Rumen Fermentation Products Research Articles

Optimum Level of Lactobacillus plantarum Supplementation as Probiotic on In Vitro Digestibility and Rumen Fermentation Products in Thai Native Cattle

The objective of this study was to determine in vitro gas production kinetics, and rumen fermentation products of total mixed ration (TMR) supplemented with different level of Lactobacillus plantarum supplementation in Thai native cattle. The experiment design was Completely Randomized Design (CRD). The in vitro procedure was completed using 200 mg DM of TMR and four different concentration of L. plantarum; CON (without supplementation of L. plantarum), T1 (107 CFU / mL of L. plantarum supplementation), T2 (108 CFU / mL of L. plantarum supplementation), and T3 (109 CFU / mL of L. plantarum supplementation). The samples were prepared in three replications and incubated for 96 hours for gas production. Rumen fermentation products (pH, NH3, VFA) and digestibility experiment were done in four replications and incubated for 24 hours. In vitro gas production for 96 hours, gas production from insoluble fraction (b), and potential extent of gas production (|a|+b) were improved in the T1 and T2 groups (P < 0.05). The in vitro dry matter and organic matter digestibility, and true digestibility were particularly enhanced in the T1 group compared to other treatments (P <0.05). The pH and NH3 in this study were significantly affected (P<0.05). The significant improvements on the in vitro rumen fermentation products and digestibility endorse L. plantarum supplementation at concentration of 107 CFU/mL as probiotic candidate.

63 Impacts of protein supplementation frequency on animal performance, rumen fermentation and methane emission from growing beef cattle

Abstract Nutrient supplementation is one of largest expenditure in forage-based beef production systems, especially when forage quality is poor or limited. Decreasing supplementation frequency may have a role in improving sustainability by increasing animal performance and minimizing cost of labor and fuel. This study evaluated the impacts of protein supplementation frequency (canola meal pellet; CMP) on animal performance, rumen fermentation, and enteric methane production from beef cattle fed forage-based diet. A total of 60 crossbred backgrounding steers [body weight (BW) = 278 ± 10 kg) was randomly assigned to one of the three treatments (n = 20/treatment): i) control (no CMP supplementation), ii) control + everyday CMP supplementation (0.83 kg/d per steer), and iii) control + every other day supplementation of CMP. The study was comprised of 21 d of adaptation followed by three 21-d periods, with enteric methane measured for 7 d per period. Animals were fed grass hay-based diets once a day at 0800 h and remained on their respective diets throughout the 63-d study. Diets were formulated considering animal BW, feed nutrient density and environmental condition in accordance with the National Academies of Sciences, Engineering and Medicine. Each treatment group was assigned to a pen, with the cattle and diets rotated among pens weekly to allow the animals to access the GreenFeed system stationed in one of the pens for enteric methane measurement. For measurement of rumen fermentation products, three ruminally canulated steers (BW = 350 ± 20 kg) were allocated to the three treatments using a 3 x 3 Latin Square Design with 21-d periods so that one animal received all the treatments over the three experimental periods. Animals were adapted to the treatments for 17 d and rumen samples were collected between d 19 and 21 at 0700 h, 1000h, 1300 h, 1600 h and 1900 h. Data were analyzed using the Mixed procedure of SAS. Relative to the control treatment (9.9 kg/d), DM intake was 4 to 5% greater (P < 0.001) following CMP supplementation regardless of supplementation frequency. Similarly, average daily gain was greater (7 to 11%, P = 0.01) for CPM supplemented treatments as compared with control (1.04 kg/d) irrespective of supplantation frequency. Rumen fermentation was affected by treatments. Total VFA concentration was greater (P = 0.01) for the every other day supplementation of CMP as compared with control and daily supplementation treatments. Conversely, rumen ammonia concentration was not affected by treatments. The control group had greater acetate and reduced propionate molar proportions that resulted in a 5 to 6% greater acetate:propionate ratio (P < 0.01) as compared with the CMP supplemented groups. Enteric methane production (g/d) was greater for the daily CMP supplementation (P = 0.02) while yield (g/kg daily weight gain) was not affected by treatment. Our results indicated that reduction of protein supplementation frequency improved animal performance without negatively impacting rumen fermentation.

In Vitro Efficacy of Formulated Protected Fat from Used Cooking Oil (UCO) on Gas Production, Nutrient Digestibility and Rumen Fermentation

This study was designed to determine in vitro gas production, nutrients digestibility, and rumen fermentation products of supplementary formulated dietary protected fat (PF) from used cooking oil (UCO). The dietary fat treatment was formulated from used cooking oil protected fat (UCOPF) and compared with other four dietary fat treatment were used cooking oil (UCO) and palm olein (PO which are active fat; palm olein protected fat (POPF) and commercial protected fat (CPF) which are inert fat added at 12 mg of dry matter (DM) in the 200 mg of basal diet (70:30 roughage to concentrate ratio). Control group contain basal diet without dietary fat supplement. Supplementation of dietary fat had no effect on gas production, pH, organic matter digestibility (OMD) and volatile fatty acid volatile fatty acids (VFA). The addition of fat in the form of oil and protected fat to in vitro setups up to 12 mg did not adversely affect the characteristics of rumen fermentation suggests that fat has a smaller impact on production of gas, digestibility of nutrients, and rumen fermentation products.

Characteristics of rumen microbiota and Prevotella isolates found in high propionate and low methane-producing dairy cows.

Ruminal methane production is the main sink for metabolic hydrogen generated during rumen fermentation, and is a major contributor to greenhouse gas (GHG) emission. Individual ruminants exhibit varying methane production efficiency; therefore, understanding the microbial characteristics of low-methane-emitting animals could offer opportunities for mitigating enteric methane. Here, we investigated the association between rumen fermentation and rumen microbiota, focusing on methane production, and elucidated the physiological characteristics of bacteria found in low methane-producing cows. Thirteen Holstein cows in the late lactation stage were fed a corn silage-based total mixed ration (TMR), and feed digestion, milk production, rumen fermentation products, methane production, and rumen microbial composition were examined. Cows were classified into two ruminal fermentation groups using Principal component analysis: low and high methane-producing cows (36.9 vs. 43.2 L/DMI digested) with different ruminal short chain fatty acid ratio [(C2+C4)/C3] (3.54 vs. 5.03) and dry matter (DM) digestibility (67.7% vs. 65.3%). However, there were no significant differences in dry matter intake (DMI) and milk production between both groups. Additionally, there were differences in the abundance of OTUs assigned to uncultured Prevotella sp., Succinivibrio, and other 12 bacterial phylotypes between both groups. Specifically, a previously uncultured novel Prevotella sp. with lactate-producing phenotype was detected, with higher abundance in low methane-producing cows. These findings provide evidence that Prevotella may be associated with low methane and high propionate production. However, further research is required to improve the understanding of microbial relationships and metabolic processes involved in the mitigation of enteric methane.

Effects of Nutritive and Non-nutritive Feed Supplements on Feed Utilization, Growth and Reproductive Performances in Mammals

Background: The feed supplements to ruminant animals have gained great attention of nutritionists to improve feed utilization, growth and reproductive performances during the past decades. Methods: The animals feed supplements were classified into nutrient and non-nutrient feed additives. They include substances, micro-organisms or preparations. The feed supplements and their purified constituents were fed to give animals’ nutritional requirements and to improve the quality of feed and animal products. Result: Changes in animals’ production, reproduction and therapeutic performances have been confirmed over feeding supplements. Numerous purified components include β-carotene, antioxidant and others. The supplements change feed intake, nutrient digestibility and rumen fermentation products. Such enhancements in feed utilization and growth performances resulted in improvements of oocytes, embryos and feti quality. Furthermore, blood corpuscles and plasma parameters, immunity and therapeutic performances were altered due to feeding supplements. Hence, the current review article was designed to collect, consolidate and discuss the effects of feed supplements on productive, reproductive and therapeutic performances on mammalian species.

Exploring the rumen microbiota of Hu lambs in response to diet with paper mulberry.

Paper mulberry (Broussonetia papyrifera), as a new woody forage with high-protein characteristic, is being widely used in ruminant feeding. However, little is known about the comprehensive microbiota picture of whole ruminal niches (liquid, solid, and epithelium) under paper mulberry diet. To gain a better understanding of feeding paper mulberry on the rumen microbiota, the effects of fresh paper mulberry, paper mulberry silage, or a conventional high-protein alfalfa silage on rumen fermentation products and microbiota in rumen niches of Hu lambs were studied. Forty-five Hu lambs were randomly divided into 3 treatments with 15 replicates in each treatment. No significant difference was observed among treatments in the average daily gain (ADG). The fresh paper mulberry treatment had lower (P < 0.05) pH and higher (P < 0.05) total volatile fatty acids (TVFA) compared with silage treatments, but the fermentation parameters did not show significant differences between paper mulberry silage and alfalfa silage treatments. The Shannon index did not show a significant difference (P < 0.05) among treatments except between fresh paper mulberry and alfalfa silage treatment in rumen epithelial niches. Butyrivibrio and Treponema were the predominant genera in the rumen epithelial fraction, while Prevotella and Rikenellaceae_RC9 dominated in both rumen liquid and solid fractions. These results indicated the paper mulberry supplement did not have distinct impact on the microbial diversity and growth performance compared with alfalfa silage, especially for paper mulberry silage, which might help us develop an alternative animal feeding strategy of replacing alfalfa with paper mulberry. KEY POINTS: • Feeding paper mulberry silage did not show significant impact on the growth performance compared with alfalfa silage treatment. • Feeding fresh paper mulberry reduced rumen pH value and increased total volatile fatty acid. • The microbial diversity did not show significant difference among treatments.

Evaluation of Megasphaera elsdenii supplementation on rumen fermentation, production performance, carcass traits and health of ruminants: a meta-analysis.

This study was conducted to evaluate the use of Megasphaera elsdenii (M. elsdenii) as a probiotic on rumen fermentation, production performance, carcass traits and health of ruminants by integrating data from various related studies using meta-analysis. A total of 32 studies (consisted of 136 data points) were obtained and integrated into a database. The parameters integrated were fermentation products, rumen microbes, production performance, carcass quality, animal health, blood and urine metabolites. Statistical analysis of the compiled database used a mixed model methodology. Different studies were considered random effects, while M. elsdenii supplementation doses were considered fixed effects. p-values and the Akaike information criterion were employed as model statistics. The model was deemed significant at p<0.05 or had a tendency to be significant when p-value between 0.05〈p〈0.10. Supplementation with M. elsdenii increased (p<0.05) some proportion of fermented rumen products such as propionate, butyrate, isobutyrate, and valerate, and significantly reduced (p<0.05) lactic acid concentration, acetate proportion, total bacterial population and methane emission. Furthermore, the probiotic supplementation enhanced (p<0.05) livestock production performance, especially in the average daily gain and body condition score. Regarding the carcass quality, hot carcass weight and carcass gain were elevated (p<0.05) due to the M. elsdenii supplementation. Animal health also showed improvement as indicated by the lower (p<0.05) diarrhoea and bloat incidences as well as the liver abscess. However, M. elsdenii supplementation had negligible effects on blood and urine metabolites of ruminants. Supplementation of M. elsdenii is capable of decreasing ruminal lactic acid concentration, enhancing rumen health, elevating some favourable rumen fermentation products, and in turn, increasing production performance of ruminants.

New probiotics (Lactobacillus plantarum and Saccharomyces cerevisiae) supplemented to fermented rice straw-based rations on digestibility and rumen characteristics in vitro.

This research was arranged to explore the effect of supplementation of a combination of Lactobacillus plantarum and Saccharomyces cerevisiae as a new probiotic in fermented rice straw-based rations on in vitro digestibility and ruminal characteristics. A randomized group design with 3 types of treatment and 4 replications as a group was used in this study. A probiotic inoculum containing L. plantarum and S. cerevisiae with 1 × 1010 colony-forming unit (CFU)/ml. Treatments were followed by: P1 = complete rations without probiotics (control), P2 = P1 supplemented 0.5% probiotics, and P3 = P1 supplemented 1% probiotics. Substrate complete rations were based on the fermented rice straw and concentrate (60%:40%). Parameters of digestibility and rumen fermentation products were determined after 48 h of incubation. Probiotics supplemented with fermented rice straw-based rations significantly increased (p < 0.05) digestibility and rumen characteristics in vitro. Supplementation with 1% probiotics (P3) produces the highest digestibility compared to other treatments: in-vitro dry matter digestibility (IVDMD) (55%), in-vitro organic matter digestibility (IVOMD) (58.28%), in-vitro crude protein digestibility (IVCPD) (84.42%), in-vitro acid detergent fiber digestibility (IVADFD) (53.99%), in-vitro neutral detergent fiber digestibility (IVNDFD) (58.39%), and in-vitro cellulose digestibility (IVCLD) (67.12%). Rumen pH (6.76-6.80) did not change significantly (p > 0.05) due to supplemented probiotics. Probiotic supplementation in rations significantly (p < 0.05) increased the content of NH3 and total volatile fatty acid (VFA). Supplementation with 1% probiotic (P3) showed the highest concentration of NH3 (26.56 mg/100 ml) and was also followed by the total VFA (115.75 mM) compared to the control (22.59 mg/100 ml and 103.00 mM, respectively). Supplementation of 1% probiotics (combination of L. plantarum and S. cerevisiae) containing 1 × 1010 CFU/ml in fermented rice straw-based rations increases nutrient digestibility, that is, IVDMD, IVOMD, IVCPD, IVADFD, IVNDFD, and IVCLD, and also increases rumen fermentation, which is the concentration of NH3 and total VFA.

Evaluation of the productivity and feed value of Wondergraze and Redlands leucaena cultivars under grazing

Context Leucaena leucocephala (leucaena) is a leguminous shrub used for beef grazing in low-rainfall regions (&lt;600–700 mm). Newer cultivars have the potential to extend adoption of the species to higher rainfall (&gt;600–700 mm), frost-free areas of Australia. Aim We compared productivity, nutritional value and animal performance of two leucaena cultivars, new psyllid-resistant Redlands and the 2010-released Wondergraze, under continuous grazing management in a higher rainfall environment. Methods Growing steers were allocated to replicated established stands of Wondergraze or Redlands with inter-row mixed grass–legume pasture from January to July 2021. Pasture and leucaena were characterised for biomass and nutritive characteristics. Botanical composition was measured. Liveweight gain, rumen fermentation, and leucaena mimosine breakdown products were measured in grazing steers. Key results At the beginning of the study, leucaena edible biomass was similar for both cultivars (P &gt; 0.05), but at subsequent samplings, biomass of Redlands was lower than of Wondergraze (P &lt; 0.01). Biomass of both cultivars declined rapidly over the grazing period. Pasture biomass increased between February and July and was significantly higher in Wondergraze paddocks (P &lt; 0.05). Animal performance was not significantly different between cultivar treatments, averaging 0.8 kg/day, but declined over time. Patterns of mimosine conversion to DHP isomers and their conjugation were similar for the two cultivars, suggesting that effectiveness of detoxification did not differ between them. Conclusion The results demonstrate that leucaena can sustain high levels of animal performance when included in tropical grass pastures in a higher rainfall environment if present in a sufficient quantity (&gt;2 t leucaena edible dry matter/ha established leucaena). Implications Grazing leucaena–grass pastures is an effective means of increasing animal productivity in parts of subtropical Australia. However, managing grass and/or leucaena growth to match animal requirements can be challenging.

Increasing the Quality of Rice Straw from IR Rice for Beef Feed Through Organic Fertilization

This study aimed to determine the nutrient content and rumen fermentation product in-vitro of rice straw from rice of the IR variety fertilized using organic and inorganic fertilization. This research used experimental methods. This study examined two paddy fields located in Datar Village, Sumbang District, Banyumas. Land A used inorganic fertilizer (urea and phonska) and Land B used organic fertilizer from cattle dung. Both of those lands were planted with IR variety rice. Samples were 20 points on each land obtained by random sampling so that all parts of the field were represented. All samples were dried in the oven at 600C. Variables measured were nutrient contents such as crude protein (CP), crude fiber (CF) and rumen fermentation product in-vitro of volatile fatty acids (VFA) and ammonia nitrogen (N-NH3 ). Statistical analysis used t-test. Result showed that CP and CF contents and rumen fermentation products of VFA of rice straw from organic fertilizer were higher (P&lt;0.05) compared to inorganic fertilizer. There was no significant difference (P&gt;0.05) in the rumen fermentation product of N-NH3 between organic and inorganic fertilizer. It can be concluded that rice straw quality from IR variety rice can be improved through organic fertilization.&#x0D; Keywords: organic, fertilizer, rumen, nutrient, rice straw

Whole-plant corn silage improves rumen fermentation and growth performance of beef cattle by altering rumen microbiota.

In recent years, whole-plant corn silage has been widely used in China. Roughage is an important source of nutrition for ruminants and has an important effect on rumen microbiota, which plays an important role in animal growth performance and feed digestion. To better understand the effects of different silages on rumen microbiota, the effects of whole-plant corn silage or corn straw silage on growth performance, rumen fermentation products, and rumen microbiota of Simmental hybrid cattle were studied. Sixty healthy Simmental hybrid cattle were randomly divided into 2 groups with 6 replicates in each group and 5 cattle in each replicate. They were fed with whole-plant corn silage (WS) diet and corn straw silage (CS) diet respectively. Compared with corn straw silage, whole-plant corn silage significantly increased daily gain and decreased the feed intake-to-weight gain ratio (F/G) of beef cattle. Whole-plant corn silage also decreased the acetic acid in the rumen and the acetate-to-propionate ratio (A/P) compared with corn straw silage. On the genus level, the relative abundance of Prevotella_1 was significantly increased while the relative abundance of Succinivibrionaceae_UCG-002 was decreased in cattle fed whole-plant corn silage compared with those fed corn straw silage. Prevotella_1 was positively correlated with acetic acid and A/P. Succinivibrionaceae_UCG-002 was positively correlated with propionic acid and butyric acid, and negatively correlated with pH. Feeding whole-plant corn silage improved amino acid metabolism, nucleotide metabolism, and carbohydrate metabolism. Correlation analysis between rumen microbiota and metabolic pathways showed that Succinivibrionaceae_UCG-002 was negatively correlated with glycan biosynthesis and metabolism, metabolism of co-factors and vitamins, nucleotide metabolism, and translation while Prevotellaceae_UCG-003 was positively correlated with amino acid metabolism, carbohydrate metabolism, energy metabolism, genetic information processing, lipid metabolism, membrane transport, metabolism of cofactors and vitamins, nucleotide metabolism, replication and repair, and translation. Ruminococcus_2 was positively correlated with amino acid metabolism and carbohydrate metabolism. Feeding whole-plant corn silage can improve the growth performance and rumen fermentation of beef cattle by altering rumen microbiota and regulating the metabolism of amino acids, carbohydrates, and nucleotides. KEY POINTS: • Feeding whole-plant corn silage could decrease the F/G of beef cattle • Feeding whole-plant corn silage improves rumen fermentation in beef cattle • Growth performance of beef cattle is related to rumen microbiota and metabolism.

Effects of urea supplementation on ruminal fermentation characteristics, nutrient intake, digestibility, and performance in sheep: A meta-analysis

Background and Aim:As a non-protein nitrogen source, urea is a popular, low cost, and easily obtained protein supplement. The objective of the present study was to perform a meta-analysis of the effects of urea supplementation on rumen fermentation and sheep performance.Materials and Methods:A total of 32 experiments from 21 articles were compiled into a dataset. The levels of dietary urea varied from 0 to 31 g/kg of dry matter (DM). Parameters observed were rumen fermentation product, nutrient intake, nutrient digestibility, and sheep performance. This dataset was analyzed using a mixed model methodology, with urea supplementation levels as fixed effects and the different experiments as random effects.Results:Increasing levels of urea were associated with increases (p=0.008) in rumen pH, butyrate (C4) production, and ammonia (NH3–N) concentration. Urea supplementation had minor effects on total volatile fatty acids (p=0.242), total protozoa (p=0.429), and the microbial N supply (p=0.619), but tended to increase methane production (CH4; p<0.001). Supplementation of urea increased the intake of dry matter (DM; p=0.004) and crude protein (CP; p=0.001). Digestibility parameters, such as DM digestibility (DMD) and CP digestibility (CPD), also increased (p<0.01) as a result of urea supplementation. Retained N (p=0.042) and N intake (p<0.001) were higher with increasing levels of urea supplementation. In terms of animal performance, supplementation of urea increased average daily gain (ADG; p=0.024), but decreased the hot carcass weight percentage (p=0.017).Conclusion:This meta-analysis reports the positive effects of urea supplementation on rumen fermentation products (i.e., pH, C4, and NH3–N), intake (DM, CP, and N), digestibility (DMD and CPD), and ADG in sheep.

Effect of Protection of Soybean Meal Using Mahogany Leaf Extract in Ruminant Diet on Rumen Fermentation Products

&lt;p class="abstrak3"&gt;&lt;span lang="IN"&gt;The study &lt;/span&gt;&lt;span&gt;was &lt;/span&gt;&lt;span lang="IN"&gt;aimed to examine effect of protecting soybean meal using mahogany leaf extract on rumen fermentation products in vitro. The material used was cow rumen fluid, basal ration consisting of concentrate and elephant grass with a ratio of 60:40%, and mahogany leaves. The research was carried out in three stages: mahogany extraction, protein protection using mahogany extract, and in vitro stages. The test was conducted in vitro &lt;/span&gt;&lt;span&gt;based on&lt;/span&gt;&lt;span lang="IN"&gt; a completely randomized design (CRD). The treatments consisted of 4 kinds of soybean meal protection with 0% tannin concentration (&lt;/span&gt;&lt;span&gt;T&lt;/span&gt;&lt;span lang="IN"&gt;0); 1.5% (&lt;/span&gt;&lt;span&gt;T&lt;/span&gt;&lt;span lang="IN"&gt;1); 3% (&lt;/span&gt;&lt;span&gt;T&lt;/span&gt;&lt;span lang="IN"&gt;2); and 4.5% (&lt;/span&gt;&lt;span&gt;T&lt;/span&gt;&lt;span lang="IN"&gt;3). &lt;/span&gt;&lt;span&gt;D&lt;/span&gt;&lt;span lang="IN"&gt;ata obtained were analyzed by analysis of variance and tested using orthogonal polynomials. &lt;/span&gt;&lt;span&gt;R&lt;/span&gt;&lt;span lang="IN"&gt;esults showed that addition of protected soybean meal with mahogany leaf extract had a cubic&lt;/span&gt;&lt;span&gt;al&lt;/span&gt;&lt;span lang="IN"&gt; effect on partial VFA, methane gas and post-rumen dissolved protein, a quadratic effect on protozoa, and a linear effect&lt;/span&gt;&lt;span&gt;on &lt;/span&gt;&lt;span lang="IN"&gt;N-NH&lt;sub&gt;3&lt;/sub&gt;, SPM, and RUDP. Giving extra mahogany leaves at a level of 1.5% produced a fermented product that was not different from the control while giving a level of 3% got the highest fermentation product. Giving mahogany leaf extract at a level of 4.5% resulted in the highest SPM, and RUDP but there was a decrease in soluble protein, which indicated the occurrence of overprotection. The addition of 3% mahogany leaf extract effectively increased rumen fermentation products, RUDP, and soluble protein without disturbing the activity of rumen bacteria.&lt;/span&gt;&lt;/p&gt;

Effects of Megasphaera elsdenii supplementation on fermentation and lactic acid concentration in the rumen: A meta-analysis of in vivo experiments

This study evaluated the effects of supplementation M. elsdenii on rumen fermentation and lactic acid concentration in vivo by integrating data from various related studies using a meta-analysis. A database was developed by integrating data from 72 treatments that originated from 17 articles. The parameters integrated were lactic acid concentration, fermentation products, and rumen microbial population. The database compiled was statistically analyzed using a mixed model methodology. Different studies were considered as random effects, and the doses of M. elsdenii were treated as fixed effects. The significance of an effect was stated when its p-value was <0.05. Results showed that supplementation of M. elsdenii linearly reduced lactic acid concentration (P=0.048), proportion of acetate (P=0.045), acetate: propionate ratio (P=0.043) and methane production (P<0.01). In addition, M. elsdenii supplementation also had a significant quadratic effect to increase total VFA (P<0.01) and linearly with pH (P<0.01), proportion of propionate (P=0.037), and valerate proportion (P=0.037). However, supplementation of M. elsdenii did not significantly affect (P>0.05) isobutyrate, isovalerate proportion, and protozoa population in the rumen. It can be concluded that M. elsdenii supplementation is proven to reduce lactic acid concentration, maintain rumen pH, reduce methane production and increase some rumen fermentation products.

In situ and in vitro methods used to evaluate food and diets of ruminants

In ruminant production systems, feeding can account for 60 to 70% of the costs of the activity, thus, the nutritional assessment of food and the formulation of balanced diets that meet the requirements of animals represent an important challenge in livestock production. Several methods have been used to evaluate the modulation of rumen fermentation and to estimate the degradation characteristics of food and diets intended for feeding ruminants. These methods involve measuring the disappearance of the substrate during incubation in the rumen (in situ), in the buffered rumen liquid (in vitro) and are mainly endpoint measurements. In addition, it is possible to evaluate the degradation kinetics by measuring the differences in residues at different incubation times. The assessment of the nutritional value of foods and diets is also possible through the use of techniques that measure gas production. These techniques measure the appearance of rumen fermentation products, such as carbon dioxide (CO2) and methane (CH4) gases, short-chain fatty acids, ammonia and microbial biomass. The aim of this review was to describe the main in situ and in vitro methods used to evaluate food for ruminants.

Profiles of Odd- and Branched-Chain Fatty Acids and Their Correlations With Rumen Fermentation Parameters, Microbial Protein Synthesis, and Bacterial Populations Based on Pure Carbohydrate Incubation in vitro.

The objectives of this study were to evaluate changes in profiles of odd- and branched-chain fatty acids (OBCFA), including pentadecanoic acid (C15:0), 13-methyltetradecanoic acid (iso-C15:0), 12-methyltetradecanoic acid (anteiso-C15:0), 14-methylpentadecanoic acid (iso-C16:0), heptadecanoic acid (C17:0), 15-methylhexadecanoic acid (iso-C17:0), and 14-methylhexadecanoic acid (anteiso-C17:0) during in vitro fermentation of pure carbohydrates mixtures in the buffer-rumen fluid. The second objective was to correlate the changes in the OBCFA profile to the corresponding changes in ruminal fermentation parameters, microbial crude protein (MCP) synthesis, and bacterial populations. Five pure carbohydrates mixtures containing different cellulose: starch (C:S) ratios, i.e., 0:100, 25:75, 50:50, 75:25, and 100:0, were incubated for 6, 12, 18, and 24 h in vitro. The results showed that there was significant interaction (P < 0.05) between C:S and incubation time for changes in all OBCFA profiles, except iso-C17:0. The highest concentration of total OBCFA (3.94 mg/g dry matter; DM) was observed in the residues after 24 h of fermentation when the C:S was 0:100, while the lowest concentration of OBCFA (1.65 mg/g DM) was produced after 6 h of incubation when the C:S was 50:50. The correlation analysis revealed that the concentration of iso-C16:0 might be a potential marker for the estimation of total volatile fatty acids (ρ = 0.78) and MCP synthesis (ρ = 0.82) in the rumen. Compared to starch degrading bacteria, cellulolytic bacteria had stronger correlations with OBCFA concentrations, and the strongest correlation was found between the population of Ruminococcus flavefaciens with C15:0 concentration (ρ = 0.70). Notably, this is the first paper reporting relationship between OBCFA with rumen fermentation products and microbial protein synthesis based on fermentation of pure carbohydrates mixtures in vitro, and thus avoid confounding interference from dietary protein and fat presence in the in vivo studies. However, more in-depth experiments are needed to substantiate the current findings.

Rumen microbiota and its relation to fermentation in lactose-fed calves

In our previous studies, we revealed the effect of lactose inclusion in calf starters on the growth performance and gut development of calves. We conducted the present study as a follow-up study to identify the shift in rumen microbiota and its relation to rumen fermentation when calves are fed a lactose-containing starter. Thirty Holstein bull calves were divided into 2 calf starter treatment groups: texturized calf starter (i.e., control; n = 15) or calf starter in which starch was replaced with lactose at 10% (i.e., LAC10; n = 15) on a dry matter basis. All calves were fed their respective treatment calf starter ad libitum from d 7, and kleingrass hay from d 35. Rumen digesta were collected on d 80 (i.e., 3 wk after weaning) and used to analyze rumen microbiota and fermentation products. There was no apparent effect of lactose feeding on the α-diversity and overall composition of rumen microbiota. Amplicon sequencing and real-time PCR quantification of the 16S rRNA gene confirmed that the abundance of butyrate-producing bacteria (i.e., Butyrivibrio group and Megasphaera elsdenii) did not differ between the control and LAC10 groups. Conversely, the relative abundance of Mitsuokella spp., which produce lactate, succinate, and acetate, was significantly higher in the rumen of calves that were fed lactose, whereas the lactate concentration did not differ between the control and LAC10 groups. These findings suggest that the lactate production can be elevated by an increase of Mitsuokella spp. and then converted into butyrate, not propionate, since the proportion of propionate was lower in lactose-fed calves. In addition, we observed a higher abundance of Coriobacteriaceae and Pseudoramibacter-Eubacterium in the LAC10 group. Both these bacterial taxa include acetate-producing bacteria, and a positive correlation between the acetate-to-propionate ratio and the abundance of Pseudoramibacter-Eubacterium was observed. Therefore, the higher abundance of Coriobacteriaceae, Mitsuokella spp., and Pseudoramibacter-Eubacterium in the rumen of lactose-fed calves partially explains the increase in the proportion of rumen acetate that was observed in our previous study.

Dynamics of rumen bacterial composition of yak (Bos grunniens) in response to dietary supplements during the cold season.

This study aimed to explore the rumen bacterial community of yak in response to dietary supplements during the cold season. In addition, the rumen fermentation products were also analyzed. Twenty-one female domestic yaks were randomly divided into three groups i.e., pure grazing (GG) group, grazing plus oats hay supplement (OG) group, and grazing plus concentrate supplement group (CG). Rumen contents were collected after 90 days to assess rumen fermentation parameters and bacterial community. The GC group presented higher concentrations of ammonia nitrogen (P < 0.001), and total volatile fatty acids (TVFA) (P < 0.001), and lower rumen pH (P < 0.001) compared to other experimental groups. The CG group displayed higher proportions of propionate, butyrate, isobutyrate, and isovalerate while lower A/P ratio compared to other experimental groups. Shannon, Chao1, and ACE values were significantly lower in the OG group compared to GG and CG groups. Anosim test showed significant differences in bacterial community structure between groups but the PCA plot was not very informative to see these differences. Bacteroidetes, Proteobacteria, and Firmicutes were the three dominant phyla in all groups. The genera Oscillospira was more abundant in GG and OG groups. Higher relative abundance of Ruminococcus and Clostridium was observed in the GG group, while Ruminobacter, Corynebacterium, and Selenomonas were more abundant in the CG group. These findings will help in improving our understanding of rumen bacteria in yaks in response to changes in diet.

Rumen un-degraded dietary protein and TCA soluble protein with gambier leave residue supplementation as a source of tannins in cattle feed supplement

This study aims to obtain high rumen undegraded dietary protein and TCA soluble protein in a rations combination of forage, concentrates, and supplements. Gambier leaf residue (GLR) supplementation in cattle feed supplement contains 29.53% crude protein and 75.01% TDN energy. There were 4 treatment rations, forage (F), F + concentrate (FC), F + supplement (FS), and FCS, where the tannin concentration of 0.117% was found in the FS and FCS rations. Rumen microbial degradation and microbial protein synthesis were evaluated in vitro method using cattle rumen fluid. The results showed that GLR supplementation as a source of condensed tannins significantly reduced the rate of protein degradation in the rumen from 1.17 to 0.99% per hour. This effect has implications for the increase in rumen undegraded dietary protein (RUDP) and Peptide-N as rumen fermentation products. Rations containing supplements (FS and FCS significantly produced higher microbial biomass and microbial protein. TCA soluble N was superior in the FCS combination ration which produced the highest amount of protein for intestine sourced from RUDP and microbial protein.

Improving Sakura Block Quality as Feed Supplement to Optimize Rumen Fermentation Products and Nutrients Digestibility In Vitro

Improving Sakura Block Quality as Feed Supplement to Optimize Rumen Fermentation Products and Nutrients Digestibility In Vitro