As a major contributor to methane production in agriculture,there is a need for a suitable methane inhibitor to reduce ruminant methane emissions and minimize the impact on the climate.This work aimed to explore the i...As a major contributor to methane production in agriculture,there is a need for a suitable methane inhibitor to reduce ruminant methane emissions and minimize the impact on the climate.This work aimed to explore the influence of cordycepin on rumen fermentation,gas production,microbiome and their metabolites.A total of 0.00,0.08,0.16,0.32,and 0.64 g L^(–1)cordycepin were added into fermentation bottles containing 2 g total mixed ration for in vitro ruminal fermentation,and then the gas produced and fermentation parameters were measured for each bottle.Samples from the 0 and 0.64 g L^(–1)cordycepin addition were selected for 16S rRNA gene sequencing and metabolome analysis.The result of this experiment indicated that the addition of cordycepin could linearly increase the concentration of total volatile fatty acid,ammonia nitrogen,the proportion of propionate,valerate,and isovalerate,and linearly reduce ruminal pH and methane,carbon dioxide,hydrogen and total gas production,as well as the methane proportion,carbon dioxide proportion and proportion of butyrate.In addition,there was a quadratic relationship between hydrogen and cordycepin addition.At the same time,the relative abundance of Succiniclasticum,Prevotella,Rikenellaceae_RC9_gut_group,NK4A214_group,Christensenellaceae_R_(7)_group,unclassified_F082,Veillonellaceae_UCG_001,Dasytricha,Ophryoscolex,Isotricha,unclassified_Eukaryota,Methanobrevibacter,and Piromyces decreased significantly after adding the maximum dose of cordycepin.In contrast,the relative abundance of Succinivibrio,unclassified_Succinivibrionaceae,Prevotellaceae_UCG_001,unclassified_Lachnospiraceae,Lachnospira,Succinivibrionaceae_UCG_002,Pseudobutyrivibrio,Entodinium,Polyplastron,unclassified_Methanomethylophilaceae,Methanosphaera,and Candidatus_Methanomethylophilus increased significantly.Metabolic pathways such as biosynthesis of unsaturated fatty acids and purine metabolism and metabolites such as arachidonic acid,adenine,and 2′-deoxyguanosine were also affected by the addition of cordycepin.Based on this,we conclude that cordycepin is an effective methane emission inhibitor that can change the rumen metabolites and fermentation parameters by influencing the rumen microbiome,thus regulating rumen methane production.This experiment may provide a potential theoretical reference for developing Cordyceps byproduct or additives containing cordycepin as methane inhibitors.展开更多
Yaks are well-adapted to the harsh environment of the Tibetan Plateau,and they emit less enteric methane(CH_(4))and digest poor-quality forage better than cattle.To examine the potential of yak rumen inoculum to mitig...Yaks are well-adapted to the harsh environment of the Tibetan Plateau,and they emit less enteric methane(CH_(4))and digest poor-quality forage better than cattle.To examine the potential of yak rumen inoculum to mitigate CH_(4)production and improve digestibility in cattle,we incubated substrate with rumen inoculum from yak(YRI)and cattle(CRI)in vitro in five ratios(YRI:CRI):(1)0:100(control),(2)25:75,(3)50:50,(4)75:25 and(5)100:0 for 72 h.The YRI:CRI ratios of 50:50,75:25 and 100:0 produced less total gas and CH_(4)and accumulated less hydrogen(H_(2))than0:100(control)at most time points.From 12 h onwards,there was a linear decrease(P<0.05)in carbon dioxide(CO_(2))production with increasing YRI:CRI ratio.At 72 h,the ratios of 50:50 and 75:25 had higher dry matter(+7.71%and+4.11%,respectively),as well as higher acid detergent fiber digestibility(+15.5%and+7.61%,respectively),when compared to the 0:100 ratio(P<0.05).Increasing the proportion of YRI generally increased total VFA concentrations,and,concomitantly,decreased the proportion of metabolic hydrogen([2H])incorporated into CH_(4),and decreased the recovery of[2H].The lower[2H]recovery indicates unknown[2H]sinks in the culture.Estimated Gibbs free energy changes(ΔG)for reductive acetogenesis were negative,indicating the thermodynamic feasibility of this process.It would be beneficial to identify:1)the alternative[2H]sinks,which could help mitigate CH_(4)emission,and 2)core microbes involved in fiber digestion.This experiment supported lower CH_(4)emission and greater nutrient digestibility of yaks compared to cattle.Multi-omics combined with microbial culture technologies developed in recent years could help to better understand fermentation differences among species.展开更多
Background In this study,the effects of L-leucine(Leu)on rumen fermentation parameters,rumen epithelium development,amino acid composition,rumen bacterial communities and rumen metabolites in beef cattle were investig...Background In this study,the effects of L-leucine(Leu)on rumen fermentation parameters,rumen epithelium development,amino acid composition,rumen bacterial communities and rumen metabolites in beef cattle were investigated.Twenty-four fattening Angus females of similar initial weight(575.5±22.1 kg)were randomly assigned to 2 treatments with 4 replicate pens(3 cattle per pen).They were fed either a basal diet or a basal diet supplemented with 6.0 g L-Leu/100 kg BW/d for 120 d.Results(1)Leu increased the ruminal concentrations of total volatile fatty acid(VFA)(P=0.017),propionate(P=0.023),isovalerate(P=0.001),and branched-chain volatile fatty acid(BCVFA)(P=0.01)at 4 h post-feeding.It also tended to increase acetate(P=0.083)and decrease the ammonia-N(NH_3-N)concentration(P=0.055),but it did not affect ruminal pH(P>0.1).Leu also increased microbial crude protein(MCP)(P=0.026)at 4 h post-feeding,but decreased MCP at 8 h post-feeding(P=0.010).(2)Supplementation with L-Leu increased the ruminal concentrations of phenylalanine(P=0.011),lysine(P=0.034),and tyrosine(P=0.033),while decreasing the cystine concentration(P=0.010).(3)Leu increased the thickness of the stratum spinosum and basal(P<0.05),while decreasing the thickness of the stratum granulosum(P<0.05).(4)Leu upregulated the relative mRNA abundance of genes involved in tight junction proteins(P<0.05)and VFA absorption and metabolism(P<0.01)in the rumen epithelium.This upregulation was positively correlated with the concentrations ruminal isovalerate and BCVFA(P<0.01).(5)L-Leu did not affect the diversity and richness of ruminal microbes(P>0.05),but differential bacterial biomarkers(LEfSe,LDA>2)were either positively or negatively correlated with ruminal MCP,NH_3-N,and BCVFA concentrations(P<0.001).Additionally,differential bacterial metabolites(OPLS-DA,VIP>1.5)were primarily enriched in the amino acid metabolism pathway and the cofactors and vitamins metabolism pathway(P<0.05).Conclusions Dietary supplementation with L-Leu altered rumen fermentation parameters and patterns,improved rumen epithelial morphology,and enhanced the expression of genes related to VFA absorption and metabolism in the rumen epithelium of beef cattle.展开更多
Epigenetic regulation in the rumen,a unique ruminant organ,remains largely unexplored compared with other tissues studied in model species.In this study,we perform an in-depth analysis of the epigenetic and transcript...Epigenetic regulation in the rumen,a unique ruminant organ,remains largely unexplored compared with other tissues studied in model species.In this study,we perform an in-depth analysis of the epigenetic and transcriptional landscapes across fetal and adult bovine tissues as well as pluripotent stem cells.Among the extensive methylation differences across various stages and tissues,we identify tissue-specific differentially methylated regions(tsDMRs)unique to the rumen,which are crucial for regulating epithelial development and energy metabolism.These tsDMRs cluster within super-enhancer regions that overlap with transcription factor(TF)binding sites.Regression models indicate that DNA methylation,along with H3K27me3 and H3K27ac,can be used to predict enhancer activity.Key upstream TFs,including SOX2,FOSL1/2,and SMAD2/3,primarily maintain an inhibitory state through bivalent modifications during fetal development.Downstream functional genes are maintained mainly in a stable repressive state via DNA methylation until differentiation is complete.Our study underscores the critical role of tsDMRs in regulating distal components of rumen morphology and function,providing key insights into the epigenetic regulatory mechanisms that may influence bovine production traits.展开更多
Background Using yeast culture as additives in ruminant feed prevents rumen microbial dysbiosis,enhances performance,and regulates rumen pH.The yeast culture used in this study was developed in-house,and has been show...Background Using yeast culture as additives in ruminant feed prevents rumen microbial dysbiosis,enhances performance,and regulates rumen pH.The yeast culture used in this study was developed in-house,and has been shown to promote rumen epithelial growth in several sheep trials.Changes in protein expression associated with the promotion of rumen epithelial development following the addition of yeast culture,along with the associated molecular mechanisms,remain unknown.We used 2045-day-old weaned lambs to investigate the specific proteins and molecular mechanisms involved in these processes.Half of the lambs were fed yeast culture,and the other half were used as controls.Results Yeast culture enhanced growth performance,facilitated rumen fermentation,and promoted rumen papilla development in weaned lambs.Proteomics data identified 4,831 proteins in the rumen epithelial tissue of lambs,comprising 87 upregulated and 425 downregulated proteins.Administration of yeast culture activated multiple molecular functions within rumen epithelial cells,including oxidative phosphorylation,glutathione metabolism,apoptosis,cell cycle,and vitamin digestion and absorption.The expression of proteins associated with cell cycle regulation increased,whereas those associated with apoptosis decreased.Administration of yeast culture also reduced the duration of the G0/G1 phase of rumen epithelial cells and accelerated the cell cycle.Furthermore,yeast culture showed increased cyclin D1,cyclin-dependent kinase(CDK)2,CDK4,CDK6,and cyclin E1 expressions and decreased cytochrome C(Cyto-c),Bcl-2-related X protein(Bax),cleaved caspase 3(C-caspase 3),caspase 3,and cleaved caspase 7(C-caspase 7)protein expressions.Yeast culture upregulated the insulin-like growth factor-1 receptor(IGF-1R)and insulin-like growth factor-binding protein 5(IGFBP-5)mRNA expressions in rumen epithelial cells.Conclusions Yeast culture facilitates rumen epithelial development by regulating the cell cycle and IGF-1 signaling and reducing the expression of proteins associated with apoptosis in rumen epithelial cells.The findings of this study provide novel insights into the molecular mechanisms through which yeast culture promotes rumen epithelial development in weaned lambs.展开更多
Background Rumen microorganisms are key regulators of ruminant growth and production performance.Identifying probiotic candidates through microbial culturomics presents a promising strategy for improving ruminant prod...Background Rumen microorganisms are key regulators of ruminant growth and production performance.Identifying probiotic candidates through microbial culturomics presents a promising strategy for improving ruminant production performance.Our previous study identified significant differences in rumen microbial communities of Holstein calves with varying average daily gain(ADG).This study aims to identify a target strain based on the findings from multi-omics analysis and literature review,isolating and evaluating the target microbial strains from both the rumen and hindgut contents for their probiotic potential.Results Parabacteroides distasonis,a strain closely associated with ADG,was successfully isolated from calf rumen content cultured with Fastidious Anaerobe Agar(FAA)medium and named Parabacteroides distasonis F4.Wholegenome sequencing and pan-genome analysis showed that P.distasonis F4 possesses a core functional potential for carbohydrate and amino acid metabolism,with the ability to produce propionate,acetate,and lactate.The results of targeted and untargeted metabolomics further validated the organic acid production and metabolic pathways of P.distasonis F4.An in vitro simulated rumen fermentation test showed that supplementation with P.distasonis F4 significantly altered rumen microbial community structure and increased the molar proportions of propionate and butyrate in the rumen.Furthermore,an in vivo study demonstrated that dietary supplementation with P.distasonis F4 significantly increased the ADG of pre-weaning calves.Conclusions This study represents the first isolation of P.distasonis F4 from rumen,highlighting its potential as a probiotic strain for improving rumen development and growth performance in ruminants.展开更多
The aim of this study was to investigate the effects of dietary fat on energy and nitrogen(N)metabolism efficiency,rumen fermentation,and microbiota in twin suckling lambs.Thirty pairs of twin male lambs were randomly...The aim of this study was to investigate the effects of dietary fat on energy and nitrogen(N)metabolism efficiency,rumen fermentation,and microbiota in twin suckling lambs.Thirty pairs of twin male lambs were randomly divided into two groups with one group receiving a high-fat diet(HF)and the other a normal-fat diet(NF).Two diets(milk replacer and starter)of equal protein and different fat levels.The metabolism test was conducted when the lambs were 50-60 days old,and nine pairs of twin lambs were randomly selected for slaughter to collect rumen fluid at 60 days old.The result showed that fat addition increased the final body weight(BW),ruminal ammonia nitrogen(NH_(3)-N)content,proportion of propionic acid,and estimated methane production(CH_(4e))(P<0.05).The high fat diet tended to improve digestive energy(DE),metabolism energy(ME),DE/ME,utilisation of N(0.05<P<0.1).However,microbial crude protein(MCP)content,total volatile fatty acids(VFA),acetic acid ratio,and the ratio of acetate to propionate(A:P)were lower than that in the NF group(P<0.05).Regardless of whether fat is added or not,no different were observed in blood metabolites between the treatment.High-throughput sequencing revealed that fat addition before weaning increased phyla Proteobacteria and genera of Succinivibrio,but decreased the relative abundance of Clostridium IV,Dialister,Roseburia,Acidaminococcus,and Megasphaera genera.These findings indicated that high fat diet improved body weight,energy and nitrogen utilization may by shifting the rumen toward propionate fermentation via the enrichment of Succinivibrio.展开更多
Background Nitrogen-Use-Efficiency(NUE)in lactating dairy cows,defined as milk nitrogen(N)output as a proportion of N consumed,is low,with the majority of excess N excreted in manure.Excreted N can be lost to the envi...Background Nitrogen-Use-Efficiency(NUE)in lactating dairy cows,defined as milk nitrogen(N)output as a proportion of N consumed,is low,with the majority of excess N excreted in manure.Excreted N can be lost to the environment as ammonia gas leading to environmental acidification and nutrient enrichment of sensitive habitats,and to watercourses contributing to aquatic eutrophication.While there is much evidence that NUE can be improved by reducing the crude protein(CP)content of dairy cow diets,the long-term impacts of feeding lower protein diets on cow performance and the rumen microbiome are less well understood.This study examined the effects of reducing the CP contents of dairy cow diets on cow performance,NUE,the relationship between NUE and residual feed intake(RFI),and the rumen microbiome.Results Dietary CP content did not affect feed intake,milk yield or milk composition(P>0.05),except for milk urea N(MUN),which increased with increasing diet CP content(P<0.05).The mean NUE was 34%,34%and 31%for the LCP(low-protein,15%),MCP(medium-protein,16%),and HCP(high-protein,17%)diets,respectively.RFI was negatively correlated with NUE(r=−0.57,P<0.001).The rumen ammonia-N concentrations increased with increasing dietary CP;however,the ruminal pH and volatile fatty acid(VFA)content of the rumen fluid remained constant.Predicted urinary N excretion was greater in the HCP and MCP diets than in the LCP diet.Reducing dietary CP content in dairy cow diets did not affect microbial composition,diversity and functional profiles.The family Bacteroidaceae was more abundant in HE(high-efficiency)cows,whereas the Methanobacteriaceae and the genus Methanobrevibacter were more abundant in LE(low-efficiency)cows.Additionally,propanoate metabolism,cysteine and methionine metabolism and amino acid biosynthesis pathways were more abundant in HE cows,whilst the methane(CH4)metabolism pathway was upregulated in LE cows.Conclusions The results demonstrate that diet CP can be reduced with no loss in cow performance,but with an associated reduction in N excretion.The abundance of microbial populations differed between low and high efficiency cows,which may contribute to the differences in efficiency observed.展开更多
Background Subacute rumen acidosis(SARA)is a common metabolic disorder in ruminants that disrupts the rumen microbiome and animal health,but diagnosis is challenging due to subtle symptoms and invasive testing require...Background Subacute rumen acidosis(SARA)is a common metabolic disorder in ruminants that disrupts the rumen microbiome and animal health,but diagnosis is challenging due to subtle symptoms and invasive testing require-ments.This study explores the potential of the buccal(oral)microbiome as a diagnostic indicator for SARA,hypoth-esizing an interaction with the rumen microbiome.Results The study involved 47 dairy goats,including 11 on a control diet and 36 on high-concentrate diets with increasing rumen-degradable starch.Animals were grouped based on dietary exposure and ruminal pH:Control,Low-RDS Tolerance/SARA(LRDST/LRDSS),and High-RDS Tolerance/SARA(HRDST/HRDSS).Transcriptomics of rumen epithelium showed heightened inflammatory pathway gene expression in SARA-susceptible goats compared to controls and tolerant groups.Alpha diversity of ruminal bacteria showed lower Shannon diversity in HRDSS goats compared to HRDST whereas buccal bacteria displayed significantly lower Chao1 diversity in LRDSS goats compared to HRDST.Beta diversity analyses revealed distinct patterns between SARA-affected goats and healthy controls in both ruminal and buccal microbiomes.Prevotellaceae_UCG-003 emerged as a candidate biomarker,with reduced abundance in SARA-susceptible goats in both rumen and buccal samples.Machine learning classifiers achieved high accuracy in distinguishing SARA-susceptible goats using this genus(rumen AUC=0.807;buccal AUC=0.779).Source tracking analysis illustrated diminished cross-population of bacteria from the buccal to rumen(2.86%to 0.25%)and vice versa(8.59%to 1.17%),signifying compromised microbial interchange in SARA-affected goats.A microbiota transplant experiment verified SARA microbiota’s ability to induce pH decline,escalate inflammation-related gene expression(MAPK10,IL17B,FOSB,SPP1),disrupt microbial transfer,and reduce Prevotellaceae_UCG-003 in recipients.Conclusion Our findings highlight SARA’s dual impact on ruminal and buccal microbiota,exacerbating epithelial inflammation gene expression.Shifts in the buccal microbiome,specifically reductions in Prevotellaceae_UCG-003,mirror ruminal changes and can be influenced by inter-compartmental bacterial transmission,thereby offering a non-invasive diagnostic approach for SARA.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 Insect meals have been identified as innovative and sustainable feedstuffs that could be used in ruminant nutrition.However,current research on the effects that their processing may have on rumen digestibil...Background Insect meals have been identified as innovative and sustainable feedstuffs that could be used in ruminant nutrition.However,current research on the effects that their processing may have on rumen digestibility and fatty acid(FA)biohydrogenation is scant.This trial aims to investigate the effects(i)of drying temperature of fullfat Hermetia illucens(HI)and Tenebrio molitor(TM)meals,and(ii)of residual ether extract(EE)content of defatted HI and TM meals,on their fermentation characteristics and FA of rumen digesta after 24-h in vitro rumen incubation.Methods The tested full-fat meals included four HI and four TM meals obtained applying drying temperatures ranging from 30℃ to 70℃,while the tested defatted meals consisted of five HI and two TM meals containing a residual EE content ranging from 4.7 to 19.7 g EE/100 g dry matter(DM).The applied statistical models(GLM ANOVA)tested the effects of insect species,drying temperature(full-fat meals)or EE content(defatted meals),and their interaction.Results Drying temperature had minor effects on in vitro ruminal digestibility and FA profile of rumen digesta.Irrespective of insect species,increasing the drying temperature led to a reduction of in vitro degradation of proteins from insect meals,as outlined by the significant decrease in ammonia production(-0.009 mmol/g DM and-0.126 g/100 g total N for each additional 1℃).Irrespective of insect species,defatting increased total gas,volatile fatty acids(VFA)and CH_(4) productions,and the proportions of total saturated and branched-chain FA in rumen digesta(+0.038 mmol/g DM,+0.063 mmol/g DM,+12.9μmol/g DM,+0.18 g/100 g FA,and+0.19 g/100 g FA for each reduced 1 g EE/100 g DM,respectively),and reduced the proportion of total PUFA(-0.12 g/100 g FA).Conclusions The applied drying temperatures of full-fat insect meals are too low to exert impactful effects on rumen digestibility and FA biohydrogenation.Fat lowered fermentation activity,probably because of an inhibitory effect on rumen microbiota.The increased ruminal digestibility of defatted insect meals suggests that they can be more suitable to be used in ruminant nutrition than full-fat ones.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 Rumen bacterial groups can affect growth performance,such as average daily gain(ADG),feed intake,and efficiency.The study aimed to investigate the inter-relationship of rumen bacterial composition,rumen fer...Background Rumen bacterial groups can affect growth performance,such as average daily gain(ADG),feed intake,and efficiency.The study aimed to investigate the inter-relationship of rumen bacterial composition,rumen fermentation indicators,serum indicators,and growth performance of Holstein heifer calves with different ADG.Twelve calves were chosen from a trail with 60 calves and divided into higher ADG(HADG,high pre-and post-weaning ADG,n=6)and lower ADG(LADG,low pre-and post-weaning ADG,n=6)groups to investigate differences in bacterial composition and functions and host phenotype.Results During the preweaning period,the relative abundances of propionate producers,including g_norank_f_Butyricicoccaceae,g_Pyramidobacter,and g_norank_f_norank_o_Clostridia_vadin BB60_group,were higher in HADG calves(LDA>2,P<0.05).Enrichment of these bacteria resulted in increased levels of propionate,a gluconeogenic precursor,in preweaning HADG calves(adjusted P<0.05),which consequently raised serum glucose concentrations(adjusted P<0.05).In contrast,the relative abundances of rumen bacteria in post-weaning HADG calves did not exert this effect.Moreover,no significant differences were observed in rumen fermentation parameters and serum indices between the two groups.Conclusions The findings of this study revealed that the preweaning period is the window of opportunity for rumen bacteria to regulate the ADG of calves.展开更多
Lycium barbarum residue(LBR),a by-product of L.barbarum processing,is packed with bioactive components and can be potentially utilized as a feed additive in animal husbandry.However,the fundamental understanding of it...Lycium barbarum residue(LBR),a by-product of L.barbarum processing,is packed with bioactive components and can be potentially utilized as a feed additive in animal husbandry.However,the fundamental understanding of its effectiveness on livestock animals is still lacking,particularly in ruminants.To explore the effects of LBR on the growth performance,rumen fermentation parameters,ruminal microbes and metabolites of Tan sheep,sixteen fattening rams(aged 4 mon)were fed a basal diet(CON,n=8)or a basal diet supplemented with 5%LBR(LBR,n=8).The experiment lasted for 70 d,with 10 d adaptation period and 60 d treatment period.The results showed that the LBR enhanced the average daily feed intake,average daily gain(P<0.05),and ruminal total volatile fatty acids(P<0.01)while decreasing ammonia-nitrogen concentration and rumen pH value(P<0.05).Additionally,the LBR improved the relative abundances of Prevotella,Succiniclasticum,Ruminococcus,Coprococcus,Selenomonas,and Butyrivibrio(P<0.05)and reduced the relative abundances of Oscillospira and Succinivibrio(P<0.05).The LBR altered the ruminal metabolome(P<0.01)by increasing the abundances of ruminal metabolites involved in amino acids(e.g.,L-proline,L-phenylalanine,L-lysine,and L-tyrosine),pyrimidine metabolism(e.g.,uridine,uracil,and thymidine),and microbial protein synthesis(e.g.,xanthine and hypoxanthine).In conclusion,LBR had positive effects on the growth rate of Tan sheep as well as on rumen fermentation parameters,rumen microbiome and rumen metabolome.展开更多
Background The dairy cow’s postpartum period is characterized by dramatic physiological changes,therefore imposing severe challenges on the animal for maintaining health and milk output.The dynamics of the ruminal mi...Background The dairy cow’s postpartum period is characterized by dramatic physiological changes,therefore imposing severe challenges on the animal for maintaining health and milk output.The dynamics of the ruminal microbiota are also tremendous and may play a crucial role in lactation launch.We aim to investigate the potential benefits of early microbial intervention by fresh rumen microbiota transplantation(RMT)and sterile RMT in postpartum dairy cows.Twelve fistulated peak-lactation dairy cows were selected to be the donors for rumen fluid collection.Thirty postpartum cows were divided into 3 groups as the transplantation receptors respectively receiving 10 L fresh rumen fluid(FR),10 L sterile rumen fluid(SR),or 10 L saline(CON)during 3 d after calving.Results Production performance,plasma indices,plasma lipidome,ruminal microbiome,and liver transcriptome were recorded.After fresh and sterile RMT,we found that the molar proportion of propionic acid was increased on d 7 in the FR and SR groups and the bacterial composition was also significantly changed when compared with the CON group.A similarity analysis showed that the similarities between the CON group and FR or SR group on d 7 were 48.40%or 47.85%,whereas the similarities between microbiota on d 7 and 21 in the FR and SR groups were 68.34%or 66.85%.Dry matter intake and feed efficiency were not affected by treatments.Plasmaβ-hydroxybutyrate concentration in the FR group was decreased and significantly different lipids mainly included phosphatidylcholine and lysophosphatidylcholine containing polyunsaturated fatty acids.Hepatic transcriptomics analysis indicated acutephase response pathways were upregulated in the SR group.Conclusions Our study suggests that RMT can shorten the transition process of the ruminal microbiota of postpartum dairy cows with no benefit on dry matter intake or feed efficiency.Inoculation with rumen fluid may not be a useful approach to promote the recovery of postpartum dairy cows.展开更多
Background Four-chambered stomach including the forestomachs(rumen,reticulum,and omasum)and abomasum allows ruminants convert plant fiber into high-quality animal products.The early development of this four-chambered ...Background Four-chambered stomach including the forestomachs(rumen,reticulum,and omasum)and abomasum allows ruminants convert plant fiber into high-quality animal products.The early development of this four-chambered stomach is crucial for the health and well-being of young ruminants,especially the immune development.However,the dynamics of immune development are poorly understood.Results We investigated the early gene expression patterns across the four-chambered stomach in Hu sheep,at 5,10,15,and 25 days of age.We found that forestomachs share similar gene expression patterns,all four stomachs underwent widespread activation of both innate and adaptive immune responses from d 5 to 25,whereas the metabolic function were significantly downregulated with age.We constructed a cell landscape of the four-chambered stomach using single-cell sequencing.Integrating transcriptomic and single-cell transcriptomic analyses revealed that the immune-associated module hub genes were highly expressed in T cells,monocytes and macrophages,as well as the defense-associated module hub genes were highly expressed in endothelial cells in the four-stomach tissues.Moreover,the non-immune cells such as epithelial cells play key roles in immune maturation.Cell communication analysis predicted that in addition to immune cells,non-immune cells recruit immune cells through macrophage migration inhibitory factor signaling in the forestomachs.Conclusions Our results demonstrate that the immune and defense responses of four stomachs are quickly developing with age in lamb's early life.We also identified the gene expression patterns and functional cells associated with immune development.Additionally,we identified some key receptors and signaling involved in immune regulation.These results help to understand the early life immune development at single-cell resolution,which has implications to develop nutritional manipulation and health management strategies based on specific targets including key receptors and signaling pathways.展开更多
Background Dietary supplements based on tannin extracts or essential oil compounds(EOC)have been repeatedly reported as a promising feeding strategy to reduce the environmental impact of ruminant husbandry.A previous ...Background Dietary supplements based on tannin extracts or essential oil compounds(EOC)have been repeatedly reported as a promising feeding strategy to reduce the environmental impact of ruminant husbandry.A previous batch culture screening of various supplements identified selected mixtures with an enhanced potential to mitigate ruminal methane and ammonia formation.Among these,Q-2(named after quebracho extract and EOC blend 2,composed of carvacrol,thymol,and eugenol)and C-10(chestnut extract and EOC blend 10,consisting of oregano and thyme essential oils and limonene)have been investigated in detail in the present study with the semi-continuous rumen simulation technique(Rusitec)in three independent runs.For this purpose,Q-2 and C-10,dosed according to the previous study,were compared with a non-supplemented diet(negative control,NC)and with one supplemented with the commercial EOC-based Agolin^(R) Ruminant(positive control,PC).Results From d 5 to 10 of fermentation incubation liquid was collected and analysed for pH,ammonia,protozoa count,and gas composition.Feed residues were collected for the determination of ruminal degradability.On d 10,samples of incubation liquid were also characterised for bacterial,archaeal and fungal communities by high-throughput sequencing of 16S rRNA and 26S ribosomal large subunit gene amplicons.Regardless of the duration of the fermentation period,Q-2 and C-10 were similarly efficient as PC in mitigating either ammonia(-37%by Q-2,-34%by PC)or methane formation(-12%by C-10,-12%by PC).The PC was also responsible for lower feed degradability and bacterial and fungal richness,whereas Q-2 and C-10 effects,particularly on microbiome diversities,were limited compared to NC.Conclusions All additives showed the potential to mitigate methane or ammonia formation,or both,in vitro over a period of 10 d.However,several differences occurred between PC and Q-2/C-10,indicating different mechanisms of action.The pronounced defaunation caused by PC and its suggested consequences apparently determined at least part of the mitigant effects.Although the depressive effect on NDF degradability caused by Q-2 and C-10 might partially explain their mitigation properties,their mechanisms of action remain mostly to be elucidated.展开更多
Background Stocker cattle diet and management influence beef cattle performance during the finishing stage,but knowledge of the dynamics of the rumen microbiome associated with the host are lacking.A longitudinal stud...Background Stocker cattle diet and management influence beef cattle performance during the finishing stage,but knowledge of the dynamics of the rumen microbiome associated with the host are lacking.A longitudinal study was conducted to determine how the feeding strategy from the stocker to the finishing stages of production affects the temporal dynamics of rumen microbiota.During the stocker phase,either dry hay or wheat pasture were provided,and three levels of monensin were administrated.All calves were then transported to a feedlot and received similar finishing diets with or without monensin.Rumen microbial samples were collected on d 0,28,85 during the stocker stage(S0,S28 and S85)and d 0,14,28,56,30 d before slaughter and the end of the trial during the finishing stage(F0,F14,F28,F56,Pre-Ba,and Final).The V4 region of the bacterial 16S rRNA gene of 263 rumen samples was sequenced.Results Higher alpha diversity,including the number of observed bacterial features and the Shannon index,was observed in the stocker phase compared to the finishing phase.The bacterial amplicon sequence variants(ASVs)differentiating different sampling time points were identified.Dietary treatments during the stocker stage temporally impact the dynamics of rumen microbiota.For example,shared bacteria,including Bacteroidales(ASV19)and Streptococcus infantarius(ASV94),were significantly higher in hay rumen on S28,S85,and F0,while Bacteroidaceae(ASV11)and Limivicinus(ASV15)were more abundant in wheat.Monensin affected rumen microbial composition at a specific time.Transportation to feedlot significantly influenced microbiome structure and diversity in hay-fed calves.Bacterial taxa associated with body weight were classified,and core microbiotas interacted with each other during the trial.Conclusions In summary,the temporal dynamics of the rumen microbiome in cattle at the stocker and finishing stage are influenced by multiple factors of the feeding strategy.Diet at the stocker phase may temporarily affect the microbial composition during this stage.Modulating the rumen microbiome in the steers at the stocker stage affects the microbial interactions and performance in the finishing stage.展开更多
Background The red macroalgae Asparagopsis is an effective methanogenesis inhibitor due to the presence of halogenated methane(CH_(4))analogues,primarily bromoform(CHBr_(3)).This study aimed to investigate the degrada...Background The red macroalgae Asparagopsis is an effective methanogenesis inhibitor due to the presence of halogenated methane(CH_(4))analogues,primarily bromoform(CHBr_(3)).This study aimed to investigate the degradation process of CHBr3 from A taxiformis in the rumen and whether this process is diet-dependent.An in vitro batch culture system was used according to a 2×2 factorial design,assessing two A taxiformis inclusion rates[0(CTL)and 2%DM diet(AT)]and two diets[high-concentrate(HC)and high-forage diet(HF)].Incubations lasted for 72 h and samples of headspace and fermentation liquid were taken at 0,0.5,1,3,6,8,12,16,24,48 and 72 h to assess the pattern of degradation of CHBr_(3) into dibromomethane(CH_(2)Br_(2))and fermentation parameters.Additionally,an in vitro experiment with pure cultures of seven methanogens strains(Methanobrevibacter smithii,Methanobrevibacter ruminantium,Methanosphaera stadtmanae,Methanosarcina barkeri,Methanobrevibacter millerae,Methanorhermobacter wolfei and Methanobacterium mobile)was conducted to test the effects of increasing concentrations of CHBr3(0.4,2,10and 50μmol/L).Results The addition of AT significantly decreased CH_(4) production(P=0.002)and the acetate:propionate ratio(P=0.003)during a 72-h incubation.The concentrations of CHBr_(3) showed a rapid decrease with nearly 90%degraded within the first 3 h of incubation.On the contrary,CH_(2)Br_(2) concentration quickly increased during the first 6 h and then gradually decreased towards the end of the incubation.Neither CHBr_(3) degradation nor CH_(2)Br_(2) synthesis were affected by the type of diet used as substrate,suggesting that the fermentation rate is not a driving factor involved in CHBr_(3)degradation.The in vitro culture of methanogens showed a dose-response effect of CHBr3 by inhibiting the growth of M.smithii,M.ruminantium,M.stadtmanae,M.barkeri,M.millerae,M.wolfei,and M.mobile.Conclusions The present work demonstrated that CHBr_(3) from A.taxiformis is quickly degraded to CH_(2)Br_(2)in the rumen and that the fermentation rate promoted by different diets is not a driving factor involved in CHBr_(3)degradation.展开更多
Background Clostridium butyricum(CB)is a probiotic that can regulate intestinal microbial composition and improve meat quality.Rumen protected fat(RPF)has been shown to increase the dietary energy density and provide ...Background Clostridium butyricum(CB)is a probiotic that can regulate intestinal microbial composition and improve meat quality.Rumen protected fat(RPF)has been shown to increase the dietary energy density and provide essential fatty acids.However,it is still unknown whether dietary supplementation with CB and RPF exerts beneficial effects on growth performance and nutritional value of goat meat.This study aimed to investigate the effects of dietary CB and RPF supplementation on growth performance,meat quality,oxidative stability,and meat nutritional value of finishing goats.Thirty-two goats(initial body weight,20.5±0.82 kg)were used in a completely randomized block design with a 2 RPF supplementation(0 vs.30 g/d)×2 CB supplementation(0 vs.1.0 g/d)factorial treatment arrangement.The experiment included a 14-d adaptation and 70-d data and sample collection period.The goats were fed a diet consisted of 400 g/kg peanut seedling and 600 g/kg corn-based concentrate(dry matter basis).Result Interaction between CB and RPF was rarely observed on the variables measured,except that shear force was reduced(P<0.05)by adding CB or RPF alone or their combination;the increased intramuscular fat(IMF)content with adding RPF was more pronounced(P<0.05)with CB than without CB addition.The pH24h(P=0.009),a*values(P=0.007),total antioxidant capacity(P=0.050),glutathione peroxidase activities(P=0.006),concentrations of 18:3(P<0.001),20:5(P=0.003)and total polyunsaturated fatty acids(P=0.048)were increased,whereas the L*values(P<0.001),shear force(P=0.050)and malondialdehyde content(P=0.044)were decreased by adding CB.Furthermore,CB supplementation increased essential amino acid(P=0.027),flavor amino acid(P=0.010)and total amino acid contents(P=0.024)as well as upregulated the expression of lipoprotein lipase(P=0.034)and peroxisome proliferator-activated receptorγ(PPARγ)(P=0.012),and downregulated the expression of stearoyl-CoA desaturase(SCD)(P=0.034).The RPF supplementation increased dry matter intake(P=0.005),averaged daily gain(trend,P=0.058),hot carcass weight(P=0.046),backfat thickness(P=0.006),concentrations of 16:0(P<0.001)and c9-18:1(P=0.002),and decreased the shear force(P<0.001),isoleucine(P=0.049)and lysine content(P=0.003)of meat.In addition,the expressions of acetyl-CoA carboxylase(P=0.003),fatty acid synthase(P=0.038),SCD(P<0.001)and PPARγ(P=0.022)were upregulated due to RPF supplementation,resulting in higher(P<0.001)content of IMF.Conclusions CB and RPF could be fed to goats for improving the growth performance,carcass traits and meat quality,and promote fat deposition by upregulating the expression of lipogenic genes of Longissimus thoracis muscle.展开更多
基金financially supported by the National Key Research and Development Program of China(2023YFD2000701)the Natural Science Foundation of Heilongjiang Province,China(YQ2023C011)+1 种基金the Key Research and Development Program of Heilongjiang Province,China(Grant no.2022ZX01A24)the Key Laboratory of Low-carbon Green Agriculture in Northeastern China,Ministry of Agriculture and Rural Affairs of China(LCGANE14)。
文摘As a major contributor to methane production in agriculture,there is a need for a suitable methane inhibitor to reduce ruminant methane emissions and minimize the impact on the climate.This work aimed to explore the influence of cordycepin on rumen fermentation,gas production,microbiome and their metabolites.A total of 0.00,0.08,0.16,0.32,and 0.64 g L^(–1)cordycepin were added into fermentation bottles containing 2 g total mixed ration for in vitro ruminal fermentation,and then the gas produced and fermentation parameters were measured for each bottle.Samples from the 0 and 0.64 g L^(–1)cordycepin addition were selected for 16S rRNA gene sequencing and metabolome analysis.The result of this experiment indicated that the addition of cordycepin could linearly increase the concentration of total volatile fatty acid,ammonia nitrogen,the proportion of propionate,valerate,and isovalerate,and linearly reduce ruminal pH and methane,carbon dioxide,hydrogen and total gas production,as well as the methane proportion,carbon dioxide proportion and proportion of butyrate.In addition,there was a quadratic relationship between hydrogen and cordycepin addition.At the same time,the relative abundance of Succiniclasticum,Prevotella,Rikenellaceae_RC9_gut_group,NK4A214_group,Christensenellaceae_R_(7)_group,unclassified_F082,Veillonellaceae_UCG_001,Dasytricha,Ophryoscolex,Isotricha,unclassified_Eukaryota,Methanobrevibacter,and Piromyces decreased significantly after adding the maximum dose of cordycepin.In contrast,the relative abundance of Succinivibrio,unclassified_Succinivibrionaceae,Prevotellaceae_UCG_001,unclassified_Lachnospiraceae,Lachnospira,Succinivibrionaceae_UCG_002,Pseudobutyrivibrio,Entodinium,Polyplastron,unclassified_Methanomethylophilaceae,Methanosphaera,and Candidatus_Methanomethylophilus increased significantly.Metabolic pathways such as biosynthesis of unsaturated fatty acids and purine metabolism and metabolites such as arachidonic acid,adenine,and 2′-deoxyguanosine were also affected by the addition of cordycepin.Based on this,we conclude that cordycepin is an effective methane emission inhibitor that can change the rumen metabolites and fermentation parameters by influencing the rumen microbiome,thus regulating rumen methane production.This experiment may provide a potential theoretical reference for developing Cordyceps byproduct or additives containing cordycepin as methane inhibitors.
基金supported by the National Natural Science Foundation of China(32072757 and U21A20250)。
文摘Yaks are well-adapted to the harsh environment of the Tibetan Plateau,and they emit less enteric methane(CH_(4))and digest poor-quality forage better than cattle.To examine the potential of yak rumen inoculum to mitigate CH_(4)production and improve digestibility in cattle,we incubated substrate with rumen inoculum from yak(YRI)and cattle(CRI)in vitro in five ratios(YRI:CRI):(1)0:100(control),(2)25:75,(3)50:50,(4)75:25 and(5)100:0 for 72 h.The YRI:CRI ratios of 50:50,75:25 and 100:0 produced less total gas and CH_(4)and accumulated less hydrogen(H_(2))than0:100(control)at most time points.From 12 h onwards,there was a linear decrease(P<0.05)in carbon dioxide(CO_(2))production with increasing YRI:CRI ratio.At 72 h,the ratios of 50:50 and 75:25 had higher dry matter(+7.71%and+4.11%,respectively),as well as higher acid detergent fiber digestibility(+15.5%and+7.61%,respectively),when compared to the 0:100 ratio(P<0.05).Increasing the proportion of YRI generally increased total VFA concentrations,and,concomitantly,decreased the proportion of metabolic hydrogen([2H])incorporated into CH_(4),and decreased the recovery of[2H].The lower[2H]recovery indicates unknown[2H]sinks in the culture.Estimated Gibbs free energy changes(ΔG)for reductive acetogenesis were negative,indicating the thermodynamic feasibility of this process.It would be beneficial to identify:1)the alternative[2H]sinks,which could help mitigate CH_(4)emission,and 2)core microbes involved in fiber digestion.This experiment supported lower CH_(4)emission and greater nutrient digestibility of yaks compared to cattle.Multi-omics combined with microbial culture technologies developed in recent years could help to better understand fermentation differences among species.
基金supported by the National Key R&D Program(Grant No.2022YFD1301101-1)National Natural Science Foundation of China(Grant No.32172758)Key Research and Development Program of Ningxia(Grant No.2024BBF01008)。
文摘Background In this study,the effects of L-leucine(Leu)on rumen fermentation parameters,rumen epithelium development,amino acid composition,rumen bacterial communities and rumen metabolites in beef cattle were investigated.Twenty-four fattening Angus females of similar initial weight(575.5±22.1 kg)were randomly assigned to 2 treatments with 4 replicate pens(3 cattle per pen).They were fed either a basal diet or a basal diet supplemented with 6.0 g L-Leu/100 kg BW/d for 120 d.Results(1)Leu increased the ruminal concentrations of total volatile fatty acid(VFA)(P=0.017),propionate(P=0.023),isovalerate(P=0.001),and branched-chain volatile fatty acid(BCVFA)(P=0.01)at 4 h post-feeding.It also tended to increase acetate(P=0.083)and decrease the ammonia-N(NH_3-N)concentration(P=0.055),but it did not affect ruminal pH(P>0.1).Leu also increased microbial crude protein(MCP)(P=0.026)at 4 h post-feeding,but decreased MCP at 8 h post-feeding(P=0.010).(2)Supplementation with L-Leu increased the ruminal concentrations of phenylalanine(P=0.011),lysine(P=0.034),and tyrosine(P=0.033),while decreasing the cystine concentration(P=0.010).(3)Leu increased the thickness of the stratum spinosum and basal(P<0.05),while decreasing the thickness of the stratum granulosum(P<0.05).(4)Leu upregulated the relative mRNA abundance of genes involved in tight junction proteins(P<0.05)and VFA absorption and metabolism(P<0.01)in the rumen epithelium.This upregulation was positively correlated with the concentrations ruminal isovalerate and BCVFA(P<0.01).(5)L-Leu did not affect the diversity and richness of ruminal microbes(P>0.05),but differential bacterial biomarkers(LEfSe,LDA>2)were either positively or negatively correlated with ruminal MCP,NH_3-N,and BCVFA concentrations(P<0.001).Additionally,differential bacterial metabolites(OPLS-DA,VIP>1.5)were primarily enriched in the amino acid metabolism pathway and the cofactors and vitamins metabolism pathway(P<0.05).Conclusions Dietary supplementation with L-Leu altered rumen fermentation parameters and patterns,improved rumen epithelial morphology,and enhanced the expression of genes related to VFA absorption and metabolism in the rumen epithelium of beef cattle.
基金funded by the Science and Technology Major Project of the Inner Mongolia Autonomous Region of China to the State Key Laboratory of Reproductive Regulation(2023KYPT0010 and 2021ZD0048)STI 2030-Major Projects(2023ZD0407504)of China+1 种基金the development plan for young scientific and technological talents in colleges and universities of Inner Mongolia Autonomous Region of China(NMGIRT2204)the National Natural Science Foundation of China(32160172).
文摘Epigenetic regulation in the rumen,a unique ruminant organ,remains largely unexplored compared with other tissues studied in model species.In this study,we perform an in-depth analysis of the epigenetic and transcriptional landscapes across fetal and adult bovine tissues as well as pluripotent stem cells.Among the extensive methylation differences across various stages and tissues,we identify tissue-specific differentially methylated regions(tsDMRs)unique to the rumen,which are crucial for regulating epithelial development and energy metabolism.These tsDMRs cluster within super-enhancer regions that overlap with transcription factor(TF)binding sites.Regression models indicate that DNA methylation,along with H3K27me3 and H3K27ac,can be used to predict enhancer activity.Key upstream TFs,including SOX2,FOSL1/2,and SMAD2/3,primarily maintain an inhibitory state through bivalent modifications during fetal development.Downstream functional genes are maintained mainly in a stable repressive state via DNA methylation until differentiation is complete.Our study underscores the critical role of tsDMRs in regulating distal components of rumen morphology and function,providing key insights into the epigenetic regulatory mechanisms that may influence bovine production traits.
基金supported by the National Key Research and Development Program of China(2023YFE0100400)Science and Technology Project of Inner Mongolia Autonomous Region(2020GG0036)+2 种基金Basic Scientific Research Business Project of Universities directly under the Inner Mongolia Autonomous Region(BR22-11-17)National Center of Technology Innovation for Dairy(2023-JSGG-5)the Special Project for Improving the Research Ability of Young Teachers of Inner Mongolia Agricultural University(BR220133).
文摘Background Using yeast culture as additives in ruminant feed prevents rumen microbial dysbiosis,enhances performance,and regulates rumen pH.The yeast culture used in this study was developed in-house,and has been shown to promote rumen epithelial growth in several sheep trials.Changes in protein expression associated with the promotion of rumen epithelial development following the addition of yeast culture,along with the associated molecular mechanisms,remain unknown.We used 2045-day-old weaned lambs to investigate the specific proteins and molecular mechanisms involved in these processes.Half of the lambs were fed yeast culture,and the other half were used as controls.Results Yeast culture enhanced growth performance,facilitated rumen fermentation,and promoted rumen papilla development in weaned lambs.Proteomics data identified 4,831 proteins in the rumen epithelial tissue of lambs,comprising 87 upregulated and 425 downregulated proteins.Administration of yeast culture activated multiple molecular functions within rumen epithelial cells,including oxidative phosphorylation,glutathione metabolism,apoptosis,cell cycle,and vitamin digestion and absorption.The expression of proteins associated with cell cycle regulation increased,whereas those associated with apoptosis decreased.Administration of yeast culture also reduced the duration of the G0/G1 phase of rumen epithelial cells and accelerated the cell cycle.Furthermore,yeast culture showed increased cyclin D1,cyclin-dependent kinase(CDK)2,CDK4,CDK6,and cyclin E1 expressions and decreased cytochrome C(Cyto-c),Bcl-2-related X protein(Bax),cleaved caspase 3(C-caspase 3),caspase 3,and cleaved caspase 7(C-caspase 7)protein expressions.Yeast culture upregulated the insulin-like growth factor-1 receptor(IGF-1R)and insulin-like growth factor-binding protein 5(IGFBP-5)mRNA expressions in rumen epithelial cells.Conclusions Yeast culture facilitates rumen epithelial development by regulating the cell cycle and IGF-1 signaling and reducing the expression of proteins associated with apoptosis in rumen epithelial cells.The findings of this study provide novel insights into the molecular mechanisms through which yeast culture promotes rumen epithelial development in weaned lambs.
基金funded by National Key Research and Development Program(2022YFA1304200)Agricultural Science and Technology Innovation Program(CAAS-ASTIP-2023-IFR-04 and CAAS-ZDRW202305)the Beijing Innovation Consortium of Livestock Research System(BAIC05-2023).
文摘Background Rumen microorganisms are key regulators of ruminant growth and production performance.Identifying probiotic candidates through microbial culturomics presents a promising strategy for improving ruminant production performance.Our previous study identified significant differences in rumen microbial communities of Holstein calves with varying average daily gain(ADG).This study aims to identify a target strain based on the findings from multi-omics analysis and literature review,isolating and evaluating the target microbial strains from both the rumen and hindgut contents for their probiotic potential.Results Parabacteroides distasonis,a strain closely associated with ADG,was successfully isolated from calf rumen content cultured with Fastidious Anaerobe Agar(FAA)medium and named Parabacteroides distasonis F4.Wholegenome sequencing and pan-genome analysis showed that P.distasonis F4 possesses a core functional potential for carbohydrate and amino acid metabolism,with the ability to produce propionate,acetate,and lactate.The results of targeted and untargeted metabolomics further validated the organic acid production and metabolic pathways of P.distasonis F4.An in vitro simulated rumen fermentation test showed that supplementation with P.distasonis F4 significantly altered rumen microbial community structure and increased the molar proportions of propionate and butyrate in the rumen.Furthermore,an in vivo study demonstrated that dietary supplementation with P.distasonis F4 significantly increased the ADG of pre-weaning calves.Conclusions This study represents the first isolation of P.distasonis F4 from rumen,highlighting its potential as a probiotic strain for improving rumen development and growth performance in ruminants.
基金supported by China Agriculture Research System of MOF and MARA(CARS-38)。
文摘The aim of this study was to investigate the effects of dietary fat on energy and nitrogen(N)metabolism efficiency,rumen fermentation,and microbiota in twin suckling lambs.Thirty pairs of twin male lambs were randomly divided into two groups with one group receiving a high-fat diet(HF)and the other a normal-fat diet(NF).Two diets(milk replacer and starter)of equal protein and different fat levels.The metabolism test was conducted when the lambs were 50-60 days old,and nine pairs of twin lambs were randomly selected for slaughter to collect rumen fluid at 60 days old.The result showed that fat addition increased the final body weight(BW),ruminal ammonia nitrogen(NH_(3)-N)content,proportion of propionic acid,and estimated methane production(CH_(4e))(P<0.05).The high fat diet tended to improve digestive energy(DE),metabolism energy(ME),DE/ME,utilisation of N(0.05<P<0.1).However,microbial crude protein(MCP)content,total volatile fatty acids(VFA),acetic acid ratio,and the ratio of acetate to propionate(A:P)were lower than that in the NF group(P<0.05).Regardless of whether fat is added or not,no different were observed in blood metabolites between the treatment.High-throughput sequencing revealed that fat addition before weaning increased phyla Proteobacteria and genera of Succinivibrio,but decreased the relative abundance of Clostridium IV,Dialister,Roseburia,Acidaminococcus,and Megasphaera genera.These findings indicated that high fat diet improved body weight,energy and nitrogen utilization may by shifting the rumen toward propionate fermentation via the enrichment of Succinivibrio.
基金funded by UK Research and Innovation(UKRI)doctoral training grant no:BB/T008776/1the Department of Agriculture,Environment and Rural Affairs(DAERA)by Trouw Nutrition and by John Thompsons and Sons Ltd.
文摘Background Nitrogen-Use-Efficiency(NUE)in lactating dairy cows,defined as milk nitrogen(N)output as a proportion of N consumed,is low,with the majority of excess N excreted in manure.Excreted N can be lost to the environment as ammonia gas leading to environmental acidification and nutrient enrichment of sensitive habitats,and to watercourses contributing to aquatic eutrophication.While there is much evidence that NUE can be improved by reducing the crude protein(CP)content of dairy cow diets,the long-term impacts of feeding lower protein diets on cow performance and the rumen microbiome are less well understood.This study examined the effects of reducing the CP contents of dairy cow diets on cow performance,NUE,the relationship between NUE and residual feed intake(RFI),and the rumen microbiome.Results Dietary CP content did not affect feed intake,milk yield or milk composition(P>0.05),except for milk urea N(MUN),which increased with increasing diet CP content(P<0.05).The mean NUE was 34%,34%and 31%for the LCP(low-protein,15%),MCP(medium-protein,16%),and HCP(high-protein,17%)diets,respectively.RFI was negatively correlated with NUE(r=−0.57,P<0.001).The rumen ammonia-N concentrations increased with increasing dietary CP;however,the ruminal pH and volatile fatty acid(VFA)content of the rumen fluid remained constant.Predicted urinary N excretion was greater in the HCP and MCP diets than in the LCP diet.Reducing dietary CP content in dairy cow diets did not affect microbial composition,diversity and functional profiles.The family Bacteroidaceae was more abundant in HE(high-efficiency)cows,whereas the Methanobacteriaceae and the genus Methanobrevibacter were more abundant in LE(low-efficiency)cows.Additionally,propanoate metabolism,cysteine and methionine metabolism and amino acid biosynthesis pathways were more abundant in HE cows,whilst the methane(CH4)metabolism pathway was upregulated in LE cows.Conclusions The results demonstrate that diet CP can be reduced with no loss in cow performance,but with an associated reduction in N excretion.The abundance of microbial populations differed between low and high efficiency cows,which may contribute to the differences in efficiency observed.
基金supported by the National Key Research and Development Program for International Science and Technology Innovation Cooperation between Governments(2023YFE0111800)the Shaanxi Province’s San Qin Talent Attraction Program for Regional Youth Talents.
文摘Background Subacute rumen acidosis(SARA)is a common metabolic disorder in ruminants that disrupts the rumen microbiome and animal health,but diagnosis is challenging due to subtle symptoms and invasive testing require-ments.This study explores the potential of the buccal(oral)microbiome as a diagnostic indicator for SARA,hypoth-esizing an interaction with the rumen microbiome.Results The study involved 47 dairy goats,including 11 on a control diet and 36 on high-concentrate diets with increasing rumen-degradable starch.Animals were grouped based on dietary exposure and ruminal pH:Control,Low-RDS Tolerance/SARA(LRDST/LRDSS),and High-RDS Tolerance/SARA(HRDST/HRDSS).Transcriptomics of rumen epithelium showed heightened inflammatory pathway gene expression in SARA-susceptible goats compared to controls and tolerant groups.Alpha diversity of ruminal bacteria showed lower Shannon diversity in HRDSS goats compared to HRDST whereas buccal bacteria displayed significantly lower Chao1 diversity in LRDSS goats compared to HRDST.Beta diversity analyses revealed distinct patterns between SARA-affected goats and healthy controls in both ruminal and buccal microbiomes.Prevotellaceae_UCG-003 emerged as a candidate biomarker,with reduced abundance in SARA-susceptible goats in both rumen and buccal samples.Machine learning classifiers achieved high accuracy in distinguishing SARA-susceptible goats using this genus(rumen AUC=0.807;buccal AUC=0.779).Source tracking analysis illustrated diminished cross-population of bacteria from the buccal to rumen(2.86%to 0.25%)and vice versa(8.59%to 1.17%),signifying compromised microbial interchange in SARA-affected goats.A microbiota transplant experiment verified SARA microbiota’s ability to induce pH decline,escalate inflammation-related gene expression(MAPK10,IL17B,FOSB,SPP1),disrupt microbial transfer,and reduce Prevotellaceae_UCG-003 in recipients.Conclusion Our findings highlight SARA’s dual impact on ruminal and buccal microbiota,exacerbating epithelial inflammation gene expression.Shifts in the buccal microbiome,specifically reductions in Prevotellaceae_UCG-003,mirror ruminal changes and can be influenced by inter-compartmental bacterial transmission,thereby offering a non-invasive diagnostic approach for SARA.
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partially granted by the Hi-Ga project,which is part of the programme of the Green ERA-Hub that has received funding from the European Union’s Horizon Europe research and innovation programme under Grant Agreement No.101056828self-financed by the DINAMIC team of the UMR Herbivores(INRAE,VetAgro Sup,Saint-Genès-Champanelle,France)。
文摘Background Insect meals have been identified as innovative and sustainable feedstuffs that could be used in ruminant nutrition.However,current research on the effects that their processing may have on rumen digestibility and fatty acid(FA)biohydrogenation is scant.This trial aims to investigate the effects(i)of drying temperature of fullfat Hermetia illucens(HI)and Tenebrio molitor(TM)meals,and(ii)of residual ether extract(EE)content of defatted HI and TM meals,on their fermentation characteristics and FA of rumen digesta after 24-h in vitro rumen incubation.Methods The tested full-fat meals included four HI and four TM meals obtained applying drying temperatures ranging from 30℃ to 70℃,while the tested defatted meals consisted of five HI and two TM meals containing a residual EE content ranging from 4.7 to 19.7 g EE/100 g dry matter(DM).The applied statistical models(GLM ANOVA)tested the effects of insect species,drying temperature(full-fat meals)or EE content(defatted meals),and their interaction.Results Drying temperature had minor effects on in vitro ruminal digestibility and FA profile of rumen digesta.Irrespective of insect species,increasing the drying temperature led to a reduction of in vitro degradation of proteins from insect meals,as outlined by the significant decrease in ammonia production(-0.009 mmol/g DM and-0.126 g/100 g total N for each additional 1℃).Irrespective of insect species,defatting increased total gas,volatile fatty acids(VFA)and CH_(4) productions,and the proportions of total saturated and branched-chain FA in rumen digesta(+0.038 mmol/g DM,+0.063 mmol/g DM,+12.9μmol/g DM,+0.18 g/100 g FA,and+0.19 g/100 g FA for each reduced 1 g EE/100 g DM,respectively),and reduced the proportion of total PUFA(-0.12 g/100 g FA).Conclusions The applied drying temperatures of full-fat insect meals are too low to exert impactful effects on rumen digestibility and FA biohydrogenation.Fat lowered fermentation activity,probably because of an inhibitory effect on rumen microbiota.The increased ruminal digestibility of defatted insect meals suggests that they can be more suitable to be used in ruminant nutrition than full-fat ones.
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funded by National Key R&D Program of China(2022YFA1304204)Agricultural Science and Technology Innovation Program(CAAS-ASTIP-2017-FRI-04)Beijing Innovation Consortium of livestock Research System(BAIC05-2023)。
文摘Background Rumen bacterial groups can affect growth performance,such as average daily gain(ADG),feed intake,and efficiency.The study aimed to investigate the inter-relationship of rumen bacterial composition,rumen fermentation indicators,serum indicators,and growth performance of Holstein heifer calves with different ADG.Twelve calves were chosen from a trail with 60 calves and divided into higher ADG(HADG,high pre-and post-weaning ADG,n=6)and lower ADG(LADG,low pre-and post-weaning ADG,n=6)groups to investigate differences in bacterial composition and functions and host phenotype.Results During the preweaning period,the relative abundances of propionate producers,including g_norank_f_Butyricicoccaceae,g_Pyramidobacter,and g_norank_f_norank_o_Clostridia_vadin BB60_group,were higher in HADG calves(LDA>2,P<0.05).Enrichment of these bacteria resulted in increased levels of propionate,a gluconeogenic precursor,in preweaning HADG calves(adjusted P<0.05),which consequently raised serum glucose concentrations(adjusted P<0.05).In contrast,the relative abundances of rumen bacteria in post-weaning HADG calves did not exert this effect.Moreover,no significant differences were observed in rumen fermentation parameters and serum indices between the two groups.Conclusions The findings of this study revealed that the preweaning period is the window of opportunity for rumen bacteria to regulate the ADG of calves.
基金supported by the National Key Research and Development Program of China(2022YFD1300905)the National Natural Science Foundation of China(31960672)+3 种基金the Key Research and Development Program of Ningxia Hui Autonomous Region,China(2021BEF02020)the Top Discipline Construction Project of Pratacultural Science(NXYLXK2017A01)the Science and Technology Development Project of Jilin Province,China(20200201140JC)the Technology Cooperation High-Tech Industrialization Project of Jilin Province,China and the Chinese Academy of Sciences,(2022SYHZ0020).
文摘Lycium barbarum residue(LBR),a by-product of L.barbarum processing,is packed with bioactive components and can be potentially utilized as a feed additive in animal husbandry.However,the fundamental understanding of its effectiveness on livestock animals is still lacking,particularly in ruminants.To explore the effects of LBR on the growth performance,rumen fermentation parameters,ruminal microbes and metabolites of Tan sheep,sixteen fattening rams(aged 4 mon)were fed a basal diet(CON,n=8)or a basal diet supplemented with 5%LBR(LBR,n=8).The experiment lasted for 70 d,with 10 d adaptation period and 60 d treatment period.The results showed that the LBR enhanced the average daily feed intake,average daily gain(P<0.05),and ruminal total volatile fatty acids(P<0.01)while decreasing ammonia-nitrogen concentration and rumen pH value(P<0.05).Additionally,the LBR improved the relative abundances of Prevotella,Succiniclasticum,Ruminococcus,Coprococcus,Selenomonas,and Butyrivibrio(P<0.05)and reduced the relative abundances of Oscillospira and Succinivibrio(P<0.05).The LBR altered the ruminal metabolome(P<0.01)by increasing the abundances of ruminal metabolites involved in amino acids(e.g.,L-proline,L-phenylalanine,L-lysine,and L-tyrosine),pyrimidine metabolism(e.g.,uridine,uracil,and thymidine),and microbial protein synthesis(e.g.,xanthine and hypoxanthine).In conclusion,LBR had positive effects on the growth rate of Tan sheep as well as on rumen fermentation parameters,rumen microbiome and rumen metabolome.
基金supported by the National Natural Science Foundation of China(32130100).
文摘Background The dairy cow’s postpartum period is characterized by dramatic physiological changes,therefore imposing severe challenges on the animal for maintaining health and milk output.The dynamics of the ruminal microbiota are also tremendous and may play a crucial role in lactation launch.We aim to investigate the potential benefits of early microbial intervention by fresh rumen microbiota transplantation(RMT)and sterile RMT in postpartum dairy cows.Twelve fistulated peak-lactation dairy cows were selected to be the donors for rumen fluid collection.Thirty postpartum cows were divided into 3 groups as the transplantation receptors respectively receiving 10 L fresh rumen fluid(FR),10 L sterile rumen fluid(SR),or 10 L saline(CON)during 3 d after calving.Results Production performance,plasma indices,plasma lipidome,ruminal microbiome,and liver transcriptome were recorded.After fresh and sterile RMT,we found that the molar proportion of propionic acid was increased on d 7 in the FR and SR groups and the bacterial composition was also significantly changed when compared with the CON group.A similarity analysis showed that the similarities between the CON group and FR or SR group on d 7 were 48.40%or 47.85%,whereas the similarities between microbiota on d 7 and 21 in the FR and SR groups were 68.34%or 66.85%.Dry matter intake and feed efficiency were not affected by treatments.Plasmaβ-hydroxybutyrate concentration in the FR group was decreased and significantly different lipids mainly included phosphatidylcholine and lysophosphatidylcholine containing polyunsaturated fatty acids.Hepatic transcriptomics analysis indicated acutephase response pathways were upregulated in the SR group.Conclusions Our study suggests that RMT can shorten the transition process of the ruminal microbiota of postpartum dairy cows with no benefit on dry matter intake or feed efficiency.Inoculation with rumen fluid may not be a useful approach to promote the recovery of postpartum dairy cows.
基金partially supported by the Natural Science Foundation of Zhejiang Province(Award number:D21C170001)the National Natural Science Foundation of China(Award number:31973000)。
文摘Background Four-chambered stomach including the forestomachs(rumen,reticulum,and omasum)and abomasum allows ruminants convert plant fiber into high-quality animal products.The early development of this four-chambered stomach is crucial for the health and well-being of young ruminants,especially the immune development.However,the dynamics of immune development are poorly understood.Results We investigated the early gene expression patterns across the four-chambered stomach in Hu sheep,at 5,10,15,and 25 days of age.We found that forestomachs share similar gene expression patterns,all four stomachs underwent widespread activation of both innate and adaptive immune responses from d 5 to 25,whereas the metabolic function were significantly downregulated with age.We constructed a cell landscape of the four-chambered stomach using single-cell sequencing.Integrating transcriptomic and single-cell transcriptomic analyses revealed that the immune-associated module hub genes were highly expressed in T cells,monocytes and macrophages,as well as the defense-associated module hub genes were highly expressed in endothelial cells in the four-stomach tissues.Moreover,the non-immune cells such as epithelial cells play key roles in immune maturation.Cell communication analysis predicted that in addition to immune cells,non-immune cells recruit immune cells through macrophage migration inhibitory factor signaling in the forestomachs.Conclusions Our results demonstrate that the immune and defense responses of four stomachs are quickly developing with age in lamb's early life.We also identified the gene expression patterns and functional cells associated with immune development.Additionally,we identified some key receptors and signaling involved in immune regulation.These results help to understand the early life immune development at single-cell resolution,which has implications to develop nutritional manipulation and health management strategies based on specific targets including key receptors and signaling pathways.
基金partially funded with Ferrero 3P projectsupported by the European Union under the European Regional Development Fund(part of the Union’s response to the COVID-19 outbreak,AXIS VI—Investment Priority 13i—Action 3.1.1)。
文摘Background Dietary supplements based on tannin extracts or essential oil compounds(EOC)have been repeatedly reported as a promising feeding strategy to reduce the environmental impact of ruminant husbandry.A previous batch culture screening of various supplements identified selected mixtures with an enhanced potential to mitigate ruminal methane and ammonia formation.Among these,Q-2(named after quebracho extract and EOC blend 2,composed of carvacrol,thymol,and eugenol)and C-10(chestnut extract and EOC blend 10,consisting of oregano and thyme essential oils and limonene)have been investigated in detail in the present study with the semi-continuous rumen simulation technique(Rusitec)in three independent runs.For this purpose,Q-2 and C-10,dosed according to the previous study,were compared with a non-supplemented diet(negative control,NC)and with one supplemented with the commercial EOC-based Agolin^(R) Ruminant(positive control,PC).Results From d 5 to 10 of fermentation incubation liquid was collected and analysed for pH,ammonia,protozoa count,and gas composition.Feed residues were collected for the determination of ruminal degradability.On d 10,samples of incubation liquid were also characterised for bacterial,archaeal and fungal communities by high-throughput sequencing of 16S rRNA and 26S ribosomal large subunit gene amplicons.Regardless of the duration of the fermentation period,Q-2 and C-10 were similarly efficient as PC in mitigating either ammonia(-37%by Q-2,-34%by PC)or methane formation(-12%by C-10,-12%by PC).The PC was also responsible for lower feed degradability and bacterial and fungal richness,whereas Q-2 and C-10 effects,particularly on microbiome diversities,were limited compared to NC.Conclusions All additives showed the potential to mitigate methane or ammonia formation,or both,in vitro over a period of 10 d.However,several differences occurred between PC and Q-2/C-10,indicating different mechanisms of action.The pronounced defaunation caused by PC and its suggested consequences apparently determined at least part of the mitigant effects.Although the depressive effect on NDF degradability caused by Q-2 and C-10 might partially explain their mitigation properties,their mechanisms of action remain mostly to be elucidated.
基金the University of Arkansas Agricultural Experiment Station,Hatch Project No.AR002234,National Natural Science Foundation of China(32170430)Guangdong Provincial Key Laboratory of Animal Molecular Design and Precise Breeding(2019B030301010)Key Laboratory of Animal Molecular Design and Precise Breeding of Guangdong Higher Education Institutes(2019KSYS011).
文摘Background Stocker cattle diet and management influence beef cattle performance during the finishing stage,but knowledge of the dynamics of the rumen microbiome associated with the host are lacking.A longitudinal study was conducted to determine how the feeding strategy from the stocker to the finishing stages of production affects the temporal dynamics of rumen microbiota.During the stocker phase,either dry hay or wheat pasture were provided,and three levels of monensin were administrated.All calves were then transported to a feedlot and received similar finishing diets with or without monensin.Rumen microbial samples were collected on d 0,28,85 during the stocker stage(S0,S28 and S85)and d 0,14,28,56,30 d before slaughter and the end of the trial during the finishing stage(F0,F14,F28,F56,Pre-Ba,and Final).The V4 region of the bacterial 16S rRNA gene of 263 rumen samples was sequenced.Results Higher alpha diversity,including the number of observed bacterial features and the Shannon index,was observed in the stocker phase compared to the finishing phase.The bacterial amplicon sequence variants(ASVs)differentiating different sampling time points were identified.Dietary treatments during the stocker stage temporally impact the dynamics of rumen microbiota.For example,shared bacteria,including Bacteroidales(ASV19)and Streptococcus infantarius(ASV94),were significantly higher in hay rumen on S28,S85,and F0,while Bacteroidaceae(ASV11)and Limivicinus(ASV15)were more abundant in wheat.Monensin affected rumen microbial composition at a specific time.Transportation to feedlot significantly influenced microbiome structure and diversity in hay-fed calves.Bacterial taxa associated with body weight were classified,and core microbiotas interacted with each other during the trial.Conclusions In summary,the temporal dynamics of the rumen microbiome in cattle at the stocker and finishing stage are influenced by multiple factors of the feeding strategy.Diet at the stocker phase may temporarily affect the microbial composition during this stage.Modulating the rumen microbiome in the steers at the stocker stage affects the microbial interactions and performance in the finishing stage.
基金funded by Blue Ocean Barns.AB has a Ramón y Cajal research contract(RYC2019-027764-I)funded by the Spanish State Research Agency(AEI)。
文摘Background The red macroalgae Asparagopsis is an effective methanogenesis inhibitor due to the presence of halogenated methane(CH_(4))analogues,primarily bromoform(CHBr_(3)).This study aimed to investigate the degradation process of CHBr3 from A taxiformis in the rumen and whether this process is diet-dependent.An in vitro batch culture system was used according to a 2×2 factorial design,assessing two A taxiformis inclusion rates[0(CTL)and 2%DM diet(AT)]and two diets[high-concentrate(HC)and high-forage diet(HF)].Incubations lasted for 72 h and samples of headspace and fermentation liquid were taken at 0,0.5,1,3,6,8,12,16,24,48 and 72 h to assess the pattern of degradation of CHBr_(3) into dibromomethane(CH_(2)Br_(2))and fermentation parameters.Additionally,an in vitro experiment with pure cultures of seven methanogens strains(Methanobrevibacter smithii,Methanobrevibacter ruminantium,Methanosphaera stadtmanae,Methanosarcina barkeri,Methanobrevibacter millerae,Methanorhermobacter wolfei and Methanobacterium mobile)was conducted to test the effects of increasing concentrations of CHBr3(0.4,2,10and 50μmol/L).Results The addition of AT significantly decreased CH_(4) production(P=0.002)and the acetate:propionate ratio(P=0.003)during a 72-h incubation.The concentrations of CHBr_(3) showed a rapid decrease with nearly 90%degraded within the first 3 h of incubation.On the contrary,CH_(2)Br_(2) concentration quickly increased during the first 6 h and then gradually decreased towards the end of the incubation.Neither CHBr_(3) degradation nor CH_(2)Br_(2) synthesis were affected by the type of diet used as substrate,suggesting that the fermentation rate is not a driving factor involved in CHBr_(3)degradation.The in vitro culture of methanogens showed a dose-response effect of CHBr3 by inhibiting the growth of M.smithii,M.ruminantium,M.stadtmanae,M.barkeri,M.millerae,M.wolfei,and M.mobile.Conclusions The present work demonstrated that CHBr_(3) from A.taxiformis is quickly degraded to CH_(2)Br_(2)in the rumen and that the fermentation rate promoted by different diets is not a driving factor involved in CHBr_(3)degradation.
基金supported by the National Key Research and Development Program of China(2022YFD1301105)the earmarked fund for CARS(CARS-36)+2 种基金the Natural Science Foundation of Heilongjiang Province(YQ2021C018)the Postdoctoral Foundation of Heilongjiang Province(LBH-Z21100)the Open Project Program of International Joint Research Laboratory in Universities of Jiangsu Province of China for Domestic Animal Germplasm Resources and Genetic Improvement(IJRLD-KF202204).
文摘Background Clostridium butyricum(CB)is a probiotic that can regulate intestinal microbial composition and improve meat quality.Rumen protected fat(RPF)has been shown to increase the dietary energy density and provide essential fatty acids.However,it is still unknown whether dietary supplementation with CB and RPF exerts beneficial effects on growth performance and nutritional value of goat meat.This study aimed to investigate the effects of dietary CB and RPF supplementation on growth performance,meat quality,oxidative stability,and meat nutritional value of finishing goats.Thirty-two goats(initial body weight,20.5±0.82 kg)were used in a completely randomized block design with a 2 RPF supplementation(0 vs.30 g/d)×2 CB supplementation(0 vs.1.0 g/d)factorial treatment arrangement.The experiment included a 14-d adaptation and 70-d data and sample collection period.The goats were fed a diet consisted of 400 g/kg peanut seedling and 600 g/kg corn-based concentrate(dry matter basis).Result Interaction between CB and RPF was rarely observed on the variables measured,except that shear force was reduced(P<0.05)by adding CB or RPF alone or their combination;the increased intramuscular fat(IMF)content with adding RPF was more pronounced(P<0.05)with CB than without CB addition.The pH24h(P=0.009),a*values(P=0.007),total antioxidant capacity(P=0.050),glutathione peroxidase activities(P=0.006),concentrations of 18:3(P<0.001),20:5(P=0.003)and total polyunsaturated fatty acids(P=0.048)were increased,whereas the L*values(P<0.001),shear force(P=0.050)and malondialdehyde content(P=0.044)were decreased by adding CB.Furthermore,CB supplementation increased essential amino acid(P=0.027),flavor amino acid(P=0.010)and total amino acid contents(P=0.024)as well as upregulated the expression of lipoprotein lipase(P=0.034)and peroxisome proliferator-activated receptorγ(PPARγ)(P=0.012),and downregulated the expression of stearoyl-CoA desaturase(SCD)(P=0.034).The RPF supplementation increased dry matter intake(P=0.005),averaged daily gain(trend,P=0.058),hot carcass weight(P=0.046),backfat thickness(P=0.006),concentrations of 16:0(P<0.001)and c9-18:1(P=0.002),and decreased the shear force(P<0.001),isoleucine(P=0.049)and lysine content(P=0.003)of meat.In addition,the expressions of acetyl-CoA carboxylase(P=0.003),fatty acid synthase(P=0.038),SCD(P<0.001)and PPARγ(P=0.022)were upregulated due to RPF supplementation,resulting in higher(P<0.001)content of IMF.Conclusions CB and RPF could be fed to goats for improving the growth performance,carcass traits and meat quality,and promote fat deposition by upregulating the expression of lipogenic genes of Longissimus thoracis muscle.
