Ruminobacter Amylophilus Research Articles

Ruminal microbial responses to Moringa oleifera feed in lactating goats (Capra hircus): A metagenomic exploration.

The purpose of the current study was to explore the effects of Moringa oleifera feed on the taxonomy and function of the rumen microbial community, and further to evaluate its impact on milk yield and body weight in lactating goats. Nineteen goats were divided into moringa leaf diet (ML; n=10) and masoor straw (MS; n=9) groups. For each group fortnight milk yield and body weight was recorded. Rumen solid and liquid fraction samples were processed for metagenomic shotgun sequencing and further analysed. The pairwise comparison between the two groups showed a significant increase (p-value- <0.01) in milk yield of the ML goats after the 4th fortnight interval onwards. The metagenomic analysis revealed Bacteroidetes and Firmicutes are the most abundant phyla, with increased Bacteroidetes in response to the moringa diet. The ML group exhibited a reduction in microbial diversity, with an increase in Prevetolla and Bacteroidales populations which are positively associated with carbohydrate, protein, and VFA metabolism, and an increased proportions of Treponema sp., Ruminococcus sp., Ruminobacter amylophilus, and Aeromonas, indicating improved cellulose and nitrogen metabolism. KEGG analysis revealed significant changes in microbial gene pool and metabolic pathways, particularly in carbohydrate metabolism, propanoate metabolism, and fatty acid synthesis genes. These microbial and functional shifts are correlated with improvements in milk yield, growth rates, and potentially reduced methane emissions.This study highlighted the potential benefits of feeding moringa in the animal production system. However, furthermore experimental evidence including genetic and environmental effects is needed for a comprehensive understanding of moringa feed's impact on goat health and productivity.

Effects of fermented jujube powder on growth performance, rumen fermentation, and antioxidant properties of simmental bulls.

Fermented jujube powder (FJP) promotes a balance between the intestinal microflora and immune factors in animals. In this study, we aimed to investigate the effects of FJP on the production performance, nutrient digestion, rumen fermentation, and antioxidant properties of bulls. Forty Simmental bulls were randomly divided into four groups based on body weight and fed a basal diet with [5, 7.5, or 10% dry matter (DM)] or without FJP. The experimental period was 20 d for adaptation and 60 d for the feeding trial. Dietary FJP supplementation did not affect DM intake (P > 0.05) but increased the average daily gain quadratically (P = 0.049) and decreased the feed conversion ratio linearly (P = 0.042). FJP quadratically enhanced DM and crude protein digestibility (P = 0.026 and P = 0.041, respectively) and linearly enhanced acid detergent fiber digestibility (P = 0.048). It also increased the total volatile fatty acid concentration quadratically (P = 0.037), acetate molar percentage, and acetate-to-propionate ratio linearly (P = 0.002 and 0.001), and reduced the ammonia nitrogen concentration linearly (P = 0.003). Additionally, xylanase and protease activities and Ruminococcus flavefaciens abundance increased linearly (P = 0.006, 0.018, and 0.009, respectively), and total bacteria, Ruminococcus albus, and Ruminobacter amylophilus abundance increased quadratically (P = 0.047, 0.011, and 0.021, respectively). FJP linearly increased serum total protein concentration and antioxidant capacity (P = 0.003 and 0.018, respectively) and decreased malonaldehyde content (P = 0.006). FJP supplementation (7.5%) enhanced production performance, nutrient digestion, rumen fermentation, and serum antioxidant capacity in bulls. The improved nutrient digestion may be due to an increase in ruminal microorganisms and total volatile fatty acids from the FJP. High blood antioxidant levels indicate that FJP may preserve proteins, thereby boosting the production performance of bulls.

Dietary supplementation of sodium butyrate enhances lactation performance by promoting nutrient digestion and mammary gland development in dairy cows

This experiment was to evaluate the influence of sodium butyrate (SB) addition on milk production, ruminal fermentation, nutrient digestion, and the development and metabolism regulation of the mammary gland in dairy cows. Forty Holstein dairy cows averaging 710 ± 18.5 kg body weight, 72.8 ± 3.66 d in milk (DIM), and 41.4 ± 1.42 kg/d milk production were divided into four treatments blocked by DIM and milk production. Treatments were control group, low SB, medium SB, and high SB with 0, 100, 200 and 300 g/d of SB addition per cow, respectively. The study lasted for 105 d. Production of milk, milk protein and lactose quadratically increased (P < 0.05), while fat-corrected milk, energy-corrected milk and milk fat yields linearly increased (P < 0.05) with increasing SB addition. The digestibility of dietary dry matter, organic matter, and crude protein linearly increased (P < 0.05), whereas the digestibility of ether extract, neutral detergent fibre, and acid detergent fibre quadratically increased (P < 0.05). Ruminal pH quadratically decreased (P = 0.04), while total volatile fatty acids (VFA) quadratically increased (P = 0.03) with increasing SB addition. The acetic acid to propionic acid ratio increased (P = 0.03) linearly due to the unaltered acetic acid molar percentage and a linear decrease in propionic acid molar percentage. Ruminal enzymatic activity of carboxymethyl-cellulase and α-amylase, populations of total bacteria, total anaerobic fungi, total protozoa, Ruminococcus albus, R. flavefaciens, Butyrivibrio fibrisolvens, Fibrobacter succinogenes, and Ruminobacter amylophilus linearly increased (P < 0.05). Blood glucose, urea nitrogen, and non-esterified fatty acids linearly decreased (P < 0.05), while total protein concentration linearly increased (P = 0.04). Moreover, the addition of SB at 200 g/d promoted (P < 0.05) mRNA and protein expression of PPARγ, SREBF1, ACACA, FASN, SCD, CCNA2, CCND1, PCNA, Bcl-2, GPR41, and the ratios of p-Akt/Akt and p-mTOR/mTOR, but decreased (P < 0.05) mRNA and protein expressions of Bax, caspase-3, and caspase-9. The results suggest that milk production and milk fat synthesis increased with SB addition by stimulating rumen fermentation, nutrient digestion, gene and protein expressions concerned with milk fat synthesis and mammary gland development.

Effects of nisin on bacterial community and fermentation profiles, in vitro rumen fermentation, microbiota, and methane emission of alfalfa silage.

Alfalfa (Medicago sativa L.) has been used widely in preparing silage. However, forage legumes are prone to contamination by spoilage bacteria during fermentation. Nisin has broad-spectrum antibacterial properties and has been applied as an inhibitor of rumen methane emissions. However, little research has been carried out on the application of nisin in silage. This study therefore aimed to investigate the impacts of different nisin concentrations on the bacterial community and fermentation dynamics, in vitro ruminal fermentation characteristics, microbiota, and methane emissions of alfalfa silage. The detection limits of organic acid in nisin-treated silages were not reached in 0.09 g kg-1 nisin (0.09 level) from days 1 to 7 of ensiling. With increasing nisin concentrations, the silage dry matter increased linearly (P < 0.05), and dry matter loss decreased linearly (P < 0.05). Moreover, both the 0.06 g kg-1 nisin (0.06 level) and 0.09 level treatments increased the relative abundance of Pediococcus acidilactici during ensiling. Concurrently, as the nisin concentrations increased, ruminal methane production decreased linearly (P < 0.05), while the relative abundances of ruminal Succinivibrio, Fibrobacter succinogenes and Ruminobacter amylophilus increased linearly (P < 0.05). The populations of ruminal total bacteria, methanogens, protozoa, and fungi decreased linearly with increasing nisin concentrations (P < 0.05). The addition of nisin delayed the fermentation process, preserved more nutrients in alfalfa silage, and promoted fermentation dominated by P. acidilactici in the late phase of ensiling. Moreover, nisin reduced in vitro rumen methane emissions without adverse effects on dry matter digestibility. © 2023 Society of Chemical Industry.

Effect of Spirulina Dietary Supplementation in Modifying the Rumen Microbiota of Ewes

Supplementing ruminant diets with microalgae, may prove an effective nutritional strategy to manipulate rumen microbiota. Forty-eight ewes were divided into four homogenous groups (n = 12) according to their fat-corrected milk yield (6%), body weight, age, and days in milk, and were fed individually with concentrate, alfalfa hay, and wheat straw. The concentrate of the control group (CON) had no Spirulina supplementation, while in the treated groups 5 (SP5), 10 (SP10), and 15 g (SP15) of Spirulina were supplemented as an additive in the concentrate. An initial screening using metagenomic next-generation sequencing technology was followed by RT-qPCR analysis for the targeting of specific microbes, which unveiled the main alterations of the rumen microbiota under the Spirulina supplementation levels. The relative abundance of Eubacterium ruminantium and Fibrobacter succinogenes in rumen fluid, as well as Ruminococcus albus in rumen solid fraction, were significantly increased in the SP15 group. Furthermore, the relative abundance of Prevotella brevis was significantly increased in the rumen fluid of the SP5 and SP10 groups. In contrast, the relative abundance of Ruminobacter amylophilus was significantly decreased in the rumen fluid of the SP10 compared to the CON group, while in the solid fraction it was significantly decreased in the SP groups. Moreover, the relative abundance of Selenomonas ruminantium was significantly decreased in the SP5 and SP15 groups, while the relative abundance of Streptococcus bovis was significantly decreased in the SP groups. Consequently, supplementing 15 g Spirulina/ewe/day increased the relative abundance of key cellulolytic species in the rumen, while amylolytic species were reduced only in the solid fraction.

Effect of dietary biochanin A on lactation performance, antioxidant capacity, rumen fermentation and rumen microbiome of dairy goat.

Biochanin A (BCA), an isoflavone phytoestrogen, is a secondary metabolite produced mainly in leguminous plants. The objective of this study was to evaluate the effect of BCA on lactation performance, nitrogen metabolism, and the health of dairy goat. Thirty mid-lactation Saanen dairy goats were divided into three groups randomly: control, 2 g/d BCA group, and 6 g/d BCA group. After 36 days of feeding, 30 dairy goats were transferred to individual metabolic cages. Subsequently, milk yield, feed intake, total feces, and urine excretion were recorded and samples were collected continuously for 3 days. Blood and ruminal fluid samples were collected over the subsequent 4 days. Milk yield, milk protein, fat content, and the feed conversion ratio of dairy goat were significantly increased by the BCA treatment. The levels of serum 17β-estradiol, growth hormone, insulin-like growth factor 1, glutathione peroxidase activity, and total antioxidant capacity were also increased significantly by BCA, indicating that BCA enhanced the antioxidant capacity of dairy goat. Amino acid degradation was significantly inhibited, while the ammonia nitrogen content was reduced significantly by BCA. Total volatile fatty acids was significantly increased by BCA supplementation. In addition, the relative abundance of Verrucomicrobiota was decreased significantly. However, the growth of nitrogen metabolism and cellulolytic bacteria was significantly increased under BCA treatment, including Prevotella sp., Treponema sp., Ruminococcus flavefaciens, and Ruminobacter amylophilus. In conclusion, supplementation with BCA improved the milk production performance, nitrogen metabolism, rumen fermentation and antioxidant capacity, and regulated the rumen microbiome of dairy goat.

Effects of coated folic acid and coated methionine on growth performance, nutrient digestibility and rumen fermentation in Simmental bulls

In one-carbon metabolism, methionine (Met) is methyl donor and folic acid (FA) is responsible for the transfer of methyl groups. Approximately 25 % of coated methionine (CMet) and coated folic acid (CFA) released in the rumen at 24 h of incubation. Therefore, the present study investigated the effects of CMet or/and CFA on growth performance, nutrient digestibility and rumen fermentation in bulls. Forty Simmental bulls, 464 ± 15.9 kg of body weight (BW), were blocked by BW and randomly assigned to four groups in a 2 × 2 factorial arrangement of treatment, with factors being CFA 0 or 6 mg FA/kg dietary dry matter (DM) and CMet 0 or 0.66 g Met/kg dietary DM. The experiment period was 81 days long with 20 days for adaptation and 61 days for data and sample collection. Dry matter intake increased (P = 0.001) with CFA or CMet addition. The CFA × CMet interaction was noticed on average daily gain (ADG; P = 0.001) and feed conversion ratio (FCR; P = 0.020); the improvements in ADG and FCR were greater for supplementing CMet in diets with CFA than in diets without CFA. The digestibility of DM, organic matter, neutral detergent fiber and acid detergent fiber increased (P < 0.050) with CFA or CMet addition. When CMet was supplemented, crude protein digestibility increased in CFA diets and was unchanged in diets without CFA. Ruminal pH decreased (P < 0.050), but total volatile fatty acid concentration increased (P < 0.050) with CFA or CMet addition. Acetate to propionate ratio was unchanged with CFA addition, but decreased (P = 0.039) with CMet addition. Rumen ammonia-N concentration decreased (P < 0.050) for either CFA or CMet addition. The activities of carboxymethyl cellulase, protease, α-amylase and cellobiase and populations of protozoa, total bacteria, fungi, dominant cellulolytic bacteria, Ruminobacter amylophilus and Butyrivibrio fibrisolvens increased (P < 0.050) with CFA or CMet supplementation. The CFA × CMet interaction was noticed on Ruminococcus albus population (P = 0.014); when CMet was supplemented, R. albus population increased for diets without CFA and was unchanged for diets with CFA. The activities of chymotrypsin in duodenum increased (P < 0.050) with CFA or CMet supplementation, and that of amylopsin and trypsin in ileum increased (P < 0.050) for bulls receiving CFA addition. The concentrations of glucose, albumin and urea nitrogen in blood were unchanged and homocysteine decreased (P < 0.050) with CFA or CMet supplementation. The CFA × CMet interaction was noticed on blood total protein concentration (P = 0.045); when CMet was added, blood total protein concentration increased for diets without CFA and was unchanged for diets with CFA. The concentration of folate in blood increased (P = 0.001) for CFA addition. The concentration of Met increased (P = 0.002) for CMet supplementation. The results indicated that dietary CFA or/and CMet supplementation improved growth performance, nutrient digestibility and rumen fermentation, and the greatest daily gain was observed for combined addition of CFA and CMet in bulls.

Inclusion of Camelina sativa Seeds in Ewes' Diet Modifies Rumen Microbiota.

Supplementing ruminant diets with unconventional feedstuffs (Camelina sativa seeds; CS) rich in bioactive molecules such as polyunsaturated fatty acids, may prove a potential eco-efficient strategy to manipulate rumen microbiome towards efficiency. Forty-eight ewes were divided into four homogenous groups (n = 12) according to their fat-corrected milk yield (6%), body weight, and age, and were fed individually with concentrate, alfalfa hay, and wheat straw. The concentrate of the control group (CON) had no CS inclusion, whereas the treated groups were supplemented with CS at 60 (CS6), 110 (CS11), and 160 (CS16) g·kg-1 of concentrate, respectively. Rumen digesta was collected using an esophageal tube and then liquid and solid particles were separated using cheesecloth layers. An initial bacteriome screening using next-generation sequencing of 16S was followed by specific microbes targeting with a RT-qPCR platform, which unveiled the basic changes of the rumen microbiota under CS supplementation levels. The relative abundances of Archaea and methanogens were significantly reduced in the solid particles of CS11 and CS16. Furthermore, the relative abundance of Protozoa was significantly increased in both rumen fluid and solid particles of the CS6, whereas that of Fungi was significantly reduced in the rumen particle of the CS16. In rumen fluid, the relative abundance of Fibrobacter succinogens and Ruminobacter amylophilus were significantly increased in the CS6 and CS11, respectively. In the solid particles of the CS11, the relative abundance of Ruminococcus flavefaciens was significantly reduced, whereas those of Butyrivibrio proteoclasticus and Ruminobacter amylophilus were significantly increased. Additionally, the relative abundance of Selenomonas ruminantium was significantly increased in both CS11 and CS16. Consequently, the highest CS content in the concentrate reduced the relative abundance of methanogens without inducing radical changes in rumen microorganisms that could impair ruminal fermentation and ewes' performance.

Effect of Dietary Inclusion of Riboflavin on Growth, Nutrient Digestibility and Ruminal Fermentation in Hu Lambs

The study evaluated the influences of riboflavin (RF) supply on the growth performance, nutrient digestibility and ruminal fermentation in lambs. Forty-eight Hu lambs were randomly assigned into four groups receiving RF of 0, 15, 30 and 45 mg/kg dry mater (DM), respectively. Increasing RF supply did not affect the DM intake, but quadratically increased the average daily gain and linearly decreased feed conversion ratio. Total-tract DM, neutral detergent fibre, acid detergent fibre and crude protein digestibility increased quadratically. Rumen pH and propionate molar percentage decreased linearly, total volatile fatty acids concentration, acetate proportion and the ratio of acetate to propionate increased linearly, but ammonia nitrogen concentration was unchanged with increasing RF supply. Linear increases were observed on the activities of carboxymethyl-cellulase, xylanase, pectinase and protease, and the populations of bacteria, fungi, protozoa, dominant cellulolytic bacteria, Ruminobacter amylophilus and Prevotella ruminicola. Methanogens population was not affected by RF supplementation. The microbial protein amount and urinary total purine derivatives excretion increased quadratically. The results indicated that 30 mg/kg DM RF supply improved growth performance, rumen fermentation and nutrient digestion in lambs.

Effects of excessive urea on rumen morphology and microbiota in Jianzhou Da'er goat (Capra hircus)

Urea is frequently used as a protein supplement in ruminant diets, but if used improperly, it can easily result in urea poisoning. The purpose of this study was to explore the effects of excessive urea feeding on rumen pathology and microbial diversity of the Jianzhou Da'er goat (Capra hircus). In this study, 9 male Jianzhou Da'er goats with an average weight of 22.9 kg were randomly divided into the control group (0% urea), 5% urea group and 10% urea group (dry matter basis, 3 goats per group). Morphological differences of rumen tissues were analyzed by Hematoxylin-Eosin staining and Prussian blue staining, and rumen microorganisms differences were analyzed by 16S rDNA sequencing on the Illumina Novaseq platform. Histopathological analysis showed that the length of rumen papilla in the 5% urea and 10% urea groups were shortened compared to the control group, and the thickness of the stratum corneum and muscular layer were significantly thinned (P < 0.05). 16S rRNA sequencing analysis indicated that microbial richness and diversity were significantly lower in goats fed on 5% urea or 10% urea, the abundance of Prevotella ruminicola was significantly decreased (P < 0.05), and the abundance of Ruminobacter amylophilus was significantly increased (P < 0.05), as compared with the control group. This study indicated that feeding 5% and 10% urea could damage rumen tissue morphology. Feeding 10% urea significantly reduced rumen microbial diversity and the abundance of Prevotella ruminicola, but increased the abundance of Ruminobacter amylophilus.

Effects of guanidinoacetic acid supplementation on lactation performance, nutrient digestion and rumen fermentation in Holstein dairy cows.

Considering the high energy demand of lactation and the potential of guanidinoacetic acid (GAA) addition on the increase in creatine supply for cows, the present study investigated the effects of 0, 0.3, 0.6 and 0.9g kg-1 dry matter (DM) of GAA supplementation on lactation performance, nutrient digestion and ruminal fermentation in dairy cows. The study used 40 mid-lactation multiparous Holstein cows and the study duration was 100 days. DM intake was not affected, but milk and milk component yields and feed efficiency increased linearly with increasing GAA addition. The total-tract digestibility of DM, organic matter, neutral detergent fibre, acid detergent fibre and non-fibre carbohydrates increased linearly and that of crude protein increased quadratically with increasing GAA addition. When the addition level of GAA increased, ruminal pH, molar percentages of butyrate, isobutyrate and isovalerate and the acetate-to-propionate ratio decreased linearly, and the total volatile fatty acids concentration and propionate molar percentage also increased linearly, whereas the acetate molar percentage and ammonia-N concentration were unaltered. The activities of fibrolytic enzymes, α-amylase and protease increased linearly. The populations of total bacteria, fungi, Ruminococcus albus, Fibrobacter succinogenes, Ruminococcus flavefaciens, Ruminobacter amylophilus and Prevotella ruminicola increased linearly, whereas protozoa and methanogens decreased linearly with increasing GAA addition. As for the blood metabolites, concentrations of glucose, urea nitrogen and methionine were unchanged, total protein, albumin, creatine and homocysteine increased linearly, and folate decreased linearly with increasing GAA supply. The results of the present study indicate that supplementation of GAA improved milk performance and rumen fermentation in lactating dairy cows. © 2022 Society of Chemical Industry.

The Gut Microbiota Determines the High-Altitude Adaptability of Tibetan Wild Asses (Equus kiang) in Qinghai-Tibet Plateau

It was acknowledged long ago that microorganisms have played critical roles in animal evolution. Tibetan wild asses (TWA, Equus kiang) are the only wild perissodactyls on the Qinghai-Tibet Plateau (QTP) and the first national protected animals; however, knowledge about the relationships between their gut microbiota and the host's adaptability remains poorly understood. Herein, 16S rRNA and meta-genomic sequencing approaches were employed to investigate the gut microbiota–host associations in TWA and were compared against those of the co-resident livestock of yak (Bos grunnies) and Tibetan sheep (Ovis aries). Results revealed that the gut microbiota of yak and Tibetan sheep underwent convergent evolution. By contrast, the intestinal microflora of TWA diverged in a direction enabling the host to subsist on sparse and low-quality forage. Meanwhile, high microbial diversity (Shannon and Chao1 indices), cellulolytic activity, and abundant indicator species such as Spirochaetes, Bacteroidetes, Prevotella_1, and Treponema_2 supported forage digestion and short-chain fatty acid production in the gut of TWA. Meanwhile, the enterotype identification analysis showed that TWA shifted their enterotype in response to low-quality forage for a better utilization of forage nitrogen and short-chain fatty acid production. Metagenomic analysis revealed that plant biomass degrading microbial consortia, genes, and enzymes like the cellulolytic strains (Prevotella ruminicola, Ruminococcus flavefaciens, Ruminococcus albus, Butyrivibrio fibrisolvens, and Ruminobacter amylophilus), as well as carbohydrate metabolism genes (GH43, GH3, GH31, GH5, and GH10) and enzymes (β-glucosidase, xylanase, and β-xylosidase, etc.) had a significantly higher enrichment in TWA. Our results indicate that gut microbiota can improve the adaptability of TWA through plant biomass degradation and energy maintenance by the functions of gut microbiota in the face of nutritional deficiencies and also provide a strong rationale for understanding the roles of gut microbiota in the adaptation of QTP wildlife when facing harsh feeding environments.

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.

Effects of folic acid and riboflavin on growth performance, nutrient digestion and rumen fermentation in Angus bulls.

This study examined the influences of coated folic acid (CFA) and coated riboflavin (CRF) on bull performance, nutrients digestion and ruminal fermentation. Forty-eight Angus bulls based on a randomised block and 2 × 2 factorial design were assigned to four treatments. The CFA of 0 or 6 mg of folic acid/kg DM was supplemented in diets with CRF 0 or 60 mg riboflavin (RF)/kg DM. Supplementation of CRF in diets with CFA had greater increase in daily weight gain and feed efficiency than in diets without CFA. Supplementation with CFA or CRF enhanced digestibility of DM, organic matter, crude protein, neutral-detergent fibre and non-fibre carbohydrate. Ruminal pH and ammonia N content decreased and total volatile fatty acids concentration and acetate to propionate ratio elevated for CFA or CRF addition. Supplement of CFA or CRF increased the activities of fibrolytic enzymes and the numbers of total bacteria, protozoa, fungi, dominant fibrolytic bacteria and Prevotella ruminicola. The activities of α-amylase, protease and pectinase and the numbers of Butyrivibrio fibrisolvens and Ruminobacter amylophilus were increased by CFA but were unaffected by CRF. Blood concentration of folate elevated and homocysteine decreased for CFA addition. The CRF supplementation elevated blood concentrations of folate and RF. These findings suggested that CFA or CRF inclusion had facilitating effects on performance and ruminal fermentation, and combined addition of CFA and CRF had greater increase in performance than CFA or CRF addition alone in bulls.

Effects of Dietary Supplementation With Clostridium butyricum on the Amelioration of Growth Performance, Rumen Fermentation, and Rumen Microbiota of Holstein Heifers.

In China, the use of antibiotics growth promoters as feed additives has been banned. The goal of raising dairy heifers is to gain a relatively high body weight on a high-fiber diet at first mating or calving, thus increasing economic benefits. The objective of this experiment was to explore the effects of supplemental Clostridium butyricum (C. butyricum) on growth performance, rumen fermentation and microbiota, and blood parameters in Holstein heifers. Twenty Holstein heifers [mean ± standard deviation (SD); age = 182 ± 4.20 d, body weight = 197.53 ± 5.94 kg, dry matter intake (DMI) = 6.10 ± 0.38 kg] were randomly assigned to one of two diets group for a 42-day feeding period: (1) basal diet (an untreated control group, i.e., the CON group) or (2) basal diet plus daily 2 × 108 (colony-forming unit, CFU) of C. butyricum per kg of DMI per heifer (the CB group). The results demonstrated that C. butyricum supplementation increased the average daily gain from d 21 to 42 and DMI compared to the control group. Supplementation with C. butyricum significantly decreased the molar proportion of acetate and the acetate to propionate ratio but increased the molar proportion of butyrate and propionate. Compared with the control group, the relative abundance of Butyrivibrio fibrisolvens, Ruminococcus albus, Ruminobacter amylophilus, Ruminococcus flavefaciens, and Streptococcus bovis increased during the trial period in the CB group. However, C. butyricum had no significant effect on the blood parameters in Holstein heifers. In conclusion, these results show that feeding C. butyricum can improve growth performance and rumen fermentation without any negative impact on blood parameters in Holstein heifers.

Effects of yeast culture supplementation on lactation performance and rumen fermentation profile and microbial abundance in mid-lactation Holstein dairy cows

The continuous trend for a narrowing margin between feed cost and milk prices across dairy farms in the United States highlights the need to improve and maintain feed efficiency. Yeast culture products are alternative supplements that have been evaluated in terms of milk performance and feed efficiency; however, less is known about their potential effects on altering rumen microbial populations and consequently rumen fermentation. Therefore, the objective of this study was to evaluate the effect of yeast culture supplementation on lactation performance, rumen fermentation profile, and abundance of major species of ruminal bacteria in lactating dairy cows. Forty mid-lactation Holstein dairy cows (121 ± 43 days in milk; mean ± standard deviation; 32 multiparous and 8 primiparous) were used in a randomized complete block design with a 7-d adaptation period followed by a 60-d treatment period. Cows were blocked by parity, days in milk, and previous lactation milk yield and assigned to a basal total mixed ration (TMR; 1.6 Mcal/kg of dry matter, 14.6% crude protein, 21.5% starch, and 38.4% neutral detergent fiber) plus 114 g/d of ground corn (CON; n = 20) or basal TMR plus 100 g/d of ground corn and 14 g/d of yeast culture (YC; n = 20; Culture Classic HD, Cellerate Yeast Solutions, Phibro Animal Health Corp.). Treatments were top-dressed over the TMR once a day. Cows were individually fed 1 × /d throughout the trial. Blood and rumen fluid samples were collected in a subset of cows (n = 10/treatment) at 0, 30, and 60 d of the treatment period. Rumen fluid sampled via esophageal tubing was analyzed for ammonia-N, volatile fatty acids (VFA), and ruminal bacteria populations via quantitative PCR amplification of 16S ribosomal DNA genes. Milk yield was not affected by treatment effects. Energy balance was lower in YC cows than CON, which was partially explain by the trend for lower dry matter intake as % body weight in YC cows than CON. Cows fed YC had greater overall ruminal pH and greater total VFA (mM) at 60 d of treatment period. There was a contrasting greater molar proportion of isovalerate and lower acetate proportion in YC-fed cows compared with CON cows. Although the ruminal abundance of specific fiber-digesting bacteria, including Eubacterium ruminantium and Ruminococcus flavefaciens, was increased in YC cows, others such as Fibrobacter succinogenes were decreased. The abundance of amylolytic bacteria such as Ruminobacter amylophilus and Succinimonas amylolytica were decreased in YC cows than CON. Our results indicate that the yeast culture supplementation seems to promote some specific fiber-digesting bacteria while decreasing amylolytic bacteria, which might have partially promoted more neutral rumen pH, greater total VFA, and isovalerate.

Changes in the Rumen Bacteriome Structure and Enzymatic Activities of Goats in Response to Dietary Supplementation with Schizochytrium spp.

With the aim to produce functional dairy products enriched with polyunsaturated fatty acids (PUFA) by using feed supplements, radical changes could occur in the rumen microbiome. This work investigated the alterations of the rumen bacteriome of goats fed with PUFA-rich marine microalgae Schizochytrium spp. For the trial, twenty-four goats were divided into four homogenous clusters (six goats/treatment) according to their fat-corrected (4%) milk yield, body weight, and age; they were individually fed with alfalfa hay and a concentrate (F/C = 50/50). The concentrate of the control group (CON) contained no microalgae, while those of the treated groups were supplemented daily with 20 (ALG20), 40 (ALG40), and 60 g (ALG60) of Schizochytrium spp./goat. Rumen fluid samples were collected using a stomach tube during the 20th and 40th days of the experiment. The microbiome analysis using a 16S rRNA sequencing platform revealed that Firmicutes were decreased in microalgae-fed goats, while Bacteroidetes showed a tendency to increase in the ALG40 group due to the enhancement of Prevotellaceae. Cellulolytic bacteria, namely Treponema bryantii, Ruminococcus gauvreauii, R. albus, and R. flavefaciens, were decreased in the ALG40 group, resulting in an overall decrease of cellulase activity. In contrast, the amylolytic potential was significantly enhanced due to an upsurge in Ruminobacter amylophilus, Succinivibrio dextrinosolvens, and Fretibacterium fastidiosum populations. In conclusion, supplementing goats’ diets with 20 g Schizochytrium spp. could be considered a sustainable and efficient nutritional strategy to modulate rumen microbiome towards the development of dairy products enriched with bioactive compounds, while higher levels induced substantial shifts in determinant microbes’ populations.

Guanidinoacetic acid and betaine supplementation have positive effects on growth performance, nutrient digestion and rumen fermentation in Angus bulls

This study evaluated the influences of guanidinoacetic acid (GAA) and betaine (BT) on growth performance, nutrient digestion and ruminal fermentation in bulls. Forty-four Angus bulls were blocked by live body weight and then randomly divided into four groups in a 2 × 2 factorial design. Betaine of 0 or 0.6 g/kg dry matter (DM) was added to diets containing 0 or 0.6 g/kg DM GAA, respectively. The experiment included a 20 day period for adaptation and a 60 day period for data collection. Average daily gain and feed efficiency were increased by GAA or BT but no further increase was observed for supplementing BT and GAA together than for addition with BT or GAA alone. Supplementary GAA or BT did not influence DM intake but increased apparent digestibility of DM, organic matter (OM), crude protein (CP) and acid detergent fibre (ADF). Digestibility of neutral detergent fibre (NDF) was increased by GAA inclusion but was unaltered with BT provision. Ruminal pH reduced but total volatile fatty acids and ammonia nitrogen elevated with dietary inclusion of GAA or BT. Rumen short chain fatty acids percentages and fermentation pattern were not influenced by GAA. Dietary inclusion of BT increased molar proportions of acetate, valerate, isobutyrate and isovalerate as well as the ratio of acetate to propionate. Rumen populations of Ruminococcus flavefaciens and Fibrobacter succinogenes increased with addition of GAA or BT and the increase was greater when BT was added in diets with GAA compared to diets without GAA. Addition of GAA or BT increased activities of cellobiase, xylanase, α-amylase and protease and populations of total bacteria, cellulolytic bacteria and Ruminobacter amylophilus but did not affect Prevotella ruminicola. Addition of BT increased carboxymethyl-cellulase and pectinase activities and total fungi population. Blood creatine content was increased by GAA or BT and was greater for addition of GAA and BT together than for GAA or BT addition alone. Serum contents of glucose, folate, arginine and methionine were unchanged but total protein increased with GAA or BT provision. Blood homocysteine content was unaffected by GAA but decreased with BT supplementation. The data showed that GAA or BT addition improved growth performance and feed efficiency but supplementing GAA and BT together did not further increase the performance of bulls when compared with GAA or BT inclusion alone.

Effects of coated copper sulphate and coated folic acid supplementation on growth, rumen fermentation and urinary excretion of purine derivatives in Holstein bulls

The study investigated the impacts of coated copper sulphate (CCS) and coated folic acid (CFA) on growth performance, nutrient digestibility and rumen fermentation in bulls. Fourty Holstein bulls were blocked by individual initial body weight and randomly allocated to one of four groups with a 2 × 2 factor design. The CCS at 0 (CCS-) or 8 mg Cu/kg (CCS+) was added to diets with CFA at 0 (CFA-) or 4 mg FA/kg (CFA+), respectively. In the rumen characteristics an interaction between CCS and CFA was observed. The decrease in rumen ammonia N and increase in xylanase activity, Ruminococcus albus population and urinary total purine derivatives were greater for supplementing CCS in CFA- diets than in CFA + diets. Dry matter intake increased with CFA inclusion and tended to be increased with CCS addition. Inclusion of CFA or CCS elevated average daily gain and apparent digestibility of dry matter, organic matter, crude protein, neutral detergent fibre and acid detergent fibre and decreased feed conversion ratio. Rumen pH was unaltered but total volatile fatty acids concentration and the ratio of acetate to propionate increased with addition of CFA or CCS. Dietary inclusion of CCS increased activities of cellulase and protease and copies of total bacteria, Butyrivibrio fibrisolvens and R. flavefaciens, but decreased α-amylase activity and copies of Prevotella ruminicola and Ruminobacter amylophilus. Rumen enzyme activity and bacteria population increased with CFA addition. The results showed that CFA and/or CCS had stimulatory impacts on growth and feed efficiency in bulls.

Effects of riboflavin supplementation on performance, nutrient digestion, rumen microbiota composition and activities of Holstein bulls

To investigate the influences of dietary riboflavin (RF) addition on nutrient digestion and rumen fermentation, eight rumen cannulated Holstein bulls were randomly allocated into four treatments in a repeated 4 × 4 Latin square design. Daily addition level of RF for each bull in control, low-RF, medium-RF and high-RF was 0, 300, 600 and 900 mg, respectively. Increasing the addition level of RF, dry matter (DM) intake was not affected, average daily gain tended to be increased linearly and feed conversion ratio decreased linearly. Total-tract digestibilities of DM, organic matter, crude protein (CP) and neutral detergent fibre (NDF) increased linearly. Rumen pH decreased quadratically and total volatile fatty acids (VFA) increased quadratically. Acetate molar percentage and acetate to propionate ratio increased linearly, but propionate molar percentage and ammonia-N content decreased linearly. Rumen effective degradability of DM increased linearly, NDF increased quadratically but CP was unaltered. Activity of cellulase and populations of total bacteria, protozoa, fungi, dominant cellulolytic bacteria, Prevotella ruminicola and Ruminobacter amylophilus increased linearly. Linear increase was observed for urinary total purine derivatives excretion. The data suggested that dietary RF addition was essential for rumen microbial growth, and no further increase in performance and rumen total VFA concentration were observed when increasing RF level from 600 to 900 mg/d in dairy bulls.