scholarly journals The degradability characteristics of fifty-four roughages and roughage neutral-detergent fibres as described by in vitro gas production and their relationship to voluntary feed intake

1997 ◽  
Vol 77 (5) ◽  
pp. 757-768 ◽  
Author(s):  
M. Blümmel ◽  
K. Becker

Fifty-four roughages of known voluntary dry-matter intakes (DMI; range 7·8−35·2 g/kg live weight per d) were examined in vitro in a gas production test. Samples (200 mg) of roughage and roughage neutral-detergent fibre (NDF) respectively were incubated in a mixed suspension of rumen contents for 96 h and the gas volumes recorded after 4,6,8,12,24,30,36,48,54,60 and 96 h. The kinetics of gas production were derived from the volume recordings described by the exponential equation Y=A+B(l—e-ct) where A is the intercept and ideally reflects the fermentation of the soluble and readily available fraction of the feed, B describes the fermentation of the insoluble (but with time fermentable) fraction and c the fractional rate at which B is fermented per h; A+B describes total fermentation. In vitro true dry matter (TD) and NDF degradabilities (NDF-D) after 24 h incubation were also determined. Of the variation in DMI, 75% was accounted for by the in vitro gas production parameters A, B and c in stepwise multiple regressions; 82% of the variation in DMI was explained by the parameters (ANDF+BNDF) and cNDF as obtained from the incubation of roughage NDF. The rate constants (c) were less important than parameters related to the extent of gas production, accounting for only 6·5 (whole roughage) and 4·1% (NDF) of the variation in DMI. There was no statistical advantage in the use of the exponential model describing extent and rate of fermentation over some of the simple gas volume measurements: 75% of the variation in DMI was accounted for by in vitro gas production of whole roughage after 8 h of incubation. On average gas production from NDF measured from 24–96 h accounted for 81% of the variation in DMI. A combination of gas volume measurements after a short period of incubation (4–8 h) with a concomitant determination of NDF-D after many hours (≥24 h) can render NDF preparations and long incubation times redundant. A method is suggested to obtain two results for DMI prediction in one single incubation. Of the variation in DMI 80% was accounted for by the incubation of 500 mg whole roughage when incubation was terminated after 24 h and the residual undegraded substrate quantified.

2020 ◽  
Vol 44 (2) ◽  
pp. 187-194
Author(s):  
L. O. Saliu ◽  
T. O. Ososanya

In vitro gas production is an indication of microbial degradability of feed samples. Thus varying levels of mixture of cassava top (CT) and maize stover (MS) ensiled with Albizia saman pods (ASP) were examined. The feedstuff were dried and milled for gas determination in a completely randomized design. Samples were incubated using in vitro gas production technique. Gas production was measured at 3, 6, 9, 12, 15, 18, 21 and 24 h post incubation to estimate total gas volume (TGV), methane (CH4), metabolisable energy (ME; MJ/Kg DM), organic matter digestibility (OMD; %) and short chain fatty acids (SCFA; ìmol/200 mg DM). dry matter (DM, %) increased significantly (p<0.05) as inclusion of Albizia saman pods increases across the treatments. The crude protein (CP, %) contents were similar across the treatments. The total gas volume (TGV mL) produced by the diets were similar across the treatments. The values ranged from 4.81 to 5.26 for ME, 35.16 to 36.32 for OMD, 0.13 to 0.21 for SCFA and 5.33 to 7.33 for CH4 production with no significant difference. The result showed that in vitro fermentation of the mixture of cassava top and maize stover ensiled with Albizia saman pods at 0:40:60% increased the dry matter degradability by 15%, enhanced metabolisable energy, organic matter digestibility and short chain fatty acids.


2014 ◽  
Vol 54 (10) ◽  
pp. 1662
Author(s):  
G. Antúnez ◽  
C. Cajarville ◽  
A. Britos ◽  
A. González ◽  
J. L. Repetto

The aim of this study was to evaluate the fermentation activity of ruminal inoculum from cattle fed fresh pasture and supplemented or not with corn grain at different daily frequencies. Twenty heifers with ruminal catheters were randomly assigned to four treatments. Animals were fed pasture ad libitum and non-supplemented (T0) or supplemented with corn grain at 1% of bodyweight offered in one (T1), two (T2) or eight (T8) meals per day. After 20 days of adaptation, ruminal inoculum of each heifer was used to evaluate fermentation activity by the in vitro gas-production technique, using alfalfa, white clover or ryegrass as substrates. Gas production was measured at 2, 4, 6, 8, 10, 12, 18, 24, 48, 72 and 96 h from the beginning of incubation. Data were fitted to an exponential model and potential gas volume, fractional rate of gas production and lag time were analysed by PROC MIXED, considering the effect of treatment and substrate, and their interaction. The three parameters were affected by the substrate. Supplementation frequency did not affect the potential gas volume or the fractional rate of gas production. An interaction between treatment and substrate was detected (P < 0.01) on lag time, but only when ryegrass was used as the substrate. In conclusion, increasing the frequency of supplementation did not show benefits for the fermentation activity of ruminal inoculum, at least when the type of pasture used in this experiment was supplemented with corn at 1% of bodyweight.


Animals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1957
Author(s):  
Margarita Novoa-Garrido ◽  
Carlos Navarro Marcos ◽  
María Dolores Carro Travieso ◽  
Eduarda Molina Alcaide ◽  
Mogens Larsen ◽  
...  

The study analyzed the characteristics, chemical composition, and in vitro gas production kinetics of Porphyra umbilicalis and Saccharina latissima silages. Each seaweed was ensiled in vacuum bags (three bags/silage) following a 2 × 3 factorial design, with two pre-treatments (unwilted or pre-wilted) and three silage types: unwashed seaweed ensiled without additive; seaweed washed and ensiled without additive; and seaweed washed and ensiled with 4 g of formic acid (FAC) per kg seaweed. Silages were kept for 3 months in darkness at 20 °C. Pre-wilting prevented (p < 0.001) effluent formation and reduced (p ≤ 0.038) the production of NH3-N and volatile fatty acids for both seaweeds. Both pre-wilting and washing increased (p < 0.05) the ruminal degradability of P. umbilicalis silages but not of S. latissima silages. The pH of the FAC-treated silages was below 4.0, but ranged from 4.54 to 6.23 in non FAC-treated silages. DL-lactate concentrations were low (≤23.0 g/kg dry matter) and acetate was the predominant fermentation product, indicating a non-lactic fermentation. The estimated ruminal degradability of the P. umbilicalis and S. latissima silages was as average, 59.9 and 86.1% of that for high-quality rye-grass silages, respectively, indicating a medium-low nutritional value of these seaweed silages for ruminants.


1997 ◽  
Vol 64 (1) ◽  
pp. 71-75 ◽  
Author(s):  
M. Blümmel ◽  
P. Bullerdieck

AbstractThe need to complement in vitro gas production measurements with residue determination is demonstrated by the recalculation and reassessment of published data on in vitro gas production, in sacco degradabilities and voluntary dry matter intake (DMI). The in sacco degradability — gas volume ratio was determined at 24 and 48 h of incubation, termed partitioning factor (PF) and combined with rate and extent parameters of in sacco degradability and in vitro gas production to predict DMI. In vitro gas production and in sacco degradability characteristics (a + b) and c as described by the equation y = a + b(1−ect) explained 0·373 and 0·668 respectively of the variation in DMI of 19 legume and grass hays. The complementation of gas production parameters by the PF24 increased the R2 value to 0·744 with PF24 accounting for 0·407 of the variation in DMI, the rate of gas production (c) for 0·218 and the extent of gas production (a + b) for 0·119 of the variation in DMI. As a single parameter, PF48 showed the highest correlation (R2 = 0·597) with DMI but the combination of PF4S with rate and extent of in sacco or in vitro gas production measurements did not improve the correlation further, probably due to an intercorrelation between rates of fermentation and PF4S. Hays which were degraded at faster rates had higher PF values indicating proportionally higher microbial yield and lower short-chain fatty acid production per unit substrate degraded. Generally, hays with high in sacco degradabilities but proportionally low gas production i.e. hays with high PF values showed higher DMI.


1998 ◽  
Vol 1998 ◽  
pp. 69-69
Author(s):  
S. Fakhri ◽  
A. R. Moss ◽  
D.I. Givens ◽  
E. Owen

The gas production (GP) technique has previously been used to estimate the gas volume (fermentable energy (FE)) of compound feed ingredients for ruminants (Newbold et al., 1996). It was shown that the FE content of feed mixtures was represented by the combination of the total gas from the incubation of the individual feeds. However this additivity might not be consistent throughout the incubation period. The objectives were to test whether 1. other GP parameters give better estimates of FE for simple mixtures and are they additive; 2. whether organic matter apparently degraded in the rumen (OMADR) explain differences in GP; and 3. to find out if there are any other better measures than OMADR for estimating FE.


Author(s):  
D. T. Q. Carvalho ◽  
A. R. F. Lucena ◽  
T. V. C. Nascimento ◽  
L. M. L. Moura ◽  
P. D. R. Marcelino ◽  
...  

Abstract The objective was to evaluate the fermentation profile, in vitro gas production and nutritional quality of pornunça (Manihot spp.) silages containing levels of condensed tannin (CT; 0, 4, 8 and 12% on dry matter (DM) basis), at five opening times (0, 3, 7, 14, 28 and 56 days). A completely randomized design in a 4 × 5 factorial arrangement was adopted, with four replications, totalling 80 experimental silos. The pH and NH3-N analyses were performed at all opening times of the silos. The other analyses were performed only with silages opened at 56 days of storage. There was an interaction effect between CT levels and silo opening times for pH and NH3-N. Tannin levels in pornunça silages after 56 days ensiling increased the pH and DM and reduced crude protein (CP) and neutral detergent fibre (NDF). There was a quadratic effect for NH3-N, acetic acid, butyric acid, gas losses, dry matter recovery (DMR), hemicellulose and acid detergent fibre. Inclusion of 4 and 8% CT in pornunça silage promotes a rapid decline in pH, being within the acceptable limit for adequate fermentation at 3 days of ensiling. Silages with 4% CT establish the pH at 28 days of opening the silos, with reduced NH3-N. Silages with 4% CT present higher concentrations of acetic and butyric acids and greater DMR. Inclusion of CT in pornunça silage after 56 days ensiling increases DM and reduces CP and NDF, directly affecting the in vitro degradability and reducing gas production.


Author(s):  
N.D. Meads ◽  
R. Tahmasbi ◽  
N. Jantasila

Greenhouse gas (GHG) emissions from livestock are an important consideration in environmental science. Estimating GHG production can be problematic at a farm or animal level, and requires controlled conditions to produce real data. An in vitro gas production technique (IVGPT) was developed to evaluate forage-based total mixed rations in digestion kinetics and GHG production. Two hundred and sixty samples of complete mixed rations (MR), which included a pasture component used in commercial lactating dairy herds, were collected around NZ across three calendar years, 2017-2019. Twenty of the 260 samples were 100% total mixed rations (TMR) with no pasture content. The samples were submitted for proximate analysis as well as IVGPT to generate GHG production figures. The results showed an average total gas production (TGP) of 129.82 ml/g dry matter (DM), 78.6% true digestibility (TDMD), 125.06 mg/g DM microbial biomass (MB), 20.16 g CH4/kg DM, and 12.8 MJME/kg DM. The average nutrient composition was dry matter (DM) 31.55%, crude protein (CP) 21.85%, neutral detergent fibre (NDF) 44.35%, and starch 7.03%. The IVGPT CH4 production was negatively correlated to NDF (r=-0.312), ADF (r=-0.193), TGP (r=-0.216), and was positively correlated with TDMD (r=0.250), apparent digestibility (ADMD) (r=0.614), starch (r=0.117) and volatile fatty acids (r=0.538). The MR diet showed a strong positive relationship with ADMD digestibility (P=0.01) and a negative relationship with fibre content (NDF, P=0.01 and ADF, P=0.01). However, CH4 production reduced linearly with increasing TGP (P=0.01). The results indicated that a greater CH4 production may be related to higher digestibility of mixed ration.


2004 ◽  
Vol 84 (1) ◽  
pp. 105-111 ◽  
Author(s):  
M. Blümmel ◽  
E. E. Grings ◽  
M. R. Haferkamp

The effects of suppression of annual bromes (Bromus japonicus Thunb. and Bromus tectorum L.) by atrazine application on the nutritive quality of extrusa diet samples (EDS) collected from the esophagus were investigated, and EDS quality estimates were compared with weight gain of grazing steers. Analysis on EDS included crude protein (CP), in vitro organic matter degradability (IVOMD), and gas production profiles in N supplemented and unsupplemented incubation media. Brome-suppression tended (P = 0.07) to increase CP content but effects on gas production kinetics and IVOMD were dependent on incubation medium N-level. In N-unsupplemented incubations, asymptotic gas production was less and rates of gas production were greater in EDS from brome-suppressed compared to undisturbed pasture. No such differences were found for N-supplemented incubations. Weight gains of steers grazing brome-suppressed pastures were 16% greater (P = 0.007) than from control pastures. The R2 for the comparison of predicted and measured gains were 0.90 (P < 0.0001), 0.96 (P < 0.0001), and 0.90 (P < 0.0001) using CP, IVOMD (N-low), and IVOMD (N-rich) as the predicting variable, respectively. Best predictions using in vitro gas production measurements were obtained from 24 h gas volume recording (R2 = 0.93, P < 0.0001). Best-fit model (sigmoidal vs. exponential) depended on grazing period and N-level, and the sigmoidal Gompertz model best described most gas production profiles. Key words: Forage quality, gas production, weight gain, beef steers


1998 ◽  
Vol 22 ◽  
pp. 207-208
Author(s):  
R. S. Lowman ◽  
N. S. Jessop ◽  
M. K. Theodorou ◽  
M. Herrero ◽  
D. Cuddeford

Following the development of the Menke technique in 1979, the measurement of gas production in vitro has become increasingly popular for investigating the kinetics of rumen fermentation. The aim of this study was to compare the gas production profiles for three foods using two in vitro gas production techniques; the Menke et al. (1979) technique (MT) and the pressure transducer technique (PTT) (Theodorou et al., 1994). Both techniques involve recording gas production throughout the incubation of a food sample with rumen fluid. The MT incubations are made in gas-tight syringes where the volume of gas produced causes the plunger to move up the syringe barrel. The PTT involves measuring gas production in fermentation bottles using a pressure transducer and syringe assembly to measure the pressure and corresponding gas volume. As the medium to rumen fluid ratios also differ between techniques; 2:1 in the Menke technique and 9:1 in the PTT, both ratios were investigated in this study.


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