Rumen Cannula Research Articles

Effects of rumen cannulation combined with different pre-weaning feeding intensities on the intestinal, splenic and thymic immune system in heifer calves several month after surgery.

Fistulation is a helpful procedure in animal nutritional research and also common practise in human medicine. However, there are indications that alterations in the upper gastrointestinal tract contribute to intestinal immune modulations. The present study aimed to investigate effects of a rumen cannulation in week 3 of life on the intestinal and tissue specific immune system of 34-week old heifers. Nutrition influences the development of the neonatal intestinal immune system to a high extent. Therefore, rumen cannulation was investigated in combination with different pre-weaning milk feeding intensities (20% (20MR) vs. 10% milk replacer feeding (10MR). Heifers of 20MR without rumen cannula (NRC) showed higher cluster of differentiation (CD)8+ T cell subsets in mesenteric lymph nodes (MSL) compared to heifers with rumen cannula (RC) and 10MRNRC heifers. CD4+ T cell subsets in jejunal intraepithelial lymphocytes (IELs) were higher in 10MRNRC heifers compared to 10MRRC heifers. CD4+ T cell subsets in ileal IELs were lower and CD21+ B cell subsets were higher in NRC heifers compared to RC heifers. CD8+ T cell subsets in spleen tended to be lower in 20MRNRC heifers compared to all other groups. Splenic CD21+ B cell subsets were higher in 20MRNRC heifers compared to RC heifers. Splenic toll like receptor (TLR) 6 expression was increased and IL4 expression tended to be increased in RC heifers than NRC heifers. Splenic TLR2, 3 and 10 gene expression was higher in 20MR compared to 10MR heifers. Jejunal prostaglandin endoperoxide synthase 2 expression was higher in RC heifers than NRC heifers, and MUC2 expression tended to increase in 20MR heifers compared to 10MR heifers. In conclusion, rumen cannulation modulated T and B cell subsets in the down streaming gastrointestinal tract and spleen. Pre-weaning feeding intensity seemed to affect intestinal mucin secretion and T and B cell subsets in MSL, spleen and thymus until several month later. Interestingly, in MSL, spleen and thymus the 10MR feeding regime evoked similar modulations of T and B cell subsets like rumen cannulation.

Effect of extrusion with molasses on the rumen undegradable protein fraction of canola oilcake meal and sweet lupins

The effect of the extrusion of canola oilcake meal (COM) and crushed sweet lupins (CSL) with molasses on the dry matter (DM) and crude protein (CP) degradability was determined in situ. Locally sourced (SOILL Moorreesburg, South Africa) COM and CSL, with the addition of 6% molasses, were extruded at a maximum temperature of 116 °C. A total of six Dohne Merino wethers (± 80 kg), fitted with rumen cannula, were used in this trial. Samples in polyester bags (5 g) were incubated in the rumen of the sheep at intervals of 0, 2, 4, 8, 16, 24, and 48 h. The DM and CP disappearances from the rumen were determined and degradability parameters were estimated. Extrusion increased the potentially degradable CP fraction by 43.5%. At each outflow rate, the average CP effective degradability of COM (68.2%) was lower than that of CSL (78.0%). Extrusion substantially lowered the CP effective degradability for both protein sources at every outflow rate tested. The biggest effect was seen at 0.08/h, where effective degradation was lowered by 25.6%. Extrusion with molasses was found to modify ruminal degradation parameters of both canola oilcake meal and crushed sweet lupins, while also decreasing the effective rumen degradation, especially at faster outflow rates. Thereby, the rumen undegradable protein fraction was increased by 85.4%. This study shows that COM and CSL extruded with 6% molasses can substantially increase RUP.

The effect of formaldehyde treatment of canola oilcake meal and sweet lupins on the in situ dry matter and crude protein digestibility

The value of feed protein sources in ruminant nutrition is measured by how effectively the protein is degraded in the rumen and converted into microbial protein. High-producing ruminants acquire high nutritional requirements to sustain their metabolic demands for production and performance. However, protein sources occasionally fall short in supplying the required amount of rumen undegradable protein and amino acids. Chemical treatment (formaldehyde) could be used to increase the efficiency of protein sources, which are highly degradable in the rumen. Canola oilcake meal (CM) and sweet lupin seed (SL) were treated with formaldehyde (40% w/v) at concentrations of 10 g/kg (F10) and 15 g/kg CP (F15). In this study, six Dohne Merino wethers fitted with rumen cannulas were used to determine the effect of formaldehyde treatment on the in situ dry matter and crude protein digestibility. The treatments entailed CM control (CMF0), CM treated with 10 g/kg CP formaldehyde (CMF10), CM treated with 15 g/kg CP formaldehyde (CMF15), SL control (SLF0) SL treated with 10 g/kg CP formaldehyde (SLF10) and SL treated with 15 g/kg CP formaldehyde (SLF15). Treatments were incubated in the rumen at time intervals of 0, 2, 4, 12, 36, 48, 72, and 96 hours. Overall, formaldehyde treatment significantly decreased rumen degradation at all outflow rates of both CM and SL. Therefore, formaldehyde treatment could be used to increase the rumen undegradable protein fraction. Potential improvement in animal performance in terms of live weight gain, average daily gain, and feed conversion efficiency has to be evaluated in production studies.

Characterization of rumen microbiome and metabolome from oro-esophageal tubing and rumen cannula in Holstein dairy cows

Less invasive rumen sampling methods, such as oro-esophageal tubing, became widely popular for exploring the rumen microbiome and metabolome. However, it remains unclear if such methods represent well the rumen contents from the rumen cannula technique. Herein, we characterized the microbiome and metabolome in the rumen content collected by an oro-esophageal tube and by rumen cannula in ten multiparous lactating Holstein cows. The 16S rRNA gene was amplified and sequenced using the Illumina MiSeq platform. Untargeted metabolome was characterized using gas chromatography of a time-of-flight mass spectrometer. Bacteroidetes, Firmicutes, and Proteobacteria were the top three most abundant phyla representing ~ 90% of all samples. Although the pH of oro-esophageal samples was greater than rumen cannula, we found no difference in alpha and beta-diversity among their microbiomes. The overall metabolome of oro-esophageal samples was slightly different from rumen cannula samples yet more closely related to the rumen cannula content as a whole, including its fluid and particulate fractions. Enrichment pathway analysis revealed a few differences between sampling methods, such as when evaluating unsaturated fatty acid pathways in the rumen. The results of the current study suggest that oro-esophageal sampling can be a proxy to screen the 16S rRNA rumen microbiome compared to the rumen cannula technique. The variation introduced by the 16S rRNA methodology may be mitigated by oro-esophageal sampling and the possibility of increasing experimental units for a more consistent representation of the overall microbial population. Studies should consider an under or over-representation of metabolites and specific metabolic pathways depending on the sampling method.

Effect of Palm Kernel Cake Supplementation on Voluntary Feed Intake, In Situ Rumen Degradability and Performance in Buffaloes in the Eastern Amazon

The objective was to evaluate the effects of palm kernel cake (PKC) supplementation on voluntary feed intake, in situ rumen degradability and performance in the wettest (WS-January to June) and less rainy seasons (LR-July to December) in the eastern Amazon. A total of 52 crossbred buffaloes that were neither lactating nor gestating were used, with 24 for the LR, aged 34 ± 04 months and an initial average weight of 503 ± 48 kg, and 24 for the WS aged 40 ± 04 months with an average weight of 605 ± 56 kg. The four treatments (levels of PKC in relation to body weight) were distributed in a completely randomized design, with 0% (PKC0), 0.25% (PKC0.2), 0.5% (PKC0.5) and 1% (PKC1) with six repetitions. The animals were housed in Marandu grass paddocks, intermittently, with access to water and mineral mixture ad libitum. Degradability was evaluated by the in situ bag technique in four other crossbred buffaloes with rumen cannulae, in a 4 × 4 Latin square (four periods and four treatments). The inclusion of PKC increased supplement consumption and production of ether extracts and reduced the intake of forage and non-fibrous carbohydrates. The dry matter degradability of Marandu grass was not affected; however, the fermentation kinetics in neutral detergent fiber (NDF) differed between the treatments. The co-product dry matter colonization time was greater in PKC1 and the highest effective degradability rates were from PKC0, but the productive performance of the animals was not influenced. Supplementation of buffaloes with PKC is recommended for up to 1% of body weight.

Effects of direct-fed Bacillus subtilis and Bacillus licheniformis on production performance and milk fatty acid profile in dairy cows

The aim of the study was to determine the effect of a Bacillus-based direct-fed microbial on performance of mid-lactating Holstein dairy cows and on their milk fatty acid composition. Six multiparous cows fitted with a rumen cannula were used in a randomized replicated crossover design. Cows received 200 g/d of either whey powder as a control or BioPlus 2B (Chr. Hansen), a commercial direct-fed microbial providing Bacillus subtilis and Bacillus licheniformis, representing a daily dose of 6.4 × 1011 cfu, and using whey powder as a carrier. The 2 experimental periods lasted 14 d and were separated by a 7-d washout interval. Samples were collected on d 0, 13, and 14 of each period. Data from d 0 were used as covariate. Significance was declared at P ≤ 0.05 and tendency at 0.05 <P ≤ 0.10. There was a 10-fold increase in the relative concentration of bacteria from the Bacillus subtilis group in the rumen when feeding direct-fed Bacillus compared with control. Treatment did not affect ruminal pH, NH3-N, or concentrations of acetate, propionate, and butyrate. However, direct-fed Bacillus increased ruminal concentrations of isovalerate and isobutyrate (tendency). Treatments did not affect lactation performance. Supplying direct-fed Bacillus enhanced milk relative concentration of anteiso 13:0 by 27.3% and of anteiso 15:0 by 6.5% and tended to increase concentrations of iso 14:0 (+41.8%) relative to control. When expressed on a yield basis, direct-fed Bacillus increased the secretion of anteiso 13:0 and decreased that of 11:0, 15:0, 17:0 (tendency), and cis-9 17:1. These variations, although limited in magnitude, indicate that milk branched-chain fatty acid composition is sensitive to ruminal microbiota modifications without changes in chemical composition of the diet.

Ruminal Degradation of Taurine and Its Effects on Rumen Fermentation In Vitro

Taurine accounts for approximately 0.1% of an animal’s body. It cannot be used for protein synthesis but plays a wide range of important roles in the animal body. Taurine does not exist in plants, while mammals can only synthesize 30–40% of the taurine they need. Supplementing taurine to beef cattle may be necessary to improve their nutrient utilization and health status. However, no data are available regarding the metabolism of taurine in the rumen. Two in vitro trials were conducted to investigate the ruminal degradability of taurine and its effects on rumen fermentation. In Trial 1, Tilley and Terry’s in vitro rumen fermentation technique was used for incubation. As treatments, two levels of taurine, i.e., 0 and 10 mg, were added into plastic tubes containing 0.4000 g of feed mixture with a calibrated volume of 50 mL. Three adult cattle fitted with rumen cannulas were used as the donors for rumen fluid. The incubation was carried out at 39 °C for 48 h. The results showed that the taurine degradability increased with incubation time (p &lt; 0.001) while its 2 h-degradability reached 99%. Taurine decreased the 48 h-dry matter degradability (DMD) (p = 0.008) and increased the 24 h- and 48 h-pH (p = 0.005; p = 0.018), respectively. In Trial 2, the Hohenheim gas test was used for incubation. Four levels of taurine, i.e., 0, 5, 10 and 20 mg, were added into glass syringes containing 0.2000 g feed mixture with a calibrated volume of 100 mL as treatments. The rumen fluid donors were the same as in Trial 1. The incubation was carried out at 39 °C for 48 h. The results showed that taurine increased the 48 h-pH (p &lt; 0.001) linearly, decreased the cumulative gas production (p &lt; 0.001) and the total volatile fatty acids (VFA) concentration (p = 0.014), and quadratically affected the ammonia–nitrogen (p &lt; 0.001) and microbial crude protein (MCP) concentrations (p &lt; 0.001). It was concluded that taurine was highly degradable in rumen fermentation. Taurine inhibits ruminal fermentation by decreasing DMD, VFA and gas production while improving MCP synthesis on a dose-dependent basis.

Degradabilidade da matéria seca e da proteína bruta de frutos de Cloroleucon mangense e Acacia cochliacantha em carneiros

Abstract The objective of this work was to determine the nutritional content and the degradability of the dry matter and protein of fruits of Chloroleucon mangense and Acacia cochliacantha and of a 1:1 mixture of both, offered as supplements to Rambouillet sheep. In situ ruminal degradation was evaluated in three adult rams, fitted with a rumen cannula, with different incubation times of 0, 6, 12, 24, 48, and 72 hours. Protein intestinal degradability was quantified with a three-step procedure: in situ ruminal incubation, in vitro enzymatic digestion, and abomasal-intestinal digestion. The fruits of C. mangense and A. cochliacantha contain 21 and 12% crude protein, 47 and 56% neutral detergent fiber, 31 and 43% acid detergent fiber, and 0.9 and 6.0% condensed tannins, respectively. The fruits of C. mangense showed a higher nutritional value and a higher dry matter and crude protein degradability (p&lt;0.05) than those of A. cochliacantha and the 1:1 mixture. The amount of protein that reaches the small intestine is higher for the 1:1, which is an indicative that its tannin concentration is enough to increase the bypass protein that can be absorbed in the small intestine.

Indigestão vagal em mini-bovinos

ABSTRACT: Vagal indigestion (VI) is a digestive disorder characterized by the dysfunction of the vagus nerve. This disorder leads to changes in forestomach motility. The causes of VI are varied. Failure to transport digestive contents may occur due to mechanical obstruction or a neurogenic origin. There are few reports in the literature regarding this disease in mini-cattle. These cattle seem to be predisposed to the development of VI. The aim of the present study was to analyze the epidemiological, clinical, laboratory, and electrocardiographic aspects of mini-cattle diagnosed with VI. The medical records of nine mini-cattle diagnosed with VI were retrospectively reviewed. Mini-cattle were referred to the Large Animal Hospital in Botucatu, Brazil, from 2002 to 2021. It was observed that VI affected young mini-cattle. The predominant clinical manifestations were intermittent gas ruminoreticular tympanism with increased volume in the left paralumbar fossa and increased volume in the right ventral region (apple/pear aspect), hypomotility in ruminal auscultation and the presence of pasty stools. The mean heart rate of the animals was 75 beats per minute. In one case, bradycardia was observed by electrocardiogram and Holter monitor system. In this case, the predominance of parasympathetic activity of the autonomic nervous system was observed. The main hematological findings were leukocytosis and lymphocytosis. The therapeutic approach included ruminal fistulation and the implantation of a permanent rumen cannula. All animals undergoing the procedure were discharged with daily care instructions.

Effects of the density of extruded pellets on starch digestion kinetics, rumen fermentation, fiber digestibilityand enteric methane production in dairy cows.

Dynamics of starch digestion in dairy cows fed extruded pellets differing in physical functional properties were investigated by measuring starch digestibility, post-prandial rumen fermentation patterns, and post-prandial duodenal starch appearance. Additionally, starch digestion effects on neutral detergent fiber (NDF) digestibility and methane (CH4 ) emission were studied. Pure barley was extruded to produce three treatments having pellets of either low-density (LD), medium-density (MD)or high-density (HD). The experiment was conducted in a 3 × 3 Latin square design using three lactating Danish Holstein cows fitted with ruminal, duodenaland ileal cannulas. After the allocation of experimental concentrate directly into the rumen through the rumen cannula, cows were fed a basal diet low in starch. Eight samples were collected on equal time intervals (9 h) from duodenal digesta, ileal digestaand feces (grab sample) to determine digestibility. For post-prandial rumen fermentation patterns, four sample sets of rumen dorsal, medialand ventral fluid were taken from each cow, whereas for post-prandial duodenal starch appearance, 14 samples of duodenal chyme were obtained from each cow relative to morning feeding of experimental concentrate at 07:00 h. Ruminal, small intestinal, hindgutand total tract digestibility of starch did not differ among treatments. Similarly, NDF digestibility and CH4 emission also remained unaffected by treatments. However, compared with the LD and MD treatments, the HD treatment showed higher acetate: propionate ratio at all positions in the rumen and a higher post-prandial duodenal starch appearance. This indicates lower ruminal starch degradation (RSD) and higher starch flow into the small intestine for HD treatment. In conclusion, the current study indicates that pellets' physical properties can manipulate RSD, where pellets with high densityand fluid stability can partly shift starch digestion from the rumen to the small intestine. Indeed, further investigations are needed.

PSIX-13 The Impact of Saccharomyces Cerevisiae Fermentation Product on in-Vitro Rumen Fermentation Characteristics, gas Production, and Ruminal Microbiome Composition

Abstract The objective of this experiment was to evaluate the effect of Saccharomyces cerevisiae products (NaturSafe) on in-vitro rumen fermentation characteristics and microbial diversity. Three crossbred feedlot steers fitted with rumen cannulae were adjusted to a moderately high-concentrate diet for 28-d. On d-29, 1 L of rumen fluid was collected from each steer and composited. A set of vaccine bottles (n=5/treatment/time + blanks and controls) containing 0.5 g of basal diet plus dietary treatments were filled with 30 ml of rumen fluid-McDougall’s buffer solution (1:1), sealed, and placed in a 39°C water bath. Treatments consisted of 1) Control (no added NaturSafe); 2) NaturSafe-dry (9 g/animal/day equivalent); 3) NaturSafe-dry (12 g/animal/day equivalent); 4) NaturSafe-liquid (14 g/animal/day equivalent); 5) NaturSafe-liquid (21 g/animal/day equivalent); and NaturSafe-liquid (28 g/animal/day equivalent). Samples were collected at 0, 6 and 12 h post-fermentation. No treatment effect on any fermentation parameters was found at 6 h. At 12-h post-incubation, dry matter digestibility (DMD) (P &amp;lt; 0.04) and molar proportions of propionic acid (P &amp;lt; 0.03) were greater for treatments containing NaturSafe compared with control. Molar proportions of acetic acid (P &amp;lt; 0.07), percent CH4 (P &amp;lt; 0.08), and NH3-N (P &amp;lt; 0.06) tended to be lesser and percent CO2 tended (P &amp;lt; 0.07) to be greater for NaturSafe treatments compared with controls. Microbiome 16S rRNA analysis results suggest that microbial communities differed (P &amp;lt; 0.05) between 6 and 12 h post-incubation. Incorporating NaturSafe into fermentation vessels revealed an inverse correlation with NaturSafe concentration and microbial diversity (P = 0.08) and that the overall microbial diversity was altered (P &amp;lt; 0.03) by NaturSafe concentration. The microbial community was not affected by additive type. These data suggest that NaturSafe alters fermentation characteristics and microbial community diversity toward improved rumen efficiency while reducing environmental impact.

Intravenous administration of xenin-25 accelerates cyclic ruminal contractions in healthy conscious sheep

The present study aimed to determine the effect and mode of action of the intravenous injection of xenin-25 on cyclic contractions of the rumen in healthy conscious sheep and mode of its action. Clinically healthy male sheep were equipped with a rumen cannula by surgery under anesthesia, and ruminal contractions were recorded with manometry in conscious animals after the recovery period. Intravenous xenin-25 injection induced a cluster of premature ruminal phasic contractions in a dose-dependent manner between 0.03 and 1 nmol/kg, and the change at the highest dose was statistically significant. In contrast, intravenous neurotensin injection inhibited the amplitude of cyclic rumen contractions. The xenin-25 effect was not significantly altered by prior injection of the neurotensin receptor subtype-1 antagonist SR 48692 at 30 and 100 nmol/kg. After euthanasia the ruminal muscles were excised for in vitro experiments. A single xenin-25 application (0.3–10 μM) to the longitudinal and circular muscle strips of the rumen did not induce any change in tension or electric field stimulation-induced phasic contractions of the muscle strips. These results demonstrated that circulating xenin-25 stimulates rumen contractions by acting on sites except the intramural intrinsic nerve plexus or smooth muscles of the rumen, implying that xenin-25 acts on the gastric center and/or cholinergic efferent nerve innervated to the ovine rumen.

Lactate uptake in the rumen and its contributions to subacute rumen acidosis of goats induced by high-grain diets.

Rumen acidosis is the consequence of feeding rapidly fermentable grain diets and it is considered the most common nutritional disorder in intensive feeding ruminants. Due to that mechanism of catabolism and transformation is driven by multi-factors, the role of ruminal lactate and its contribution to subacute rumen acidosis has not been well defined yet. The aim of this study is to evaluate the effects of SARA on the production, absorption, circulation, and transformation of lactate in the rumen. In this study, rumen samples were collected from 12 adult Saanen goats (44.5 ± 4.6 kg BW) equipped with permanent rumen cannula to measure rumen fermentation parameters, organic acids production, microbial profiles, and blood indicators to identify the occurrence of SARA. To further investigate the change in the disappearance rate of ruminal lactate, rumen fluid was collected and a batch culture was performed. The results showed that the clearance rate of ruminal lactate was accelerated by SARA, and the concentration of the ruminal lactate pool was stable. In addition, the rumen liquid dilution rate and the rumen liquid flow rate under the SARA condition of goats were lower than that in normal conditions. The ruminal lactate flow rate had no difference throughout the process of fermentation. However, in vitro data showed that the disappearance of lactate was reduced in SARA. By measuring the conversion of sodium L-[3-13C]-lactate in batch culture, it was found that the percentage of lactate converted to propionate was significantly lower in the SARA treatment and 16.13% more lactate converted to butyrate under SARA condition. However, the percentage of lactate transformed into acetate and butyrate was significantly increased in the SARA treatment than that of control. The relative population of total protozoa count in SARA was significantly reduced, while the relative population of Lactobacillus fermentum, Streptococcus bovis, Butyrivibrio fibrisolvens, Megasphaera elsdenii, and Selenomonas ruminantium in the SARA treatment was significantly induced (p < 0.05). It is concluded that the transformation of lactate into butyrate may promote the development of SARA. These findings provide some references to the diet formulation for preventing SARA.

Impact of orange essential oil on enteric methane emissions of heifers fed bermudagrass hay.

In this study, the effects of orange essential oil (OEO) on the rumen fermentation, nutrient utilization, and methane (CH4) emissions of beef heifers fed a diet of bermudagrass (Cynodon dactylon) were examined. In addition, in vitro and in situ experiments were conducted. The in vitro experiment consisted of three treatments: control (CTL, no OEO), OEO1 (0.25% OEO), and OEO2 (0.5% OEO). The forage to concentrate ratio was 70:30 (dry matter [DM] basis) in all treatments. No changes in pH, proportions of volatile fatty acids, and the acetate:propionate ratio were observed (P > 0.05). The addition of 0.25% OEO resulted in a reduction in CH4 production (mL/g) relative to the control (P < 0.05). In the in situ experiment, 5 g of total mixed ration (CTL, OEO1, and OEO2) were incubated for 6, 12, 24, 48, and 72 h. Potential and effective degradability were not affected by OEO supplementation (P > 0.05). In the in vivo study, six crossbred beef heifers (Bos indicus × Bos taurus), fitted with rumen cannulas, were assigned to three different treatments: no additive (CTL), 0.25% OEO (OEO1), and 0.5% OEO (OEO2) in a replicated 3 × 3 Latin square (21-day periods). Heifers were fed at 2.8% body weight. In vivo CH4 production was measured in open-circuit respiration chambers. Reductions in gross energy consumption, apparent total tract digestibility, and rumen valerate concentration were observed for OEO2 compared to the control (P < 0.05). Additionally, decreases in CH4 emissions (g/day; P < 0.05) and CH4 (MJ gross energy intake/day; P < 0.05) were observed in response to supplementation of 0.5% OEO as compared to the CTL treatment. Thus, supplementation of 0.5% OEO reduced CH4 emissions (g/day) by 12% without impacting the DM intake of heifers fed bermudagrass hay as a basal ration.

Evaluation of Stockpiled Perennial Forage Compared to Grass-legume Hay for Chemical Composition and Rumen Degradation Kinetics

The objective of this study was to determine the chemical composition and in situ degradability of dry matter (DM), crude protein (CP), acid detergent fiber (ADF), and neutral detergent fiber (NDF) of stockpiled perennial forage (SPF) or sun-cured hay (HAY) when collected at the start or end (October vs. December) of fall grazing. Selected 6, 4-ha paddocks consisting of meadow bromegrass and alfalfa, were randomly assigned to 1 of 2 replicated (n = 3) winter feeding systems (SPF and HAY). Sampling was done twice per year at the beginning (October) and end (December) from (a) stockpiled perennial forage (SPF) in field paddocks and from (b) harvested round bale hay (HAY) over 2 consecutive years. Selected 6, 4-ha paddocks consisting of meadow bromegrass and alfalfa, were randomly assigned two winter feeding systems (SPF (n=3) and HAY (n=3)). Sampling were done twice per year at the beginning (October) and end (December) from (a) SPF (b) HAY over 2 consecutive years. To evaluate in situ degradability, duplicate nylon bags from each experimental unit were incubated for 0, 3, 6, 10, 13, 25, 48, 72, and 96 h in five Hereford heifers fitted with rumen cannula. Relative to HAY, SPF had greater (p = 0.01) OM (906 vs. 916 g/kg DM) and NDF (653 vs. 631 g/kg DM) concentrations. Sampling date had no effect (p &amp;gt; 0.05) on CP, OM, and ADF in both forages, whereas the NDF was greater (p = 0.01) in forages sampled in December. The in situ soluble fraction (S) of DM was greater (p = 0.01) for SPF collected in October, HAY collected in October, and HAY collected in December s (156, 138, and 152 g/kg DM, respectively) relative to SPF collected in December (106 g/kg DM). The potentially degradable fraction (D) of CP was less (p &amp;lt; 0.05) for HAY December samples compared to SPF December and HAY October samples (257 vs. 522 and 523 g/kg CP, respectively). The SPF had a greater (p &amp;lt; 0.05) potentially degradable ADF (749 vs. 587 g/kg ADF) and potentially degradable NDF (770 vs. 591 g/kg NDF) compared to HAY. The effect of forage type and sampling date did not affect (p &amp;gt; 0.05) effective degradability of NDF. Regardless of the forage type the potentially degradable fraction of NDF decreased from October to December (SPF: 770 to 730 g/kg NDF) (HAY: 680 g/kg to 491 g/kg NDF). These findings suggest SPF grazing is a robust substitute to hay feeding systems for beef cows.

Rumen sampling methods bias bacterial communities observed.

The rumen is a complex ecosystem that plays a critical role in our efforts to improve feed efficiency of cattle and reduce their environmental impacts. Sequencing of the 16S rRNA gene provides a powerful tool to survey the bacterial and some archaeal. Oral stomach tubing a cow to collect a rumen sample is a rapid, cost-effective alternative to rumen cannulation for acquiring rumen samples. In this study, we determined how sampling method (oral stomach tubing vs cannulated grab sample), as well as rumen fraction type (liquid vs solid), bias the bacterial and archaeal communities observed. Liquid samples were further divided into liquid strained through cheesecloth and unstrained. Fecal samples were also collected to determine how these differed from the rumen sample types. The abundance of major archaeal communities was not different at the family level in samples acquired via rumen cannula or stomach tube. In contrast to the stable archaeal communities across sample type, the bacterial order WCHB1-41 (phylum Kiritimatiellaeota) was enriched in both liquid strained and unstrained samples as well as the family Prevotellaceae as compared to grab samples. However, these liquid samples had significantly lower abundance of Lachnospiraceae compared with grab samples. Solid samples strained of rumen liquid most closely resembled the grab samples containing both rumen liquid and solid particles obtained directly from the rumen cannula; therefore, inclusion of particulate matter is important for an accurate representation of the rumen bacteria. Stomach tube samples were the most variable and were most representative of the liquid phase. In comparison with a grab sample, stomach tube samples had significantly lower abundance of Lachnospiraceae, Fibrobacter and Treponema. Fecal samples did not reflect the community composition of the rumen, as fecal samples had significantly higher relative abundance of Ruminococcaceae and significantly lower relative abundance of Lachnospiraceae compared with grab samples.

Dry malt extract from barley partially replacing ground corn in diets of dairy cows: Nutrient digestibility, ruminal fermentation, and milk composition

Dry malt extract (DME) has been used in animal nutrition as an alternative source of rapidly fermentable carbohydrate. An experiment was conducted to evaluate the partial replacement of ground corn with DME in diets of dairy cows on apparent digestibility, ruminal fermentation, predicted rumen microbial protein supply, N excretion, serum urea-N concentration, and milk yield and composition. Twenty-eight Holstein cows (35.3 ± 5.88 kg/d milk yield and 148 ± 78 d in milk), 4 of which were rumen cannulated, were blocked according to the presence of rumen cannulas, parity, milk yield, and days in milk and enrolled into a crossover design experiment. Experimental periods lasted 21 d, of which the first 14 d were allowed for treatment adaptation and 7 d were used for data collection and sampling. Treatment sequences were composed of control (CON) or DME from barley (Liotécnica Tecnologia em Alimentos) replacing ground corn at 7.62% diet dry matter (~2 kg/d). Data were analyzed using the MIXED procedure of SAS (SAS Institute Inc.) modeling the fixed effects of treatment, period, and their interaction, in addition to the random effect of animal. Ruminal fermentation data were analyzed as repeated measures including time and its interaction with treatment in the previous model as fixed effects. Treatments did not affect nutrient intake or feed sorting. Dry malt extract increased apparent digestibility of CP. Feeding DME decreased ruminal pH and molar percentage of butyrate and increased molar percentage of acetate. No treatment effects were detected for predicted rumen microbial protein supply or N excretion. Cows fed DME had lower serum urea-N concentration than CON cows. Dry malt extract increased yields of actual milk, 3.5% fat-corrected milk, fat, and protein, and improved feed efficiency (fat-corrected milk ÷ dry matter intake). Cows fed DME had lower milk urea nitrogen content in comparison with CON cows. Dry malt extract can partially replace ground corn in the diet while improving milk yield and feed efficiency.

Use of tannin extract as a strategy to reduce methane in Nellore and Holstein cattle and its effect on intake, digestibility, microbial efficiency and ruminal fermentation.

This study was carried out to evaluate the use of tannin extract from Acacia mearnsii as a strategy to reduce methane (CH4 ) in two distinct cattle genotypes and its effect on intake, digestibility, microbial efficiency and ruminal fermentation. Four Nellore (Bos indicus) and four Holstein (Bos taurus) dry cows fitted with rumen cannula were assigned to two 4 × 4 Latin square design, in a 2 × 4 factorial arrangement, where each genotype represented a square receiving four tannin levels (commercial extract of A.mearnsii) in the diet (0%, 0.5%, 1.0%and 1.5% of dry matter). Tannin levels used did not cause a reduction in feed intake or rumen passage rate for both genotypes (p > 0.05), although there was a linear reduction in the degradation rate and ruminal disappearance of diet (p < 0.05). The increase in tannin levels reduced the amount of entodiniomorph protozoa in the Nellore cattle (p < 0.05). There was no change in N retention or microbial efficiency (p > 0.05), despite the linear reduction of nutrient digestibility and the synthesis of microbial nitrogen (p < 0.05). The ruminal CH4 production was reduced (p < 0.05) without reducing the short-chain fatty acidproduction. The threshold of 0.72% of tannin in the diet was estimated as the starting point for the reduction of ruminal CH4 production with long-term efficacy. Therefore, the use of low levels of tannin extract from A. mearnsii is a potential option to manipulate rumen fermentation in Nellore and Holstein cattle and needs to be further investigated.

Comparison of the Effect of Synthetic (Tannic Acid) or Natural (Oak Bark Extract) Hydrolysable Tannins Addition on Fatty Acid Profile in the Rumen of Sheep.

Simple SummaryTannins are known as water-soluble polyphenols with the ability to form complexes with macromolecules of dietary and endogenous origin. Thus, they are becoming increasingly popular among scientists as an invaluable “tool” for targeted modification of digestive processes in the rumen. The aim of the study was to compare the effect of tannins of various origin—oak bark extract (natural) vs. tannic acid (synthetic) on the fatty acid composition in the ruminal fluid of sheep. It was shown that both sampling time and animal diet had a significant effect on tested parameters, but this effect was varied. The addition of tannic acid to sheep diet had a greater influence on the fatty acid profile in the rumen than oak bark extract. Differences in the effects of tested additives may arise from the presence of various types of tannins in oak bark extract. Increased concentrations of C18:2 c9c12 and C18:3 c9c12c15 in sheep fed diet with tannic acid addition may suggest inhibition of the initial stage of fatty acid biohydrogenation. These promising results may increase knowledge about the action of such compounds on lipid metabolism in the rumen, and provide the basis for further research on health-promoting properties of ruminant products.The aim of the study was to compare two sources of tannins on fatty acids (FA) composition in rumen. Treatments were (g tannins/kg diet as-feed-basis) as follows: (1) no supplemental tannin addition (CON), (2) addition of 13 g of oak bark extract (OAK), and (3) 4 g of tannic acid (TAN). The basal diet contained 55:45 forage to concentrate ratio. Net consumption of tannins (g/d) was 4 g for both tannins sources. The study was performed on three Polish Mountain ewes fitted with rumen cannulas, and was divided into three experimental periods (I, II, and III). Both sampling time and animal diet had a significant effect on FA profile in the rumen fluid. In general, FA concentrations were higher before feeding in comparison to samples collected 2 and 4 h after feeding. In terms of dietary effect, it was shown that TAN addition had a greater influence on FA profile in the ruminal fluid than the OAK diet. Briefly, in the TAN group significantly increased concentrations of C18:2 c9c12 (linoleic acid, LA) 8 h after feeding (vs. control, CON and OAK), C18:3 c9c12c15 (α-linolenic acid, LNA) 4 h after feeding (vs. OAK), C20:3 n-6 before feeding (vs. CON), C20:4 before feeding (vs. CON and OAK) and 8 h after feeding (vs. OAK) were recorded. In contrast, OAK addition significantly reduced C20:3 n-6 concentration 2 h after feeding (vs. CON). In conclusion, increased concentrations of both LA and LNA in the rumen indicated that supplemental tannic acid may inhibit the initial stage of FA biohydrogenation in the rumen.

Characterization and Comparison of the Rumen Luminal and Epithelial Microbiome Profiles Using Metagenomic Sequencing Technique.

Bacterial dysbiosis as a result of nutritional, bacterial, viral, and parasitic gastrointestinal infections can adversely affect the metabolism, productivity, and overall health of cattle. The purpose of this project was to characterize the commensal microbiota present in two locations of the rumen concomitantly in vivo with the animals undergoing habitual husbandry, as it was hypothesized that there are major differences in the commensal microbiota present in the two locations of the adult bovine major forestomach. A surgically fitted rumen cannula was used to allow ruminal lumen contents and mucosal biopsies to be collected from six crossbred yearling steers. In order to assess as much environmental and individual steer microbiota variation as possible, each animal was randomly sampled three times over a 3 week period. 16S rRNA sequencing was performed to provide a detailed descriptive analysis from phylum to genus taxonomic level. Significant differences were observed between luminal and epimural bacterial populations in the bovine rumen. As expected, a core microbiome composed by Firmicutes and Bacteroidetes represented over 90% of the microbiome, however, further analysis showed distinct diversity and distribution of the microbiome between the two locations. Characterizing the gastrointestinal microbiome in vivo is imperative. The novelty and the contribution of this study to the literature is the use of live cattle which allowed real-time sample collections and analysis of the rumen microbiome providing an understanding of what is normal in the live animal.