scholarly journals Removal of digesta components from the rumen of steers determined by sieving techniques and fluid, particulate and microbial markers

1985 ◽  
Vol 53 (2) ◽  
pp. 347-362 ◽  
Author(s):  
R. M. Dixon ◽  
L. P. Milligan
Keyword(s):  
Particle Size ◽  
Small Particle ◽  
Rumen Fluid ◽  
Size Group ◽  
Progressive Decline ◽  
Mesh Screen ◽  
Outflow Rate ◽  
The Mean ◽  
Micro Organisms

1. When 103Ru-labelled Tris (1, 10-phenanthroline) ruthenium II chloride (103Ru-P) particulate marker in aqueous solution was added to the rumen of four steers given 5.5 kg grass hay/d at two-hourly intervals, the distribution of 103Ru-P marker among rumen particles of various sizes was the same at 4 h, 3 d and 7 d after administration, the concentration of 103Ru-P/g dry matter (DM) was inversely related to particle size and 0.30 of the 103Ru-P was associated with the DM of particles too large to be moved from the rumen at a meaningful rate. Thus, fractional outflow rate (FOR) of 103Ru-P would reflect, but was not a direct measure of, the FOR of the small particle pool in the rumen.2. When rumen digesta were labelled with 103Ru-P, placed in nylon cloth bags and incubated in vitro with unlabelled digesta, 59% of the 103Ru-P disappeared from the nylon bag in 24 h, and 74% in 48 h. Similar results were obtained when large particles (retained by a 3.2 mm mesh screen during wet sieving) from rumen digesta were subjected to this procedure.3. In a further experiment, the steers were given the hay in either the long or ground form and drinking water to which 10 g sodium chloride/l were, or were not, added.4. The FOR of 51CrEDTA in centrifuged rumen fluid was increased (P < 0.05) from 1.78 to 2.10/d by grinding of the hay diet, but was not influenced by the intake of an additional 257 g NaCl/d. The FOR values of 103Ru-P in mixed rumen digesta and organic 35S in micro-organisms were linearly correlated (P < 0.05) and were not affected (P < 0.05) by grinding and salt treatments. On average, the FOR of organic 35S in micro-organisms was 0.41 of that of 51CrEDTA in centrifuged rumen fluid and 0.85 of that of 103Ru-P in rumen digesta respectively.5. Grinding of the hay did not (P > 0.05) change the proportion of rumen DM (0.476–0.515) or faecal DM (0.107–0.153) retained by the 3.2 mm mesh and larger screens.6. FOR from the rumen of a given size group of particles was calculated as the ratio, estimated daily flow from the rumen of the size group: rumen pool of the group. With increasing particle size there was a progressive decline in FOR; values of FOR for groups of particles greater than 4.0 mm were negligible. If the rumen DM was considered to behave as two pools, the 3.2 mm mesh screen appeared to be an appropriate division between the large-particle and the small-particle DM pools.7. FOR of lignin present in mixed rumen digesta was 0.48 of the mean of the FOR values of the particle groups of the small-particle pool, while the FOR of lignin present in the small-particle pool was 0.92 of the mean small-particle FOR.

scholarly journals Hydrolysis of14C-labelled proteins by rumen micro-organisms and by proteolytic enzymes prepared from rumen bacteria

1983 ◽  
Vol 50 (2) ◽  
pp. 345-355 ◽  
Author(s):  
R. J. Wallace
Keyword(s):  
Proteolytic Enzymes ◽  
Rumen Fluid ◽  
Performic Acid ◽  
Cross Linking ◽  
Acid Oxidation ◽  
Rumen Bacteria ◽  
Rate Of Hydrolysis ◽  
Micro Organisms ◽  
Hydrolysis Of

1. Proteins were labelled with14C in a limited reductive methylation using [14C]formaldehyde and sodium borohydride.2. The rate of hydrolysis of purified proteins was little (< 10%) affected by methylation and the14C-labelled digestion products were not incorporated into microbial protein during a 5 h incubation with rumen fluid in vitro. It was therefore concluded that proteins labelled with14C in this way are valid substrates for study with rumen micro-organisms.3. The patterns of digestion of14C-labelled fish meal, linseed meal and groundnut-protein meal by rumen micro-organisms in vitro were similar to those found in vivo.4. The rates of hydrolysis of a number of14C-labelled proteins, including glycoprotein II and lectin from kidney beans (Phaseolus vulgaris), were determined with mixed rumen micro-organisms and with proteases extracted from rumen bacteria. Different soluble proteins were digested at quite different rates, with casein being most readily hydrolysed.5. Proteins modified by performic acid oxidation, by cross-linking using 1,6-di-iso-cyanatohexane or by diazotization were labelled with14C. Performic acid treatment generally increased the susceptibility of proteins to digestion, so that the rates of hydrolysis of performic acid-treated proteins were more comparable than those of the unmodified proteins. Cross-linking resulted in a decreased rate of hydrolysis except with the insoluble proteins, hide powder azure and elastin congo red. Diazotization had little effect on the rate of hydrolysis of lactoglobulin and albumin, but inhibited casein hydrolysis and stimulated the breakdown of γ-globulin.

Repeatability of in vitro digestibility assays of forages when using fresh, frozen or freeze-dried cow faeces instead of sheep rumen liquor as sources of micro-organisms

1995 ◽  
Vol 1995 ◽  
pp. 110-110 ◽  
Author(s):  
S Akhter ◽  
E Owen ◽  
M K Theodorou ◽  
S L Tembo ◽  
E R Deaville
Keyword(s):  
Freeze Drying ◽  
Rumen Fluid ◽  
In Vitro Digestibility ◽  
Two Stage ◽  
Freeze Dried ◽  
Fresh Frozen ◽  
Sheep Rumen ◽  
Micro Organisms

Previous studies (El Shaer, Omed and Axford, 1987; Akhter, Owen, Fall, O'Donovan and Theodorou, 1994) with the two-stage in vitro procedure of Tilley and Terry (1963) have shown a high correlation between digestibilities of forages as determined using either sheep rumen liquor, sheep faeces or cow faeces as the microbial inoculum. In the first study of the of the present investigation one objective was to examine the repeatability of these digestibility measurements when made on different occasions. A second objective was to assess whether the correlations between faecal and rumen fluid based inocula could be improved if microorganisms were obtained from pairs rather than individual animals. The objective in the second study using forages of known in vivo digestibility, was to investigate the effect of freezing or freeze-drying of faeces on the repeatability of digestibilities of forages determined in vitro using micro-organisms from cow faeces.

scholarly journals Physicochemical Properties andIn VitroCytotoxicity Studies of Chitosan as a Potential Carrier for Dicer-Substrate siRNA

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Maria Abdul Ghafoor Raja ◽  
Haliza Katas ◽  
Zariyantey Abd Hamid ◽  
Nur Atiqah Razali
Keyword(s):  
Particle Size ◽  
Cost Effectiveness ◽  
Zeta Potential ◽  
Small Interfering Rna ◽  
Ionic Gelation ◽  
Rapid Degradation ◽  
The Mean ◽  
Afm Micrographs ◽  
Interfering Rna

Recently, Dicer-substrate small interfering RNA (DsiRNA) has gained attention owing to its greater potency over small interfering RNA (siRNA). However, the use of DsiRNA is restricted by its rapid degradationin vitro. To address this issue, chitosan nanoparticulate deliver yplatform for the Dicer-substrate siRNA (DsiRNA) was developed and characterized. Nanoparticles were prepared by simple complexation and ionic gelation methods. The mean particle size of DsiRNA-adsorbed chitosan nanospheres (DsiRNA-CS NPs) prepared by the ionic gelation method ranged from 225 to 335 nm, while simple complexation yielded DsiRNA-chitosan complexes (DsiRNA-CS complexes) ranging from 270 to 730 nm. The zeta potential of both types of nanoparticles ranged from +40 to +65 mV. TEM and AFM micrographs revealed spherical and irregular morphology of DsiRNA-CS NPs and DsiRNA-CS complexes. ATR-FTIR spectroscopy confirmed the presence of DsiRNA in the CS NPs/complexes. Both types of nanoparticles exhibited sustained release and high binding and encapsulation (100%) efficiency of DsiRNA. DsiRNA-CS NPs/complexes showed low, concentration-dependent cytotoxicityin vitro. DsiRNA-CS NPs showed better stability than the complexes when stored at 4 and 25°C. Thus, it is anticipated that CS NPs are promising vectors for DsiRNA delivery due to their stability, safety, and cost-effectiveness.

scholarly journals A comparative study of ruminal activity in Churra and Merino sheep offered alfalfa hay

1997 ◽  
Vol 65 (1) ◽  
pp. 121-128 ◽  
Author(s):  
M. J. Ranilla ◽  
M. D. Carro ◽  
C. Valdés ◽  
F. J. Giráldez ◽  
S. López
Keyword(s):  
Cell Wall ◽  
Rumen Fluid ◽  
Merino Sheep ◽  
Rumen Ph ◽  
Sheep Rumen ◽  
Fermentation Parameters ◽  
Micro Organisms ◽  
Kinetics Of

AbstractA study was carried out to compare the fermentation parameters and kinetics of digestion of a range of different foods in the rumen of two breeds of sheep (Churra and Merino). Ten mature sheep (five Churra and five Merino), each fitted with a rumen cannula, were used in this study. In situ rumen degradability of both dry matter (DM) and cell wall was greater in Churra than in Merino sheep, the breed differences being significant for most of the foods used in the study (P < 0·05). These differences were greater when the foods had a higher cell wall concentration and this could be related to differences in the ruminal environment. However, when the foods were incubated with rumen fluid their in vitro organic matter (OM) degradability was similar in both breeds. Rumen pH was higher (P < 0·05) and ammonia concentrations were lower (P < 0·05) in Churra than in Merino sheep. Rumen volatile fatty acid concentrations tended to be higher in Merino than in Churra sheep, though differences were only significant just before feeding (P < 0·05). The ratio acetate: propionate was higher in the Churra than Merino breed before and 12 h after feeding (P < 0·05). Protozoa numbers in rumen liquid were similar for both genotypes. The greater degradation of forages in the rumen of Churra sheep is discussed in relation to the possible higher activity of fibre-degrading micro-organisms and the greater buffering capacity of the rumen contents against fermentation acids, which could result in more favourable conditions for the microbial degradation of foods in the rumen.

EVALUATION OF A DEHYDROGENASE ASSAY BASED ON TETRAZOLIUM REDUCTION FOR RAPID IN VITRO ESTIMATION OF FERMENTATION ACTIVITY IN RUMEN CONTENTS

1978 ◽  
Vol 58 (3) ◽  
pp. 501-511 ◽  
Author(s):  
G. A. JONES ◽  
B. A. HUMPHREY
Keyword(s):  
Dehydrogenase Activity ◽  
Rumen Fluid ◽  
Stomach Tube ◽  
Triphenyltetrazolium Chloride ◽  
Activity Maximum ◽  
Alfalfa Hay ◽  
The Mean ◽  
Ph Range ◽  
Second Peak

Rumen contents obtained from fistulated steers fed brome–alfalfa hay was used to evaluate a dehydrogenase assay based on the reduction of 2,3,5-triphenyltetrazolium chloride (TTC) to triphenylformazan (TPF) for rapid in vitro estimation of fermentation activity. Maximum absorbance of TPF occurred at 485 nm over the pH range 3–10. TPF formed from TTC was stable to atmospheric O2. Absorbance decreased if TPF was exposed to light. In the presence of excess TTC, production of TPF in strained rumen fluid (SRF) at 39 °C was linear with elapsed incubation times up to at least 5 min. Dehydrogenase activity was abolished in the presence of air. It was significantly increased if the CO2 gas phase above SRF was replaced with N2 or H2, owing, at least in part, to an increase in the pH of the fermentation. The dehydrogenase activity of SRF was maximal at pH 7.8–8.0. Fractionation of SRF by differential centrifugation showed that about 50% of the dehydrogenase activity was associated with a protozoal fraction sedimenting at 188 × g, and 42% with a bacterial fraction sedimenting at 1,475 × g. Neither the cell-free supernatant obtained by centrifuging SRF at 21,500 × g, nor boiled SRF, nor the hay fed to the animals showed dehydrogenase activity. Whole rumen contents (WRC) showed a mean dehydrogenase activity that was 58% higher than that of SRF. The dehydrogenase activity of SRF was increased in the presence of substrates representing major plant carbohydrates, the greatest stimulatory effect being shown by ground brome–alfalfa hay. When rumen contents were sampled at the same time by stomach tube and through the fistula, the mean dehydrogenase activity of SRF prepared from the stomach tube samples was 137% higher than that of SRF prepared from the fistula samples. In an animal fed at 12-h intervals, the dehydrogenase activity of SRF rose within 2 h after feeding, declined for the next 6 h, and showed a second peak at 9 h. Activity then declined to the pre-feeding level. The dehydrogenase activity of WRC showed a similar pattern but the peaks of activity were less pronounced. It was concluded that dehydrogenase activity based on TTC reduction provides a simple and rapid means of estimating the fermentation activity of rumen contents which may reflect the availability of energy substrates to the microbiota.

scholarly journals Excretion of purine derivatives by ruminants: recycling of allantoin into the rumen via saliva and its fate in the gut

1990 ◽  
Vol 63 (2) ◽  
pp. 197-205 ◽  
Author(s):  
X. B. Chen ◽  
F. D. DeB. Hovell ◽  
E. R. ØRskov
Keyword(s):  
Fatty Acids ◽  
Uric Acid ◽  
Urinary Excretion ◽  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
Purine Derivatives ◽  
Complete Destruction ◽  
Series Of Experiments ◽  
Micro Organisms

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.

An in vitro cultured rumen inoculum improves nitrogen digestion in mulga-fed sheep

1997 ◽  
Vol 48 (4) ◽  
pp. 403 ◽  
Author(s):  
S. M. Miller ◽  
A. V. Klieve ◽  
J. J. Plumb ◽  
R. Aisthorpe ◽  
L. L. Blackall
Keyword(s):  
Rumen Fluid ◽  
Mixed Cultures ◽  
Microbial Composition ◽  
Widespread Adoption ◽  
The Difference ◽  
Micro Organisms ◽  
Laboratory Fermentor ◽  
Feral Goat ◽  
Goat Rumen

Mixed cultures of anaerobic micro-organisms were derived from feral goat rumen fluid (FGRF) using a laboratory fermentor to selectively culture microbes actively degrading mulga, and were evaluated as rumen inocula in digestion and liveweight studies with mulga-fed sheep. When placed in the rumen of sheep, FGRF enhances mulga digestion; however, limited supplies of feral goats, the labour involved in locating and mustering goats, and likely variations in the microbial composition of FGRF between animals and localities make the production of an in vitro cultured inoculum a desirable alternative to enable widespread adoption. The cultured inoculum significantly (P < 0·05) improved nitrogen digestion and retention in mulga-fed sheep by 16 and 76%, respectively. Inocula consisting of simplified mixtures of bacteria isolated from sheep, feral goats, and native marsupials did not affect mulga digestion. In the first of 2 liveweight studies, sheep inoculated with the fermentor inoculum lost significantly less weight than uninoculated sheep for the first 57 days (0·3 v. 4·6 kg); however, after 83 days the difference in the rate of liveweight loss between the fermentor inoculum group and the uninoculated sheep was not significant (53 v. 95 g/day). In the second study, liveweight loss was not significantly reduced by the fermentor inoculum. An inoculum based on FGRF, and produced in vitro using a fermentor, is potentially valuable to grazing enterprises reliant on mulga-fed sheep. However, problems in generating a consistent inoculum need to be addressed before such an inoculum can be generally considered.

A comparison between equine faeces and caecal digesta as sources of inoculum for in vitro fermentation studies using the pressure transducer technique

1996 ◽  
Vol 1996 ◽  
pp. 225-225
Author(s):  
R.S. Lowman ◽  
M.K. Theodorou ◽  
A.C. Longland ◽  
D. Cuddeford
Keyword(s):  
Pressure Transducer ◽  
Rumen Fluid ◽  
In Vitro Fermentation ◽  
Faecal Material ◽  
Micro Organisms

Several studies have shown high correlations between in vtvo and in vitro degradation of fibrous feeds when preparations from either rumen fluid or ruminant faeces have been used as the inocula for the in vitro studies (El Shaer et al., 1987; Akhter et al., 1994 & 1995; Harris et al., 1995). Use of an inoculum prepared from faecal material is attractive, for unlike that obtained from rumen fluid, it precludes the need to prepare and maintain fistulated donor animals. This study investigated the use of pony faeces, as an alternative to pony caecal digesta, as a source of micro-organisms for in vitro feed degradability studies.

scholarly journals Estimation of the degradability of dietary protein in the sheep rumen by in vivo and in vitro procedures

1985 ◽  
Vol 54 (2) ◽  
pp. 545-561 ◽  
Author(s):  
R. C Siddons ◽  
J Paradine ◽  
D. L. Gale ◽  
R. T. Evans
Keyword(s):  
Rumen Fluid ◽  
Flow Measurements ◽  
Fractional Rate ◽  
Outflow Rate ◽  
Bean Meal ◽  
Sheep Rumen ◽  
Soya Bean Meal ◽  
Microbial N

1. Estimates of degradability of nitrogen in the sheep rumen for a basal hay diet and for soya-bean meal (SBM), groundnut meal (GNM) and fish meal (FM), when given together with the hay, were determined from measurements of (1) duodenal N flow, (2) ammonia kinetics and (3) rumen N disappearance from polyester bags and rumen outflow rate. The ability of various in vitro procedures to predict in vivo N degradability was also examined.2. Four sheep were given a basal hay diet (800 g dry matter (DM) and 19 g N/d) either alone or supplemented with isonitrogenous amounts (15 g N/d) of SBM, GNM or FM. Duodenal non-ammonia-N flow (g/d) was increased more by FM (8.0) than by GNM (5.9) and SBM (5.8), whilst microbial N flow (g/d) was increased more by SBM (3.9) than by GNM (2.3) and FM (1.6). N degradability values calculated from these results were 0.88, 0.76 and 0.57 for the SBM, GNM and FM respectively. The corresponding value for hay was calculated to be 0.76.3. The irreversible loss of ammonia in the forestomachs (g N/d) was increased more by SBM (11.9) than by GNM (7.2) and FM (5.8) whilst ammonia outflow from the rumen (g N/d) was increased to a similar extent by all supplements ( I.1, 0.9 and 0.8 respectively), as was the amount of microbial N (g/d) synthesized from sources other than rumen ammonia (1.8, 2.0 and 1.9 respectively). N degradability values calculated from these results were 0.84, 0.54 and 0.45 for the SBM, GNM and FM respectively.4. The fractional rate of N disappearance (/h) when the feedstuffs were incubated in polyester bags in the rumen of sheep receiving the basal hay diet (800 g DM/d) was the highest for SBM (0,145) and lowest for FM (0.037), with the hay (0.082) and GNM (0.071) intermediate, whilst the fractional outflow rates from the rumen (/h) of the three supplements were similar (0.034, 0.038 and 0,030 for SBM, GNM and FM espectively). N degradability values calculated from these results were 0.82, 0.67 and 0.60 for the SBM, GNM and FM respectively; the value for the hay was 0.73.5. Of a number of in vitro procedures tested, only N solubility in sodium hydroxide and ammonia or total non-protein-N (NPN) production during incubation with rumen fluid in the absence of hydrazine sulphate ranked the supplements, although not the hay, in the same order as the in vivo degradability procedures. In terms of absolute values, N solubility in NaOH, at room temperature, gave estimates similar to those derived from the duodenal flow measurements; estimates derived from ammonia and total NPN production were lower.

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