Search Results (11)

This study investigated the effects of isoacid supplementation on in vitro rumen fermentation characteristics, nutrient degradability, and bacterial community diversity in yaks using corn silage–highland barley straw-based substrates. An in vitro fermentation experiment was conducted with a substrate consisting of 80% whole-plant corn silage and 20% highland barley straw. Treatments included a control (without isoacids) and four isoacid supplemental levels (0.1%, 0.2%, 0.3%, and 0.4% of substrate dry matter, DM), each with six replicates. A 72 h in vitro gas production experiment was performed to measure cumulative gas production, fermentation parameters, nutrient degradability, and bacterial community diversity. Cumulative gas production increased by 12.96% with 0.2% isoacid supplementation compared to the control (p < 0.05). The contents of microbial protein (MCP), acetate, propionate, and total volatile fatty acids (TVFA) exhibited quadratic responses to the increasing isoacid dosage (p < 0.05). Specifically, MCP content reached a maximum of 0.76 mg/mL with 0.2% isoacids, representing a 31.03% increase compared to the control (p < 0.05). TVFA content was highest (146.85 mmoL/L) at 0.2% isoacid supplementation, with a 16.40% increase compared to the control (p < 0.05). Acetate content increased by 17.99% (p < 0.05), while propionate tended to increase with 0.2% isoacid supplementation (p = 0.08). Supplementation with 0.2% and 0.4% isoacids did not alter the bacterial composition and diversity (p > 0.05). However, at the genus level, g_Ruminococcus, g__Elusimicrobium, g_norank_f_Atopobiaceae, g_norank_o_Coriobacteriales, and g_Romboutsia were identified as differential biomarkers showing significant responses to isoacid supplementation (p < 0.05). Mantel-test analysis revealed positive correlation between g_Ruminococcus abundance and NH₃-N content (r < 0.4, p < 0.05); g_Romboutsia abundance and acetate content (r < 0.40, p < 0.05); g_Defluviitaleaceae_UCG-011 abundance and both NH₃-N content and the pH of rumen fluid (r < 0.40, p < 0.05); g_norank_o_Coriobacteriales abundance and rumen pH (r < 0.40, p < 0.01). Supplementation with 0.2% isoacids to corn silage–barley straw substrates improved in vitro rumen fermentation characteristics in yaks, which was associated with altered abundances of key bacterial genera including g_Ruminococcus, g__Elusimicrobium, g_norank_f_Atopobiaceae, g_norank_o_Coriobacteriales. Full article

Edible trees, such as Bordão-de-velho (BVP; Samanea tubulosa), are being studied for their nutritional potential and the presence of bioactive compounds that influence ruminal fermentation. This study aimed to evaluate, using an in vitro assay, the effects of increasing the inclusion of BVP pods in dairy cow diets formulated with different energy levels. The experiment was conducted with eight treatments obtained from a 4 × 2 factorial arrangement, containing four levels of pod inclusion (0, 100, 200, and 300 g/kg dry matter) and two dietary energy levels (high and low). Increasing BVP levels resulted in a linear reduction in gas production from digestible organic matter in low-energy diets, without altering dry matter and organic matter digestibility or methane production. There was an increase in pH and in the acetate/propionate ratio, along with a reduction in the concentrations of short-chain fatty acids and isoacids. In conclusion, Samanea tubulosa pods improve fermentation efficiency and reduce gas production, making them a promising forage source for low-productivity animal diets. Full article

The aim of this study comprises the effect of fermented grape pomace (FGP) in experimental total mixed rations (TMR) at different rates (0, 7.5%, 15%, and 22.5%) on the in vitro cumulative gas production (6th, 12th, 18th and 24th hours), methane production, ruminal fermentation values, pH and ammonia-nitrogen and straight and branched short-chain fatty acids (SCFA and BCFA) concentration. The method of in vitro total gas production was carried out in glass syringes. Ruminal in vitro methane production linearly decreased by adding up to 22.5% FGP in experimental TMR (p < 0.05). The molarities of acetic, propionic, butyric, and valeric acids in the in vitro fermentation fluid linearly decreased with the addition of FGP to TMR (p < 0.05). FGP up to 22.5% in experimental TMRs decreased the molarity of iso-valeric acid and iso-butyric acid from BSCFAs (p < 0.05). As a result, it was concluded that the use of FGP, containing a low level of total condensed tannins (TCTs), up to 22.5% in the experimental TMR based on dry matter (DM) did not adversely affect the in vitro ruminal fermentation value and had an anti-methanogenic effect. In addition, some SCFA (acetic, propionic, butyric, and valeric acids) molarities and iso-acid BSCFA (iso-butyric and iso-valeric acid) did not change up to 15% rate of FGP in the ration. Still, these values decreased by using a 22% rate of FGP. The dose-dependent effect of FGP on ruminal iso-acids has been associated with the ability of TCTs to inhibit ruminal protein degradation partially. Full article

Gut dysbiosis presents in many digestive diseases. The aim of this study is to investigate the composition of the gut microbiota and its metabolic activity in patients with diarrhea-predominant irritable bowel syndrome combined with functional dyspepsia (I + D). This study included 60 patients with I + D and 20 healthy controls. Gut microbiota composition was studied using 16S rRNA gene sequencing. The short-chain fatty acids (SCFAs) spectrum was determined via gas–liquid chromatography. Patients with I + D had an increase in the abundance of Holdemanella, Erysipelotrichaceae, Erysipelotrichales, Prevotellaceae, Agathobacter, Slackia, Lactococcus, Pseudomonadaceae, Stenotrophomonas, Xanthomonadaceae, Rhizobiaceae, Erysipelatoclostridiaceae, Lachnospiraceae, and other taxa in addition to a decrease in the abundance of Frisingicoccus, Ralstonia, Burkholderiaceae, Hungatella, Eisenbergiella, Parabacteroides, Peptostreptococcaceae, Merdibacter, Bilophila, Rikenellaceae, Tannerellaceae, Bacteroidaceae, and Flavonifractor in comparison to controls. Patients with I + D showed significantly higher total SCFA content in feces; increased absolute content of acetic acid, propionic acid, butyric acid, and isoacids; and a significant negative shift in the anaerobic index. The relative levels of the main SCFAs and isoacids in the patient group did not differ significantly from those in the control group. The fecal acetate and isoacid levels correlated with the severity of diarrhea. The fecal butyrate level correlated with the severity of flatulence. Full article

We investigated the effects of betaine and zinc on the in vitro fermentation of pigs under heat stress (HS). Twenty-four Iberian pigs (43.4 ± 1.2 kg) under HS (30 °C) were assigned to treatments for 4 weeks: control (unsupplemented), betaine (5 g/kg), and zinc (0.120 g/kg) supplemented diet. Rectal content was used as the inoculum in 24-hincubations with pure substrates (starch, pectin, inulin, cellulose). Total gas, short-chain fatty acid (SCFA), and methane production and ammonia concentration were measured. The abundance of total bacteria and several bacterial groups was assessed. Betaine increased the acetate production with pectin and inulin, butyrate production with starch and inulin, and ammonia concentration, and decreased propionate production with pectin and inulin. The abundance of Bifidobacterium and two groups of Clostridium decreased with betaine supplementation. Zinc decreased the production of SCFA and gas with starch and inulin, associated with diminished bacterial activity. Propionate production decreased with starch, pectin, and inulin while butyrate production increased with inulin, and isoacid production increased with cellulose and inulin in pigs supplemented with zinc. The ammonia concentration increased for all substrates. The Clostridium cluster XIV abundance decreased in pigs fed zinc supplemented diets. The results reported were dependent on the substrate fermented, but the augmented butyrate production with both betaine and zinc could be of benefit for the host. Full article

The hypothesis tested was that tropical steers supplemented with the Desmanthus legume and lucerne, a widely characterized temperate legume of high nutritive value, would elicit similar responses in plasma metabolite profiles, productive performance, nitrogen retention, and volatile fatty acids (VFA). The tannin-binding compound, polyethylene glycol-4000 (PEG), was added to the diets (160 g/kg Desmanthus dry matter) with the objective of further exploring nitrogen (N) utilization in the animals supplemented with Desmanthus relative to lucerne. From February to June 2020, sixteen yearling Brangus steers (average liveweight of 232 ± 6 kg) were fed a background diet of Rhodes grass (Chloris gayana) hay for 28 days, before introducing three Desmanthus cultivars (Desmanthus virgatus cv. JCU2, D. bicornutus cv. JCU4, D. leptophyllus cv. JCU7) and lucerne (Medicago sativa) at 30% dry matter intake (DMI). Relative to the backgrounding period, all supplemented steers exhibited similar growth performance. Steers supplemented with Desmanthus recorded a lower DMI and animal growth performance, but higher fecal N concentration than animals supplemented with lucerne. Among the three Desmanthus cultivars, there were no significant differences in N concentrations, VFA, and plasma metabolite profiles. The addition of PEG induced higher rumen iso-acid concentrations and fecal N excretion. However, feeding Desmanthus spp. to tropical Bos indicus steers could be a valuable means of increasing N utilization, which is attributable to the presence of tannins, and, consequently, improve animal productive performance. Since supplementation with lucerne resulted in higher liveweight, daily liveweight gains, and overall animal performance than supplementing with Desmanthus, the tested hypothesis that both supplements will elicit similar animal performance does not hold and must be rejected. Further in vivo investigation is needed to better understand the impact of tannins in Desmanthus on N utilization. Full article

Heat stress reduces the feed intake and growth of pigs. We hypothesized that heat stress affects the intestinal fermentation capacity of pigs. Sixteen Iberian pigs (44 ± 1.0 kg) were randomly assigned to one of two treatments (eight pigs/treatment) for 4 weeks—heat stress (HS; 30 °C) ad libitum or thermoneutral (TN; 20 °C) pair feeding. Frozen rectum contents were used as inocula for 24 h in vitro incubations in which a mixture of starches, citrus pectin, inulin from chicory, and cellulose were the substrates. Cellulose was poorly degraded, whereas pectin and the mixture of starches were the most fermentable substrates according to total short-chain fatty acid (SCFA) production. The mixture of starches and inulin produced the greatest amount of gas. For all substrates, heat stress enhanced gas production (8%, p = 0.001), total SCFA production (16%, p = 0.001), and the production of acetate and propionate (12% and 42%, respectively; p = 0.001). The increased isoacid production (33%, p = 0.001) and ammonia concentration (12%, p = 0.001) may indicate protein fermentation under heat stress. In conclusion, the in vitro intestinal fermentation capacity of pigs under heat stress was increased compared to thermoneutral conditions, which may indicate an adaptive response to heat stress. Full article

The main objective of this study was to investigate the effect of supplementing beef cattle with incremental levels of Desmanthus leptophyllus cv. JCU1 and Desmanthus bicornutus cv. JCU4 on in vivo methane (CH₄) emissions and the role of tannins in rumen fermentation. Fourteen yearling Droughtmaster steers were allocated to each of the two Desmanthus species and offered a basal diet of Rhodes grass (Chloris gayana) hay plus fresh Desmanthus at 0%, 15%, 22%, and 31% of dry matter intake (DMI). The 15% and 31% Desmanthus periods lasted 21 days and the 22 and 0% Desmanthus periods, 14 days. Methane production was measured by open-circuit gas exchange in the last two days of each period. The results showed a linear increase in DMI and reduction in CH₄ yield with the increasing level of Desmanthus and subsequently condensed tannins in the diet. The added tannin binder polyethylene glycol-4000 did not affect CH₄ yield but increased rumen NH₃-N and iso-acid concentrations. Therefore, on a low-quality diet, Desmanthus has the potential to increase intake and reduce CH₄ emissions. Even though its tannins can bind rumen proteins, the beef cattle anti-methanogenic response to supplementation with Desmanthus may be a combination of rumen fermentation and tannin effects. Full article

The purpose of this research was to evaluate whether relationships exist between odd- and branched-chain fatty acids (OBCFAs) originating from milk fat and the corresponding data of ruminal fermentation parameters, microbial populations, and base contents that were used to mark microbial protein in rumen. Nine lactating Holstein dairy cows with similar body weights and parity were selected in this study, and the samples of rumen and milk were collected at the early, middle, and late stages, respectively. The rumen and milk samples were collected over three consecutive days from each cow, and the ruminal and milk OBCFA profiles, ruminal fermentation parameters, bacterial populations, and base contents were measured. The results showed that the concentrations of OBCFAs, with the exception of C11:0 and C15:0, were significantly different between milk and rumen (p < 0.05). The concentrations of anteiso-fatty acids in milk were higher than those in rumen, and the contents of linear odd-chain fatty acids were higher than those of branched-chain fatty acids in both milk and rumen. Significant relationships that existed between the concentrations of C11:0, iso-C15:0, anteiso-C15:0, C15:0, and anteiso-C17:0 in rumen and milk (p < 0.05). The total OBCFA content in milk was positively related to the acetate molar proportion but negatively correlated with isoacid contents (p < 0.05). The populations of Ruminococcus albus, R. flavefacients, and Eubacterium ruminantium were significantly related to milk C13:0 contents (p < 0.05). The adenine/N ratio was negatively related to milk OBCFA content (p < 0.05) but positively associated with the iso-C15:0/iso-C17:0 ratio (p < 0.05). Milk OBCFAs were significantly correlated with ruminal fermentation parameters, ruminal bacterial populations, and base contents. Milk OBCFAs had the potential to predict microbial nitrogen flow, and the prediction equations for ruminal microbial nitrogen flow were established for OBCFAs in dairy milk. Full article

The gut microbiota plays the important role to support the immunological tolerance. To study a metabolic activity of the intestinal microflora the 44 patients suffering from bronchial asthma and 17 healthy volunteers were tested. The short-chain fatty acids (SCFA) spectrum was determined using the method of gas-liquid chromatographic analysis. We have detected a significant decrease the total content of the fatty acids in the feces (P<0.001), the absolute concentrations of the individual acids (acetate, propionate, butyrate; P<0.001) and the total content of isoacids (P<0.001) for all of the patients with bronchial asthma in the study, regardless of the phenotype. The anaerobic type of the SCFA spectrum was detected for the majority (83%) of the patients tested. The aerobic type of the SCFA metabolic profile was detected for another part (17%) of the patients tested. Being detected the parameters change could play the principal role as for the bronchial asthma course as to support the organism sensibilisation. Full article

The purpose of this study was to examine the effects of two pasture feeding systems—perennial ryegrass (GRS) and perennial ryegrass and white clover (CLV)—and an indoor total mixed ration (TMR) system on the (a) rumen microbiome; (b) rumen fluid and milk metabolome; and (c) to assess the potential to distinguish milk from different feeding systems by their respective metabolomes. Rumen fluid was collected from nine rumen cannulated cows under the different feeding systems in early, mid and late lactation, and raw milk samples were collected from ten non-cannulated cows in mid-lactation from each of the feeding systems. The microbiota present in rumen liquid and solid portions were analysed using 16S rRNA gene sequencing, while ¹H-NMR untargeted metabolomic analysis was performed on rumen fluid and raw milk samples. The rumen microbiota composition was not found to be significantly altered by any feeding system in this study, likely as a result of a shortened adaptation period (two weeks’ exposure time). In contrast, feeding system had a significant effect on both the rumen and milk metabolome. Increased concentrations of volatile fatty acids including acetic acid, an important source of energy for the cow, were detected in the rumen of TMR and CLV-fed cows. Pasture feeding resulted in significantly higher concentrations of isoacids in the rumen. The ruminal fluids of both CLV and GRS-fed cows were found to have increased concentrations of p-cresol, a product of microbiome metabolism. CLV feeding resulted in increased rumen concentrations of formate, a substrate compound for methanogenesis. The TMR feeding resulted in significantly higher rumen choline content, which contributes to animal health and milk production, and succinate, a product of carbohydrate metabolism. Milk and rumen-fluids were shown to have varying levels of dimethyl sulfone in each feeding system, which was found to be an important compound for distinguishing between the diets. CLV feeding resulted in increased concentrations of milk urea. Milk from pasture-based feeding systems was shown to have significantly higher concentrations of hippuric acid, a potential biomarker of pasture-derived milk. This study has demonstrated that ¹H-NMR metabolomics coupled with multivariate analysis is capable of distinguishing both rumen-fluid and milk derived from cows on different feeding systems, specifically between indoor TMR and pasture-based diets used in this study. Full article