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BMC Microbiology Nov 2020Ruminants burp massive amounts of methane into the atmosphere and significantly contribute to the deposition of greenhouse gases and the consequent global warming. It is...
BACKGROUND
Ruminants burp massive amounts of methane into the atmosphere and significantly contribute to the deposition of greenhouse gases and the consequent global warming. It is therefore urgent to devise strategies to mitigate ruminant's methane emissions to alleviate climate change. Ruminal methanogenesis is accomplished by a series of methanogen archaea in the phylum Euryarchaeota, which piggyback into carbohydrate fermentation by utilizing residual hydrogen to produce methane. Abundance of methanogens, therefore, is expected to affect methane production. Furthermore, availability of hydrogen produced by cellulolytic bacteria acting upstream of methanogens is a rate-limiting factor for methane production. The aim of our study was to identify microbes associated with the production of methane which would constitute the basis for the design of mitigation strategies.
RESULTS
Moderate differences in the abundance of methanogens were observed between groups. In addition, we present three lines of evidence suggesting an apparent higher abundance of a consortium of Prevotella species in animals with lower methane emissions. First, taxonomic classification revealed increased abundance of at least 29 species of Prevotella. Second, metagenome assembly identified increased abundance of Prevotella ruminicola and another species of Prevotella. Third, metabolic profiling of predicted proteins uncovered 25 enzymes with homology to Prevotella proteins more abundant in the low methane emissions group.
CONCLUSIONS
We propose that higher abundance of ruminal Prevotella increases the production of propionic acid and, in doing so, reduces the amount of hydrogen available for methanogenesis. However, further experimentation is required to ascertain the role of Prevotella on methane production and its potential to act as a methane production mitigator.
Topics: Animals; Bacteria; Buffaloes; Colombia; Euryarchaeota; Fermentation; Gastrointestinal Microbiome; Hydrogen; Methane; Prevotella; Propionates; Rumen
PubMed: 33246412
DOI: 10.1186/s12866-020-02037-6 -
BMC Genomics May 2024Bacteria of the genera Xylanibacter and Segatella are among the most dominant groups in the rumen microbiota. They are characterized by the ability to utilize different...
Bacteria of the genera Xylanibacter and Segatella are among the most dominant groups in the rumen microbiota. They are characterized by the ability to utilize different hemicelluloses and pectin of plant cell-wall as well as plant energy storage polysaccharides. The degradation is possible with the use of cell envelope bound multiprotein apparatuses coded in polysaccharide utilization loci (PULs), which have been shown to be substrate specific. The knowledge of PUL presence in rumen Xylanibacter and Segatella based on bioinformatic analyses is already established and transcriptomic and genetic approaches confirmed predicted PULs for a limited number of substrates. In this study, we transcriptomically identified additional different PULs in Xylanibacter ruminicola KHP1 and Segatella bryantii TF1-3. We also identified substrate preferences and found that specific growth rate and extent of growth impacted the choice of substrates preferentially used for degradation. These preferred substrates were used by both strains simultaneously as judged by their PUL upregulation. Lastly, β-glucan and xyloglucan were used by these strains in the absence of bioinformatically and transcriptomically identifiable PUL systems.
Topics: Animals; Xylans; Polysaccharides; Gene Expression Profiling; Rumen; Glucans; beta-Glucans; Substrate Specificity; Bacteroidetes; Transcriptome
PubMed: 38769483
DOI: 10.1186/s12864-024-10421-z -
Journal of Animal Physiology and Animal... May 2024Biotin (BI) and cobalamin (CA) are essential for rumen propionate production and hepatic gluconeogenesis. The study evaluated the influence of BI or/and coated CA (CCA)...
Biotin (BI) and cobalamin (CA) are essential for rumen propionate production and hepatic gluconeogenesis. The study evaluated the influence of BI or/and coated CA (CCA) on milk performance and nutrient digestion in cows. Sixty Holstein dairy cows were assigned in a 2 × 2 factorial arrangement and randomised block design to four groups. The factors were BI at 0 or 20 mg/day and CCA at 0 or 9 mg CA/day. Dry matter intake increased with BI addition but was unchanged with CCA supply. Addition of BI or CCA increased fat-corrected milk, milk fat and milk protein yields and feed efficiency. Moreover, lactose yield was increased by CCA addition. Dry matter, organic matter, crude protein and acid detergent fibre total-tract digestibility increased for BI or CCA supply. When CCA was supplemented, positive response of neutral detergent fibre digestibility to BI addition was enhanced. Supplementing BI did not affect pH, propionate content and acetate to propionate ratio, but increased total volatile fatty acids (VFA) and acetate contents. Supplementing CCA decreased pH and acetate to propionate ratio, but increased total VFA, acetate and propionate contents. Rumen protease and carboxymethyl-cellulase activities and fungi, bacteria and Butyrivibrio fibrisolvens numbers increased for BI or CCA supply. In addition, protozoa increased for BI addition, and protease activity and Prevotella ruminicola increased for CCA supply. When CCA was supplemented, positive responses of R. albus and Ruminobacter amylophilus numbers to BI addition were enhanced. Blood glucose concentration was unchanged with BI supply, but increased for CCA supply. Blood nonesterified fatty acids and β-hydroxybutyrate contents reduced with BI or CCA supply. Supplementation with BI or CCA increased blood BI or CA content. The results showed that supplementing BI or/and CCA improved lactation performance and nutrient digestion, and CCA supply did not enhance the lactation performance response to BI supply.
Topics: Animals; Cattle; Female; Animal Feed; Animal Nutritional Physiological Phenomena; Biotin; Diet; Dietary Supplements; Digestion; Fermentation; Lactation; Milk; Rumen; Vitamin B 12
PubMed: 38197588
DOI: 10.1111/jpn.13920 -
Frontiers in Microbiology 2022Mastitis, mainly caused by bacterial intramammary infections, is the main problem in the breeding of dairy animals. The inflammations of the mammary gland is separated...
Mastitis, mainly caused by bacterial intramammary infections, is the main problem in the breeding of dairy animals. The inflammations of the mammary gland is separated by types of mastitis, being subclinical, clinical, and the most severe, gangrenous mastitis. Here, we used 16S rRNA amplicon sequencing to characterize the bacterial microbiota of goat milk in the different types of goat mastitis caused by bacteria. We used 72 goat milk samples from a region of the state of Minas Gerais in Brazil, of which 12 were from clinically healthy animals, 42 from animals diagnosed with subclinical mastitis, 16 from animals with clinical mastitis, and 2 from animals with gangrenous mastitis. The group related to gangrenous mastitis was the most divergent in terms of alpha and beta diversity. The most abundant genus among samples of the groups was spp., and we found a high abundance of sp. in the milk of animals diagnosed with clinical mastitis. The most statistically relevant microorganisms among the groups were sp., , sp., and sp. We highlight a new association of bacterial agents in gangrenous mastitis among sp./ sp. and sp. and provide the second report of the genus sp., in milk samples. Only the taxa sp., sp., , and sp., were present in all groups. The superpathway of L-tryptophan biosynthesis metabolites and the sucrose degradation III (sucrose invertase) pathway were the most prominent ones among the groups. In this study, we demonstrate how a rich microbiota of goat milk from healthy animals can be altered during the aggravation of different types of mastitis, in addition to demonstrating new bacterial genera in milk not previously detected in other studies as well as new associations between agents.
PubMed: 36090116
DOI: 10.3389/fmicb.2022.918706 -
Bioresource Technology Jul 2022Herein, the xylanase and feruloyl esterase domains of the xylanase/feruloyl esterase bifunctional enzyme (Xyn-Fae) from Prevotella ruminicola 23 were identified using N-...
Herein, the xylanase and feruloyl esterase domains of the xylanase/feruloyl esterase bifunctional enzyme (Xyn-Fae) from Prevotella ruminicola 23 were identified using N- and C-terminal truncation mutagenesis. In addition, a novel and more efficient xylanase/feruloyl esterase bifunctional enzyme XynII-Fae was constructed, and its synergistic action with a commercial cellulase for lignocellulose hydrolysis was studied. When 40% cellulase was replaced by XynII-Fae, the production of reducing sugars increased by 65% than that with the cellulase alone, and the conversions of xylan and glucan were increased by 125.1% and 54.3%, respectively. When 80% cellulase was substituted by XynII-Fae, up to 43.5 μg/mL ferulic acid and 418.7 μg/mL acetic acid were obtained. The XynII-Fae could also accelerate the hydrolysis of wheat straw and sugarcane bagasse with commercial cellulase. These results indicated that the synergistic action of XynII-Fae with cellulase could dramatically improve the hydrolysis efficiency of lignocellulose, showing the great potential for industrial applications.
Topics: Carboxylic Ester Hydrolases; Cellulase; Cellulose; Hydrolysis; Lignin; Saccharum
PubMed: 35489578
DOI: 10.1016/j.biortech.2022.127244 -
Tropical Animal Health and Production Feb 2021The effect of the association of non-protein nitrogen, yeast, and bacterial probiotics on the ruminal microbiome of beef cattle intensively finished on pasture was...
The effect of the association of non-protein nitrogen, yeast, and bacterial probiotics on the ruminal microbiome of beef cattle intensively finished on pasture was evaluated. The experiment was carried out in a completely randomized design with five treatments and four replications. The treatments consisted of a group of animals kept on pasture that received low consumption supplementation (LS) and four groups that received for 98 days, 17.5 g concentrate kg body weight. The supplements were composed of the association of additives: urea (U), slow-release non-protein nitrogen (U+SRN), yeast (Saccharomyces cerevisiae; U+SRN+Y), and bacterial probiotics (live strains of bacteria; U+SRN+Y+BP). All supplements also contained salinomycin and virginiamycin. After slaughtering the animals, samples of ruminal content were collected to quantify groups of fibrolytic bacteria (Ruminococcus albus and Fibrobacter succinogenes), non-fibrolytic (Prevotella ruminicola, Selenomonas ruminantium, and Streptococcus bovis), Archaea, and ciliate protozoa, using the qPCR technique. The abundance of F. succinogenes was the same for the LS animals and those that received the supplement U+SRN+Y (1.42×10 copies mL) but higher than the other treatments. Supplementation reduced by 90% the abundance of S. bovis compared to the LS. The inclusion of yeast increased the abundance of fibrolytic bacteria by 2.2-fold. For animals that received the supplement U+SRN+Y+BP and the LS, there was no difference for non-fibrolytic bacteria (3.07×10 copies mL). The use of yeasts and sources of non-protein nitrogen in high-concentrate diets for beef cattle stimulates the growth of fibrolytic bacteria, which can contribute to the reduction of digestive disorders and metabolic diseases in animals that receive diets with high concentrate in pasture intensive termination systems.
Topics: Animal Feed; Animals; Bacteria; Cattle; Diet; Fermentation; Fibrobacter; Ionophores; Probiotics; Rumen; Ruminococcus; Saccharomyces cerevisiae
PubMed: 33598856
DOI: 10.1007/s11250-021-02617-2 -
Animal : An International Journal of... Jun 2020The combined addition of branched-chain volatile fatty acids (BCVFAs) and folic acid (FA) could improve growth performance and nutrient utilization by stimulating...
The combined addition of branched-chain volatile fatty acids (BCVFAs) and folic acid (FA) could improve growth performance and nutrient utilization by stimulating ruminal microbial growth and enzyme activity. This study was conducted to evaluate the effects of BCVFA and FA addition on growth performance, ruminal fermentation, nutrient digestibility, microbial enzyme activity, microflora and excretion of urinary purine derivatives (PDs) in calves. Thirty-six Chinese Holstein weaned calves (60 ± 5.4 days of age and 107 ± 4.7 kg of BW) were assigned to one of four groups in a randomized block design. Treatments were control (without additives), FA (with 10 mg FA/kg dietary DM), BCVFA (with 5 g BCVFA/kg dietary DM) and the combined addition of FA and BCVFA (10 mg/kg DM of FA and 5 g/kg DM of BCVFA). Supplements were hand-mixed into the top one-third of total mixed ration. Dietary concentrate to maize silage ratio was 50 : 50 on a DM basis. Dietary BCVFA or FA addition did not affect dry matter intake but increased average daily gain (ADG) and feed conversion efficiency. Ruminal pH and ammonia N were lower, and total volatile fatty acids (VFAs) concentration was higher for BCVFA or FA addition than for control. Dietary BCVFA or FA addition did not affect acetate proportion but decreased propionate proportion and increased acetate to propionate ratio. Total tract digestibility of DM, organic matter, CP and NDF was higher for BCVFA or FA addition than for control. Dietary BCVFA or FA addition increased activity of carboxymethyl cellulase and cellobiase, population of total bacteria, fungi, Ruminococcus albus, R. flavefaciens, Fibrobacter succinogenes and Prevotella ruminicola as well as total PD excretion. Ruminal xylanase, pectinase and protease activity and Butyrivibrio fibrisolvens population were increased by BCVFA addition, whereas population of protozoa and methanogens was increased by FA addition. The BCVFA × FA interaction was significant for acetate to propionate ratio, cellobiase activity and total PD excretion, and these variables increased more with FA addition in diet without BCVFA than in diet with BCVFA. The data indicated that supplementation with BCVFA or FA increased ADG, nutrient digestibility, ruminal total VFA concentration and microbial protein synthesis by stimulating ruminal microbial growth and enzyme activity in calves.
Topics: Ammonia; Animals; Cattle; Cellulase; Diet; Dietary Supplements; Digestion; Fatty Acids, Volatile; Female; Fermentation; Folic Acid; Gastrointestinal Microbiome; Nutrients; Rumen; Silage; Weaning
PubMed: 31840620
DOI: 10.1017/S1751731119002969 -
Asian-Australasian Journal of Animal... Jun 2019Fasting may lead to changes in the microbiota and activity in the rumen. In the present study, the effects of fasting on rumen microbiota and the impact of fasting on in...
OBJECTIVE
Fasting may lead to changes in the microbiota and activity in the rumen. In the present study, the effects of fasting on rumen microbiota and the impact of fasting on in vitro rumen fermentation were evaluated using molecular culture-independent methods.
METHODS
Three ruminally cannulated Holstein steers were fed rice straw and concentrates. The ruminal fluids were obtained from the same steers 2 h after the morning feeding (control) and 24 h after fasting (fasting). The ruminal fluid was filtrated through four layers of muslin, collected for a culture-independent microbial analysis, and used to determine the in vitro rumen fermentation characteristics. Total DNA was extracted from both control and fasting ruminal fluids. The rumen microbiota was assessed using denaturing gradient gel electrophoresis (DGGE) and quantitative polymerase chain reaction. Microbial activity was evaluated in control and fasting steers at various intervals using in vitro batch culture with rice straw and concentrate at a ratio of 60:40.
RESULTS
Fasting for 24 h slightly affected the microbiota structure in the rumen as determined by DGGE. Additionally, several microorganisms, including Anaerovibrio lipolytica, Eubacterium ruminantium, Prevotella albensis, Prevotella ruminicola, and Ruminobacter amylophilus, decreased in number after fasting. In addition, using the ruminal fluid as the inoculum after 24 h of fasting, the fermentation characteristics differed from those obtained using non-fasted ruminal fluid. Compared with the control, the fasting showed higher total gas production, ammonia, and microbial protein production (p<0.05). No significant differences, however, was observed in pH and dry matter digestibility.
CONCLUSION
When in vitro techniques are used to evaluate feed, the use of the ruminal fluid from fasted animals should be used with caution.
PubMed: 30208688
DOI: 10.5713/ajas.18.0489 -
Animal : An International Journal of... Dec 2020Guanidinoacetic acid (GAA) can improve the growth performance of bulls. This study investigated the influences of GAA addition on growth, nutrient digestion, ruminal...
Guanidinoacetic acid (GAA) can improve the growth performance of bulls. This study investigated the influences of GAA addition on growth, nutrient digestion, ruminal fermentation and serum metabolites in bulls. Forty-eight Angus bulls were randomly allocated to experimental treatments, that is, control, low-GAA (LGAA), medium-GAA (MGAA) and high-GAA (HGAA), with GAA supplementation at 0, 0.3, 0.6 and 0.9 g/kg DM, respectively. Bulls were fed a basal diet containing 500 g/kg DM concentrate and 500 g/kg DM roughage. The experimental period was 104 days, with 14 days for adaptation and 90 days for data collection. Bulls in the MGAA and HGAA groups had higher DM intake and average daily gain than bulls in the LGAA and control groups. The feed conversion ratio was lowest in MGAA and highest in the control. Bulls receiving 0.9 g/kg DM GAA addition had higher digestibility of DM, organic matter, NDF and ADF than bulls in other groups. The digestibility of CP was higher for HGAA than for LGAA and control. The ruminal pH was lower for MGAA, and the total volatile fatty acid concentration was greater for MGAA and HGAA than for the control. The acetate proportion and acetate-to-propionate ratio were lower for MGAA than for LGAA and control. The propionate proportion was higher for MGAA than for control. Bulls receiving GAA addition showed decreased ruminal ammonia N. Bulls in MGAA and HGAA had higher cellobiase, pectinase and protease activities and Butyrivibrio fibrisolvens, Prevotella ruminicola and Ruminobacter amylophilus populations than bulls in LGAA and control. However, the total protozoan population was lower for MGAA and HGAA than for LGAA and control. The total bacterial and Ruminococcus flavefaciens populations increased with GAA addition. The blood level of creatine was higher for HGAA, and the activity of l-arginine glycine amidine transferase was lower for MGAA and HGAA, than for control. The blood activity of guanidine acetate N-methyltransferase and the level of folate decreased in the GAA addition groups. The results indicated that dietary addition of 0.6 or 0.9 g/kg DM GAA improved growth performance, nutrient digestion and ruminal fermentation in bulls.
Topics: Animal Feed; Animals; Cattle; Diet; Dietary Supplements; Digestion; Fermentation; Glycine; Male; Nutrients; Rumen; Ruminococcus; Succinivibrionaceae
PubMed: 32580813
DOI: 10.1017/S1751731120001603 -
Journal of Dairy Science Aug 2022Residual feed intake (RFI) measures feed efficiency independent of milk production level, and is typically calculated using data past peak lactation. In the current...
Residual feed intake in peripartal dairy cows is associated with differences in milk fat yield, ruminal bacteria, biopolymer hydrolyzing enzymes, and circulating biomarkers of immunometabolism.
Residual feed intake (RFI) measures feed efficiency independent of milk production level, and is typically calculated using data past peak lactation. In the current study, we retrospectively classified multiparous Holstein cows (n = 320) from 5 of our published studies into most feed-efficient (M-eff) or least feed-efficient (L-eff) groups using performance data collected during the peripartal period. Objectives were to assess differences in profiles of plasma biomarkers of immunometabolism, relative abundance of key ruminal bacteria, and activities of digestive enzymes in ruminal digesta between M-eff and L-eff cows. Individual data from cows with ad libitum access to a total mixed ration from d -28 to d +28 relative to calving were used. A linear regression model including dry matter intake (DMI), energy-corrected milk (ECM), changes in body weight (BW), and metabolic BW was used to classify cows based on RFI divergence into L-eff (n = 158) and M-eff (n = 162). Plasma collected from the coccygeal vessel at various times around parturition (L-eff = 60 cows; M-eff = 47 cows) was used for analyses of 30 biomarkers of immunometabolism. Ruminal digesta collected via esophageal tube (L-eff = 19 cows; M-eff = 29 cows) was used for DNA extraction and assessment of relative abundance (%) of 17 major bacteria using real-time PCR, as well as activity of cellulase, amylase, xylanase, and protease. The UNIVARIATE procedure of SAS 9.4 (SAS Institute Inc.) was used for analyses of RFI coefficients. The MIXED procedure of SAS was used for repeated measures analysis of performance, milk yield and composition, plasma immunometabolic biomarkers, ruminal bacteria, and enzyme activities. The M-eff cows consumed less DMI during the peripartal period compared with L-eff cows. In the larger cohort of cows, despite greater overall BW for M-eff cows especially in the prepartum (788 vs. 764 kg), no difference in body condition score was detected due to RFI or the interaction of RFI × time. Milk fat content (4.14 vs. 3.75 ± 0.06%) and milk fat yield (1.75 vs. 1.62 ± 0.04 kg) were greater in M-eff cows. Although cumulative ECM yield did not differ due to RFI (1,138 vs. 1,091 ± 21 kg), an RFI × time interaction due to greater ECM yield was found in M-eff cows. Among plasma biomarkers studied, concentrations of nonesterified fatty acids, β-hydroxybutyrate, bilirubin, ceruloplasmin, haptoglobin, myeloperoxidase, and reactive oxygen metabolites were overall greater, and glucose, paraoxonase, and IL-6 were lower in M-eff compared with L-eff cows. Among bacteria studied, abundance of Ruminobacter amylophilus and Prevotella ruminicola were more than 2-fold greater in M-eff cows. Despite lower ruminal activity of amylase in M-eff cows in the prepartum, regardless of RFI, we observed a marked linear increase after calving in amylase, cellulase, and xylanase activities. Protease activity did not differ due to RFI, time, or RFI × time. Despite greater concentrations of biomarkers reflective of negative energy balance and inflammation, higher feed efficiency measured as RFI in peripartal dairy cows might be associated with shifts in ruminal bacteria and amylase enzyme activity. Further studies could help address such factors, including the roles of the liver and the mammary gland.
Topics: Amylases; Animal Feed; Animals; Bacteria; Biomarkers; Biopolymers; Body Weight; Cattle; Cellulases; Diet; Eating; Female; Humans; Lactation; Milk; Peptide Hydrolases; Retrospective Studies
PubMed: 35840400
DOI: 10.3168/jds.2021-21274