Fractional Rate Of Gas Production Research Articles

Nutritional Values and In Vitro Fermentation Characteristics of 29 Different Chinese Herbs

The present study evaluated the nutritional values and in vitro fermentation characteristics of 29 different Chinese herbs in order to develop effective feed additives for livestock nutrition. The Chinese herbs were analyzed for their chemical composition. The in vitro fermentation characteristics were evaluated using the gas production technique with swine cecal chyme inoculum. The results showed that the Allium tuberosum Rottl (Semen allii tuberosi, SAT) had the highest gross energy (GE), crude protein (CP), ether extract (EE), and total amino acid (TAA) contents, whereas Anemones raddeanae Rhizoma (Agstache rugosus, AR) had the highest crude fiber, neutral detergent fiber, and acid detergent fiber contents compared with the other Chinese herbs. The Rhus chinensis Mill (Chinese gall, CG), Scrophularia ningpoensis Hemsl (Radix scrophulariae, RS), Punica granatum L (Punica granatum L, PGL), Atractylodes macrocephala Koidz (White atractylodes rhizome, WAR), Sanguisorbae radix (Garden burnet, GB), Anemarrhena asphodeloides Bunge (Rhizoma anemarrhenaw, RA), and Rhei radix Et Rhizoma (Rheum officinale, RO) had a higher non-fiber carbohydrate content than the other Chinese herbs. The in vitro fermentation kinetic analysis showed that the RS, WAR, and RA had a higher gas production, a theoretical gas production, and a fractional rate of gas production than the other groups. Furthermore, the RA, WAR, RS, and Crataegi fructus (Crataegus pinnatifida Bun, CPB) had a higher total short-chain fatty acids (SCFAs) concentration, and CPB had the highest acetate concentration, whereas the WAR and RS had higher propionate and butyrate concentrations than the other groups. Moreover, the Isatis indigotica Fort (Folium isatidis, FI) and SAT had higher ammonia-N concentration than the other groups. In summary, among the 29 different Chinese herbs, the SAT had the highest nutritional value, which is reflected in the highest contents of GE, CP, EE, and TAA, whereas the RA, WAR, and RS showed better intestinal fermentation profiles, which is reflected in the higher fermentation degree and suitable SCFAs fermentation pattern. These findings provide a theoretical basis for using Chinese herbs as feed additives or microbial carbon sources in the intestines of animals.

Kinetics of In Vitro Gas Production and Fitting Mathematical Models of Corn Silage

This study aimed at examining the effects of rumen inoculum of steers receiving different combinations of ionophore and probiotics in their diets on in vitro gas production of corn silage. The fitting of gas production was performed with five mathematical models and its kinetics was evaluated. Four crossbred steers (403.0 ± 75.5 kg body weight) with ruminal cannula were assigned to a 4 × 4 Latin square design. The additives used were Monensin sodium (Rumensin® 100, 3 g/day), Bacillus toyonensis (Micro-Cell Platinum® 109, 1 g/day) and Saccharomyces cerevisiae boulardii (ProTernative®20, 0.5 g/day). Additives were arranged into the following treatments, supplied daily into total mixed diet: (1) Monensin; (2) Monensin + B. toyonensis; (3) Monensin + S. boulardii; and (4) B. toyonensis + S. boulardii. The gas production data were fitted into the models of Gompertz, Groot, Ørskov, Brody, Richards, and Dual-pool Logistic. A perfect agreement between observed and predicted values in curves of accumulated in vitro gas production was observed in the Groot and Richards models, with higher coefficient of determination (R2 = 0.770 and 0.771, respectively), concordance correlation coefficient (CCC = 0.871 and 0.870, respectively), and root mean square error of prediction (RMSEP = 1.14 and 1.15, respectively). Evaluating the feed additives throughout the Groot model, the B. toyonensis + S. boulardii treatment presented higher VF (12.08 mL/100 mg of DM; p = 0.0022) than Monensin and Monensin + S. boulardii (9.16 and 9.22 mL/100 mg of DM, respectively). In addition, the fractional rate of gas production (k) was higher (p = 0.0193) in B. toyonensis + S. boulardii than in Monensin, not presenting a statistical difference (p > 0.05) from the other two treatments. Additionally, with the time of beginning to gas production, the lag time (λ), was greater (p < 0.001) with Monensin and Monensin + B. toyonensis than with Monensin + S. boulardii and B. toyonensis + S. boulardii. The combination of Monensin and probiotics (B. toyonensis + S. boulardii) resulted in better kinetics of degradation of corn silage, being that the Groot and Richards models had the best fit for estimates of the in vitro gas production data of corn silage tested with different feed additive combinations.

Effect of Alfalfa Hay Substitution by Raw Garlic Leaves on In vitro Gas Methane Production and Ruminal Fermentation

Background: The aim of present research was to evaluate under in vitro conditions, the effect of alfalfa hay substitution by raw garlic leaves on ruminal fermentation patterns and methane production in diets ruminants. Methods: Four treatments were evaluated: (T1) alfalfa hay (50%); (T2) alfalfa hay (33%) + raw garlic leaves (17%); (T3) alfalfa hay (17%) + raw garlic leaves (33%) and (T4) raw garlic leaves (50%). Result: The highest values of fractional rate of gas production (kd), ammonia-nitrogen (NH3-N), propionate and microbial biomass synthesis (MBS) was recorded in T4 and the lowest in T1 (P less than 0.05). In contrast, the highest methane production was recorded in T1 and the lowest in T4 (P less than 0.05). It was concluded that the substitution of alfalfa hay by raw garlic leaves in diet with 50% roughages and 50% concentrate result in an improvement in vitro rumen fermentation pattern and decreases the methane production.

Effects of incorporating plantain, chicory, and alfalfa into a ryegrass-based diet on in vitro gas production and fermentation characteristics

The objective of these experiments was to determine how altering the proportion of ryegrass ( Lolium perenne L.) to chicory ( Cichorium intybus L.), alfalfa ( Medicago sativa L.), or plantain ( Plantago lanceolata L.) or a mixture (equal parts DM of chicory, alfalfa, and plantain) affects the in vitro fermentation rates and formation of fermentation products. In vitro experiments were conducted using the ANKOM RF gas production modules (ANKOM). Experiment 1 examined increasing inclusion level (0, 50, 100%) of chicory, plantain, or alfalfa with ryegrass, and Exp. 2 examined increasing inclusion level (0, 25, 50, 75, 100%) of ryegrass to a mixture (equal parts DM of chicory, plantain, and alfalfa). In Exp. 1, there was a positive linear effect for 24-h gas production per gram of DM as inclusion increased for chicory ( P < 0.01) and plantain ( P < 0.01). A negative linear relationship was detected for ammonia (NH 3 ) and branched-chain VFA with increased level of inclusion of plantain ( P < 0.01) and chicory ( P < 0.01). In Exp. 2, there were linear ( P < 0.01), quadratic ( P < 0.01), and cubic ( P < 0.01) effects on both the asymptote of the gas production curve (mL/g of DM) and the fractional rate of gas production (%/h) with increasing mixture inclusion. There was a linear decrease in the total VFA composed of iso-butyrate ( P < 0.01) and iso-valerate ( P < 0.01) as the level of chicory, plantain, and alfalfa inclusion increased. Incorporating greater levels of chicory; plantain; or a mixture of chicory, plantain, and alfalfa with ryegrass increased gas production and reduced NH 3 and branched-chain VFA in rumen fluid, which could imply a greater nutrient supply from the rumen to the host animal. Further research is required to evaluate whether these results translate to in vivo benefits on animal performance and reductions of urinary N excretion.

The influence of extended supplementation of quebracho extract to beef steers consuming a hay diet on digestion, ruminal, and blood parameters.

The addition of natural plant secondary compounds to ruminant feed has been extensively studied because of their ability to modify digestive and metabolic functions, resulting in a potential reduction in greenhouse gas emissions, among other benefits. Condensed tannin (CT) supplementation may alter ruminal fermentation and mitigate methane (CH4) emissions. This study's objective was to determine the effect of quebracho CT extract [QT; Schinopsis quebracho-colorado (Schltdl.) F.A. Barkley & T. Meyer] within a roughage-based diet on ruminal digestibility and kinetic parameters by using the in situ and in vitro gas production techniques, in addition to blood urea nitrogen (BUN) and ruminal (volatile fatty acid [VFA], NH3-N, and protozoa count) parameters. Twenty rumen-cannulated steers were randomly assigned to four dietary treatments: QT at 0%, 1%, 2%, and 3% of dry matter (DM; QT0: 0% CT, QT1: 0.70% CT, QT2: 1.41% CT, and QT3: 2.13% CT). The in situ DM digestibility increased linearly (P = 0.048) as QT inclusion increased, whereas in situ neutral detergent fiber digestibility (NDFD) was not altered among treatments (P = 0.980). Neither total VFA concentration nor acetate-to-propionate ratio differed among dietary treatments (P = 0.470 and P = 0.873, respectively). However, QT3 had lower isovalerate and isobutyrate concentrations compared with QT0 (P ≤ 0.025). Ruminal NH3 and BUN tended to decline (P ≤ 0.075) in a linear fashion as QT inclusion increased, suggesting decreased deamination of feed protein. Ruminal protozoa count was reduced in quadratic fashion (P = 0.005) as QT inclusion increased, where QT1 and QT2 were lower compared with QT0 and QT3. Urinary N excretion tended to reduce in a linear fashion (P = 0.080) as QT increased. There was a treatment (TRT) × Day interaction for in vitro total gas production and fractional rate of gas production (P = 0.013 and P = 0.007, respectively), and in vitro NDFD tended to be greater for QT treatments compared with no QT inclusion (P = 0.077). There was a TRT × Day interaction (P = 0.001) on CH4 production, with QT3 having less CH4 production relative to QT0 on day 0 and QT2 on days 7 and 28. Feeding QT up to 3% of the dietary DM in a roughage-based diet did not sacrifice the overall DM digestibility and ruminal parameters over time. Still, it is unclear why QT2 did not follow the same pattern as in vitro gas parameters. Detailed evaluations of amino acid degradation might be required to fully define CT influences on ruminal fermentation parameters and CH4 production.

44 Effect of Quebracho (Schinopsis balansae) extract inclusion in a high roughage diet upon in vitro gas production

Abstract The utilization of natural plant secondary compounds as feed additives in animal nutrition has been extensively studied because of their ability to modify digestive and metabolic functions. Condensed tannin (CT) supplementation can potentially alter ruminal fermentation, and mitigate methane (CH4) emissions. The objective of this study was to determine the effect of quebracho CT extract (QT; Schinopsis balansae) within a roughage-based diet on overall fermentability and CH4 production utilizing the in vitro gas production technique (IVGP). Twenty rumen cannulated steers (227 ± 19 kg) were randomly assigned to four dietary treatments (n=4): QT at 0, 1, 2, and 3% of DM (QT0, QT1, QT2, and QT3). A roughage-based diet containing 88% bermudagrass hay and 12% concentrate was fed daily at 2.1% of shrunk body weight. The animals were adapted to the basal diet for 24-d then introduced to predetermined treatments for 35d. Rumen inoculum was collected weekly from each steer to perform the incubations. Two hundred milligrams of air-dried base diet were incubated for 48-h with a composite rumen inoculum for each treatment over 5 wk. Kinetic analysis of cumulative 48h gas production was performed using Gasfit. Measurements of CH4 were performed via gas chromatography and digested residue was determined post-incubation. Data were analyzed using a random coefficients model. Total gas production was higher for QT0 compared to QT1 and QT3 (P = 0.001), but not different from QT2 (P = 0.554). The fractional rate of gas production was higher for QT2 compared to QT0 (P = 0.011). First and second pool gas production decreased linearly as QT inclusion increased (P = 0.042 and 0.010, respectively). There was no dietary effect in ivNDFD (P = 0.567). However, there was a linear tendency to decrease CH4 production with the addition of QT (P=0.071) likely due to changes in the microbial population.

Effects of salts of branched-chain volatile fatty acids protected with different combinations of encapsulation materials on gas production dynamics when incubated in vitro with Brachiaria brizantha ‘Marandu’

This study evaluated the effects of 7 different encapsulations (treatments S1–S7) of salts of branched-chain VFA, using different combinations and material sources (dioxides, maltodextrin, and celluloses), on the in vitro gas production dynamics of Brachiaria brizantha ‘Marandu.’ Air-dried Brachiaria brizantha with the addition of salts were incubated for 48 h with fresh rumen inoculum collected from 4 ruminally cannulated steers. Salts were investigated at 2 inclusion levels (IL; IL3 = 3% and IL6 = 6% of DM). Incubations were performed with (n = 3) or without (n = 3) the addition of casein and cysteine (C&C). Enumeration of in vitro NDF digestibility and methane (CH 4 ) production was performed for all samples. With C&C inclusion, S1 produced more gas than S5 and reduced lag time compared with S6 and S7. The S5, S6, and S7 had lower CH 4 production relative to S3. The IL3 had greater computed TDN and ME than IL6. Without C&C inclusion, there was an interaction of salt × IL on total gas production, fractional rate of gas production, lag time, gas production of fibrous and nonfibrous carbohydrate pools, CH 4 , and energy values. The inclusion of C&C altered the fermentation parameters of salts of branched-chain VFA with the IL of salts appearing to be dependent on N availability. Our study indicated that the utilization of S1 salt is recommended for maximal TDN of Brachiaria brizantha compared with other combinations of encapsulation materials.

EFFECTS OF REPLACING LOW STARCH BY-PRODUCTS FOR BARLEY GRAIN ON in situ RUMEN DEGRADABILITY AND in vitro GAS PRODUCTION PROPERITES OF A TOTAL MIXED RATION

This study was conducted to study the effects of different sources of low starch by-products substituted for barley grain on in situ rumen degradability and in vitro gas production properties of a total mixed ration. The experimental treatments consisted of 370 g/kg roughages and 630 g/kg concentrates. The total mixed diets contained 100 g /kg dry matter (DM) barley grains (BG, control diet), sugar beet pulp (SBP, treatment 2), wheat bran (WB, treatments 3), or dried citrus pulp (DCP, treatment 4). In the first experiment, the experimental diets were evaluated for in-situ rumen degradability by the nylon bag technique. In the second experiment, treatments were evaluated for in vitro gas production parameters. Data were analyzed as a completely randomized design. The data on in situ experiment indicated that non-soluble degradation fraction (b), the fractional degradation rate (c) and potential degradability (a+b) were not affected by the diets (P&gt;0.05). However, soluble degradable fraction (a) was highest for a diet with DCP (P&lt;0.05). The in vitro gas production data showed there were no significant differences among treatments for gas produced at different times of incubation (P&gt;0.05). Besides, the potential gas production (b), and OMD did not differ among treatments (P&gt;0.05). But, the fractional rate of gas production (c) was lowest for diet with DCP (P&lt;0.05). Still, SCFA varied among various treatments (P&lt;0.05), and it was higher for DCP treatment than other groups. It concluded that replacing low starch by-products, such as dried citrus pulp and sugar beet pulp, for up to 10% of diet DM instead of barley grain can improve the DM digestibility of a total mixed ration without any adverse effect on ruminal fermentation in ruminants.

PSVIII-7 In vitro fermentation of different dietary fibers selectively changed sow gut microbiota composition

Abstract In vitro fermentation experiments with modified starch 1 (MS1), modified starch 2 (MS2), guar gum (GG), xanthan gum (XG), konjac flour (KF), wheat brain (WB), and inulin (I) were conducted for 48 h to investigate the effects on gilt gut microbiota. Fecal examples were obtained from three gilts; the fermentation kinetics parameters were analysed in Logistic-Exponential (LE) model such as the final asymptotic gas volume (Vf, ml/g), initial fractional rate of degradation at t-value=0 (FDR0, h-1), fractional rate of gas production at particular time (k, h-1) and half-time to asymptote (T1/2, h). Samples were collected after fermentation for short chain fatty acids (SCFAs) and 16S rDNA microbial analysis. MS1, MS2, and I had the highest Vf (P &amp;lt; 0.01). The k of GG and I were significant higher (P &amp;lt; 0.01). FDR0 of MS2, GG, and I were the lowest following KF, MS1, WB, and XG, successively (P &amp;lt; 0.01). T1/2 of MS1, KF, WB, and GG were lower (P &amp;lt; 0.01). MS1, MS2, and GG produced more acetate (P &amp;lt; 0.05) and total SCFAs (P &amp;lt; 0.01), and butyrate produced by MS2 was significant higher (P &amp;lt; 0.01). The microbiota composition changed dramatically after fermentation, decreasing bacteria abundance and alpha-diversity (P &amp;lt; 0.01). The relative abundance of phyla Firmicutes and Bacteroidetes decreased, while phyla Spirochaetes, Proteobacteria, Kiritimatiellaeota, and Fusobacteria were selectively promoted by DF. The LEfSe analysis showed Proteobacteria, Gammaproteobacteria, and Aeromonadales were enriched in MS1 treatment; Clostridiales, Clostridia, and Anaerosporobacter were enriched in MS2 treatment; Bacteroidales, Bacteroidia, and Bacteroidetes were enriched in GG treatment; Ruminococcaceae and Ruminococcaceae_UCG_013 were enriched in XG treatment; Lachnospiraceae, Lachnospiraceae_NK4A136_group, and Ruminiclostridium were enriched in KF treatment; Enterobacteriales, Enterobacteriaceae, and Lactobacillales, were enriched in I treatment. In conclusion, different type of DFs may play a specific role in gilt gut microbiota changing and composition.

Storage time and condensed tannin content of high-moisture sorghum grains: Effects on in vitro fermentation and mold populations

Silage of high moisture sorghum grains is a highly relevant source of energy in cattle production systems in South America. There is little information related to the chemical characteristics, the kinetics of fermentation and the toxic fungal populations of these feedstuffs. The aim of this study was to evaluate the effect of storage time and condensed tannins content of the grain on chemical composition, in vitro fermentation parameters, and toxicogenic fungal populations of moist sorghum grain stored in silo-bags. Samples of 2 varieties of sorghum grains (high-tannin [HT] and low-tannin [LT]), were obtained during the grain harvest before silage making and after 30, 90, and 180 d of storage (n = 16). High-tannin grains had higher acid detergent fiber, tannins, gas production (P < 0.05) and lower starch and rate of gas production (P < 0.01). Interaction variety × storage time were observed for all chemical parameters (P < 0.01), except for neutral detergent fiber assayed with a heat stable amylase and expressed inclusive of residual ash (aNDF) and pH. Starch and protein content increased in both varieties, tannins decreased in HT and LT, and organic matter (OM) increased in HT and declined in LT (P < 0.05). The rate of gas production increased with the storage time for HT and LT (P < 0.01). A linear reduction in the Aspergillus number of colonies in the HT varieties was observed (P < 0.01), whereas a linear increase in Penicillium isolation was detected in the LT sorghums (P < 0.01). The storage time was beneficial in terms of decreasing the condensed tannins, increasing fractional rate of gas production and minimizing fungal contamination, particularly on HT grains.

Mitigation of ruminal biogases production from goats using Moringa oleifera extract and live yeast culture for a cleaner agriculture environment

The present investigation was assessed to explore the sustainable mitigation of methane and carbon dioxide production from goats using Moringa oleifera extract and live yeast culture (Saccharomyces cerevisiae) as feed supplements. Treatments include supplementation of 0 (control), 0.6, and 1.8 mL/g dry matter of M. oleifera extract and 0 (control), 2, and 4 mg/g dry matter of commercially available S. cerevisiae into the feeding diet. Higher doses of M. oleifera extract and S. cerevisiae increased the asymptotic gas production from 88.8 to 147.5 mL/g dry matter. The fractional rate of gas production was increased (P < 0.05) due to the supplementation of M. oleifera extract and S. cerevisiae. Lag time increased linearly from 1.32 to 3.99 h but only M. oleifera extract affected it quadratically (P = 0.041). The asymptotic methane production, rate of methane emission, and lag time decreased (P > 0.05) with the varied doses of additives. M. oleifera extract × S. cerevisiae interaction had non-significant (P > 0.05) influence on asymptotic carbon dioxide emission, fractional rate of carbon dioxide emission, and lag time. Furthermore, the inclusion of S. cerevisiae exhibited increased gas production in a time dependent manner. The proportional methane production was estimated to be decreased (P > 0.05) at high doses of M. oleifera extract and S. cerevisiae at 72 h of incubation with the lowest emission of 11.7%. In contrary to this, the proportional carbon dioxide production was reduced (quadratic effect, P = 0.031) at 72 h of incubation with the lowest emission of 50.3%. In conclusion, the addition of M. oleifera extract and S. cerevisiae in diets would be an invaluable approach for mitigating methane and carbon dioxide emission from goats. These additives at diversified concentrations may be utilized as pronounced cleaner product and additive agents for the ecosystem as well as livestock.

Effects of elemental magnesium and magnesium oxide on hydrogen, methane and volatile fatty acids production in in vitro rumen batch cultures

This study aimed to examine the hypothesis that extra molecular hydrogen (H2) produced by elemental magnesium (Mg) could alter rumen fermentation and methanogenesis in in vitro batch incubation. As elevated Mg2+ may exert negative effects on rumen fermentation, magnesium oxide (MgO) was also included for comparison. Mulberry leaf and corn grain had contrast chemical composition and thus were selected as substrates for incubation. Both elemental Mg and MgO were supplemented at two levels, i.e. 0.625 and 1.25 mmol/bottle. The in vitro incubation was performed for 48 h to measure gas production (GP), H2 gas (gH2) and methane gas (gCH4) production, dissolved H2 and CH4 concentrations, and volatile fatty acids (VFA) production. Elemental Mg or MgO supplementation increased (Plinear < 0.001) Mg2+ concentration and pH in comparison to the control without supplements. There was no statistical difference (P> 0.05) in ruminal Mg2+ concentration between MgO and elemental Mg supplementation. Elemental Mg increased (P < 0.001) gH2 and gCH4 production, dissolved H2 and CH4 concentrations, in comparison to the control and MgO supplementation. Elemental Mg and MgO supplementation had lower (Plinear < 0.001) initial fractional rate of degradation, fractional rate of gas production, GP and VFA concentration than the control. Elemental Mg supplementation decreased (P < 0.05) GP and acetate molar percentage and increased (P < 0.001) propionate molar percentage, in comparison to the control and MgO supplementation. In summary, high Mg2+ concentration (> 5.5 mM) inhibits ruminal fermentation. Extra H2 produced by elemental Mg supplementation has a biological function to inhibit rumen fermentation, enhances ruminal methanogenesis and shifts the fermentation pathway from acetate to propionate production.

In vitro evaluation of mixed silage of Pennisetum purpureum and orange fleshed sweet potato vines

The study was aimed at determining the in vitro nutritive value of mixed silages of pennisetum purpureum and orange-fleshed sweet potato vines and evaluating their potential of being a new feed resource for ruminants during the dry season. Pennisetum purpureum (Pp) and orange-fleshed sweet potato vines (OFPV) were ensiled in experimental silos bottles after wilting for 24 hours in the following proportions viz:100%Pp (T1), 75%Pp +25%OFPV (T2), 50%Pp +50%OFPV (T3), 25% Pp +75% OFPV (T4) and 100% OFPV (T5). Each treatment was replicated ten (10) times and was kept for 14 and 28 days in the laboratory at a room temperature (20 – 25°C). The chemical composition of the silage at 14 and 28 days was determined. In vitro gas production of the silages was carried out for 48 hours. In vitro fermentation kinetics and gas production parameters of the silages were also estimated. Results revealed that ensiling periods had significant (p&lt;0.05) effect on the dry matter (DM), crude protein (CP), neutral detergent fibre (NDF) and acid detergent fibre (ADF) contents of the silages. Silage of 28 days had highest CP (13.45%) and lowest NDF and ADF contents (40.10 and 25.48% respectively). Silage containing 100% OFPV recorded highest (p&lt;0.05) crude protein (15.95%), ash (15.81%) and lowest NDF (32.25%) and ADF (22.50%) contents. Gas production was lowest (p&lt;0.05) in T1 at all incubation periods, and it increases with inclusion of OFPV, T5 had significant (p&lt;0.05) highest gas production. Least gas production was observed in T1 at 42 and 48 hours incubation period (15.17 and 17.17 mL/200mg DM respectively). Silage of 28 days had the best potential gas production (37.51 mL). Fractional rate of gas production was higher in 28 days silage (0.06mL/hr), T3 (0.05mL/hr), T4 (0.05mL/hr) and T5 (0.06mL/hr) while lag phase was lowest in these silages. In vitro dry matter digestibility (IVDMD), metabolisable energy (ME) and short chain fatty acids (SCFA) were greater in silage of 28 days (63.73%, 5.01MJ/Kg DM and 0.02mL) with least percentage methane production (33.34%). Also, IVDMD, in vitro organic matter digestibility (OMD), ME, and SCFA increased as level of OFPV in the silages increases with T5 having the highest values for these parameters. Percentage methane production was least (p &lt; 0.05) in T5 (26.55%). It can therefore be concluded that Pennisetum purpureum be supplemented with OFPV up to 75% and ensiled for 28 days or beyond to produce better quality feed resource for ruminants during the dry season. Ensiling 100% OFPV is also highly recommended as it exhibited the best nutritive potential.

Time of rumen fluid collection relative to feeding alters in vitro fermentation gas parameters.

The objective of this study was to determine the effect of time of rumen fluid collection relative to feeding on gas production kinetics for in vitro rumen fermentation. Three ruminally cannulated Holstein heifers were rumen fluid donors. Feed was removed from heifers 12 h prior to feeding, rumen fluid was collected from each heifer before feeding (0 h), and at 2, 4, and 6 h after feeding, repeated on three separate incubation days. Buffered rumen fluid (100 mL) was incubated in 250-mL bottles containing 1.4 g of dried TMR, in duplicate for each heifer at each collection time. All bottles were incubated for 24 h at 39°C and constant agitation (60 rpm), and capped with monitors to capture temperature and pressure every 15 min (RF1, Ankom Technology, Macedon, NY). At the end of incubation, final pH was recorded. Gas data were fit with nonlinear regression comparison of fit in GraphPad Prism 7 to find best fit regression. The formula with best fit was as follows: y = Vm(1 - (e(-Kd(x - lag)))), where y is gas produced at time X (mmol), Vm is the asymptotic gas production (mmol), Kd indicates the fractional rate of gas production (mmol/h), X is time (h), and lag refers to the lag time before the start of fermentation (h) as indicated by positive gas production (R 2 = 0.98). Data were analyzed using PROC GLIMMIX of SAS, with donor as the experimental unit and day as the random blocking factor; significance is defined as P ≤ 0.05. Time of rumen fluid collection significantly affected gas production kinetics (lag P = 0.01, Vm P = 0.03, Kd P <0.0001). Gas production was highest in fermenter units fed with rumen fluid collected 2-h post-feeding. Fractional rate of fermentation (Kd) was fastest in rumen fluid collected at 0 h. Lag time was longest in rumen fluid collected at 4-h post-feeding and slowest in rumen fluid collected at 0 h. Time of rumen fluid collection did not alter final pH. Our findings suggest that gas production is maximized when rumen fluid is collected between 2 and 4 h after feeding.

Assessment of some browse tree leaves on gas production and sustainable mitigation of CH4 and CO2 emissions in dairy calves at different age

The present context was aimed to determine the in vitro gas production (GP), mitigation of methane (CH4) and carbon dioxide (CO2) emission, and ruminal fermentation from nine different tree leaves as suitable alternatives for alfalfa hay. Tree leaves and alfalfa hay were incubated with rumen inoculum from calves at different ages (20, 40, and 60 d). The level of asymptomatic GP [mL/g dry matter (DM)] differed (P < 0.05) between different tree leaves compared with alfalfa hay. Most of the plant leaves showed differed (P < 0.05) asymptomatic CH4 production (mL/g DM), fractional rate of GP and lag time. The asymptomatic CO2 production and fractional rate of CO2 production decreased effectively (P < 0.01) with the different tree leaves. In vitro rumen CH4 and CO2 productions (mL/g incubated DM) by species incubated in the rumen liquor of calves collected at 60 d of age increased effectively. Fermentation pH (P < 0.001) was found to be significant parameter but DM degradability (P > 0.05) was not significant by dose and substrate × dose interaction. Tree leaves showed lower production of CH4 (mL/g incubated DM) and proportional CH4 emission when compared to alfalfa hay after the required period of incubation at significant level (P < 0.05). However, different tree leaves had no influence (P > 0.05) on CO2 production (mL/g incubated DM and mL/g degraded DM) and proportional CO2 production. The incorporation of tested tree leaves in diet would be a valuable alternative of alfalfa hay with sustainable reduction properties of CH4 and CO2 productions. These potent tree leaves can be used as valuable cleaner product and feeding stuffs for the environment and ruminants respectively due to their in vitro fermentative properties.

Addressing sustainable ruminal methane and carbon dioxide emissions of soybean hulls by organic acid salts

The current study aimed to study the sustainable mitigation of methane (CH4) and carbon dioxide (CO2) emissions as well as ruminal fermentation kinetics by replacing dietary corn grain (CG) with soybean hulls (SH) in the presence of organic acid salts (OAS). Three total mixed rations were prepared where CG was replaced with SH at three levels (/kg DM): 0 g (Control), 75 g (SH75) or 150 g (SH150). The OAS was used at three levels (dose): 0, 5 and 10 mg/g DM of substrates. Increasing SH level increased (P < 0.05) the fractional rate of gas production (GP) and lag time. The SH75 and SH150 rations quadratically decreased (P < 0.001) the asymptotic CO2 production and the lag time of CO2 production. Moreover, the high level of OAS quadratically decreased (P ≤ 0.05) CO2 production. The OAS inclusion increased (P < 0.05) CH4 production (expressed as mL/g incubated DM and mL/g degraded DM). Increasing SH in the rations increased (P < 0.05) proportional CH4 production. Inclusion of OAS also increased proportional CH4 production. Replacing corn grain with soybean hulls could be a valuable means of sustainable mitigation of CH4 and CO2 emissions and improvement of the environmental conditions as well as provision of good feedstuff for ruminant livestock due to its in vitro fermentation characteristics. The organic acid salts did not affect ruminal gas production but decreased CO2 emissions; thus its supplementation when soybean hulls replace corn grain is perhaps redundant, though may be considered as environmental friendly way of feeding livestock.

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.

Comparisons of manual and automated incubation systems: Effects of venting procedures on in vitro ruminal fermentation

Gas produced was measured based on headspace pressures in both manual and automated in vitro incubation systems, which were always vented at pre-set fixed times (FT) and at a pre-set threshold of fixed pressure (FP) respectively. This study was to investigate these two venting procedures (VP) on kinetics of total gas, methane (CH4) and hydrogen gas (gH2), substrate degradation and volatile fatty acid (VFA) production. Corn grain, rice straw, rice grain and tall fescue were selected for in vitro ruminal batch incubation. Headspace pressure of FT procedure was manually released at incubation times being 2, 4, 8, 12, 20, 28, 36, 48 and 72h in manual incubation system, while headspace pressure of FP procedure was automatically released at threshold pressure being 9kPa/bottle in automated incubation system. The FT procedure had particular high venting headspace pressure (> 40kPa) at some incubation times for corn grain and rice grain. The FT procedure had a lower gas volume (P<0.001) and fractional rate of gas production (P<0.001) than FP procedure, which was caused by the decreased (P=0.01) substrate degradation and increased partial dissolution of CO2 under higher venting headspace pressure. The FP procedure had higher (P=0.016) fractional rate of CH4 production than FT procedure. The FT procedure had lower final asymptotic gH2 volume (P=0.01) and fractional rate of gH2 formation (P=0.002), and higher propionate production (P=0.05), in comparison with FP procedure. The higher propionate production under FT procedure indicated that more H2 was entering to VFA production, leading to less gH2 released into the headspace of bottle. In summary, the rate of gas, CH4 and gH2 generation could be different between VP and VT procedure, and higher venting headspace pressure caused by FT procedure altered kinetics of gas, CH4 and gH2 volume, substrate degradation and VFA production.

Kinetics of biogas production in Anaerobic Filters

This study investigates methane production kinetics from individual volatile fatty acids (VFA) in an Upflow Anaerobic Filter (AF). 1gCOD in the form of acetic (HAc), propionic (HPr) or butyric acid (HBu) was injected into the AF while operating at an organic loading rate (OLRCOD) of 3.5gL-1d-1. A new method is introduced to separate gas production of the baseload from the product formation of VFA degradation after the injection. The lag phase, fractional rate of gas production and half-life has been determined for the methane production of the three VFAs. The half-lives were in the order HAc<HBu<HPr showing a slower gas production from the C3 acid than from the C4 acid. The results can be used for prediction models for on-demand biogas production, a vital approach that provides the transforming energy market with balancing power.

Cinética de fermentação ruminal das silagens de três híbridos de milho comerciais em diferentes estádios de maturação

Foi avaliada a cinética de fermentação ruminal in vitrode três híbridos comerciais de milho (BRS 1035, BRS 1031 e BRS 1001) colhidos em três estádios de maturidade (pastoso, farináceo e farináceo-duro). Após 96 horas de fermentação, não houve diferença na PCG entre as silagens dos híbridos colhidos nos diferentes estádios de maturidade (P&gt;0,05). O potencial máximo de produção de gases das silagens de todos os híbridos reduziu com o avançar da maturidade da planta, sendo a variação encontrada de 259,3 a 280,0mL/g de matéria seca (MS). Os valores de tempo de colonização variaram de 0h06min a 1h54min. Para as silagens dos híbridos BRS 1035 e BRS 1001, houve aumento no tempo de colonização com o avançar da maturidade da planta. Para as silagens do híbrido BRS 1031, houve aumento dos valores de tempo de colonização quando a planta avançou do estádio pastoso para farináceo, e reduziu quando a maturidade alcançou o estádio farináceo-duro. A taxa fracional de produção de gases "µ" variou entre 0,03mL/h a 0,05mL/h. Com o avançar da maturidade fisiológica, as silagens dos híbridos BRS 1035 e BRS 1001 apresentaram aumento nos valores de µ; já para as silagens do híbrido BRS 1031, os valores de µ aumentaram quando o estádio de maturidade avançou de pastoso para farináceo, e reduziu para farináceo-duro. Os valores das degradabildades efetivas foram superiores para as silagens dos diferentes híbridos colhidas no estádio pastoso. As degradabilidades da MS com o tempo de fermentação de 96 horas variaram de 70,1 a 76,4%. A silagem do híbrido BRS 1035 apresentou melhor valor nutricional quando colhida no estádio pastoso de maturidade. Já a silagem do híbrido BRS 1031 apresentou valor nutricional superior no estádio farináceo, enquanto a silagem do híbrido BRS 1001 apresentou melhor valor nutricional no estádio farináceo-duro.