Rumen Concentrations Research Articles

Effects of water extracts of Artemisia annua L. on rumen immune and antioxidative indexes, fermentation parameters and microbials diversity in lambs.

The present study investigated the effects of water extracts of Artemisia annua L. (WEAA) on rumen immune and antioxidative indexes, fermentation parameters and microbial diversity in lambs. A total of 32 3-month-old Dorper × Han female lambs having comparable body weights (24±0.09 kg) were selected and were randomly assigned to four treatments, with eight repetitions for each treatment. The basal diet, consisting of 45% concentrate and 55% forage, was solely provided to the control group. For the other treatment groups, the basal diet was supplemented with WEAA at dosages of 500, 1000, and 1500 mg/kg diet, respectively. Rumen tissue samples were collected for the analysis of immune and antioxidative parameters, as well as related gene expression. Rumen fluid samples were collected to assess rumen fermentation parameters on days 30 and 60 and to evaluate the microbiota on day 60. Results showed that WEAA supplementation linearly or quadratically increased the content of sIgA, IL-4, IL-2 and the gene expression level of MyD88, IκB-α, IL-4, COX-2, iNOS in rumen tissue (p < 0.05), as well as the bacteria negatively associated with IL-6 (g_ [Eubacterium] _cellulosolvens_group). Furthermore, the addition of WEAA linearly or quadratically increased rumen T-SOD, GSH-Px (p < 0.05) and the gene expression level of Nrf2, SOD2, GSH-Px, HO-1 (p < 0.05), and decreased the rumen concentration of malondialdehyde (MDA) and gene expression level of Keap1 (p < 0.05), as well as the bacteria positively associated with T-AOC, T-SOD and GSH-Px (g_Lachnospiraceae_NK3A20_group, g_Saccharofermentans, g__Marvinbryantia, g_unclassified_f_Eggerthellaceae). The supplementation of WEAA caused the concentration of microprotein (MCP), total volatile fatty acids (TVFA), propionate to increase either linearly or quadratically, while reducing the concentration of NH3-N and the acetate/propionate ratio (A:P) in rumen fluid (p < 0.05). The addition of WEAA linearly or quadratically increased the abundance of Actinobacteriota, Cyanobacteria and Lachnospiraceae_NK3A20_group (p < 0.10), and g__Lachnospiraceae_NK3A20_group, g_Saccharofermentans, g_Marvinbryantia, g_Bifidobacterium were significantly abundant as specific microflora in the 1000 mg/kg WEAA supplementation group. In conclusion, dietary inclusion of 1000 mg/kg WEAA improved the rumen immune function, antioxidant status, rumen fermentation, and composition of rumen microbes in lambs.

Relationship between the rumen microbiome and liver transcriptome in beef cattle divergent for feed efficiency

BackgroundFeed costs account for a high proportion of the variable cost of beef production, ultimately impacting overall profitability. Thus, improving feed efficiency of beef cattle, by way of determining the underlying genomic control and selecting for feed efficient cattle provides a method through which feed input costs may be reduced whilst also contributing to the environmental sustainability of beef production. The rumen microbiome dictates the feed degradation capacity and consequent nutrient supply in ruminants, thus potentially impacted by feed efficiency phenotype. Equally, liver tissue has been shown to be responsive to feed efficiency phenotype as well as dietary intake. However, although both the rumen microbiome and liver transcriptome have been shown to be impacted by host feed efficiency phenotype, knowledge of the interaction between the rumen microbiome and other peripheral tissues within the body, including the liver is lacking. Thus, the objective of this study was to compare two contrasting breed types (Charolais and Holstein-Friesian) divergent for residual feed intake (RFI) over contrasting dietary phases (zero-grazed grass and high-concentrate), based on gene co-expression network analysis of liver transcriptome data and microbe co-abundance network of rumen microbiome data. Traits including RFI, dry matter intake (DMI) and growth rate (ADG), as well as rumen concentrations of volatile fatty acids were also included within the network analysis.ResultsOverall, DMI had the greatest number of connections followed by RFI, with ADG displaying the fewest number of significant connections. Hepatic genes related to lipid metabolism were correlated to both RFI and DMI phenotypes, whilst genes related to immune response were correlated to DMI. Despite the known relationship between RFI and DMI, the same microbes were not directly connected to these phenotypes, the Succiniclasticum genus was however, negatively connected to both RFI and ADG. Additionally, a stepwise regression analysis revealed significant roles for both Succiniclasticum genus and Roseburia.faecis sp. in predicting RFI, DMI and ADG.ConclusionsResults from this study highlight the interactive relationships between rumen microbiome and hepatic transcriptome data of cattle divergent for RFI, whilst also increasing our understanding of the underlying biology of both DMI and ADG in beef cattle.

Ruminal acidosis and its definition: A critical review

Ruminal acidosis occurs as a continuum of disorders, stemming from ruminal dysbiosis and disorders of metabolism, of varying severity. The condition has a marked temporal dynamic expression resulting in cases expressing quite different rumen concentrations of VFA, lactic acid, ammonia, and rumen pH over time. Clinical ruminal acidosis is an important condition of cattle and subclinical ruminal acidosis (SRA) is very prevalent in many dairy populations with estimates between 10 to 26% of cows in early lactation. Estimates of the duration of a case suggest the lactational incidence of the condition may be as high as 500 cases per 100 cows in the first 100 d of lactation. Historical confusion about the etiology and pathogenesis of ruminal acidosis led to definitions that are not fit for purpose as acidic ruminal conditions solely characterized by ruminal pH determination at a single point fail to reflect the complexity of the condition. Use of a model, based on integrated ruminal measures including VFA, ammonia, lactic acid, and pH, for evaluating ruminal acidosis is fit for purpose, as indicated by meeting postulates for assessing metabolic disease, but requires a method to simplify application in the field. While it is likely that this model, that we have termed the Bramley Acidosis Model (BAM), will be refined, the critical value in the model is that it demonstrates that ruminal acidosis is much more than ruminal pH. Disease, milk yield and milk composition are more associated with the BAM than rumen pH alone. Two single VFA, propionate and valerate are sensitive and specific for SRA, especially when compared with rumen pH. Even with the use of such a model, astute evaluations of the condition whether in experimental or field circumstances will be aided by ancillary measures that can be used in parallel or in series to enhance diagnosis and interpretation. Sensing methods including rumination detection, behavior, milk analysis, and passive analysis of rumen function have the potential to improve the detection of SRA; however, these may advance more rapidly if SRA is defined more broadly than by ruminal pH alone.

Exploring the combination of Asparagopsis taxiformis and phloroglucinol to decrease rumen methanogenesis and redirect hydrogen production in goats

Many strategies for mitigating enteric methane (CH4) emissions in ruminants have focused on suppressing the activity of rumen methanogens, but this often leads to excess dihydrogen (H2) accumulation in the rumen, which is subsequently expelled and represents a potential energy loss. We hypothesized that phloroglucinol could act as a H2 acceptor when rumen methanogenesis is inhibited and be potentially transformed into beneficial compounds for the animal. Eight adult goats were randomly assigned to a replicated 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments: two levels of Asparagopsis taxiformis as CH4 inhibitor [0 vs. 5 g/kg on a dry matter (DM) basis; AT- and AT+, respectively] and two levels of phloroglucinol as alternative H2 acceptor (0 vs. 20 g/kg DM, PG- and PG+, respectively). Therefore, four dietary treatments were considered: i) basal diet (AT-PG-); ii) A. taxiformis alone (AT+PG-); iii) phloroglucinol alone (AT-PG+); and iv) the combination of A. taxiformis and phloroglucinol (AT+PG+). Animals were fed a maintenance diet with a 70:30 forage-to-concentrate ratio. After 10 d of adaptation to the diet, enteric gas emissions were measured in respiration chambers during 3 d prior to rumen content sampling on d 14. Dietary supplementation with A. taxiformis decreased CH4 production (-33.9 %) and increased H2 emissions (+3465 %), along with greater rumen propionate concentration. In contrast, phloroglucinol supplementation alone did not impact CH4 emissions or the rumen concentration of the main microbial groups but substantially increased acetate molar proportion (+10.2 %) which could act as an alternative H2 acceptor. Moreover, when A. taxiformis was combined with phloroglucinol, it resulted in a decrease in H2 emissions (-68.1 %). However, this decrease in H2 emissions was not fully explained by the increase in the acetate as phloroglucinol led to an increase in acetate both when methanogenesis was inhibited and when it was not. These findings suggest that the rumen fermentation of phloroglucinol may capture some of the additional H2 arising from the inhibition of methanogenesis by A. taxiformis through pathways other than acetate formation. Moreover, H2 emissions were not eliminated and most of the decrease occurred during the post-prandial stage, suggesting that the efficiency of H2 redirection could be further improved.

Effect of Adding Yeast Cultures to High-Grain Conditions on Production Performance, Rumen Fermentation Profile, Microbial Abundance, and Immunity in Goats.

It is a common practice among farmers to utilize high-grain diets with the intention of promoting ruminant growth. However, this approach bears the risk of inducing rumen disorders and nutrient metabolism diseases. Yeast culture (YC) showed advantages in ruminant applications. The objective of this study was to evaluate the effects of adding two different types of YC to high-grain conditions on production performance, rumen fermentation profile, microbial abundance, and immunity in goats. A total of 30 male goats with similar body condition were randomly distributed into 3 dietary treatments with 10 replicates per treatment as follows: basic diet group (CON); basic diet + 0.5% yeast culture 1 (YC1) group; basic diet + 0.5% yeast culture 2 (YC2) group. The trial lasted for 36 days. The results demonstrated that dietary YC supplementation led to an increase in the average daily gain and a reduction in feed intake and weight gain ratio in goats. It increased the apparent digestibility of crude protein, NDF, and ADF (p < 0.05). The serum concentrations of interleukin (IL)-1β, IL-6, and Tumor Necrosis Factor-α in the control group were significantly higher than those of the YC groups (p < 0.05). The serum concentrations of Immunoglobulin (Ig)A and IgG in the control group were significantly lower than those in the YC groups (p < 0.05). The rumen concentration of microbial protein (MCP) in the control group was significantly lower than that in the YC groups (p < 0.05). There was a negative correlation between the concentration of IL-10 and Bacteroidota, Spirochaetota, and Succinivibrio, while there was a positive correlation between concentrations of IL-10 and Firmicutes. Nevertheless, discrepancies were observed in the impact of the two different types of YC on the physiological and biochemical indicators of the animals. The concentration of triglyceride in the YC1 group was significantly higher than that of the CON and YC2 groups, while the concentration of urea in the YC2 group was significantly higher than that of the CON and YC1 groups (p < 0.05). At the phylum level, the addition of YC2 to the diet significantly increased the relative abundance of Bacteroidota and Fibrobacterota and significantly decreased Firmicutes compared to the control. At the genus level, the addition of YC1 to the HGD significantly reduced the relative abundance of Rikenellaceae_RC9_gut_group, while the addition of YC2 to the HGD significantly increased the relative abundance of Prevotellace-ae_UCG-001, Fibrobacter, and Prevotellaceae_UCG-003 (p < 0.05). The addition of YC significantly improved growth performance, increased nutrient digestibility, beneficially manipulated ruminal fermentation and microbial diversity, and improved immune function. The choice of yeast cultures can be customized according to specific production conditions.

A Meta-Analysis of 3-Nitrooxypropanol Dietary Supplementation on Growth Performance, Ruminal Fermentation, and Enteric Methane Emissions of Beef Cattle

This study aimed to evaluate the effects of dietary supplementation with 3-nitrooxypropanol (3-NOP) on growth performance, ruminal fermentation, and enteric methane emissions of beef cattle using a meta-analytic approach. The final meta-analysis database included results from 15 scientific articles. The response variables were analyzed through random effects models, where the results were reported as weighted mean differences (WMD) between the treatments without 3-NOP and those supplemented with 3-NOP. The dietary inclusion of 3-NOP decreased (p &lt; 0.001) dry matter intake but did not affect (p &gt; 0.05) average daily gain and increased (p &lt; 0.05) feed efficiency. In the rumen, 3-NOP supplementation increased (p &lt; 0.01) the pH and ruminal concentration of propionate, butyrate, valerate, isobutyrate, and isovalerate. In contrast, dietary supplementation with 3-NOP decreased (p &lt; 0.001) the rumen concentration of ammonia nitrogen, total volatile fatty acids, acetate, and the acetate/propionate ratio. Furthermore, daily methane (CH4) emission, CH4 yield, and CH4 emission as a percentage of gross energy ingested decreased (p &lt; 0.001) in response to 3-NOP dietary supplementation. In conclusion, dietary supplementation with 3-nitrooxypropanol can be used as a nutritional strategy to improve feed efficiency and ruminal fermentation in beef cattle and, at the same time, reduce enteric methane emissions.

Capsaicin as a Dietary Additive for Dairy Cows: A Meta-Analysis on Performance, Milk Composition, Digestibility, Rumen Fermentation, and Serum Metabolites.

This study aimed to evaluate the effects of dietary supplementation with capsaicin (CAP) on productive performance, milk composition, nutrient digestibility, ruminal fermentation, and serum metabolites of dairy cows using a meta-analytical approach. The database included 13 studies, from which the response variables of interest were obtained. Data were analyzed using a random effects model, and results were expressed as weighted mean differences between treatments supplemented with and without CAP. Dietary supplementation with CAP increased (p < 0.05) dry matter intake, milk yield, feed efficiency, milk fat yield, and milk fat content. However, CAP supplementation did not affect (p > 0.05) milk protein and lactose yield, milk urea nitrogen, or milk somatic cell count. Greater (p < 0.05) apparent digestibility of dry matter and crude protein was observed in response to the dietary inclusion of CAP. Likewise, supplementation with CAP increased (p < 0.05) the rumen concentration of total volatile fatty acids. In contrast, CAP supplementation did not affect (p > 0.05) ruminal pH or the ruminal concentration of ammonia nitrogen, acetate, propionate, and butyrate. In blood serum, CAP supplementation increased (p < 0.05) the glucose concentration and decreased (p < 0.05) the concentration of non-esterified fatty acids. However, CAP supplementation did not affect (p > 0.05) the serum concentration of urea and beta-hydroxybutyrate. In conclusion, capsaicin can be used as a dietary additive to improve the productive performance, milk composition, and nutrient digestibility in dairy cows and, at the same time, improve the ruminal concentration of total volatile fatty acids and serum levels of glucose and non-esterified fatty acids.

Investigations of morphological development, digestive enzymes and microbiome of the gastrointestinal tract in goat kids from birth to adulthood

ABSTRACT The development of gastrointestinal tracts in goats after birth is critical for establishment of digestion and absorption function, growth, immunity and health of adults. However, this process from birthday to adulthood is lacking. This study was conducted to determine the anatomical, morphological, physiological and microbiome development of the gastrointestinal tract of Leizhou goats. The weights of rumen, reticulum, omasum and abomasum increased with age. The weights of each intestinal segment increased with age. The length and width of rumen papilla, muscular thickness, cuticle thickness and wall thickness were significantly increased with developmental stage. Consistently, the villus length and width and crypt depth of the small intestine increased significantly with age. The volatile fatty acids (VFAs) concentration in both rumen and caecum increased with ages. Specifically, VFAs were not detected at birthday rumen, while they showed in caecum. The activities of digestive enzymes in both rumen and caecum had a similar pattern with VFAs. The microbial diversity and composition were distinct between the rumen and caecum after birth. We observed a rapid influx of microbes in rumen and caecum at birthday and gradually changed from 1 month of age to adulthood. This study provides insights into feeding and health maintenance strategies.

Effects of direct-fed microbial supplement on ruminal and plasma metabolome of early-lactation dairy cows: Untargeted metabolomics approach

We examined the effects of 2 multispecies direct-fed microbial (DFM) supplements on ruminal and plasma metabolome of early-lactation dairy cows using a high-coverage untargeted metabolomics approach. A total of 45 multiparous Holstein cows (41 ± 7 DIM) were enrolled for the 14-d pre-experimental and 91-d experimental period and were a subset from a lactation performance study, which used 114 cows. Cows were blocked using pre-experimental energy-corrected milk yield and randomly assigned within each block to 1 of 3 treatments: (1) corn silage-based diet with no DFM supplement (control; CON), (2) basal diet top-dressed with a mixture of Lactobacillus animalis and Propionibacterium freudenreichii at 3 × 109 cfu/d (PRO-A), or (3) basal diet top-dressed with a mixture of L. animalis, P. freudenreichii, Bacillus subtilis, and Bacillus licheniformis at 11.8 × 109 cfu/d (PRO-B). The basal diet was fed ad libitum daily as a TMR at 0600 and 1200 h for a duration of 91 d. Rumen fluid and blood samples were taken on d -3, 28, 49, 70, and 91 and immediately stored at -80°C. Before analysis, ruminal and plasma samples from d 28, 49, 70, and 91 were composited. An in-depth, untargeted metabolome profile of the composite rumen and plasma samples and the d -3 samples was developed by using a chemical isotope labeling/liquid chromatography-mass spectrometry (LC-MS)-based technique. Differentially abundant metabolites (taking into account fold change [FC] values and false discovery rates [FDR]) were identified with a volcano plot. In the rumen, compared with the CON diet, supplemental PRO-A increased (FC ≥1.2; FDR ≤0.05) the relative concentrations of 9 metabolites, including 2-hydroxy-2,4-pentadienoic acid, glutaric acid, quinolinic acid, and shikimic acid, and PRO-B increased relative concentrations of 16 metabolites, including 2-hydroxy-2,4-pentadienoic acid, glutaric acid, 16-hydroxypalmitic acid, and 2 propionate precursors (succinic and methylsuccinic acids). Relative to PRO-A, supplemental PRO-B increased (FC ≥1.2; FDR ≤0.05) relative rumen concentrations of 3 metabolites, 16-hydroxypalmitic acid, indole-3-carboxylic acid, and 5-aminopentanoic acid, but reduced relative rumen concentrations of 13 metabolites, including carnitine, threonic acid, and shikimic acid. Compared with the CON diet, relative concentrations of 13 plasma metabolites, including myxochelin A and glyceraldehyde, were increased (FC ≥1.2; FDR ≤0.05) by PRO-A supplementation, whereas those of 9 plasma metabolites, including 4-(2-aminophenyl)-2,4-dioxobutanoic acid, N-acetylornithine, and S-norlaudanosolin, were reduced (FC ≤0.83; FDR ≤0.05). Supplemental PRO-B increased (FC ≥1.2; FDR ≤0.05) relative concentrations of 9 plasma metabolites, including trans-o-hydroxybenzylidenepyruvic acid and 3-methylsalicylaldehyde, and reduced relative concentrations of 4 plasma metabolites, including β-ethynylserine and kynurenine. Pathway analysis of the differentially abundant metabolites in both rumen and plasma revealed that these metabolites are involved in AA and fatty acid metabolism and have antimicrobial and immune-stimulating properties. The results of this study demonstrated that dietary supplementation with either PRO-A or PRO-B altered the plasma and ruminal metabolome. Notably, ruminal and plasma metabolites involved in the metabolism of AA and fatty acids and those with immunomodulatory properties were altered by either or both of the 2 microbial additives.

Effects of adding Sophora alopecuroides to high concentrate diet on rumen fermentation parameters and microbial diversity of sheep.

The purpose of this study was to investigate the effects of different doses of Sophora alopecuroides (SA) on the rumen fermentation and microbial diversity of sheep. A total of 32 healthy Dumont crossbred male lambs weighing 25.73 ± 2.17 kg were randomly assigned to 4 treatment groups with 8 replicates each: a control group (CG) fed a basal diet with a concentrate-to-forage ratio of 7:3 and three experimental groups - the 0.1% group(TG1), 0.3% group (TG2), and 0.5% group (TG3), which were fed the same basal diet but supplemented with increasing doses of SA. (1) Increasing the SA dose led to a significant linear increase (p-< 0.05) in acetate, propionate, butyrate, and total volatile fatty acid (TVFA) concentrations in the rumen, as well as a significant quadratic effect (p-< 0.05) on the propionate concentration. In contrast, there was a significant linear decrease (p-< 0.05) in the NH3-N concentration in the rumen. (2) At the level of rumen bacterial phyla, the abundance of Bacteroidetes in the rumen increased, and that of Firmicutes decreased (p = 0.08). At the genus level, the rumen abundances of Ruminococcus and Phocaeicola of sheep in the three experimental groups were significantly higher than in the control group (p-< 0.05), and the abundances of Clostridiales and Candidatus-Hepatincola were significantly increased in the 0.1% and 0.3% groups (p < 0.05). (3) Regarding rumen anaerobic fungi, the differences between the control group and experimental groups at the phylum level and genus level were not significant (p > 0.05), but the relative abundances of Neocallimastigomycota and Piromyces in the 0.1% group were significantly higher than that in the control group. SA addition to a high grain diet could increase the VFA concentration and pH in the sheep rumen, reduce the NH3-N concentration in the rumen and improve rumen fermentation function. Although there was no significant change in rumen bacterial or fungal diversity, SA addition increased the rumen abundances of Bacteroidetes, Ruminococcus, Phocaeicola, Clostridiales, Neocallimastigomycota and Piromyces, decreased the rumen abundance of Firmicutes, and had a positive effect on the rumen microbiota to improve sheep health.

Effect of Blend-Pelleted Products Based on Carinata Meal or Canola Meal in Combination with Lignosulfonate on Ruminal Degradation and Fermentation Characteristics, Intestinal Digestion, and Feed Milk Value When Fed to Dairy Cows

The objectives of this study were to investigate the effect of newly developed blend-pelleted products based on carinata meal (BPPCR) or canola meal (BPPCN) in combination with peas and lignosulfonate on ruminal fermentation characteristics, degradation kinetics, intestinal digestion and feed milk values (FMV) when fed to high-producing dairy cows. Three dietary treatments were Control = control diet (common barley-based diet in western Canada); BPPCR = basal diet supplemented with 12.3%DM BPPCR (carinata meal 71.4% + pea 23.8% + lignosulfonate4.8%DM), and BPPCN = basal diet supplemented with 13.3%DM BPPCN (canola meal 71.4% + pea 23.8% + lignosulfonate 4.8%DM). In the whole project, nine mid-lactating Holstein cows (body weight, 679 ± 124 kg; days in milk, 96 ± 22) were used in a triplicated 3 × 3 Latin square study for an animal production performance study. For this fermentation and degradation kinetics study, the experiment was a 3 × 3 Latin square design with three different dietary treatments in three different periods with three available multiparous fistulated Holstein cows. The results showed that the control diet was higher (p &lt; 0.05) in total VFA rumen concentration (138 mmol/L) than BPPCN. There was no dietary effect (p &gt; 0.10) on the concentration of rumen ammonia and ruminal degradation kinetics of dietary nutrients. There was no significant differences (p &gt; 0.10) among diets on the intestinal digestion of nutrients and metabolizable protein. Similarly, the feed milk values (FMV) were not affected (p &gt; 0.10) by diets. In conclusion, the blend-pelleted products based on carinata meal for a new co-product from the bio-fuel processing industry was equal to the pelleted products based on conventional canola meal for high producing dairy cattle.

Consumo e digestibilidade aparente dos nutrientes, parâmetros ruminais e balanço de N de cordeiros confinados recebendo dietas com milho e sem forragem com bicarbonato de sódio

ABSTRACT: This study evaluated forage-free diets supplemented with sodium bicarbonate (SB) based on ground flint corn on intake, apparent nutrient digestibility, ruminal parameters, and N balance. Four rumen-cannulatedDorper × Santa Inês lambs, with a body weight of 43.4 ± 0.85 kg (mean ± standard deviation) were used. The experimental design was a 4×4 Latin square. Each experimental period lasted 21 days. Experimental diets were: positive control, a diet without SB containing 400 g/kg DM of soybean hulls (CONT), and three diets based on ground flint corn, containing 10 (10SB), 20 (20SB) or 30 (30SB) g/kg DM of SB. Intake of neutral and acid detergent fiber was greater for CONT (P &lt; 0.01) when compared to SB. Intake and apparent nutrient digestibility of dry and organic matter, ether extract, and crude protein did not differ. Intake (P = 0.01) and digestibility (P &lt; 0.01) of non-fiber carbohydrates were greater for SB diets and neutral detergent fiber digestibility was greater (P = 0.03) for CONT. The total digestible nutrients and metabolizable energy were greater for SB (P = 0.04). Rumen concentrations of acetate (P &lt; 0.01), isobutyrate (P &lt; 0.01), butyrate (P &lt; 0.01), isovalerate (P &lt; 0.01), and total short-chain fatty acids (P &lt; 0.01) were greater for CONT. Ruminal pH showed a quadratic (P = 0.05) response to SB levels, with greater values for 20SB. Sodium bicarbonate was efficient in increasing ruminal pH at the level of 20 g/kg DM without interfering with the intake and apparent nutrient digestibility characteristics.

Effects of supplementation of sodium acetate on rumen fermentation and microbiota in postpartum dairy cows.

The primary product of rumen fermentation is acetic acid, and its sodium salt is an excellent energy source for post-partum cows to manage negative energy balance (NEB). However, it is unknown how adding sodium acetate (NAc) may affect the rumen bacterial population of post-partum cows. Using the identical nutritional total mixed ration (TMR), this research sought to characterize the impact of NAc supplementation on rumen fermentation and the composition of bacterial communities in post-partum cows. After calving, 24 cows were randomly assigned to two groups of 12 cows each: a control group (CON) and a NAc group (ACE). All cows were fed the same basal TMR with 468 g/d NaCl added to the TMR for the CON group and 656 g/d NAc added to the TMR for the ACE group for 21 days after calving. Ruminal fluid was collected before morning feeding on the last day of the feeding period and analyzed for rumen bacterial community composition by 16S rRNA gene sequencing. Under the identical TMR diet conditions, NAc supplementation did not change rumen pH but increased ammonia nitrogen (NH3-N) levels and microbial crude protein (MCP) concentrations. The administration of NAc to the feed upregulated rumen concentrations of total volatile fatty acids (TVFA), acetic, propionic, isovaleric and isobutyric acids without affecting the molar ratio of VFAs. In the two experimental groups, the Bacteroidota, Firmicutes, Patescibacteria and Proteobacteria were the dominant rumen phylum, and Prevotella was the dominant rumen genus. The administration of NAc had no significant influence on the α-diversity of the rumen bacterial community but upregulated the relative abundance of Prevotella and downregulated the relative abundance of RF39 and Clostridia_UCG_014. In conclusion, the NAc supplementation in the post-peripartum period altered rumen flora structure and thus improved rumen fermentation in dairy cows. Our findings provide a reference for the addition of sodium acetate to alleviate NEB in cows during the late perinatal period.

Dietary Supplementation of Fruit from Nitraria tangutorum Improved Immunity and Abundance of Beneficial Ruminal Bacteria in Hu Sheep.

The fruit of Nitraria tangutorum (FNT) is reputed to possess medicinal properties; however, its effect on sheep (Ovis aries) is unknown. The aim of this study was to fill this gap. In a 3 × 3 Latin square design, six 12-month-old rumen-fistulated Hu rams (56.2 ± 8.26 kg; mean ± SD) were penned individually and offered one of three levels of FNT, namely, 0 g/d (control; CON), 16 g/d (N16), and 48 g/d (N48). The concentration of serum immunoglobulin G increased linearly (p = 0.03) with an increasing intake of FNT. The serum concentration of β-hydroxybutyrate in the N48 group was lower than in the CON group (p = 0.01) and decreased linearly with increasing FNT (p = 0.001). The concentration of serum lactate dehydrogenase tended to decrease (p = 0.07) linearly with an increase in FNT intake, while the concentration of glucose did not differ among groups (p = 0.14) but displayed a quadratic curve with an increase in FNT (p = 0.05). The rumen concentration of lipase decreased linearly with increasing FNT (p = 0.04). The rumen fermentation variables were not affected by FNT. The FNT intake increased the abundance of beneficial ruminal bacteria, such as Lachnoclostridium, Rhodocyclaceae, and Candidatus Arthromitus. Prevotella, Rikenellaceae_RC9_gut_group, Ruminococcus, Olsenella, Lachnospiraceae_NK3A20_group, and Quinella were the dominant bacterial genera in all treatments. We conclude that FNT can improve immunity and increase the relative abundance of beneficial ruminal bacteria in sheep.

Intake, digestibility, ruminal parameters, and performance in lamb fed with increasing levels of red propolis extract.

The objective of this study was to examine the effect of increasing levels of red propolis extract (RPE) on the intake, digestibility, feeding behavior, rumen parameters, metabolic parameters, and performance of feedlot lambs. Thirty-five uncastrated male Santa Inês lambs with an initial weight of 17.08 ± 2.36kg were used in a completely randomized design with five treatments (0, 7, 14, 21, or 28mL RPE/animal/day). The animals were confined for 68days. Red propolis extract induced a negative quadratic response (P < 0.05) in the intakes of dry matter, organic matter, crude protein, ether extract, neutral detergent fiber, non-fibrous carbohydrates, and metabolizable energy. The apparent digestibility coefficients of dry matter, organic matter, and neutral detergent fiber, as well as the rumen concentration of NH3-N, also responded quadratically (P < 0.05) to RPE. Feeding efficiency increased linearly (P < 0.05) with the inclusion of RPE, whereas rumination efficiency was maximum (P < 0.05) at the RPE level of 16mL/day. Red propolis extract induced a linear response (P < 0.05) in serum total protein, albumin, creatinine, and gamma-glutamyl transpeptidase. There was a quadratic effect on final body weight and average daily gain with minimum values for inclusion of RPE of 12.89mL/day and 10.93mL/day respectively. Feed efficiency rose linearly (P < 0.05) with the increasing concentrations of RPE in the diet. The inclusion of 21mL RPE/day (8.5mg total flavonoids/mL) in the diet of feedlot lambs is recommended to reduce the rumen NH3-N production and increase the animals' performance.

PSII-B-18 Açai Seed as Fiber Source on Intake, Digestibility and Ruminal Parameters in Zebu Beef Cattle fed a High Concentrate Diet

Abstract This study was designed to evaluate the effects of açaí seed (AS) as a fiber source on intake, digestibility, and ruminal fermentation parameters of beef cattle fed a high concentrate diet. Five rumen-fistulated Zebu bulls were used in a 5x5 Latin-square design. Treatments consisted of five diets with different inclusion rates of AS: 0, 5, 10, 15, and 20% of the diet dry matter (DM). The total mixed ration contained 75% of concentrate and 25% of roughage. Mombasa grass silage and AS were used as the roughage sources. The concentrate portion of the diet contained cracked corn (61.8%), soybean meal (8%) and vitamin/mineral premix (5.2% of DM). Each experimental period lasted 25 d and the last 11 d were used for data collection. Total fecal collections were performed over three days. Titanium dioxide was used to estimate the omasal outflow. Statistical significance was declared at P &amp;lt; 0.05, and tendency at 0.05 &amp;gt; P &amp;lt; 0.10. A linear increase was observed for DM (P= 0.07), organic matter (P &amp;lt; 0.05), crude protein (CP, P &amp;lt; 0.05), and neutral detergent fiber (NDF) intake with the inclusion rate of AS. Intake was greatest in bulls receiving diets containing 20% AS. A linear decrease (P&amp;lt; 0.05) in NDF digestibility was detected with the inclusion rate of AS. DM, CP digestibility, and metabolic energy were similar across treatments (P &amp;gt; 0.10). Ruminal and intestinal DM and nutrient digestibility were similar between the treatments (P &amp;gt; 0.10). Rumen concentrations of acetic acid increased (P &amp;lt; 0.05), and total short-chain fatty acids (P = 0.07) and butyrate (P = 0.08) tended to increase linearly with the inclusion of AS. Açaí seed as a source of fiber in confined Zebu bulls diets alters DM intake and rumen fermentation but has no impact on total tract DM digestibility.

Effects of rumen-protected lysine and methionine supplementation in low-crude protein diets on lactation performance, nitrogen metabolism, rumen fermentation, and blood metabolites in Holstein cows

The objective of the study was to investigate the effects of supplementing a low-protein diet with rumen-protected lysine (RP-Lys) and RP-methionine (RP-Met) on milk production, nitrogen metabolism, and rumen fermentation in dairy cows. Forty-eight Holstein dairy cows were blocked by parity (2.1 ± 0.17), milk production (32.1 ± 3.41 kg/d), and days in milk (124 ± 28 d), and randomly assigned to 1 of 4 dietary treatments: control diet (CON, 16 % CP), low-protein diet (LP, 14 % CP, negative control), a moderate diet supplemented with RP-Met (31 g/d) and RP-Lys (MPML, 15 % CP, 110 g/d), and LP diet with RP-Met (50 g/d) and RP-Lys (LPML, 14 % CP, 150 g/d). Dry matter intake (DMI), feed efficiency, and the apparent total tract digestibility of nutrients was not affected by treatments. Compared with the CON, the milk yield was increased in the MPML treatment (P = 0.03) while decreased in the LP treatment (P = 0.02). Milk protein yield in the MPML treatment was higher than that in the other treatments (P < 0.05). The LP, LPML, and MPML treatments had lower concentrations of milk urea-N and plasma urea-N than CON treatments (P < 0.01). The LP, LPML, and MPML treatments decreased the plasma histidine (His) concentration (P < 0.01), while the LP and LPML treatments decreased plasma arginine (Arg) concentration (P < 0.05) compared to the CON treatment. Plasma Met concentration in the MPML treatment was increased (P < 0.01), whereas was decreased in the LP treatment, compared with the CON (P < 0.05). The N intake (g/d) in the LP, LPML, and MPML treatments was lower than that in the CON treatment (P < 0.01), while fecal N (g/d) was not affected by treatments. However, CON treatment increased the urine N (g/d), total excreta N (g/d), N secretion and excretion (g/d), and the proportions of urine N to N intake, whereas decreased the proportion of milk N to N intake and milk N efficiency, compared to the other three treatments (P < 0.01). The rumen concentration of ammonia nitrogen in the LP, LPML, and MPML treatments was lower than that in the CON treatment (P < 0.05). Collectively, the low-protein diets supplemented with RP-Met and RP-Lys could increase milk N efficiency and dramatically decrease urinary N losses. From the perspective of N emission reduction, a 2% reduction in dietary CP was rational.

Influence of partial replacement of alfalfa with two Salicornia forages on digestion, rumen variables, blood biochemistry metabolites and antioxidant capacity in sheep

In a completely randomized design, 24 Shall rams (average initial body weight [BW]: 43 ± 1.4 kg, aged 1.5 years) were used to evaluate the effects of partial replacement of alfalfa (Medicago sativa) hay with 2 species of Salicornia forage (i.e. bigelovii and persica) on in vivo total tract apparent digestibility, estimated microbial N synthesis (EMNS), rumen fluid parameters, blood metabolites, total antioxidant capacity (TAC) and production of methane in vitro. The three diets offered to sheep (8 per diet) prepared on a dry matter basis were 1- alfalfa hay (990 g/kg DM) + 10 g/kg DM vitamin-mineral supplement (control; AD), 2- alfalfa hay + Salicornia bigelovii (SBF) + vitamin-mineral supplement at a ratio of 690:300:10 (SBD), and 3- alfalfa hay + Salicornia persica (SPF) + vitamin-mineral supplement at a ratio of 690:300:10 (SPD). Salicornia diets did not affect DM, organic matter, crude protein or neutral detergent fiber digestibility. There was no dietary effect on in vivo ruminal pH, volatile fatty acids, or in vitro methane production. Salicornia diets increased rumen concentration of ammonia-N, total numbers of protozoa, and the population of Entodiniinae, whereas the cellulolytic bacteria population and EMNS decreased. Feeding SBD and SPD had no effect on the concentration of plasma albumin, cholesterol, glucose, total protein, triglyceride, and the albumin-globulin ratio but urea-N and TAC increased. Overall, replacing part of the alfalfa hay ration with SBF or SPF improved TAC in sheep with no negative effects on nutrient digestibility or in vitro methane production. This trial showed that Salicornia could be used as a partial substitute for conventional forage in the diet of sheep.

TECHNICAL NOTE: Analysis of volatile fatty acids in rumen fluid by gas chromatography mass spectrometry using a dimethyl carbonate extraction.

Analysis of rumen fluid volatile fatty acids (VFA) is typically conducted by injecting acidified aqueous rumen fluid into a gas chromatograph (GC) with a flame ionization detector (FID). Aqueous samples are highly problematic because of the large vapor volume that can lead to poor peak shape and contamination of inlets, potentially causing sample carryover. Methods using aqueous samples are not well suited for use in a mass spectrometer (MS) detector system. The objective of this project was to validate a dimethyl carbonate (DMC) extraction process and GCMS method for rumen VFA analysis. To perform the extraction, 100 µL of sample, KHSO4 (500 g/L), and 2-ethylbutyrate (internal standard; 8.5 mM) were added to a microcentrifuge tube (in order) followed by 1 mL of DMC. The mixture was thoroughly vortexed and centrifuged. The organic layer (top) was removed and placed in a GC vial. The DMC extract was injected (0.5 µL) into an Agilent 5977B GCMS (8:1 split injection) with a polar DB-FFAP column. The column was held at 105 °C for 5 min, increased at 10 °C/min to 150 °C, then 65 °C/min to 240 °C, and held constant for 10 min. The peak area of acetate relative to the internal standard is linear from approximately 2 mM to at least 130 mM and encompasses the expected values of rumen concentrations for the other VFA. Recovery of VFA from spiked rumen fluid was tested at three concentrations in rumen fluid from steers fed a finishing diet or grazing wheat pasture. Recovery was not affected by the diet of the animals (P > 0.10) or the amount of VFA spiked (P > 0.19) for acetate, propionate, isobutyrate, or butyrate. There was an interaction of amount of VFA spiked and the diet of the animal (P = 0.021) for valerate and a tendency for an interaction (P = 0.051) for isovalerate, due to the recovery of the VFA being lower in the medium spike amount in rumen fluid from cattle on wheat pasture. Overall, recovery was greatest for propionate (101.9 ± 1.67%) and lowest for valerate (95.7 ± 1.95%). Including the 10-min hold at 240 °C at the end of each run prevented carryover from sample to sample. This method appears to perform well in a GCMS system and accurately and precisely quantifies rumen fluid VFA.

Effects of País grape marc inclusion in high and low forage diets: ruminal fermentation, methane production and volatile fatty acids

The objective of this study was to evaluate the effects of the inclusion of País grape marc (GM) in high (HF) and low forage (LF) ruminant diets on rumen methane (CH4) production and fermentation parameters in an in vitro (batch) culture. Experimental treatments replaced forage for GM at increasing concentrations (0, 10%, 20% dry matter [DM]) in the incubation substrates. Gas production (GP) and CH4 production were measured at 6, 12 and 24 h of incubation and in vitro DM disappearance, volatile fatty acids (VFA) and ammonia nitrogen (NH3-N) were determined at 24 h. The inclusion of 10% and 20% of GM reduced NH3-N concentrations (p < 0.001) by 48% and 58% respectively, and GM20 inclusion reduced BCVFA concentrations (p = 0.049) by 21% for HF and by 11% LF. Inclusion of 20% GM reduced the percentage of CH4 in gas (p = 0.038), CH4 production (p = 0.004) and CH4 yield (p = 0.027), but leads to a reduction of in vitro dry matter disappearance (IVDMD) (p < 0.001), gas production (p < 0.001) and total VFA (p = 0.001). In conclusion, in batch culture conditions, partial substitution of fibre sources by País GM in high and low fibre diets has the potential to reduce NH3-N concentrations and CH4 production and yield with a reduction of IVDMD. HIGHLIGHTS País GM reduces up to 58% in vitro NH3-N rumen concentrations regardless of forage level in the diet. Partial substitution of fibre sources with País GM reduces methane production by up to 15%. Partial substitution of forage sources with País grape marc has the potential to improve livestock systems sustainability.