College of Agriculture and Life Science/MAFES Undergraduate Research Scholars Program。
文摘Gut-brain communication via the peripheral neural network is vital for regulating local digestive function and systemic physiology.Gut microbiota,which produces a wide array of neuroactive compounds,is a critical modulator in this bidirectional dialog.Perturbations in the gut microbiota have been implicated in neurological disorders such as depression and stress.Distinct from humans and other monogastric animals,ruminants possess a unique,microbially dense gastrointestinal compartment,the rumen,that facilitates the digestion of fibrous plant materials.These ruminal microbes are likely key contributors to rumen-brain crosstalk.Unlike certain microbe-derived neuroactive compounds produced in the hindgut that are minimally absorbed and primarily excreted in feces,those generated in rumen can reach the small intestine,where they are largely absorbed and affect central nervous system through systemic regulation in addition to the vagal pathway.Notably,emerging evidence suggests that rumen microbiota dysbiosis under stress is associated with abnormal behavior,altered hormonal and neurotransmitter levels.In this review,we introduce the concept of the rumen-microbiome-brain axis by comparing the anatomical structures and microbial characteristics of the intestine and the rumen,emphasizing the neuroactive potential of rumen microbiome and underlying mechanisms.Advances in this frontier hold tremendous promise to reveal a novel dimension of the gut-microbiome-brain axis,providing transformative opportunities to improve ruminant welfare,productivity,and agricultural sustainability.
基金funded by the Integrated Demonstration of Scalable and Efficient Healthy Breeding for Cattle and Sheep(Grant No.2022YFD1301100)Instant Intelligent Diagnosis and Risk Warning Methods for Nutritional and Metabolic-Type Periparturient Cow Paralysis(Grant No.2024-YWF-ZYSQ-10)。
文摘Background Methane(CH_(4))emissions from ruminants significantly contribute to greenhouse gas effects and energy loss in livestock production.Methyl-coenzyme M reductase(MCR)is the key enzyme in methanogenesis,making it a promising target for CH_(4) mitigation.This study aimed to identify and validate plant-derived inhibitors by using molecular docking to screen compounds with strong binding affinity to the F430 active site of MCR and assessing their efficacy in reducing CH_(4) emissions.Results Molecular docking analysis identified salvianolic acid C(SAC)as a potent inhibitor of MCR,showing a strong binding affinity to the F430 active site(binding energy:-8.2 kcal/mol).Enzymatic inhibition assays confirmed its inhibitory effect,with a half-maximal inhibitory concentration(IC50)of 692.3μmol/L.In vitro rumen fermentation experiments demonstrated that SAC supplementation(1.5 mg/g DM)significantly reduced CH_(4)production(P<0.01)without negatively affecting major fermentation parameters.Microbial community analysis using 16S rRNA sequencing and metagenomics revealed that SAC selectively altered the rumen microbiota,increasing the relative abundance of Bacteroidota while significantly reducing Methanobrevibacter(P=0.04).Moreover,metagenomic analysis showed the downregulation of key methanogenesis-related genes(mcrA and rnfC),suggesting a dual mechanism involving direct enzymatic inhibition and microbial community modulation.Conclusions These findings indicate that SAC effectively reduces CH_(4)production by inhibiting MCR activity and reshaping the rumen microbial community.As a plant-derived compound with strong inhibitory effects on methanogenesis,SAC presents a promising and sustainable alternative to synthetic CH_(4) inhibitors,offering potential applications for mitigating CH_(4)emissions in livestock production.
基金partially funded by grants from the National Key Research and Development Program of China (2018YFD0501600)the Scientific Research Project for Major Achievements of The Agricultural Science and Technology Innovation Program (ASTIP)(No. CAAS-ZDXT2019004+3 种基金CAASXTCX2016011–01ASTIP-IAS07)Beijing Dairy Industry Innovation Team(BAIC06–2019)the USDA National Institute of Food and Agriculture(award number:2019–67030-29003)。
文摘Background: Dietary energy source and level in lactation diets can profoundly affect milk yield and composition.Such dietary effects on lactation performance are underpinned by alteration of the rumen microbiota, of which bacteria, archaea, fungi, and protozoa may vary differently. However, few studies have examined all the four groups of rumen microbes. This study investigated the effect of both the level and source of dietary energy on rumen bacteria, archaea, fungi, and protozoa in the rumen of lactating dairy cows. A 2 × 2 factorial design resulted in four dietary treatments: low and high dietary energy levels(LE: 1.52–1.53;and HE: 1.71–1.72 Mcal/kg dry matter) and two dietary energy sources(GC: finely ground corn;and SFC: steam-flaked corn). We used a replicated 4 × 4 Latin square design using eight primiparous Chinese Holstein cows with each period lasting for 21 d. The rumen microbiota was analyzed using metataxonomics based on kingdom-specific phylogenetic markers [16 S r RNA gene for bacteria and archaea, 18 S r RNA gene for protozoa, and internally transcribed spacer 1(ITS1) for fungi] followed with subsequent functional prediction using PICRUSt2.Results: The GC resulted in a higher prokaryotic(bacterial and archaeal) species richness and Faith's phylogenetic diversity than SFC. For the eukaryotic(fungi and protozoa) microbiota, the LE diets led to significantly higher values of the above measurements than the HE diets. Among the major classified taxa, 23 genera across all the kingdoms differed in relative abundance between the two dietary energy levels, while only six genera(none being protozoal)were differentially abundant between the two energy sources. Based on prokaryotic amplicon sequence variants(ASVs) from all the samples, overall functional profiles predicted using PICRUSt2 differed significantly between LE and HE but not between the two energy sources. Fish Taco analysis identified Ruminococcus and Coprococcus as the taxa potentially contributing to the enriched KEGG pathways for biosynthesis of amino acids and to the metabolisms of pyruvate, glycerophospholipid, and nicotinate and nicotinamide in the rumen of HE-fed cows. The co-occurrence networks were also affected by the dietary treatments, especially the LE and GC diets, resulting in distinct co-occurrence networks. Several microbial genera appeared to be strongly correlated with one or more lactation traits.Conclusions: Dietary energy level affected the overall rumen multi-kingdom microbiota while little difference was noted between ground corn and steam-flaked corn. Some genera were also affected differently by the four dietary treatments, including genera that had been shown to be correlated with lactation performance or feed efficiency.The co-occurrence patterns among the genera exclusively found for each dietary treatment may suggest possible metabolic interactions specifically affected by the dietary treatment. Some of the major taxa were positively correlated to milk properties and may potentially serve as biomarkers of one or more lactation traits.
基金supported by grants from Natural Science and Engineering Research Council(NSERC)of Canada Collaborative Research and Development(CRD)programNSERC Discovery program,Dairy Farmers of Manitoba,and Diamond V,USA,to EK and JCP。
文摘Background Subacute ruminal acidosis(SARA)is a common metabolic disorder of high yielding dairy cows,and it is associated with dysbiosis of the rumen and gut microbiome and host inflammation.This study evaluated the impact of two postbiotics from Saccharomyces cerevisiae fermentation products(SCFP)on rumen liquid associated microbiota of lactating dairy cows subjected to repeated grain-based SARA challenges.A total of 32 rumen cannulated cows were randomly assigned to 4 treatments from 4 weeks before until 12 weeks after parturition.Treatment groups included a Control diet or diets supplemented with postbiotics(SCFPa,14 g/d Original XPC;SCFPb-1X,19 g/d Nutri Tek;SCFPb-2X,38 g/d Nutri Tek,Diamond V,Cedar Rapids,IA,USA).Grain-based SARA challenges were conducted during week 5(SARA1)and week 8(SARA2)after parturition by replacing 20%DM of the base total mixed ration(TMR)with pellets containing 50%ground barley and 50%ground wheat.Total DNA from rumen liquid samples was subjected to V3–V416S r RNA gene amplicon sequencing.Characteristics of rumen microbiota were compared among treatments and SARA stages.Results Both SARA challenges reduced the diversity and richness of rumen liquid microbiota,altered the overall composition(β-diversity),and its predicted functionality including carbohydrates and amino acids metabolic pathways.The SARA challenges also reduced the number of significant associations among different taxa,number of hub taxa and their composition in the microbial co-occurrence networks.Supplementation with SCFP postbiotics,in particular SCFPb-2X,enhanced the robustness of the rumen microbiota.The SCFP supplemented cows had less fluctuation in relative abundances of community members when exposed to SARA challenges.The SCFP supplementation promoted the populations of lactate utilizing and fibrolytic bacteria,including members of Ruminococcaceae and Lachnospiraceae,and also increased the numbers of hub taxa during non-SARA and SARA stages.Supplementation with SCFPb-2X prevented the fluctuations in the abundances of hub taxa that were positively correlated with the acetate concentration,andα-andβ-diversity metrics in rumen liquid digesta.Conclusions Induction of SARA challenges reduced microbiota richness and diversity and caused fluctuations in major bacterial phyla in rumen liquid microbiota in lactating dairy cows.Supplementation of SCFP postbiotics could attenuate adverse effects of SARA on rumen liquid microbiota.
基金supported by funds from Diamond V(Cedar Rapids,IA)the China Agriculture(Dairy Cow)Research System(CARS-37)
文摘Background： A possible option to meet the increased demand of forage for dairy industry is to use the agricultural byproducts, such as corn stover. However, nutritional value of crop residues is low and we have been seeking technologies to improve the value. A feeding trial was performed to evaluate the effects of four levels of Saccharomyces cerevisiae fermentation product（SCFP; Original XP; Diamond V） on lactation performance and rumen fermentation in mid-lactation Holstein dairy cows fed a diet containing low-quality forage. Eighty dairy cows were randomly assigned into one of four treatments： basal diet supplemented with 0, 60, 120, or 180 g/d of SCFP per head mixed with 180, 120, 60, or 0 g of corn meal, respectively. The experiment lasted for 10 wks, with the first 2 weeks for adaptation.Results： Dry matter intake was found to be similar（P 〉 0.05） among the treatments. There was an increasing trend in milk production（linear, P ≤ 0.10） with the increasing level of SCFP supplementation, with no effects on contents of milk components（P 〉 0.05）. Supplementation of SCFP linearly increased（P 〈 0.05） the N conversion, without affecting rumen pH and ammonia-N（P 〉 0.05）. Increasing level of SCFP linearly increased（P 〈 0.05） concentrations of ruminal total volatile fatty acids, acetate, propionate, and butyrate, with no difference in molar proportion of individual acids（P 〉 0.05）. The population of fungi and certain cel ulolytic bacteria（Ruminococcus albus, R. flavefaciens and Fibrobacter succinogenes）increased linearly（P 〈 0.05） but those of lactate-utilizing（Selenomonas ruminantium and Megasphaera elsdeni） and lactate-producing bacteria（Streptococcus bovis） decreased linearly（P ≤ 0.01） with increasing level of SCFP. The urinary purine derivatives increased linearly（P 〈 0.05） in response to SCFP supplementation, indicating that SCFP supplementation may benefit for microbial protein synthesis in the rumen.Conclusions： The SCFP supplementation was effective in maintaining milk persistency of mid-lactation cows receiving diets containing low-quality forage. The beneficial effect of SCFP could be attributed to improved rumen function; 1）microbial population shift toward greater rumen fermentation efficiency indicated by higher rumen fungi and cel ulolytic bacteria and lower lactate producing bacteria, and 2） rumen microbial fermentation toward greater supply of energy and protein indicated by greater ruminal VFA concentration and increased N conversion. Effects of SCFP were dose-depended and greater effects being observed with higher levels of supplementation and the effect was more noticeable during the high THI environment.
基金upported by the National Key R&D Program of China (22022YFD1301000)the Agnicultural Science and Technology Innovation Program (ASTIP-IAS12)the earmarked fund for CARS (CARS-36).
文摘The transition period for dairy cows usually refers to the 3 weeks pre-calving to the 3 weeks post-calving.During this period,dairy cows undergo metabolic and physiological adaptations because of their susceptibility to metabolic and infectious diseases.Poor feeding management under these circumstances may adversely affect the health and subsequent production performance of the cows.Owing to long-term adaptation and evolution,the rumen has become a unique ecosystem inhabited by a complex microbial community closely associated with its natural host.Dietary components are metabolized by the rumen microbiota,and volatile fatty acids and microbial protein products can be used as precursor substances for synthesizing meat and milk components.The successful transition of perinatal dairy cows includes changes in diet,physiology,and the rumen microbiota.Rumen microbial profiles have been confirmed to be heritable and repairable;however,adverse circumstances affect rumen microbial composition,host digestion and metabolism,as well as postpartum production traits of dairy cows for a certain period.Preliminary evidence indicates a close relationship between the rumen microbiota and animal performance.Therefore,changes in rumen microbes during the transition period and the intrinsic links between the microbiota and host postpartum phenotypic traits need to be better understood to optimize production performance in ruminants.
基金This work was supported by the National Natural Science Foundation of China(No.31702133)the Central Public-interest Scientific Institution Basal Research Fund of Chinese Academy of Agricultural Sciences(No.Y2021GH18-2).
文摘Developing alternatives to antibiotics for prevention of gastrointestinal dysbiosis in early-weaning farmed animals is urgently needed.This study was to explore the potential effects of trans-10,cis-12 conjugated linoleic acid(CLA)on maintaining ruminal homeostasis of young ruminants during the weaning transition period.Thirty neonatal lambs were selected(6 lambs per group)and euthanized for rumen microbial and epithelial analysis.The lambs were weaned at 28 d and experienced the following 5 treatments:euthanized on d 28 as the pre-weaning control(CON0),fed starter feed for 5(CON5)or 21(CON21)d,fed starter feed with 1%of CLA supplemented for 5(CLA5)or 21(CLA21)d.Results showed that the average daily weight gain and dry matter intake were significantly higher in CLA5 than CON5 group.As compared with the CON5 and CON21 group,the relative abundances of volatile fatty acid(VFA)producing bacteria including Bacteroides,Treponema,Parabacteroides and Anaerovibrio,as well as the concentrations of acetate,butyrate and total VFA were significantly increased in CLA5 and CLA21 group,respectively.Integrating microbial profiling and epithelial transcriptome results showed that 7 downregulated inflammatory signaling-related host genes IL2RA,CXCL9,CD4,CCR4,LTB,SPP1,and BCL2A1 with CLA supplementation were significantly negatively correlated with both VFA concentration and VFA producing bacteria,while 3(GPX2,SLC27A2 and ALDH3A1)and 2(GSTM3 and GSTA1)upregulated metabolism-related genes,significantly positively correlated with either VFA concentration or VFA producing bacteria,respectively.To confirm the effects of CLA on epithelial signal transduction,in vitro experiment was further conducted by treating rumen epithelial cells without or with IL-17A+TNF-αfor 12 h after pretreatment of 100μM CLA or not(6 replicates per treatment).The results demonstrated the anti-inflammatory effect of CLA via suppressing the protein expression of NF-кB p-p65/p65 with the activation of peroxisome proliferator-activated receptor gamma(PPARγ).In conclusion,CLA supplementation enhanced the ruminal microbiota-driven transcriptional regulation in healthy rumen epithelial development via rumen VFA production,and CLA may therefore serve as an alternative way to alleviate early-weaning stress and improve physiological and metabolic conditions of young ruminants.
基金National Key R&D Program of China(Beijing,China,grant no.2023YFE0116900 and 2023YFD1801400)National Natural Science Foundation of China(Beijing,China,grant no.32473105,32302943,and 32302941)Postdoctoral Fellowship Program of CPSF(GZC20230951).
文摘Background During the transition period,excessive negative energy balance(NEB)lead to metabolic disorders and reduced milk yield.Rumen microbes are responsible for resolving plant material and producing volatile fatty acids(VFA),which are the primary energy source for cows.In this study,we aimed to investigate the effect of citrus peel extract(CPE)supplementation on rumen microbiota composition,energy metabolism and milk performance of peri-partum dairy cows.Methods Dairy cows were fed either a basal diet(CON group)or the same basal diet supplemented with CPE via intragastric administration(4 g/d,CPE group)for 6 weeks(3 weeks before and 3 weeks after calving;n=15 per group).Samples of serum,milk,rumen fluid,adipose tissue,and liver were collected to assess the effects of CPE on rumen microbiota composition,rumen fermentation parameters,milk performance,and energy metabolic status of dairy cows.Results CPE supplementation led to an increase in milk yield,milk protein and lactose contents,and serum glucose levels,while reduced serum concentrations of non-esterified fatty acid,β-hydroxybutyric acid,insulin,aspartate aminotransferase,alanine aminotransferase,and haptoglobin during the first month of lactation.CPE supplemen-tation also increased the content of ruminal VFA.Compared to the CON group,the abundance of Prevotellaceae,Methanobacteriaceae,Bacteroidales_RF16_group,and Selenomonadaceae was found increased,while the abun-dance of Oscillospiraceae,F082,Ruminococcaceae,Christensenellaceae,Muribaculaceae UCG-011,Saccharimona-daceae,Hungateiclostridiaceae,and Spirochaetaceae in the CPE group was found decreased.In adipose tissue,CPE supplementation decreased lipolysis,and inflammatory response,while increased insulin sensitivity.In the liver,CPE supplementation decreased lipid accumulation,increased insulin sensitivity,and upregulated expression of genes involved in gluconeogenesis.Conclusions Our findings suggest that CPE supplementation during the peripartum period altered rumen micro-biota composition and increased ruminal VFA contents,which further improved NEB and lactation performance,alleviated lipolysis and inflammatory response in adipose tissue,reduced lipid accumulation and promoted gluconeo-genesis in liver.Thus,CPE might contribute to improve energy metabolism and consequently lactation performance of dairy cows during the transition period.
基金supported by the National Natural Science Foundation of China(32330105 and 32301247)National Key R&D Program of China(2023YFD1801100)。
文摘Background An imbalance in the rumen microbiota caused by high-concentrate diets(HCD)is a significant endogenous trigger of mastitis.However,the underlying mechanisms remain largely unknown.Microbial extracellular vesicles(mEVs)are critical mediators of microbe-host communication.However,the role of mEVs in rumen microbiota-mediated mastitis has not yet been reported.In this study,we used an HCD-induced rumen microbiota dysbiosis model to investigate the role of mEVs-derived from rumen microbiota in the pathogenesis of mastitis.Results Our results indicate that HCD leads to mastitis and systemic inflammation.Meanwhile,HCD-fed goats exhibited substantial rumen microbiota dysbiosis and the disruption of the rumen barrier.Transplanting rumen microbiota from HCD goats into mice induced both mastitis and systemic inflammation in the recipients.Specifically,HCD increases the production of mEVs carrying microbial DNA,which can translocate across the compromised rumen barrier to the mammary gland,triggering a mammary inflammatory response via activation of the cGAS-STING-NF-κB/NLRP3 pathway.Furthermore,treating mice with mEVs isolated from the rumen fluid of HCD goats directly induced mastitis,whereas depletion of microbial DNA attenuated mEVs-induced mastitis.Conclusion Our findings suggest that HCD induces rumen microbiota dysbiosis and impairs rumen barrier function.This dysfunction leads to an increase in microbial DNA-containing mEVs,which subsequently leak into the mammary gland.Once there,these mEVs activate the cGAS-STING-NF-κB/NLRP3 signaling pathway,ultimately inducing mastitis.This study provides a new perspective on the“rumen microbiota-mammary gland axis”and enhances the understanding of the pathogenesis of mastitis.
