Effects of rumen-protected creatine pyruvate on blood biochemical parameters and rumen fluid characteristics in transported beef cattle

Background The fasting and stress associated with road transportation contributes to a lack of energy and a decline in the immune system of beef cattle. Therefore, it is essential for beef cattle to enhance energy reserves before transportation. Creatine pyruvate (CrPyr) is a new multifunctional nutrient that can provide both pyruvate and creatine, which are two intermediate products of energy metabolism. To investigate the effects of transport and rumen-protected (RP)-CrPyr on the blood biochemical parameters and rumen fluid characteristics of beef cattle, twenty male Simmental crossbred cattle (659 ± 16 kg) aged 18 months were randomly allocated to four groups (n = 5) using a 2 × 2 factorial arrangement with two RP-CrPyr supplemental levels (0 or 140 g/d) and two transport treatments (5 min or 12 h): T_CrPyr140, T_CrPyr0, NT_CrPyr140, and NT_CrPyr0. After feeding for 30 days, three cattle per treatment were slaughtered. Results Compared with nontransport, transport decreased the total antioxidant capacity, catalase activity, contents of IgA, interferon γ, interleukin-1β (IL-1β), and IL-6 in serum, and the amounts of total volatile fatty acids (TVFA), acetate, and butyrate in rumen (P < 0.05); increased the serum lipopolysaccharide (LPS) level, contents of rumen LPS and ammonia nitrogen (P < 0.05). RP-CrPyr supplementation decreased the levels of cortisol and LPS in serum and the butyrate concentration in the rumen of beef cattle compared with those in the unsupplemented groups (P < 0.05). RP-CrPyr and transport interaction had a significant effect on the contents of serum tumour necrosis factor-α, IL-6, LPS, ruminal pH, acetate content, and acetate/propionate (P < 0.05). In terms of ruminal bacterial composition, group T_CrPyr0 increased the Prevotella genus abundance compared with group NT_CrPyr0 (P < 0.05), while group T_CrPyr140 increased Firmicutes phylum abundance and decreased Bacteroidetes phylum and genus Prevotella abundance compared with group T_CrPyr0 (P < 0.05). Moreover, Bacteroidetes was positively correlated with serum LPS. Conclusions These results indicated that dietary supplementation with RP-CrPyr might be beneficial to alleviate transport stress by decreasing serum cortisol and LPS levels and promoting the restoration of the rumen natural flora.

In vitro Inoculation of Fresh or Frozen Rumen Fluid Distinguishes Contrasting Microbial Communities and Fermentation Induced by Increasing Forage to Concentrate Ratio

In vitro rumen batch culture is a technology to simulate rumen fermentation by inoculating microorganisms from rumen fluids. Although inocula (INO) are commonly derived from fresh rumen fluids, frozen rumen fluids are also employed for the advantages of storing, transporting, and preserving rumen microorganisms. The effects of frozen INO on microbial fermentation and community may be interfered with by substrate type, which has not been reported. This study was designed to test whether rumen fluid treatments (i.e., fresh and frozen) could interact with incubated substrates. A complete block design with fractional arrangement treatment was used to investigate the effects of INO (fresh or frozen rumen fluids) and concentrate-to-forage ratios (C/F, 1:4 or 1:1) on rumen fermentation and microbial community. The effects of increasing C/F were typical, including increased dry matter (DM) degradation and total volatile fatty acids (VFA) concentration (P &lt; 0.001), and decreased acetate to propionate ratio (P = 0.01) and bacterial diversity of richness and evenness (P ≤ 0.005) with especially higher fermentative bacteria such as genus Rikenellaceae_RC, F082, Prevotella, Bacteroidales_BS11, Muribaculaceaege, and Christensenellaceae_R-7 (P ≤ 0.04). Although frozen INO decreased (P &lt; 0.001) DM degradation and altered rumen fermentation with lower (P ≤ 0.01) acetate to propionate ratio and molar proportion of butyrate than fresh INO, typical effects of C/F were independent of INO, as indicated by insignificant INO × C/F interaction on substrate degradation, VFA profile and bacterial community (P ≥ 0.20). In summary, the effect of C/F on fermentation and bacterial diversity is not interfered with by INO type, and frozen INO can be used to distinguish the effect of starch content.

Multi-Omics Study of The Salivary Modulation of The Rumen Microbiome

Ruminants are able to produce large quantities of saliva which enter into the rumen. Although previous research has indicated that salivary immunoglobulins can partially modulate the rumen microbial activity, the role of the salivary components other than ions on the rumen microbial ecosystem has not been thoroughly investigated in ruminants. A total of 16 semi-continuous in vitro cultures were used to incubate rumen fluid from 4 donor goats inoculated with autoclaved saliva (AUT) as negative control, saliva from the same rumen fluid donor (OWN) as positive control, and either GOAT or SHEEP saliva as experimental interventions. Fermentation was monitored throughout the 7 days of incubation and the prokaryotic communities and metabolome were analysed at day 7 of incubation. Characterization of the salivas used prior to incubation showed a high degree of individual variability in terms of the salivary metabolites and proteins, including immunoglobulins. The prokaryotic community composition in AUT incubators was the most divergent across treatments, suggesting a modulatory effect of active salivary components, which were not affected in the other treatments (OWN, GOAT and SHEEP). The differences across treatments in microbial diversity were mostly caused by a greater abundance of Proteobacteria and Rikenellacea and lower of Prevotellaceae, a key rumen bacterium with greater abundance in GOAT and SHEEP treatments. These results suggest that specific salivary components contribute to host-associated role in selecting the rumen commensal microbiota and its activity.

DHA-Rich Aurantiochytrium Biomass, a Novel Dietary Supplement, Resists Degradation by Rumen Microbiota without Disrupting Microbial Activity

We first sought to evaluate the effect of dietary supplementation with the docosahexaenoic acid (DHA)-rich microalgae, Aurantiochytrium limacinum (AURA), on rumen fermentation and the resistance of DHA to degradation and biohydrogenation by rumen microbes through ex vivo fermentation experiments. Subsequently, we sought to quantify the diet-derived DHA content of milk and the impact of AURA on microbial composition and metabolism in a pilot feeding trial with rumen-cannulated dairy cows. To achieve our aims, rumen fluid from cannulated cows was used as inoculum, and the effect of AURA inclusion on fermentation ex vivo was examined. At doses corresponding to the amount of AURA recommended for commercial production animals, only ~10% of DHA was degraded or biohydrogenated by rumen microorganisms. The results show that feeding with AURA had no effect on either total bacterial density or short-chain fatty acid production. Real-time quantitative PCR analysis of the rumen fluid samples collected during a seven-week in vivo trial revealed that microbes related to lactic acid metabolism and methanogenesis were significantly suppressed by the AURA-supplemented diet. The DHA concentration in milk increased over 25-fold with the AURA-supplemented diet and dropped by 30–40% within one week of washout. The addition of A. limacinum biomass to dairy cow diets resulted in positive effects on rumen microbial composition with no adverse effect on fermentation activity. AURA-derived DHA was stable, with only modest degradation in the rumen, and was successfully deposited in milk. This is the first study to investigate the effect of supplementing the diet of dairy cows with a protist-based biomass, namely, on important rumen fermentation parameters and on DHA deposition in milk, using a combination of ex vivo and in vivo approaches.

Rumen Inoculum Enhances Cathode Performance in Single-Chamber Air-Cathode Microbial Fuel Cells

During the last decade, bioprospecting for electrochemically active bacteria has included the search for new sources of inoculum for microbial fuel cells (MFCs). However, concerning power and current production, a Geobacter-dominated mixed microbial community derived from a wastewater inoculum remains the standard. On the other hand, cathode performance is still one of the main limitations for MFCs, and the enrichment of a beneficial cathodic biofilm emerges as an alternative to increase its performance. Glucose-fed air-cathode reactors inoculated with a rumen-fluid enrichment and wastewater showed higher power densities and soluble chemical oxygen demand (sCOD) removal (Pmax = 824.5 mWm−2; ΔsCOD = 96.1%) than reactors inoculated only with wastewater (Pmax = 634.1 mWm−2; ΔsCOD = 91.7%). Identical anode but different cathode potentials suggest that differences in performance were due to the cathode. Pyrosequencing analysis showed no significant differences between the anodic community structures derived from both inocula but increased relative abundances of Azoarcus and Victivallis species in the cathodic rumen enrichment. Results suggest that this rarely used inoculum for single-chamber MFCs contributed to cathodic biofilm improvements with no anodic biofilm effects.

The rumen liquid metatranscriptome of post-weaned dairy calves differed by pre-weaning ruminal administration of differentially-enriched, rumen-derived inocula

Background Targeted modification of the dairy calf ruminal microbiome has been attempted through rumen fluid inoculation to alter productive phenotypes later in life. However, sustainable effects of the early life interventions have not been well studied, particularly on the metabolically active rumen microbiota and its functions. This study investigated the sustained effects of adult-derived rumen fluid inoculations in pre-weaning dairy calves on the active ruminal microbiome of post-weaned dairy calves analyzed via RNA-sequencing. Results Two different adult-derived microbial inocula (bacterial- or protozoal-enriched rumen fluid; BE or PE, respectively) were administered in pre-weaned calves (3–6 weeks) followed by analyzing active rumen microbiome of post-weaned calves (9 weeks). The shared bacterial community at the genus level of 16S amplicon-seq and RNA-seq datasets was significantly different (P = 0.024), 21 out of 31 shared major bacterial genera differed in their relative abundance between the two analytic pipelines. No significant differences were found in any of the prokaryotic alpha- and beta-diversity measurements (P > 0.05), except the archaeota that differed for BE based on the Bray–Curtis dissimilarity matrix (P = 0.009). Even though the relative abundances of potentially transferred microbial and functional features from the inocula were minor, differentially abundant prokaryotic genera significantly correlated to various fermentation and animal measurements including butyrate proportion, body weight, and papillae length and counts. The overall microbial functions were affected quantitatively by BE and qualitatively by PE (P < 0.05), and this might be supported by the individual KEGG module and CAZymes profile differences. Exclusive networks between major active microbial (bacterial and archaeal genera) and functional features (KEGG modules) were determined which were differed by microbial inoculations. Conclusions This study demonstrated that actively transcribed microbial and functional features showed reliable connections with different fermentations and animal development responses through adult rumen fluid inoculations compared to our previous 16S amplicon sequencing results. Exclusive microbial and functional networks of the active rumen microbiome of dairy calves created by BE and PE might also be responsible for the different ruminal and animal characteristics. Further understanding of the other parts of the gastrointestinal tract (e.g., abomasum, omasum, and small intestine) using metatranscriptomics will be necessary to elucidate undetermined biological factors affected by microbial inoculations.

The potential of frozen rumen fluid for ruminant feed evaluation using in vitro gas production technique

The aim of this study was to determine the potential of frozen rumen fluid (RF) for ruminant feed evaluation using in vitro gas production (IVGP) technique. This study used a factorial randomized block design with a 3 × 3 × 3 pattern, consisting three feeding regimes varying in forage to concentrate proportion, namely 20%:80% (feed A), 40%:60% (feed B), and 60%:40% (feed C), respectively; three storage time (2, 11, and 19 days); and RF from 3 breeds of indigenous cattle, namely Bali, crossbred Ongole and Madura cattle as groups. The results showed that the effects of feeding regimes, inoculum source, or storage time on total gas production, potential of gas production, rate of gas production, dry matter and organic matter degradability. Based on the results, it can be concluded that frozen RF may be used as inoculum source for feed evaluation using the IVGP technique and hence it supports the previous findings reported in the literature. Considering that the effects of different feeds, inoculum sources, and storage times gave the specific values, it is advisable that to use RF from slaughtered animals should be taken from the same breed to allow accurate comparison for feed evaluation using IVGP technique.

Evaluation of nutritive values and digestibility’s cacao( Theobroma cacao L.) pod husk fermented with lingzhi mushroom (Ganoderma lucidum) at different concentration and incubation time

Cacao pod husk has been widely utilized as animal feed. The purpose of this study is to evaluate nutritive values and digestibility of fermented cacao pod husk with different concentration and incubation time. A completely randomized factorial design consisting two factors; lingzhi mushroom concentration (K1 = 7,5%; K2 = 15%) and incubation time (L1 = 15 d; L2 =30 d; L3 = 45 d) was employed in this study (n=3 replicates). Proximate analysis was performed to determine nutritive values of fermented cacao pod husk. Fermented samples were then subjected to an in vitro digestibility with rumen fluid and McDougall’s buffer mixture. The results of study reveal that cacao pod husk fermented with the concentration of 15% at 15d and 30 d significantly increased (P<0.05) crude protein content but not for other parameters. Dry and organic matter digestibility of cacao pod husk fermented with 7.5% of lingzhi mushroom at 45 d significantly improved (P<0.05) in vitro dry and organic matter of treatment. In conclusion, cacao pod husk fermented with different concentration and incubation time was able to improve the nutritive values and in vitro digestibility of cacao pod husk.

Rumen Microbiota Alterations During Ketosis is Associated with the Development of Mastitis in Dairy Cows

Backgroud: Mastitis is the most serious disease endangering animal husbandry, especially dairy farming. Clinical investigations indicated that cows suffering from ketosis have a higher probability of mastitis. Rumen microbiota is closely related to ruminant health. However, it is not clear what role it plays in this process.Results: The microbiota in rumen fluid and milk from ketosis cows were determined by 16S rRNA gene sequencing. The results showed that the richness of bacterial community both in rumen and milk were changed in ketosis cows. The abundance of genus Prevotella, Ruminococcus, Succinivibrionaceae_UCG-001 and Streptococcus in rumen fluid from ketosis cows decreased significantly and were negatively correlated with blood BHBA and milk SCC. In contrast, the abundance of genus Luteimonas, Thermomonas, Christensenellaceae_R-7_group, Rikenellaceae_RC9_gut_group, NK4A214_group, Paracoccus, Acetitomaculum, Prevotellaceae_UCG-003, Deinococcus, Saccharofermentans and Butyrivibrio in rumen fluid from ketosis cows increased significantly and were positively correlated with blood BHBA and milk SCC. In addition, the abundance of F082 and Thermomonas were increased, while the abundance of genus Acinetobacter and UCG-005 were reduced both in milk and rumen fluid in ketosis cows than healthy cows. Conclusions: Ketosis in dairy cows is capable of inducing mastitis. The rumen microbiota of ketotic cows changed significantly and is associated with the development of mastitis. Targeting rumen microbiota regulation may be a promising strategy to prevent metabolism disorder and its secondary diseases in dairy cows.