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Gut Microbes 2019Methane is generated in the foregut of all ruminant animals by the microorganisms present. Dietary manipulation is regarded as the most effective and most convenient way... (Review)
Review
Methane is generated in the foregut of all ruminant animals by the microorganisms present. Dietary manipulation is regarded as the most effective and most convenient way to reduce methane emissions (and in turn energy loss in the animal) and increase nitrogen utilization efficiency. This review examines the impact of diet on bovine rumen function and outlines what is known about the rumen microbiome. Our understanding of this area has increased significantly in recent years due to the application of omics technologies to determine microbial composition and functionality patterns in the rumen. This information can be combined with data on nutrition, rumen physiology, nitrogen excretion and/or methane emission to provide comprehensive insights into the relationship between rumen microbial activity, nitrogen utilisation efficiency and methane emission, with an ultimate view to the development of new and improved intervention strategies.
Topics: Animals; Cattle; Diet; Dietary Proteins; Food Industry; Gastrointestinal Microbiome; Metagenomics; Methane; Nitrogen; Rumen
PubMed: 30207838
DOI: 10.1080/19490976.2018.1505176 -
Journal of Applied Microbiology Oct 2017Although fat content in usual ruminant diets is very low, fat supplements can be given to farm ruminants to modulate rumen activity or the fatty acid (FA) profile of... (Review)
Review
Although fat content in usual ruminant diets is very low, fat supplements can be given to farm ruminants to modulate rumen activity or the fatty acid (FA) profile of meat and milk. Unsaturated FAs, which are dominant in common fat sources for ruminants, have negative effects on microbial growth, especially protozoa and fibrolytic bacteria. In turn, the rumen microbiota detoxifies unsaturated FAs (UFAs) through a biohydrogenation (BH) process, transforming dietary UFAs with cis geometrical double-bonds into mainly trans UFAs and, finally, into saturated FAs. Culture studies have provided a large amount of data regarding bacterial species and strains that are affected by UFAs or involved in lipolysis or BH, with a major focus on the Butyrivibrio genus. More recent data using molecular approaches to rumen microbiota extend and challenge these data, but further research will be necessary to improve our understanding of fat and rumen microbiota interactions.
Topics: Animal Feed; Animals; Dietary Fats; Fatty Acids; Gastrointestinal Microbiome; Rumen; Ruminants
PubMed: 28557277
DOI: 10.1111/jam.13501 -
Microbial Cell Factories Apr 2022The gut microbiota play an important role in maintaining host metabolism, the immune system and health, while sex, genotype, diet and health have specific effects on the...
BACKGROUND
The gut microbiota play an important role in maintaining host metabolism, the immune system and health, while sex, genotype, diet and health have specific effects on the composition of the gut microbiota. Therefore, to explore the sex differences in the structure and function of rumen microbiota in Tibetan goats, herein we analyzed sex differences in rumen fermentation parameters, rumen microbiota and the expression of genes related to VFA transport in Tibetan goats.
RESULTS
The results showed that the contents of acetic acid and propionic acid in the rumen of TGM (Tibetan goat male) were significantly higher than those in TGFm (Tibetan goat female) (P < 0.05), and total VFAs was significantly higher in TGM than TGFm (P < 0.05). Expression of the VFA transport-related genes DRA, AE2, MCT-1, NHE1, and NHE2 in the rumen epithelium of TGFm was significantly higher than that in TGM. Analysis of the composition and structure of the rumen microbiota revealed significant sex differences. At the phylum level, Firmicutes and Bacteroidetes were the dominant phyla in Tibetan goats. In addition, Fibrobacteres and Spirochaetes had significantly greater relative abundances in TGFm than in TGM (P < 0.05). At the genus level, the relative abundance of Fibrobacter, Ruminococcus_1 and Pyramidobacter was significantly higher in TGFm than in TGM (P < 0.05). The functional prediction results showed that replication, recombination and repair, RNA processing and modification were mainly enriched in TGFm (P < 0.05).
CONCLUSIONS
Correlation analysis revealed significant associations of some rumen microbiota with the fermentation product VFAs and VFA transport-related genes. We concluded that yearling TGM and TGFm have distinct fermentation and metabolism abilities when adapting to the plateau environment, which provides a certain sex reference basis for Tibetan goat adaptation to the plateau environment.
Topics: Animals; Bacteria; Female; Fermentation; Goats; Male; Microbiota; Rumen; Sex Characteristics; Tibet
PubMed: 35392919
DOI: 10.1186/s12934-022-01783-8 -
Environmental Research Jul 2023Ruminant animals house a dense and diverse community of microorganisms in their rumen, an enlarged compartment in their stomach, which provides a supportive environment... (Review)
Review
Ruminant animals house a dense and diverse community of microorganisms in their rumen, an enlarged compartment in their stomach, which provides a supportive environment for the storage and microbial fermentation of ingested feeds dominated by plant materials. The rumen microbiota has acquired diverse and functionally overlapped enzymes for the degradation of plant cell wall polysaccharides. In rumen Bacteroidetes, enzymes involved in degradation are clustered into polysaccharide utilization loci to facilitate coordinated expression when target polysaccharides are available. Firmicutes use free enzymes and cellulosomes to degrade the polysaccharides. Fibrobacters either aggregate lignocellulose-degrading enzymes on their cell surface or release them into the extracellular medium in membrane vesicles, a mechanism that has proven extremely effective in the breakdown of recalcitrant cellulose. Based on current metagenomic analyses, rumen Bacteroidetes and Firmicutes are categorized as generalist microbes that can degrade a wide range of polysaccharides, while other members adapted toward specific polysaccharides. Particularly, there is ample evidence that Verrucomicrobia and Spirochaetes have evolved enzyme systems for the breakdown of complex polysaccharides such as xyloglucans, peptidoglycans, and pectin. It is concluded that diversity in degradation mechanisms is required to ensure that every component in feeds is efficiently degraded, which is key to harvesting maximum energy by host animals.
Topics: Animals; Metagenome; Rumen; Lignin; Bacteria; Polysaccharides; Bacteroidetes
PubMed: 37086884
DOI: 10.1016/j.envres.2023.115925 -
Animal : An International Journal of... Dec 2022Compared with maize silage- and concentrate-based diets, herbage-based diets were repeatedly shown to favourably influence the milk fatty acid (FA) profile. However, it...
Compared with maize silage- and concentrate-based diets, herbage-based diets were repeatedly shown to favourably influence the milk fatty acid (FA) profile. However, it is unclear how the herbage feeding mode (grazing vs indoor green-feeding) and conservation (fresh herbage vs hay vs silage) modify the milk FA profile. Therefore, the aim of the present experiment was to investigate the effect of different herbage utilisation methods (including herbage feeding mode and herbage conservation method) on the ruminal biohydrogenation of dietary FA and the consequences on the milk FA composition in cows of two breeds (Holstein and Montbéliarde). Concomitant effects of botanical composition and phenological stage of the herbage on milk FA profile were controlled for by harvesting barn-dried hay and silage simultaneously as first cut from the same ryegrass-dominated grassland in a semi-mountainous region. Seven weeks later, the first regrowth of the same plot was used as fresh herbage, either grazed or fed indoor (indoor green-feeding). Twenty-four Montbéliarde and 24 Holstein cows were randomly allocated to four groups of 12 cows balanced by breed, parity, and milk yield. In a free-stall barn, three groups were given ad libitum access to hay, silage, or fresh herbage, respectively. The fourth group was strip-grazing. All cows were supplemented with 3 kg DM/day of the same energy-rich concentrate. After 2 weeks of adaptation to the forage, samples of forage, concentrate, milk, blood, and rumen fluid were collected. Fatty acid composition of forages, rumen fluid, and milk was analysed by gas chromatography. Haymaking reduced total FA content of the herbage, in particular that of linoleic acid (LA) and α-linolenic acid (ALA). Still, rumen fluid lipids of hay-fed cows had the highest proportion of rumenic acid, LA, ALA, and total polyunsaturated fatty acids (PUFAs). Milk fat from hay-fed cows had the highest proportion of LA, and the apparent transfer rates from feed to milk of LA and ALA were higher in hay-fed cows than in silage-fed cows. The proportion of PUFAs was highest in milk fat from grazing and indoor green-fed Montbéliarde cows and lowest in silage-fed cows of both breeds. In conclusion, the herbage utilisation method affects the ruminal biohydrogenation of LA and ALA, whereby herbage drying particularly increases their transfer from herbage to milk.
Topics: Female; Animals; Cattle; Fatty Acids; Milk; Rumen; Lactation; Plant Breeding; Diet; Linoleic Acid; Silage; Fatty Acids, Unsaturated
PubMed: 36434984
DOI: 10.1016/j.animal.2022.100674 -
Journal of Dairy Science Mar 2023Early-life gut microbial colonization and development exert a profound impact on the health and metabolism of the host throughout the life span. The transmission of...
Early-life gut microbial colonization and development exert a profound impact on the health and metabolism of the host throughout the life span. The transmission of microbes from the mother to the offspring affects the succession and establishment of the early-life rumen microbiome in newborns, but the contributions of different maternal sites to the rumen microbial establishment remain unclear. In the present study, samples from different dam sites (namely, oral, rumen fluid, milk, and teat skin) and rumen fluid of yak calves were collected at 6 time points between d 7 and 180 postpartum to determine the contributions of the different maternal sites to the establishment of the bacterial and archaeal communities in the rumen during early life. Our analysis demonstrated that the dam's microbial communities clustered according to the sites, and the calves' rumen microbiota resembled that of the dam consistently regardless of fluctuations at d 7 and 14. The dam's rumen microbiota was the major source of the calves' rumen bacteria (7.9%) and archaea (49.7%) compared with the other sites, whereas the potential sources of the calf rumen microbiota from other sites varied according to the age. The contribution of dam's rumen bacteria increased with age from 0.36% at d 7 to 14.8% at d 180, whereas the contribution of the milk microbiota showed the opposite trend, with its contribution reduced from 2.7% at d 7 to 0.2% at d 180. Maternal oral archaea were the main sources of the calves' rumen archaea at d 14 (50.4%), but maternal rumen archaea became the main source gradually and reached 66.2% at d 180. These findings demonstrated the potential microbial transfer from the dam to the offspring that could influence the rumen microbiota colonization and establishment in yak calves raised under grazing regimens, providing the basis for future microbiota manipulation strategies during their early life.
Topics: Female; Animals; Cattle; Milk; Rumen; Microbiota; Bacteria; Archaea
PubMed: 36710176
DOI: 10.3168/jds.2022-22655 -
Scientific Reports Aug 2021Cardoon meal is a by-product of oil extraction from the seeds of Cynara cardunculus and can serve as a novel alternative feedstuff for ruminants. This study examined the...
Cardoon meal is a by-product of oil extraction from the seeds of Cynara cardunculus and can serve as a novel alternative feedstuff for ruminants. This study examined the rumen fermentation, biohydrogenation of fatty acids (FA) and microbial community in lambs fed a concentrate diet containing 15% dehydrated lucerne (CON, n = 8) or cardoon meal (CMD, n = 7) for 75 days pre-slaughter. Diets did not influence rumen fermentation characteristics and the abundance of bacteria, methanogens, fungi, or protozoa. Rumen digesta in CMD-fed lambs displayed a higher concentration of total saturated FA and lower total odd- and branched-chain FA and monounsaturated FA. Feeding CMD decreased total trans-18:1 isomer and the ratio of trans-10 to trans-11 C18:1, known as the "trans-10 shift". Amplicon sequencing indicated that the rumen bacterial community in CMD-fed lambs had lower diversity and a higher relative phyla abundance of Proteobacteria at the expense of Bacteroidetes and Fibrobacteres. At the genus level, CMD mediated specific shifts from Prevotella, Alloprevotella, Solobacterium and Fibrobacter to Ruminobacter, suggesting that these genera may play important roles in biohydrogenation. Overall, these results demonstrate that cardoon meal can be used as a feedstuff for ruminants without negatively affecting rumen fermentation and microbiota but its impact on biohydrogenation may influence the FA composition in meat or milk.
Topics: Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Cynara; Diet; Fatty Acids; Fermentation; Hydrogenation; Meals; Rumen; Sheep
PubMed: 34376766
DOI: 10.1038/s41598-021-95691-3 -
Animal : An International Journal of... Jun 2013Vaccination against rumen methanogens offers a practical approach to reduce methane emissions in livestock, particularly ruminants grazing on pasture. Although... (Review)
Review
Vaccination against rumen methanogens offers a practical approach to reduce methane emissions in livestock, particularly ruminants grazing on pasture. Although successful vaccination strategies have been reported for reducing the activity of the rumen-dwelling organism Streptococcus bovis in sheep and S. bovis and Lactobacillus spp. in cattle, earlier approaches using vaccines based on whole methanogen cells to reduce methane production in sheep have produced less promising results. An anti-methanogen vaccine will need to have broad specificity against methanogens commonly found in the rumen and induce antibody in saliva resulting in delivery of sufficiently high levels of antibodies to the rumen to reduce methanogen activity. Our approach has focussed on identifying surface and membrane-associated proteins that are conserved across a range of rumen methanogens. The identification of potential vaccine antigens has been assisted by recent advances in the knowledge of rumen methanogen genomes. Methanogen surface proteins have been shown to be immunogenic in ruminants and vaccination of sheep with these proteins induced specific antibody responses in saliva and rumen contents. Current studies are directed towards identifying key candidate antigens and investigating the level and types of salivary antibodies produced in sheep and cattle vaccinated with methanogen proteins, stability of antibodies in the rumen and their impact on rumen microbial populations. In addition, there is a need to identify adjuvants that stimulate high levels of salivary antibody and are suitable for formulating with protein antigens to produce a low-cost and effective vaccine.
Topics: Animals; Bacteria; Bacterial Vaccines; Cattle; Eukaryota; Euryarchaeota; Methane; Protozoan Vaccines; Rumen; Sheep
PubMed: 23739467
DOI: 10.1017/S1751731113000682 -
BMC Microbiology Sep 2021Rumen is a natural fermentation system and the microorganisms inside can effectively utilize plant bioresource and interact with host metabolism. Here, analysis of rumen...
BACKGROUND
Rumen is a natural fermentation system and the microorganisms inside can effectively utilize plant bioresource and interact with host metabolism. Here, analysis of rumen microbiome, together with animal performance and serum metabolism in a lamb model were performed to identify the potential use of mulberry leaf silage (MS) to replace alfalfa silage (AS) as a new functional feed resource and to mining the novel specific mulberry leaf associated rumen bacteria interact with host metabolism.
RESULTS
The lambs fed with MS diet showed improved antioxidant capacity and immune function compared to those fed AS diet. The MS diet significantly altered rumen microbiota α- and β-diversity and taxonomic composition. Microbial analysis revealed that Bifidobacterium, Lactobacillus and Schwartzia were enhanced, and Ruminococcaceae UCG-010 and Lachnospiraceae_XPB1014_group were down-regulated in the rumen of MS group. A strong association was also found between these rumen microbial taxa and host antioxidant and immunomodulatory capacity.
CONCLUSION
These findings indicated that mulberry leaf silage can be a high-quality feed source or bioactive pharmaceutical that is responsible for ruminant's health benefits. The modified rumen microbial community by mulberry leaf silage were associated with the enhanced antioxidant capacity and immunomodulatory of lambs.
Topics: Age Factors; Animal Feed; Animals; Fermentation; Gastrointestinal Microbiome; Immunologic Factors; Medicago sativa; Morus; Plant Leaves; Rumen; Sheep; Silage
PubMed: 34544373
DOI: 10.1186/s12866-021-02311-1 -
Journal of Dairy Science Aug 2018The rumen is a large bioreactor that enables dairy cattle to derive nutrition from otherwise indigestible plant polymers and compounds. Despite the direct contribution... (Review)
Review
The rumen is a large bioreactor that enables dairy cattle to derive nutrition from otherwise indigestible plant polymers and compounds. Despite the direct contribution of the rumen's microbial community toward the nutrition of the dairy cow, only a general knowledge has been gained of the metabolic processes within the rumen, and less still is known about most of the individual microbial species that colonize the organ. What has been discovered is that the rumen contains a diverse community of microbial species from all of the major domains of life, and that the contents of the rumen can vary greatly among individual animals. Preliminary evidence also indicates that rumen microbial profiles are heritable and sustainable within an individual, and that rumen microbial community structure can revert to its original profile within a short period following substantial perturbation. Much progress has been made in recent years to identify the diversity of microbial species in the rumen; however, the most popular methods used to identify microbial species often lack the predictive power necessary to associate particular microbial profiles with rumen metabolic activity. This represents the most significant barrier to the design of models that can estimate the direct effects of rumen microbial content on downstream dairy production traits. If such challenges can be overcome, it is possible that rumen microbial content could be assessed as a new phenotypic trait in cattle. In the future, we may estimate dairy production using a "genotype × environment × microbial" interaction model that accurately combines all factors affecting milk production.
Topics: Animal Feed; Animals; Cattle; Diet; Female; Gastrointestinal Microbiome; Lactation; Milk; Rumen
PubMed: 29102146
DOI: 10.3168/jds.2017-13328