scholarly journals Ruminal biohydrogenation as affected by tanninsin vitro

2008 ◽  
Vol 102 (1) ◽  
pp. 82-92 ◽  
Author(s):  
Valentina Vasta ◽  
Harinder P. S. Makkar ◽  
Marcello Mele ◽  
Alessandro Priolo

The aim of the present work was to study the effects of tannins from carob (CT;Ceratonia siliqua), acacia leaves (AT;Acacia cyanophylla) and quebracho (QT;Schinopsis lorentzii) on ruminal biohydrogenationin vitro.The tannins extracted from CT, AT and QT were incubated for 12 h in glass syringes in cow buffered ruminal fluid (BRF) with hay or hay plus concentrate as a substrate. Within each feed, three concentrations of tannins were used (0·0, 0·6 and 1·0 mg/ml BRF). The branched-chain volatile fatty acids, the branched-chain fatty acids and the microbial protein concentration were reduced (P < 0·05) by tannins. In the tannin-containing fermenters, vaccenic acid was accumulated (+23 %,P < 0·01) while stearic acid was reduced ( − 16 %,P < 0·0005). The concentration of total conjugated linoleic acid (CLA) isomers in the BRF was not affected by tannins. The assay on linoleic acid isomerase (LA-I) showed that the enzyme activity (nmol CLA produced/min per mg protein) was unaffected by the inclusion of tannins in the fermenters. However, the CLA produced by LA-I (nmol/ml per min) was lower in the presence of tannins. These results suggest that tannins reduce ruminal biohydrogenation through the inhibition of the activity of ruminal micro-organisms.

2020 ◽  
Author(s):  
Hangshu Xin ◽  
Xin Liu ◽  
Xin Jiang ◽  
Chunlong Liu ◽  
Shuzhi Zhang ◽  
...  

Abstract Background: The objectives of this study were to evaluate the profiles of odd- and branched-chain fatty acids (OBCFA; including C15:0, iso-C15:0, anteiso-C15:0, iso-C16:0, C17:0, iso-C17:0 and anteiso-C17:0) during pure carbohydrates incubation in vitro and whether they correlated with ruminal fermentation parameters, microbial crude protein (MCP) synthesis, and bacterial populations. The pure substrates containing five different ratios of fiber and starch (F:S; 0:100, 25:75, 50:50, 75:25 and 100:0) were incubated for 6 h, 12 h, 18 h and 24 h. Results: Except iso-C17:0, OBCFA concentrations were interacted by F:S and incubation time. The highest concentration of total OBCFA was found in the fermented mixture after 24 h of incubation when the F:S = 0:100; while the lowest level was 1.65 mg/g DM produced after 6 h of incubation with F:S = 50:50. The concentrations of total volatile fatty acids (TVFA) and MCP remarkably decreased linearly as the inclusion of fiber in the substrates increased, as expected. The proportions of investigated cellulolytic bacteria in our study were increased linearly (or linearly and quadratically) while those of R. amylophilus and S. bovis were decreased as fiber inclusion increased. The correlation analysis indicated that iso-C16:0 concentration might have potential as a marker of productions of TVFA and MCP with ρ being 0.78 and 0.82 respectively. Compared to starch degrading bacteria, cellulolytic bacteria had more correlations with OBCFA profiles, and the strongest association was found on the population of R. flavefaciens with C15:0 concentration (ρ = 0.70). Conclusions: Our study shows there might be scope for iso-C16:0 to predict rumen productions of VFA and MCP. Notedly, this is the first paper reporting linkage of OBCFA with rumen function based on pure carbohydrate in vitro incubation, which would avoid confounding interference from dietary protein and fat presence. However, more in-depth experiments are needed to substantiate the current findings.


2006 ◽  
Vol 95 (6) ◽  
pp. 1199-1211 ◽  
Author(s):  
I. Wąsowska ◽  
M. R. G. Maia ◽  
K. M. Niedźwiedzka ◽  
M. Czauderna ◽  
J. M. C. Ramalho Ribeiro ◽  
...  

Dietarycis-9,trans-11-conjugated linoleic acid (CLA) is generally thought to be beneficial for human health. Fish oil added to ruminant diets increases the CLA concentration of milk and meat, an increase thought to arise from alterations in ruminal biohydrogenation of unsaturated fatty acids. To investigate the mechanism for this effect,in vitroincubations were carried out with ruminal digesta and the main biohydrogenating ruminal bacterium,Butyrivibrio fibrisolvens. Linoleic acid (LA) or α-linolenic acid (LNA) was incubated (1·67g/l) with strained ruminal digesta from sheep receiving a 50:50 grass hay–concentrate ration. Adding fish oil (up to 4·17g/l) tended to decrease the initial rate of LA (P=0·025) and LNA (P=0·137) disappearance, decreased (P<0·05) the transient accumulation of conjugated isomers of both fatty acids, and increased (P<0·05) the accumulation oftrans-11-18:1. Concentrations of EPA (20:5n-3) or DHA (22:6n-3), the major fatty acids in fish oil, were low (100mg/l or less) after incubation of fish oil with ruminal digesta. Addition of EPA or DHA (50mg/l) to pure cultures inhibited the growth and isomerase activity ofB. fibrisolvens, while fish oil had no effect. In contrast, similar concentrations of EPA and DHA had no effect on biohydrogenation of LA by mixed digesta, while the addition of LA prevented metabolism of EPA and DHA. Neither EPA nor DHA was metabolised byB. fibrisolvensin pure culture. Thus, fish oil inhibits ruminal biohydrogenation by a mechanism which can be interpreted partly, but not entirely, in terms of its effects onB. fibrisolvens.


1990 ◽  
Vol 63 (2) ◽  
pp. 197-205 ◽  
Author(s):  
X. B. Chen ◽  
F. D. DeB. Hovell ◽  
E. R. ØRskov

The saliva of sheep was shown to contain significant concentrations of uric acid (16 (sd) 4.5) μmol/l) and allantoin (120 (sd 16.4) μmol/l), sufficient to recycle purine derivatives equivalent to about 0.10 of the normal urinary excretion. When allantoin was incubated in vitro in rumen fluid, it was degraded at a rate sufficient to ensure complete destruction of recycled allantoin. In a series of experiments in which allantoin was infused into the rumen of sheep fed normally, or into the rumen or abomasum of sheep and the rumen of cattle completely nourished by intragastric infusion of volatile fatty acids and casein, no additional allantoin was recovered in the urine. These losses were probably due to the degradation of allantoin by micro-organisms associated with the digestive tract. It is concluded that all allantoin and uric acid recycled to the rumen via saliva will be similarly degraded. Therefore, the use of urinary excretion of purine derivatives as an estimator of the rumen microbial biomass available to ruminants will need to be corrected for such losses.


2003 ◽  
Vol 2003 ◽  
pp. 151-151
Author(s):  
B. Vlaeminck ◽  
V. Fievez ◽  
H. van Laar ◽  
D. Demeyer

Rumen microbes contain a high proportion (20 to 50%) of their fatty acids (FA) as odd and branched chain fatty acids (OBCFA; C15:0, iso C15:0, anteiso C15:0, C17:0; iso C17:0; anteiso C17:0 and C17:1) and different bacterial classes have distinctive OBCFA ‘fingerprints’. As OBCFA make up around 5% of FA in milk, it has been suggested that there is scope for these compounds to be used in on-farm diagnostic milk-based tests in relation to the rumen fermentation pattern. Correlations of milk OBCFA with rumen fermentation pattern were recently shown (Vlaeminck et al., 2002). In the current in vitro study, the potential of rumen OBCFA to predict the production of volatile fatty acids (VFA) was evaluated.


1976 ◽  
Vol 36 (2) ◽  
pp. 311-315 ◽  
Author(s):  
J. W. Czerkawski

1. A procedure is described for using pivalic acid as an inert reference substance in determination of changes in concentrations of volatile fatty acids (VFA).2. Pivalic acid in concentrations of up to 80 mmol/l had no effect on production of methane or VFA by rumen contents.3. Pivalic acid was inert during incubation with rumen contents from sheep given different diets and with samples taken at different times with respect to feeding.


2013 ◽  
Vol 152 (4) ◽  
pp. 686-696 ◽  
Author(s):  
H. J. YANG ◽  
H. ZHUANG ◽  
X. K. MENG ◽  
D. F. ZHANG ◽  
B. H. CAO

SUMMARYThe effects of melamine on gas production (GP) kinetics, methane (CH4) production and fermentation of diets differing in forage content (low-forage (LF) diet: 200 g/kg and high-forage (HF) diet: 800 g/kg) by rumen micro-organismsin vitrowere studied using batch cultures. Rumen contents were collected from three Simmental×Luxi crossbred beef cattle. Melamine was added to the incubation bottles to achieve final concentration of 0 (control), 2, 6, 18, 54, 162 and 484 mg/kg of each diet. Cumulative GP was continuously measured in an automated gas recording instrument during 72 h of incubation, while fermentation gas end-products were collected to determine molar proportions of carbon dioxide (CO2), CH4and hydrogen gas (H2) in manually operated batch cultures. Differences in GP kinetics and fermentation gases were observed in response to the nature of the diets incubated. Although melamine addition did not affect GP kinetics and fermentation gas pattern compared to the control, the increase of melamine addition stimulated the yield of CH4by decreasing CO2, especially during the fermentation of the HF diet. The concentrations of ammonia nitrogen (N), amino acid N and microbial N in culture fluids were greater in the fermentation of LF- than HF diets, and these concentrations were increased by the increase of melamine addition after 72-h fermentation. The concentrations of total volatile fatty acids (VFA) were greater in HF than LF diets. The addition of melamine decreased total VFA concentrations and this response was greater in HF than LF diet fermentations. Melamine addition did not affect molar proportions of acetate, butyrate, propionate and valerate compared with the control; however, branched-chain VFA production, which was lower in the HF than the LF diet, was increased by the melamine addition, especially in the HF diet fermentation. The ratio of non-glucogenic to glucogenic acids was lower in the HF than the LF diet, but it was not affected by melamine addition. In brief, the greater reduction in the rate and extent of rumen fermentation found for the HF diet in comparison with the LF diet suggested that rumen fermentation rate and extentin vitrodepended mainly on the nature of the incubated substrate, and that they could be further inhibited by the increase of melamine addition.


2006 ◽  
Vol 95 (4) ◽  
pp. 688-695 ◽  
Author(s):  
Renaville Bénédicte ◽  
Anne Mullen ◽  
Fiona Moloney ◽  
Yvan Larondelle ◽  
Yves-Jacques Schneider ◽  
...  

Stearoyl-CoA desaturase (SCD) is a key enzyme that determines the composition and metabolic fate of ingested fatty acids, in particular the conversion of trans-vaccenic acid (TVA) to conjugated linoleic acid (CLA). The present study addressed the hypothesis that intestinal TVA absorption and biotransformation into CLA can be modulated by EPA and 3,10-dithia stearic acid (DSA) via altered SCD mRNA levels and desaturation indices (cis-9, trans-11-CLA:TVA and oleic acid:stearic acid ratios) in Caco-2 and T84 cells, two well-established in vitro models of the human intestinal epithelium. The study determined the effect of acute (3h with 0·3mm-EPA or 0·3mm-DSA) and acute-on-chronic (1 week with 0·03mm-EPA or -DSA, followed by respectively, 0·3mm-EPA or -DSA for 3h) treatments. In both cell lines, acute EPA treatment did not alter SCD desaturation indices, whereas the acute-on-chronic treatment affected these surrogate markers of SCD activity. This was associated with reduced sterol regulatory-element binding protein-1c and SCD mRNA levels. In contrast, acute and acute-on-chronic DSA treatments significantly reduced SCD desaturation indices without affecting SCD mRNA levels in Caco-2 cells. The present study on intestinal cells shows that the conversion rate of TVA to c9, t11-CLA is affected by other fatty acids present in the diet such as EPA, confirming previous observations in hepatic and mammary cell models.


2007 ◽  
Vol 2007 ◽  
pp. 26-26
Author(s):  
S.E. Grace ◽  
A.P. Moloney ◽  
D.A. Kenny

The myriad putative health benefits of conjugated linoleic acid (CLA) and in particular the cis-9, trans-11 isomer, have stimulated interest in increasing its concentration in food. Ruminant fat is the main dietary source of CLA for humans and CLA is produced in the rumen by incomplete biohydrogenation of dietary linoleic acid (LA). It is now accepted that most CLA is synthesised post-ruminally by desaturation of vaccenic acid (VA) produced during ruminal biohydrogenation of (LA) and linolenic acid (LNA) (Griinari et al., 2000). Enhancement of VA synthesis in the rumen is therefore an important element of strategies to increase CLA concentration in tissue. The objective of this experiment was to determine the effect of controlling the rate of release of oil from camelina seeds, a novel source of both LA and LNA, on the accumulation of intermediates during ruminal biohydrogenation.


1961 ◽  
Vol 56 (1) ◽  
pp. 131-136 ◽  
Author(s):  
I. H. Bath ◽  
M. J. Head

1. A new technique has been used to study the fermentation of hemicellulose and α-cellulose in vitro. This involved the use of 14C-labelled carbohydrates fermented in the presence of normal herbage material in an artificial rumen.2. A method of growing grass in an atmosphere of 14CO2, its fractionation into hemicellulose and α-cellulose and the analysis of the labelled V.F.A. end-products are described.


Sign in / Sign up

Export Citation Format

Share Document