scholarly journals In vitro caecal fermentation of carbohydrate-rich feedstuffs in rabbits as affected by substrate pre-digestion and donors' diet

2018 ◽  
Vol 26 (1) ◽  
pp. 15 ◽  
Author(s):  
C. Ocasio-Vega ◽  
R. Abad-Guamán ◽  
R. Delgado ◽  
R. Carabaño ◽  
M.D. Carro ◽  
...  
Keyword(s):  
Sugar Beet ◽  
In Vitro Digestion ◽  
Lag Time ◽  
Gas Production ◽  
Soluble Fibre ◽  
Production Values ◽  
Endogenous Substrates ◽  
A Minor ◽  
Caecal Fermentation

The influence of substrate pre-digestion and donors’ diet on <em>in vitro</em> caecal fermentation of different substrates in rabbits was investigated. Eight crossbreed rabbits were fed 2 experimental diets containing either low (LSF; 84.0 g/kg dry matter [DM]) or high soluble fibre (HSF; 130 g/kg DM) levels. <em>In vitro</em> incubations were conducted using batch cultures with soft faeces as inoculum and four fibrous or fibre-derived, low-starch and low-protein substrates: D-cellobiose (CEL), sugar beet pectin (PEC), sugar beet pulp (SBP) and wheat straw (WS). Substrates in half of the cultures were subjected to a 2-step pepsin/pancreatin in vitro digestion without filtration, and the whole residue (soluble, insoluble and added enzymes) was incubated at 39°C. Gas production was measured until 144 h, and volatile fatty acid (VFA) production at 24 h incubation was determined. Cultures without substrate (blanks) were included to correct gas production values for gas released from endogenous substrates and added enzymes. Pre-digestion had no influence on <em>in vitro</em> gas production kinetic of WS, and only reduced the time before gas production begins (lag time; by 31%; P=0.042) for SBP, but for both substrates the pre-digestion decreased the molar proportion of acetate (by 9%; P≤0.003) and increased those of propionate and butyrate (P≤0.014). For CEL, the pre-digestion increased the gas and total VFA production (by 30 and 114%), shortened the lag time (by 32%), and only when it was combined with LSF inoculum 38 percentage units of acetate were replaced by butyrate (P≤0.039). Treatments had a minor influence on in vitro fermentation traits of SBP pectin. The results showed that the pre-digestion process influenced the in vitro caecal fermentation in rabbits, but the effects were influenced by donors’ diet and the incubated substrate. Pre-digestion of substrate is recommended before conducting <em>in vitro</em> caecal fermentations. The level of soluble fibre in the donors’ diet also influenced the <em>in vitro</em> caecal fermentation, but its effect depended on the type of substrate.

scholarly journals 133 Porcine in vitro degradation and fermentation characteristics of heat-pretreated and multi-enzyme-supplemented soybean hulls

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 114-115
Author(s):  
Cienna J Boss ◽  
Jung Wook Lee ◽  
Rob Patterson ◽  
Tofuko A Woyengo
Keyword(s):  
In Vitro Digestion ◽  
Gas Production ◽  
In Vitro Digestibility ◽  
Soybean Hulls ◽  
In Vitro Fermentation ◽  
Heat Pretreatment ◽  
Fractional Rate ◽  
Enzyme Supplementation ◽  
Kinetics Of

Abstract A study was conducted to determine effects of pretreating and supplementing soybean hulls with multi-enzyme on porcine in vitro digestion and fermentation characteristics. Treatments were untreated and heat-pretreated (160 °C and 70 psi for 20 min) soybean hulls without or with multi-enzyme in a 2 × 2 factorial arrangement. The multi-enzyme supplied 2,800 U of cellulase, 1,800 U of pectinase, 400 U of mannanase, 1,000 U of xylanase, 600 U of glucanase, and 200 U of protease/kilogram of feedstuff. Feedstuffs were subjected to in vitro digestion with porcine pepsin and pancreatin, followed by in vitro fermentation for 72 h. Accumulated gas production was recorded and modeled to estimate kinetics of gas production. On DM basis, untreated and pretreated soybean hulls contained 10.4 and 10.6% CP, and 63.2 and 49.5% ADF, respectively. Pretreatment and multi-enzyme supplementation did not interact on in vitro digestibility of DM (IVDDM). Untreated and pretreated soybean hulls did not differ in IVDDM (24.8 vs. 25.7%). Multi-enzyme increased (P &lt; 0.05) IVDDM of soybean hulls by a mean of 45.5%. Pretreatment and multi-enzyme unaffected total gas production. Pretreatment and multi-enzyme interacted (P &lt; 0.05) on fractional rate of degradation such that the fractional rate of degradation for pretreated soybean hulls was greater (P &lt; 0.05) than that of untreated soybean hulls when soybean hulls were supplemented with multi-enzyme (0.045 vs. 0.062 h-1), but not when soybean hulls were unsupplemented with multi-enzyme (0.053 vs. 0.059 h-1). In conclusion, multi-enzyme supplementation increased IVDDM, implying that the multi-enzyme used in the study can be used to enhance utilization of soybean hulls. Heat pretreatment increased the rate of fermentation of multi-enzyme-supplemented soybean hulls, implying that the rate of fermentation of soybean hulls in the hindgut of pigs can be enhanced by a combination of heat pretreatment and multi-enzyme supplementation.

Relative efficacy of inocula from rumen fluid or faecal solution for determining in vitro digestibility and gas production

1998 ◽  
Vol 78 (4) ◽  
pp. 673-679 ◽  
Author(s):  
A. El-Meadaway ◽  
Z. Mir ◽  
P. S. Mir ◽  
M. S. Zaman ◽  
L. J. Yanke
Keyword(s):  
Rumen Fluid ◽  
Relative Size ◽  
Barley Grain ◽  
Gas Production ◽  
Barley Straw ◽  
In Vitro Digestibility ◽  
Production Values ◽  
Cattle Faeces ◽  
Faecal Suspension

Three experiments were conducted to study the effects of substituting rumen fluid (RF) with faecal suspension (FS) as an inoculum for determination of in vitro dry matter digestibility (IVDMD, experiment 1) and gas production (exp. 2). Barley grain (BG), Persian clover (PC), alfalfa (ALF), bromegrass (BR) and barley straw (BS) were used to evaluate the efficacy of the two inocula. In exp. 1, IVDMD was determined using RF or FS containing 3, 6 and 9% fresh cattle faeces as inocula. Except for BS, IVDMD values obtained with either RF or FS containing 3% faeces were not different (P > 0.05). In contrast, FS containing 6 or 9% faeces resulted in lower (P < 0.05) IVDMD than those obtained with RF. Total VFA, butyric and valeric acids of in vitro supernatant were higher (P < 0.05) in RF than FS incubated buffers. Molar proportions of acetic and propionic acids were variable among feeds. Mean acetic:propionic ratio was similar (except for BG) for RF or FS. In exp. 2, substitution of RF with FS containing 6, 11 or 16% cattle faeces as inoculum generally resulted in an increased lag time for four feeds (PC was not included). The rate of gas production was lower when FS was used instead of RF for ALF and BR. For BG however, use of FS resulted in a higher (P < 0.05) rate of gas production than when RF was used. Total gas production values were similar within all the feeds regardless of the source of inoculum. In experiment 3, the relative size of the total and cellulolytic populations were higher for RF than for FS, with a greater diversity of genera of bacteria isolated from RF. Results from this study indicate that FS has the potential to be used instead of RF to obtain IVDMD and gas production for BG and forage hay but not for poor quality roughages such as BS. However, more research with FS is required to confirm these findings. Key words: IVDMD, gas production, rumen fluid, faecal suspension

In vitromicrobial growth and rumen fermentation of different substrates as affected by the addition of disodium malate

2005 ◽  
Vol 81 (1) ◽  
pp. 31-38 ◽  
Author(s):  
M. L. Tejido ◽  
M. J. Ranilla ◽  
R. García-Martínez ◽  
M. D. Carro
Keyword(s):  
Dry Matter ◽  
Microbial Growth ◽  
Rumen Fermentation ◽  
Gas Production ◽  
Mean Values ◽  
Batch Cultures ◽  
Production Values ◽  
Micro Organisms ◽  
Microbial N

AbstractThe effects of two concentrations of disodium malate on thein vitrofermentation of three substrates differing in their forage: concentrate ratio (0·8: 0·2, 0·5: 0·5 and 0·2: 0·8; g/g dry matter; low-, medium- and high-concentrate substrates, respectively) by rumen micro-organisms were studied using batch cultures. Rumen contents were collected from four Merino sheep offered lucerne hay ad libitum and supplemented daily with 400 g concentrate. Disodium malate was added to the incubation bottles to achieve final concentrations of 0, 4 and 8 mmol/l malate and15N was used as a microbial marker. Gas production was measured at regular intervals from 0 to 120 h of incubation to study fermentation kinetics. When gas production values were corrected for gas released from added malate, no effects (P> 0·05) of malate were detected for any of the estimated gas production parameters. In 17-h incubations, the final pH and total volatile fatty acid (VFA) production were increased (P< 0·001) by the addition of malate, but no changes (P> 0·05) were detected in the final amounts of ammonia-N and lactate. When net VFA productions were corrected for the amount of VFA produced from malate fermentation itself, adding malate did not affect (P> 0·05) the production of acetate, propionate and total VFA. Malate reduced methane (CH4) production by proportionately 0·058, 0·013 and 0·054 for the low-, medium- and high-concentrate substrates, respectively. Adding malate to batch cultures increased (P< 0·01) rumen microbial growth (mean values of 16·6, 18·3 and 18·4 mg of microbial N for malate at 0, 4 and 8 mmol/l, respectively), but did not affect (P> 0·05) its efficiency of growth (55·5, 56·7 and 54·3 mg of microbial N per g of organic matter apparently fermented for malate at 0, 4 and 8 mmol/l, respectively). There were no interactions (P> 0·05) malate × substrate for any of the measured variables, and no differences (P> 0·05) in pH, CH4production and microbial growth were found between malate at 4 and 8 mmol/l. The results indicate that malate had a beneficial effect on in vitro rumen fermentation of substrates by increasing VFA production and microbial growth, and that only subtle differences in the effects of malate were observed between substrates. Most of the observed effects, however, seem to be due to fermentation of malate itself.

scholarly journals Do fibrolytic, proteolytic and amylolytic enzymes influence the in vitro fermentation characteristics of forage?

2018 ◽  
Vol 39 (3) ◽  
pp. 1143
Author(s):  
Lucien Bissi da Freiria ◽  
Joanis Tilemahos Zervoudakis ◽  
Nelcino Franciso de Paula ◽  
Luciano Da Silva Cabral ◽  
Luis Orlindo Tedeschi ◽  
...  
Keyword(s):  
Lag Time ◽  
Gas Production ◽  
Neutral Detergent Fiber ◽  
Liquid Volume ◽  
Brachiaria Brizantha ◽  
In Vitro Fermentation ◽  
Time Points ◽  
In Vitro Gas Production ◽  
Fermentation Profile

The effects of increasing doses of three exogenous enzymes preparations with fibrolytic activity (FIB - 0, 0.6, 1.2, 1.8, and 2.4 mg mL-1liquid volume incubated), amylolytic activity (AMZ - 0, 0.05, 0.10, 0.15, and 0.20 mg mL-1liquid volume incubated), and proteolytic activity (PRO - 0, 0.05, 0.10, 0.15, and 0.20 mg mL-1 liquid volume incubated ) on gas production (GP), kinetic parameters, and fermentation profile of Brachiaria brizantha cv. Marandu were evaluated using the in vitro gas production technique. Ruminal liquid was obtained from two rumen-cannulated Santa Inês sheep maintained on pasture. Accumulated gas production was measured during 96 hours of incubation, measured at 18 different time points. The determined parameters were pH, asymptotic gas production (mL g-1), rate of gas production (h-1), lag time (h), organic matter digestibility (OMD, g g-1 DM), metabolizable energy (ME, MJ kg-1 DM), and neutral detergent fiber digestibility (NDFD, mg g-1 DM). Increasing the FIB dose linearly increased (P < 0.05) the asymptotic gas production. However, the rate of gas production and the lag time showed linear decreases (P < 0.05). Addition of FIB also linearly increased (P < 0.05) the GP at all incubation times, as well as the OMD, NDFD and ME. Addition of AMZ linearly increased (P < 0.05) the asymptotic gas production, but GP linear increased (P < 0.05) only at the 6-hour and 12-hour time points. The rate of gas production and the lag time decreased linearly (P < 0.05) in response to increasing AMZ addition. Inclusion of PRO did not affect (P > 0.05) asymptotic gas production, but there was quadratic effect (P < 0.05) on the rate of gas production, the lag time, and the GP at the 6-hour and 12-hour time points. The OMD, NDFD and ME were not affected by PRO addition. Thus, fibrolytic, amylolytic and proteolytic enzymes are effective in reducing the lag time and increasing the in vitro gas production from Brachiaria Brizantha cv. Marandu forage, and fibrolytic enzymes improve the in vitro fermentation profile.

Digestion and microbial fermentation ofEragrostis curvulasupplemented with tallow

1999 ◽  
Vol 69 (2) ◽  
pp. 447-455 ◽  
Author(s):  
M. Fondevila ◽  
G. Cufré ◽  
J.C.M. Nogueira ◽  
L. Godio ◽  
G. Alcantu
Keyword(s):  
Bacterial Adhesion ◽  
Lag Time ◽  
Gas Production ◽  
Similar Amount ◽  
Microbial Fermentation ◽  
Ether Extract ◽  
Fat Level ◽  
Gas Volume ◽  
Matter Basis

AbstractTwoin vitroexperiments were conducted in order to determine if microbial fermentation of Eragrostis curvula hay is depressed by high levels of added tallow. Two levels of tallow, to reach 0.06 (T6) and 0.12 (T12) of the ether extract (organic matter basis) in food were compared with a control (T0, 25 g ether extract per kg). The first experiment studied the pattern of gas production. From 24 h onwards, gas volume for T0 was higher (P < 0.05) than for T6 and T12. However, lag time was shorter with tallow, probably because of utilization of the released glycerol. Fermentation of a similar amount of fat included in T6 and T12 as the only substrate (fat-6 and fat-12) depressed gas production compared with the blank, irrespective of fat level. In a second experiment, characteristics of microbial fermentation were studied, including volatile fatty acid (VFA) production, bacterial adhesion to fibrous particles (measured according to purine bases concentration) and polysaccharidase and glycosidase activities, at 6, 12, 24 and 48 h incubation. Total VFA was higher (P < 0.05) in T0 compared with T6 but not with T12. Acetate: propionate ratio diminished with tallow in the food. Higher total xylosidase (P > 0⋅05) and glycosidase (P < 0⋅001) activities were observed for T0 than for T6 and T12 and similar responses were observed regarding specific activities. Bacterial adhesion was not different between T0 and T6 but it was smaller in T12. The inhibition of microbial fermentation by tallow addition is more related to specific polysaccharidase and glycosidase activities, rather than to a depressed bacterial adhesion.

scholarly journals Assessment of cutting time on nutrient values, in vitro fermentation and methane production among three ryegrass cultivars

2020 ◽  
Vol 33 (8) ◽  
pp. 1242-1251
Author(s):  
Chunmei Wang ◽  
Fujiang Hou ◽  
Metha Wanapat ◽  
Tianhai Yan ◽  
Eun Joong Kim ◽  
...  
Keyword(s):  
Methane Production ◽  
Dry Matter ◽  
Lag Time ◽  
Time Of Day ◽  
Gas Production ◽  
Neutral Detergent Fiber ◽  
In Vitro Fermentation ◽  
Daily Gain ◽  
Production Response

Objective: The 3×3 factorial arrangement was used to investigate if either high watersoluble carbohydrates (WSC) cultivars or suitable time of day that the grass cut could improve nutrient values and <i>in vitro</i> fermentation characteristics.Methods: The 3 cultivars were mowed at 3 diurnal time points and included a benchmark WSC ryegrass cultivar ‘Premium’, and 2 high WSC cultivars AberAvon and AberMagic, which contained, on average, 157, 173, and 193 g/kg dry matter (DM) of WSC, and 36.0, 36.5, and 34.1 g/kg DM of N during 7th regrowth stage, respectively. The fermentation jars were run at 39°C with gas production recorded and sampled at 2, 5, 8, 11, 14, 17, 22, 28, 36, and 48 h. The rumen liquid was collected from 3 rumen fistulated cows grazing on ryegrass pasture.Results: High WSC cultivars had significantly greater WSC content, <i>in vitro</i> DM digestibility (IVDMD) and total gas production (TGP), and lower lag time than Premium cultivar. Methane production for AberMagic cultivar containing lower N concentration was marginally lower than that for AberAvon and Premium cultivars. Grass cut at Noon or PM contained greater WSC concentration, IVDMD and TGP, and lower N and neutral detergent fiber (NDF) contents, but CH<sub>4</sub> production was also increased, compared to grass cut in AM. Meanwhile, the effects of diurnal cutting time were influenced by cultivars, such as <i>in vitro</i> CH<sub>4</sub> production for AberMagic was not affected by cutting time. The IVDMD and gas production per unit of DM incubated were positively related to WSC concentration, WSC/N and WSC/NDF, respectively, and negatively related to N and NDF concentrations.Conclusion: These results imply either grass cut in Noon or PM or high WSC cultivars could improve nutrient values, IVDMD and <i>in vitro</i> TGP, and that AberMagic cultivar has a slightly lower CH<sub>4</sub> production compared to AberAvon and Premium. Further study is necessary to determine whether the increase of CH<sub>4</sub> production response incurred by shifting from AM cutting to Noon and/or PM cutting could be compensated for by high daily gain from increased WSC concentration and DM digestibility.

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