Molar Proportions Of Valerate Research Articles

Effects of a liquid and dry Saccharomyces cerevisiae fermentation product feeding program on ruminal fermentation, total tract digestibility, and plasma metabolome of Holstein steers receiving a grain-based diet.

The study aimed to determine the effects of a postbiotic feeding program consisting of liquid and dry Saccharomyces cerevisiae fermentation product (SCFP) on ruminal fermentation, digestibility, and plasma metabolome of Holstein steers receiving a grain-based diet. Eight Holstein steers (body weight, BW, 467 ± 13.9kg) equipped with rumen cannulas were used in a crossover design study, with 21 d per period and a 7-d washout period in between periods. Steers were stratified by initial BW and assigned to 1 of 2 treatments. The treatments were 1) Control, basal finishing diet only (CON); 2) SCFP, 1-d feeding of liquid SCFP (infused into the rumen via the cannula at 11mL/100kg BW) followed by daily feeding of dry SCFP (12g/d, top-dressed). Feed and spot fecal samples were collected during days 17 to 20 for determination of digestibility and fecal excretion of N, P, Cu, and Zn. Digestibility was measured using acid-insoluble ash as an internal marker. Blood samples were collected on day 21 before the morning feeding. Rumen fluid samples were collected on days 0, 1, 2, 3, 5, and 21 via rumen cannula. Results were analyzed with the GLIMMIX procedure of SAS 9.4 (SAS, 2023). Treatment did not affect dry matter intake (P = 0.15) and digestibility (P ≥ 0.62). The fecal output and absorption of Zn, Cu, P, and N were not affected (P > 0.22) by treatment. On day 1, the liquid SCFP supplementation tended to reduce (P = 0.07) ruminal VFA concentration and increased (P < 0.01) the molar proportion of valerate. Feeding SCFP tended to increase total ruminal VFA on day 5 (P = 0.08) and significantly increased total VFA on day 21 (P = 0.05). Ruminal NH3-N was reduced (P = 0.02) on day 21 by supplementing SCFP. Treatment did not affect the production of proinflammatory cytokines, interleukin (IL)-1β (P > 0.19), and IL-6 (P > 0.12) in the whole blood in response to various toll-like receptor stimulants in vitro. Feeding SCFP enriched (P ≤ 0.05) plasma metabolic pathways, including citric acid cycle, pyrimidine metabolism, glycolysis/gluconeogenesis, retinol metabolism, and inositol phosphate metabolism pathways. In summary, supplementing liquid SCFP with subsequent dry SCFP enhanced ruminal total VFA production and reduced NH3-N concentration in the rumen. Furthermore, feeding SCFP enriched several important pathways in lipid, protein, and glucose metabolism, which may improve feed efficiency of energy and protein in Holstein steers.

PSXVI-23 The influence of trace mineral source on digestion, ruminal fermentation characteristics, and mineral solubility in beef cattle fed a high concentrate feedlot diet

Abstract Twelve Angus steers (BW 530.9 ± 22.7kg) fitted with ruminal cannulae were used to determine the impact of trace mineral (TM) source on digestibility and ruminal VFA and soluble concentrations of Cu, Mn, and Zn. Steers were fed a high concentrate diet balanced to meet the requirement of finishing feedlot steers for 21d. Treatments consisted of Cu, Mn, and Zn supplemented at 18, 40, and 90 mg/kg DM, respectively, from either sulfate (STM) or hydroxy trace mineral (HTM) sources (n = 6 steers/treatment; experimental unit = steer). Following a 21-d adaptation period total fecal output was collected for 5 d. Trace mineral sources had no impact on nutrient digestibility. On d 6, rumen fluid was collected at 0, 2, and 4 h post-feeding for VFA analysis. There were no treatment x time interactions for any VFA measured. However, HTM steers had greater (P &amp;lt; 0.05) ruminal molar proportions of propionate and tended (P &amp;lt; 0.07) to have greater molar proportions of valerate compared to STM steers. Steers fed STM had greater (P &amp;lt; 0.05) molar proportions of butyrate compared to HTM steers. Steers were then fed the same high concentrate diet without supplemental Cu, Zn, or Mn for 14 d. On d 15 steers received a pulse dose (via rumen cannula) from either STM or HTM. Ruminal samples were obtained at 2 h intervals starting at -4 and ending at 24 h relative to dosing. There was a treatment x time interaction (P &amp;lt; 0.05) for ruminal soluble Cu concentrations. Ruminal soluble mineral concentrations were greater (P &amp;lt; 0.05) for Cu at 4, 6, 8, and 16 h post-dosing in STM compared to HTM supplemented steers. Results indicate that ruminal solubility of Cu differs between STM and HTM sources and may impact rumen fermentation characteristics.

Association of fibre degradation with ruminal dissolved hydrogen in growing beef bulls fed with two types of forages.

The present study investigated the association between fibre degradation and the concentration of dissolved molecular hydrogen (H2) in the rumen. Napier grass (NG) silage and corn stover (CS) silage were compared as forages with contrasting structures and degradation patterns. In the first experiment, CS silage had greater 48-h DM, neutral-detergent fibre (NDF) and acid-detergent fibre degradation, and total gas and methane (CH4) volumes, and lower 48-h H2 volume than NG silage in 48-h in vitro incubations. In the second experiment, twenty-four growing beef bulls were fed diets including 55 % (DM basis) NG or CS silages. Bulls fed the CS diet had greater DM intake (DMI), average daily gain, total-tract digestibility of OM and NDF, ruminal dissolved methane (dCH4) concentration and gene copies of protozoa, methanogens, Ruminococcus albus and R. flavefaciens, and had lower ruminal dH2 concentration, and molar proportions of valerate and isovalerate, in comparison with those fed the NG diet. There was a negative correlation between dH2 concentration and NDF digestibility in bulls fed the CS diet, and a lack of relationship between dH2 concentration and NDF digestibility with the NG diet. In summary, the fibre of CS silage was more easily degraded by rumen microorganisms than that of NG silage. Increased dCH4 concentration with the CS diet presumably led to the decreased ruminal dH2 concentration, which may be helpful for fibre degradation and growth of fibrolytic micro-organisms in the rumen.

Sanguinarine and resveratrol affected rumen fermentation parameters and bacterial community in calves

Plant extracts can be used in calf feed as alternatives to antibiotics, but their effects on colonization of microbial populations remains to be determined. Thus, we evaluated the effects of dietary plant extracts on rumen fermentation parameters and rumen bacterial community in calves, and we followed them up to 9 months of age to determine the persistence of any effects. Fifty-four female Holstein calves were randomly assigned to three treatments consisting of basal diet alone (MR group) or supplemented with sanguinarine (SAG group) or resveratrol (RES group) at 7 days of age. Body weight was measured at the beginning of the experiment and 2 or 6 months of age. Rumen fluid was sampled at 1, 2, 3, 4, 5, 6, and 9 months of age to monitor rumen fermentation parameters. Rumen samples at 3 and 6 months of age were used to analyze the bacterial community by amplicon sequencing. The copy number of Desulfovibrio and methanogenic archaea was determined using droplet digital PCR. The results demonstrated that ADG of calves was similar among groups during 7 d-2 m, 2 m-6 m and 7 d-6 m, respectively. At 3 months, ruminal pH was lower in the SAG and RES groups than in the MR group. The concentration of total volatile fatty acids (TVFA) was greater in the SAG group than in the MR group. At 4 months, the ammonia nitrogen (NH3-N) concentration and the molar proportion of butyrate were lower in the SAG group than in the other two groups. The molar proportion of acetate and the ratio of acetate to propionate (A:P ratio) were lower in the RES group than in the SAG group. The molar proportion of valerate was greater in the RES group than in the other groups. At 5 months, the NH3-N concentration was lower in the SAG group than in the other groups. The molar proportion of valerate was lower in the RES and SAG groups than in the MR group. No differences were observed in rumen fermentation parameters among groups at 1, 2, 6, and 9 months of age. The observed species, Chao1, and abundance-based coverage estimator (ACE) values were greater in the MR group than in the other groups at 3 months of age. The community structure of bacteria in the MR group was distinct from that of the SAG and RES groups at 3 months of age. Desulfovibrio population was increased by sanguinarine and resveratrol, whereas methanogenic archaea population was decreased by resveratrol. No difference was observed in alpha and beta measures among all groups at 6 months of age. In summary, dietary sanguinarine or resveratrol affected rumen fermentation parameters and bacterial community in calves during 3–5 months of age. No effects of plant extract on rumen environment was detected at 6 and 9 months of age.

Effects of replacing soybean meal with canola meal differing in rumen-undegradable protein content on ruminal fermentation and gas production kinetics using 2 in vitro systems

Previous research indicated that there were significant differences in rumen-undegradable protein (RUP) among canola meals (CM), which could influence the nutritional value of CM. The objectives of this study were to (1) evaluate the effects of feeding CM with different RUP contents on ruminal fermentation, nutrient digestion, and microbial growth using a dual-flow continuous culture system (experiment 1) and (2) evaluate ruminal gas production kinetics, in vitro organic matter (OM) digestibility, and methane (CH4) production of soybean meal (SBM) and CM with low or high RUP in the diet or as a sole ingredient using a gas production system (experiments 2 and 3). In experiment 1, diets were randomly assigned to 6 fermentors in a replicated 3 × 3 Latin square. The only ingredient that differed among diets was the protein supplement. The treatments were (1) solvent-extracted SBM, (2) low-RUP solvent-extracted CM (38% RUP as a percentage of crude protein), and (3) high-RUP solvent-extracted CM (50% RUP). Diets were prepared as 3 concentrate mixtures that were combined with 25% orchardgrass hay and 15% wheat straw (dry matter basis). Experiments 2 and 3 had the same design with 24 bottles incubated 3 times for 48 h each. During the 48-h incubation, the cumulative pressure was recorded to determine gas production kinetics, in vitro OM digestibility, and CH4 production. In experiment 1, N flow (g/d), efficiency of N use, efficiency of bacterial N synthesis, total volatile fatty acids (mM), and molar proportion of acetate, propionate, and isobutyrate were not affected by treatments. There were tendencies for a decrease in ruminal NH3-N and an increase in molar proportion of butyrate for the SBM diet compared with both CM diets. The molar proportion of valerate was greater in both CM diets, whereas the molar proportion of isovalerate and total branched-chain volatile fatty acids was lower for the CM diets compared with the SBM diet. In experiments 2 and 3, the SBM diet had a greater gas pool size than both CM diets. The SBM diet increased in vitro OM digestibility; however, it also tended to increase CH4 production (mM and g/kg of DM) compared with both CM diets. Based on the results of this study, CM with RUP varying from 38 to 50% of crude protein does not affect ruminal fermentation, nutrient digestion, and microbial growth when CM is included at up to 34% of the diet.

Digestibility, ruminal fermentation, blood metabolites and antioxidant status in ewes supplemented with DL‐methionine or hydroxy‐4 (methylthio) butanoic acid isopropyl ester

The effects of supplementing ewe diets with either DL-methionine (DL-Met) or 2-hydroxy-4 (methylthio) butanoic acid isopropyl ester (HMBi) were investigated on ruminal insitu degradability of grain and forage diets, invivo digestibility, rumen fermentation, blood metabolites and antioxidant status. Six ruminally cannulated ewes were used in a replicated 3×3 Latin square design with 28-day periods. The dietary treatments were as follows: (i) no supplemental Met (control; CON), (ii) DL-Met at 1.2g/kg DM intake and (iii) HMBi at 1.8g/kg dry matter (DM) intake. Corn grain, barley grain and alfalfa hay were evaluated for their ruminal degradability by both insitu incubation and effective degradability measurements of DM, neutral detergent fibre (NDF) and acid detergent fibre (ADF). Compared to other treatments, HMBi supplementation increased (p<0.05) the digestibility of organic matter, crude protein and NDF and also tended (p=0.08) to increase the digestibility of DM and ADF. Moreover, HMBi supplementation increased (p<0.01) total VFA concentrations, the molar proportions of valerate and iso-butyrate in the rumen. Compared to the CON treatment, DL-Met and HMBi treatments tended (p=0.08) to increase the molar proportion of acetate but decreased (p<0.05) ruminal ammonia-N concentration. Ewes supplemented with HMBi and DL-Met recorded greater (p<0.05) serum concentrations of glutathione peroxidase, total antioxidant capacity and superoxide dismutase than the CON treatment. Serum concentrations of glucose, total protein, albumin, high-density lipoprotein and very low-density lipoprotein were greater (p<0.01) and serum urea nitrogen (p<0.05), malonyl dialdehyde and triglyceride were lower (p<0.02) in the HMBi and DL-Met animals than in the CON ewes. The results concluded that HMBi is a very effective form of dietary Met supplementation for ewes with a positive effect on digestion, rumen fermentation and serum antioxidant function.

Effects of Momordica charantia Saponins on In vitro Ruminal Fermentation and Microbial Population.

This study was conducted to investigate the effects of Momordica charantia saponin (MCS) on ruminal fermentation of maize stover and abundance of selected microbial populations in vitro. Five levels of MCS supplements (0, 0.01, 0.06, 0.30, 0.60 mg/mL) were tested. The pH, NH3-N, and volatile fatty acid were measured at 6, 24, 48 h of in vitro mixed incubation fluids, whilst the selected microbial populations were determined at 6 and 24 h. The high dose of MCS increased the initial fractional rate of degradation at t-value = 0 (FRD0) and the fractional rate of gas production (k), but decreased the theoretical maximum of gas production (VF) and the half-life (t0.5) compared with the control. The NH3-N concentration reached the lowest concentration with 0.01 mg MCS/mL at 6 h. The MSC inclusion increased (p<0.001) the molar proportion of butyrate, isovalerate at 24 h and 48 h, and the molar proportion of acetate at 24 h, but then decreased (p<0.05) them at 48 h. The molar proportion of valerate was increased (p<0.05) at 24 h. The acetate to propionate ratio (A/P; linear, p<0.01) was increased at 24 h, but reached the least value at the level of 0.30 mg/mL MCS. The MCS inclusion decreased (p<0.05) the molar proportion of propionate at 24 h and then increased it at 48 h. The concentration of total volatile fatty acid was decreased (p<0.001) at 24 h, but reached the greatest concentration at the level of 0.01 mg/mL and the least concentration at the level of 0.60 mg/mL. The relative abundance of Ruminococcus albus was increased at 6 h and 24 h, and the relative abundance of Fibrobacter succinogenes was the lowest (p<0.05) at 0.60 mg/mL at 6 h and 24 h. The relative abundance of Butyrivibrio fibrisolvens and fungus reached the greatest value (p<0.05) at low doses of MCS inclusion and the least value (p<0.05) at 0.60 mg/mL at 24 h. The present results demonstrates that a high level of MCS quickly inhibits in vitro fermentation of maize stover, while MCS at low doses has the ability to modulate the ruminal fermentation pattern by regulating the number of functional rumen microbes including cellulolytic bacteria and fungi populations, and may have potential as a feed additive applied in the diets of ruminants.

Intake, rumen fermentation and nutrient flow to the omasum in beef cattle fed grass silage fortified with sucrose and/or supplemented with concentrate

The objective was to determine the relative effects of a specific increase in grass silage sucrose concentration, or a specific supplement of a starch-based concentrate, on rumen fermentation and nutrient supply to the omasum in beef cattle. Four ruminally cannulated Holstein–Friesian steers were fed grass silage only (G), G plus 3 kg concentrates/day (GC), G plus 90 g sucrose/kg dry matter (DM) (GS) and G plus 90 g sucrose/kg DM plus 3 kg concentrates/day (GCS) in a 4 × 4 Latin Square design experiment. Omasal flow was estimated using Co-EDTA, Yb-acetate and indigestible neutral detergent fibre (INDF) as digesta flow markers and purine bases as microbial markers. Concentrate supplementation reduced ( P < 0.01) silage and increased ( P < 0.001) total DM intake whereas sucrose had no effect. There was a sucrose × concentrate interaction ( P < 0.05) for rumen pH whereby addition of sucrose to grass silage alone decreased pH and to grass silage plus concentrate had no effect. Rumen ammonia N ( P < 0.01), total volatile fatty acid (VFA) concentration ( P < 0.05) and the molar proportions of valerate ( P < 0.05) and butyrate ( P < 0.001) increased with concentrate supplementation whereas, sucrose supplementation had no effect on rumen fermentation parameters. Organic matter (OM) intake, omasal OM flow, the quantities of OM apparently (OMAD) and truly digested (OMTD) in the rumen ( P < 0.001) and total tract OM digestibility ( P < 0.01) increased, and apparent and true ruminal OM digestibility decreased ( P < 0.05) with concentrate supplementation. Supplementation with concentrate decreased ( P < 0.05) ruminal neutral detergent fibre (aNDFom) digestibility and increased ( P < 0.05) aNDFom omasal flow. There was a tendency for addition of sucrose to increase ( P < 0.1) ruminal OMAD and OMTD, while there was no effect of sucrose addition on intake or digestion of aNDFom. Concentrate supplementation increased ( P < 0.001) N intake, flows of N, non-ammonia N (NAN), microbial N (MN) ( P < 0.05) and non-ammonia non-microbial N (NANMN) ( P < 0.01) and apparent total tract digestibility of N ( P < 0.01), whereas sucrose reduced ( P < 0.05) N intake and apparent ruminal N digestibility. There was no effect of concentrate or sucrose on N use efficiency or efficiency of microbial protein synthesis. Concentrate supplementation increased ( P < 0.001) plasma β-hydroxybutyrate levels. In comparison to supplementing unwilted, well preserved grass silage of moderate digestibility with 3 kg starch-based concentrate per day, the limited response to the rate of sucrose supplementation employed suggests that increasing the water-soluble carbohydrate (WSC) concentration of grass silage through agronomic and/or ensiling practices will have relatively little effect on intake, rumen digestion or efficiency of microbial N synthesis.

Influence of Supplemental Chromium on Concentrations of Liver Triglyceride, Blood Metabolites and Rumen VFA Profile in Steers Fed a Moderately High Fat Diet

This study evaluated the effects of supplemental Cr on liver triglycerides and blood metabolites in Holstein steers fed a moderately high fat (approximately 5.6% of dry matter) diet. Fourteen Holstein steers were blocked by BW and randomly assigned to a basal diet (control) or control diet supplemented with 0.8 mg/kg of Cr as chromium picolinate. Supplemental Cr had no effect on dry matter intake, average daily gain, serum glucose, insulin, cholesterol, and molar proportions of ruminal volatile fatty acids (VFA). Steers fed the diet supplemented with chromium picolinate had smaller concentrations of serum triglycerides at wk 3, plasma ßbeta;-hydroxybutyrate concentrations at wk 6, and liver triglycerides at wk 9. An in vitro mixed ruminal microorganism fermentation study was conducted to examine the effect of Cr on in vitro VFA production. Ruminal fluid from animals fed fescue hay and 1.1kg of concentrate twice daily was added into a mixture containing 5g of concentrate diet formulated to contain one of five concentrations of Cr (0, 0.2, 0.4, 0.8, or 1.6 mg/kg of Cr). The culture was incubated for 12 or 24h. The molar proportion of propionate decreased, whereas butyrate and isobutyrate increased linearly with increasing Cr content at 12h of incubation. Molar proportion of valerate alone increased linearly with increasing Cr content at 24h of incubation. A second in vitro study evaluated the supplementation of Cr at concentrations of 0, 0.8, 1.6, 3.2, 6.4, 12.8, or 25.6 mg/kg. Molar proportions of acetate, propionate, and isovalerate, and total VFA production responded quadratically with increasing Cr content at 24h. Results suggest that supplemental Cr may alter systemic lipid metabolism. In vitro fermentation altered VFA production with graded concentration of Cr and was not toxic to ruminal microorganisms at concentrations up to 25.6 mg/kg.

Effects of ardacin supplementation on rumen fermentation and protein degradability in steers

Ardacin is an antibacterial glycopeptide with ruminal activity. The objective of this study was to determine its effects on rumen fermentation, soyabean meal degradability and concentrations of selected metabolites in plasma of steers. Six rumen fistulated steers (initial bodyweight 622, S.D. 99.8 kg) were used in a replicated 3 (0, 0.5 or 1.0 mg ardacin kg −1 bodyweight) by 3 (21 day periods) Latin square experiment and fed a diet of 450 g concentrate and 550 g grass silage kg −1 dry matter (DM) at a daily allowance of 13.5 g DM kg −1 bodyweight. Dietary inclusion of ardacin did not affect mean rumen fluid pH or concentrations of ammonia or total volatile fatty acids in rumen fluid. Dietary inclusion of ardacin increased (linear, P < 0.05) the molar proportion of propionate, decreased (linear P < 0.001) the molar proportion of acetate and decreased (linear, P < 0.01) the acetate: propionate ratio in rumen fluid. At 8 h after the first feed, the butyrate proportion was higher ( P < 0.05) in animals fed 1.0 mg ardacin kg −1 bodyweight than in the other treatments. When compared to animals not offered ardacin, the molar proportion of valerate was lower ( P < 0.05) in animals fed 0.5 mg kg −1 bodyweight and tended to be higher ( P < 0.1) in those fed 1.0 mg kg −1 bodyweight. The rate of disappearance of soyabean meal from nylon bags incubated in the rumen was lower (linear, P < 0.05) in steers fed ardacin. Plasma concentrations of glucose, non-esterified fatty acids and 1-lactic acid were unaffected by inclusion of ardacin in the diet. Plasma urea concentration tended to be increased in the 8–12 h period after the first feed. It is concluded that ardacin altered rumen fermentation in a dose-dependent manner in a direction suggestive of improved growth and/or feed conversion efficiency and may increase the quantity of dietary protein supplied to the small intestine.