Search Results (77)

The objective of this experiment was to explore the effects of three-way hybridization on rumen microbes and metabolites in sheep using rumen metagenomics and metabolomics. Healthy Hu and CAH (Charolais × Australian White × Hu) male lambs of similar birth weight and age were selected for short-term fattening after intensive weaning to collect rumen fluid for sequencing. Rumen metagenomics diversity showed that Hu and CAH sheep were significantly segregated at the species, KEGG-enzyme, and CAZy-family levels. Moreover, the CAH significantly increased the ACE and Chao1 indices. Further, correlation analysis of the abundance of the top 80 revealed that the microorganisms were interrelated at the species, KEGG-enzyme, and CAZy-family levels. Overall, the microbiome significantly affected metabolites of the top five pathways, with the strongest correlation found with succinic acid. Meanwhile, species-level microbial markers significantly affected rumen differential metabolites. In addition, rumen microbial markers in Hu sheep were overall positively correlated with down-regulated metabolites and negatively correlated with up-regulated metabolites. In contrast, rumen microbial markers in CAH lambs were overall negatively correlated with down-regulated metabolites and positively correlated with up-regulated metabolites. These results suggest that three-way crossbreeding significantly affects rumen microbial community and metabolite composition, and that significant interactions exist between rumen microbes and metabolites. Full article

Ruminants exhibit stronger tolerance to gossypol, an anti-nutritional factor, compared to monogastric animals. We transplanted Hu sheep rumen microbiota into male mice to investigate the role of rumen microbiota in animal gossypol tolerance. Thirty specific-pathogen-free (SPF) male C57BL/6 mice were randomly divided into three groups: normal diet (CK group), gossypol diet (FG group), and rumen microbiota transplantation (FMT group, gossypol diet). The pathological changes in the liver and small intestine of the mice, the organ coefficient, and sperm parameters were analyzed. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels in the blood and lactate dihydrogen-X (LDH-X) levels in the testicular tissue were also measured. The results showed that body weight, feed intake, sperm concentration, sperm motility, and LDH-X levels in the FMT group increased (p < 0.05) compared with the FG group, while the enzyme activities of ALT, AST, and AST/ALT decreased (p < 0.05). In the FMT group, the injury to liver cells was alleviated, the structure of the small intestine was intact, and the villus height and the ratio of villus height to crypt depth (V/C) were higher than those in the FG group (p < 0.05). And there were no differences in various organ coefficients and sperm deformity rates among the three groups (p > 0.05), but compared with the FG group, mice in the FMT group showed tendencies closer to those in the CK group. Rumen microbiota transplantation relieved the reproductive toxicity and liver damage induced by gossypol in male mice and improved the tolerance of recipient animals to gossypol. Additionally, rumen microbes improved the intestinal structural integrity of recipients. Full article

This experiment investigated gastrointestinal microbes’ role in milk fatty acid differences between Murrah and Nili-Ravi buffaloes. After 30 days of a basal diet, rumen microbial diversity was similar, but Murrah buffaloes had greater partially unsaturated fatty acids like C18:2c9t11. Rumen bacteria like Acetobacter, Ruminococcus, and Prevotellaceae_YAB2003_group correlated positively with milk fatty acids C22:5n-6 and C18:3 in Murrah. Fecal microbial beta diversity differed, with UCG-005 and Prevolla positively correlated with C18:2c9t11 and C22:5n-6. The greater quantity of milk fatty acids C18:3, C18:2c9t11, and C22:5n-6 in Murrah milk was linked to rumen and fecal microbes. This suggests that gastrointestinal microbes like Acetobacter, Ruminococcus, and UCG_005 regulate milk fatty acid concentrations in buffaloes. Full article

Essential oils are natural feed additives that improve animal health and enhance their performance. This study investigated the effects of the rumen infusion of five essential oil blends (EOBs) on greenhouse gas (GHG) emissions, rumen fermentation parameters, and rumen metabolome and metabolic pathways in Black Angus cows. Using a 6 × 6 Latin Square experimental design, a 90-day study was conducted with six cattle. A daily dosage of 4 mL of EOBs was administered during each infusion. Volcano plot analyses between the control (CON) and each of the EOBs (EOB1, EOB2, EOB3, EOB4, and EOB5) revealed several differentially abundant (p ≤ 0.05; absolute fold change ≥1.5) metabolites. The EOB5 treatment exhibited the most significant impact, with 26 differentially abundant metabolites, including elevated valine and reduced gallic acid. Volatile fatty acids (VFAs), including valerate, isobutyrate, and isovalerate, were significantly increased (p < 0.05). GHG emissions were not significantly affected, but a numerical decrease was observed in the animals infused with the EOB5 treatment. Ammonia nitrogen concentrations remained within the suitable range for rumen microbes’ growth, indicating a normal internal environment for microbial crude protein synthesis. In conclusion, the study has demonstrated that the direct infusion of EOBs significantly improved the generation of VFAs and impacted the energy production, protein synthesis, and microbial activity of the animals. Full article

Although both L-glutamate (Glu) and L-glutamine (Gln) have long been considered nutritionally nonessential in ruminants, these two amino acids have enormous nutritional and physiological importance. Results of recent studies revealed that extracellular Gln is extensively degraded by ruminal microbes, but extracellular Glu undergoes little catabolism by these cells due to the near absence of its uptake. Ruminal bacteria hydrolyze Gln to Glu plus ammonia and, intracellularly, use both amino acids for protein synthesis. Microbial proteins and dietary Glu enter the small intestine in ruminants. Both Glu and Gln are the major metabolic fuels and building blocks of proteins, as well as substrates for the syntheses of glutathione and amino acids (alanine, ornithine, citrulline, arginine, proline, and aspartate) in the intestinal mucosa. In addition, Gln and aspartate are essential for purine and pyrimidine syntheses, whereas arginine and proline are necessary for the production of nitric oxide (a major vasodilator) and collagen (the most abundant protein in the body), respectively. Under normal feeding conditions, all diet- and rumen-derived Glu and Gln are extensively utilized by the small intestine and do not enter the portal circulation. Thus, de novo synthesis (e.g., from branched-chain amino acids and α-ketoglutarate) plays a crucial role in the homeostasis of Glu and Gln in the whole body but may be insufficient for maximal growth performance, production (e.g., lactation and pregnancy), and optimal health (particularly intestinal health) in ruminants. This applies to all types of feeding systems used around the world (e.g., rearing on a milk replacer before weaning, pasture-based production, and total mixed rations). Dietary supplementation with the appropriate doses of Glu or Gln [e.g., 0.5 or 1 g/kg body weight (BW)/day, respectively] can safely improve the digestive, endocrine, and reproduction functions of ruminants to enhance their productivity. Both Glu and Gln are truly functional amino acids in the nutrition of ruminants and hold great promise for improving their health and productivity. Full article

In ruminants, supplementing appropriate amounts of amino acids improves growth, feed utilization efficiency, and productivity. This study aimed to assess the effects of different Lys/Met ratios on the ruminal microbial community and the metabolic profiling in Tibetan sheep using 16S rDNA sequencing and non-target metabolomics. Ninety-two-month-old Tibetan rams (initial weight = 15.37 ± 0.92 kg) were divided into three groups and fed lysine/methionine (Lys/Met) of 1:1 (LP-L), 2:1 (LP-M), and 3:1 (LP-H) in low-protein diet, respectively. Results: The T-AOC, GSH-Px, and SOD were significantly higher in the LP-L group than in LP-H and LP-M groups (p < 0.05). Cellulase activity was significantly higher in the LP-L group than in the LP-H group (p < 0.05). In the fermentation parameters, acetic acid concentration was significantly higher in the LP-L group than in the LP-H group (p < 0.05). Microbial sequencing analysis showed that Ace and Chao1 indicators were significantly higher in LP-L than in LP-H and LP-M (p < 0.05). At the genus level, the abundance of Rikenellaceae RC9 gut group flora and Succiniclasticum were significantly higher in LP-L than in LP-M group (p < 0.05). Non-target metabolomics analyses revealed that the levels of phosphoric acid, pyrocatechol, hydrocinnamic acid, banzamide, l-gulono-1,4-lactone, cis-jasmone, Val-Asp-Arg, and tropinone content were higher in LP-L. However, l-citrulline and purine levels were lower in the LP-L group than in the LP-M and LP-H groups. Banzamide, cis-jasmone, and Val-Asp-Arg contents were positively correlated with the phenotypic contents, including T-AOC, SOD, and cellulase. Phosphoric acid content was positively correlated with cellulase and lipase activities. In conclusion, the Met/Lys ratio of 1:1 in low-protein diets showed superior antioxidant status and cellulase activity in the rumen by modulating the microbiota and metabolism of Tibetan sheep. Full article

This study investigates the impact of varying concentrate levels in the diets of Angus beef cattle on their performance, nutrient digestion, and metabolism during the growth (7 to 12 months) and fattening (13 to 30 months) phases. Fifteen Angus steers were continuously fed and divided into low-concentrate (L) and high-concentrate (H) groups based on the fattening period and dietary formulations. Throughout each 9-week trial phase, a comprehensive range of parameters was systematically measured, including dry matter intake (DMI), average daily gain (ADG), gain-to-feed ratio (G/F), blood parameters, rumen fluid composition, and microbial diversity. In the fattening phases, an increase in concentrate levels resulted in a significant rise in the cattle’s DMI. Although there was a minor increase in ADG compared to the growing phases, this increase was not statistically significant. The efficiency of nitrogen (N) utilization in the cattle decreased, accompanied by a significant reduction in the apparent digestibility of nutrients. Ruminal fermentation produced more energy substances; however, there was a notable decrease in the abundance of fiber-decomposing microbes (such as the NK4A214_group, Ruminococcus, Papillibacter, and Acetitomaculum) and a significant increase in the abundance of starch-degrading microbes (including Bacteroidota and Prevotellaceae). Additionally, there was a significant reduction in the abundance of immune system-related functional pathways. This suggests that high-concentrate fattening does not necessarily lead to improved growth performance and may negatively affect metabolic health and nutrient digestion. Full article

Oxidative stress (OS) in ruminants is closely associated with disease; thus, improving antioxidant capacity is an important strategy for maintaining host health. Bupleuri Radix (BR) could significantly improve host health and stress levels. However, the clear antioxidant mechanism of the function of BR remains unknown. In the current study, LC-MS metabolomics combined with 16S rRNA gene sequencing was employed to explore the effects of BR on rumen microbiota and metabolites in Shanbei Fine-Wool Sheep (SFWS), and Spearman correlation analyses of rumen microbiota, metabolites, and OS were performed to investigate the mechanism of antioxidant function of BR. Our results indicated that as SFWS grows, levels of OS and antioxidant capacity increase dramatically, but providing BR to SFWS enhances antioxidant capacity while decreasing OS. Rumen microbiota and OS are strongly correlated, with total antioxidant capacity (T-AOC) showing a significant negative correlation with Succiniclasticum and a positive correlation with Ruminococcus. Importantly, the Chao1 index was significantly negatively correlated with malondialdehyde (MDA) and positively correlated with superoxide dismutase (SOD) and T-AOC. Two biomarkers connected to the antioxidant effects of BR, 5,6-DHET and LPA (a-25:0/0:0), were screened according to the results of metabolomics and Spearman analysis of rumen contents, and a significant relationship between the concentration of rumen metabolites and OS was found. Five metabolic pathways, including glycerolipid, glutathione, nucleotide, D-amino acid, and inositol phosphate metabolism, may have a role in OS. The integrated results indicate that rumen microbiota and metabolites are strongly related to OS and that BR is responsible for reducing OS and improving antioxidant capacity in post-weaned SFWS. These findings provide new strategies to reduce OS occurring during SFWS growth. Full article

The rumen is divided into multiple rumen sacs based on anatomical structure, and each has its unique physiological environment. Tarim wapiti preserved roughage tolerance after domestication, and adaptation to the desertified environment led to the development of a unique rumen shape and intraruminal environment. In this work, six Tarim wapiti were chosen and tested for fermentation parameters, microbes, and histomorphology in four rumen areas (Dorsal sac, DS; Ventral sac, VS; Caudodorsal blind sac, CDBS; Caudoventral blind sac, CVBS). Tarim wapiti’s rumen blind sac had better developed rumen histomorphology, the ventral sac was richer in VFAs, and the dominant bacteria varied most notably in the phylum Firmicutes, which was enriched in the caudoventral blind sac. The ventral sac biomarkers focused on carbohydrate fermentation-associated bacteria, the dorsal sac focused on N recycling, and the caudoventral blind sac identified the only phylum-level bacterium, Firmicutes; we were surprised to find a probiotic bacterium, Bacillus clausii, identified as a biomarker in the ventral sac. This research provides a better understanding of rumen fermentation parameters, microorganisms, and histomorphology in the Tarim wapiti rumen within a unique ecological habitat, laying the groundwork for future regulation targeting the rumen microbiota and subsequent animal production improvement. Full article

The pigments consumed in grazing give the milk from dual-purpose cows raised in tropical conditions a yellowish color, affecting the quality and price of the milk. This study aimed to develop an economical method with supplementary pectin to antagonize the availability of carotenes by designing microparticles with shellac and palm oil as a viable alternative to protect pectin degradation against rumen microbes. Three preparations of microparticles based on citrus pectin were synthesized: unprotected (PnP), protected with palm oil (PwP), and protected with palm oil and shellac (PwPL) microparticles. Samples were roughly characterized by spectroscopy and electron microscopy techniques. The effect of PnP, PwP, and PwPL on blood metabolites and physicochemical characteristics of the milk of grazing lactating cows was evaluated through in vivo assays. The release of citrus pectin from microparticles was determined as uronic acids using solutions with distinct pH, whereas its degradation was studied using in situ tests. Results revealed that PnP, PwP, and PwPL are amorphous structures with sizes that range from 60 to 265 nm or 750 to 3570 µm and have surface charges that range from −11.5 to −50.2 mV. Samples exhibited characteristic peaks during FTIR analyses that corresponded to O-H, C=O, and COOCH₃ groups and bands within the UV-vis region that indicated the absorption of pectin. The EDS analysis revealed the presence of carbon, oxygen, or calcium in samples. The release of uronic acids was higher at pH 2–3 with PwPL. The in situ degradability of PnP, PwP, and PwPL was 99, 28.4, and 17.7%, respectively. Moreover, PwPL decreased the blood concentration of glucose, cholesterol, and lactate. In contrast, 100 g of pectin per animal daily during the feed process reduced yellow coloring. In conclusion, designing particles protected with lipids and polymers as shellac is an economical method that resists degradation at pH levels greater than five. Full article

The rumen contains a complex mixture of microbes, crucial for the animal’s ability to degrade feed. Some of the feed-derived carbon is released as methane, a potent greenhouse gas, into the atmosphere. There is growing interest in reducing the loss of feed-derived carbon, making it available to the animal and improving animal productivity. Artificial rumen systems (ARSs) have been widely used to evaluate novel feed additives in terms of their ability to reduce methane production in the rumen and their effect on the rumen microbiome function prior to conducting resource-intensive animal trials. While the value of ARSs is widely acknowledged, it remains unclear which of these in vitro systems simulate the natural system most accurately. Here, we evaluated three different ARSs and compared them to in vivo rumen metrics. The results showed that all systems were capable of maintaining stable pH, redox potential, and temperature over time. The batch-style ARS simulated the rumen over 48 h. The semi-continuous ARS mimicked the volatile fatty acid profile and microbiota of the in vivo rumen for up to 120 h. Similarly, all ARSs maintained the prokaryotic and eukaryotic rumen populations over the duration of the study, with the semi-continuous ARS maintaining the natural rumen microbiome more accurately and for up to 120 h. In sum, our results suggest that three of the widely used ARSs simulate the rumen ecosystem adequately for many short-term rumen microbiome studies, with the more advanced semi-continuous ARS being more accurate when rumen simulation is extended to over 48 h. Full article

Simple indigestion in cows leads to substantial economic losses in the dairy industry. Despite ongoing efforts, an effective treatment for this issue remains elusive. Previous studies have emphasized the vital role of rumen microbes in maintaining ruminant health. To deepen our comprehension of the intricate interplay between rumen microbiota and simple indigestion, we undertook a study involving the analysis of rumen fluid from eight cows with simple indigestion and ten healthy cows. Additionally, we collected data pertaining to milk production, rumination behavior, and rumen characteristics. The results showed that cows with simple indigestion displayed significantly lower milk yield, reduced rumination duration, and weakened rumen contraction when contrasted with the healthy cows (p < 0.05). However, no significant difference in microbiota α-diversity emerged (p > 0.05). Principal coordinate analysis (PCoA) illuminated substantial variations in rumen microbial structure among the two groups (p < 0.05). Further analysis spotlighted distinctive bacteria in the rumen of the cows with indigestion, including Allisonella, Synergistes, Megasphaera, Clostridium_XIVb, Campylobacter, and Acidaminococcus. In contrast, Coraliomargarita, Syntrophococcus, and Coprococcus are the dominant bacterial genera in the rumen of healthy dairy cows. Importantly, these key bacterial genera also dominated the overarching microbial interaction network. The observation suggests that changes in the abundance of these dominant bacterial genera potentially underlie the principal etiology of cows with simple indigestion. The present findings can provide insights into simple indigestion prevention and treatment in dairy cows. Full article

Sampling of ruminant saliva has gained interest as a non-invasive proxy for exploring the structure of the rumen microbiome. However, the subsequent data analysis assumes that bacteria originating from the oral cavity are merely passengers in the rumen and play no active role. In this study, it was hypothesised that metabolically active oral bacteria present in the salivary microbiome play a role in the ruminal degradation of plant material. In vitro cultivation-based enumeration confirmed that the ruminant oral cavity harbours a significant number of anaerobic and cellulolytic bacteria that are metabolically active under ruminal conditions. Bacterial 16S rRNA gene profiling of in vitro enrichments also confirmed that oral-derived bacteria were capable of colonising plant material. Preliminary analysis of the colonising bacteria indicated that bacteria belonging to the genus Streptococcus were of particular interest. In conclusion, the findings of the current study clearly indicate that bolus-associated bacteria have the potential to play a metabolically active role in terms of ruminal colonisation and the degradation of plant material. This evidence confirms the merit of the hypothesis that the metabolically active oral bacteria present in the salivary microbiome may play a role in the ruminal degradation of plant material. Full article

Yaks live in the harsh environment of the Qinghai–Tibet Plateau, and the cold climate causes lower growth efficiency. The aim of this experiment was to explore the effects of drinking warm water on the growth performance in yak calves and investigate the underlying physiological mechanisms. A total of 24 Datong yak calves were selected and randomly assigned into the cold water group (group C, water temperature around 0–10 °C without any heating; 58.03 ± 3.111 kg) and the warm water group (group W, water constantly heated at 2 °C; 59.62 ± 2.771 kg). After the 60-day experiment, body weight was measured, and rumen fluid and blood serum samples were collected for analysis. The results show that the body weight and average daily gain of yaks that drank warm water were higher compared to those that drank cold water (p < 0.05). The acetic, propionic, isobutyric, valeric, and isovaleric acid concentrations were higher in group W than in group C (p < 0.05). Additionally, warm water changed the ruminal microbes at different levels. At the phylum level, the relative abundance of Tenericutes, Kiritimatiellaeota, and Elusimicrobiota was higher in group C (p < 0.05). At the genus level, three genera were increased by warm water, including Ruminococcoides and Eubacteriales Family XIII. Incertae Sedis, and 12 genera were decreased, including Ruminococcus (p < 0.05). At the species level, unclassified Prevotellaceae and Ruminococcoides bili were increased by warm water compared to cold water (p < 0.05). According to the metabolomics results, metabolites, including valine, isoleucine, PC (15:0/22:2(13Z,16Z)), and LysoPC (18:0/0:0), were increased in the warm water group compared to the cold water group (p < 0.05), and were enriched in glycerophospholipid and amino acid metabolism pathways. This study analyzed the differences in ruminal microbes and metabolomes of yak calves provided with water at different temperatures and revealed the potential mechanism for better performance promoted by warm drinking water. Full article

Enteric fermentation is one of the largest contributors of methane release to the environment from the livestock sector. Plant bioactive compounds can modulate rumen fermentation for reduced methanogenesis and fatty acid biohydrogenation. The present study investigates the effects of tannin extract from Ficus glomerata (FG) leaves on the rumen fermentation, methanogenesis, feed digestibility and fatty acid biohydrogenation of a total mixed ration with the aim of developing a feed supplement for enhanced livestock production and product quality with lower methane emission. The tannin extract (70% aqueous acetone extract) of FG leaves in the total mixed ration (oat hay/concentrate mixture; 1:1) was studied at four graded dose regimens (0.0 (control), 0.25 mL (FG-0.25), 0.50 mL (FG-0.50) and 1.0 mL (FG-1.0) per 60 mL of buffered rumen fluid) in three replicates for each treatment in a radio-frequency-based automatic gas production system (ANKOM-RF) at 39 °C for 24 h following the standard in vitro gas production protocol. The total gas production (mL or mL/g incubated dry matter (DM)) was gradually reduced (p < 0.01) at dose levels of FG-0.50 and FG-1.0; however, it remained intermediary and comparable (p > 0.05) for FG-0.25 with the control and FG-0.50. Compared to the control, the methane concentration (%) in the head space gas, as well as the total methane production (mL or mL/g DM incubated, or mL/g DM digested), were found to be gradually reduced (p < 0.01) with increasing doses (0.25–1.0 mL) of FG extract. The reduced (p < 0.05) feed degradability at higher levels (0.50–1.0 mL) of FG extract supplementation and the comparative (p > 0.05) effects with the control at a lower level of supplementation (FG-0.25) are suggestive of the dose-responsive detrimental effects of tannins on fibrolytic microbes in the rumen. However, the ammonia concentration decreased (p < 0.05) in all of the incubations compared to the control. Among the volatile fatty acids, acetate remained comparable (p > 0.05) with enhanced (p < 0.05) propionate at a lower dose (FG-0.25); however, a dose-dependent reduction was evident at higher dose levels (FG-0.50 and FG-1.0). The production of stearic acid (C18:0), which is a product of the rumen biohydrogenation process, was reduced (p < 0.05), irrespective of the concentration of the FG extract. Compared to the control, the concentration of t-vaccenic acid (C18:1), which is a precursor of conjugated linoleic acid (CLA) in animal products, was increased in all the FG-extract-supplemented groups. It may be concluded that Ficus glomerata leaf tannins can modulate rumen fermentation for reduced methanogenesis and fatty acid biohydrogenation in a total mixed ration. As a higher level of inclusion negatively affects feed digestibility, a lower dose (0.25 mL FG extract per 60 mL fermentation fluid or 4.17 mL FG extract per L of fermentation fluid) is suggested to achieve desirable effects on methane abatement (30%) and an improvement in fatty acid profiles in animal products. Full article