scholarly journals Effect of defaunation on the metabolism of rumen micro-organisms

1979 ◽  
Vol 42 (3) ◽  
pp. 515-524 ◽  
Author(s):  
D. I. Demeyer ◽  
C. J. Van Nevel
Keyword(s):  
Total Synthesis ◽  
Volatile Fatty Acids ◽  
Ammonium Bicarbonate ◽  
Energetic Efficiency ◽  
Specific Rate ◽  
N Incorporation ◽  
Micro Organisms ◽  
Acetate Butyrate ◽  
Microbial N

1. Rumen contents of a fasted fistulated wether, obtained in a faunated, defaunated and refaunated period were incubated in vitro with a mixture of cellobiose and maltose, in the presence of ammonium bicarbonate and32PO43−. Total synthesis of microbial N (Nt) was calculated from32P incorporation and N:P determined in microbial matter. The N:P value was not affected by defaunation. Net synthesis of microbial N (Nn) was calculated from ammonia-N incorporation. An estimate of degradation of microbial N was calculated as Nt–Nn. Energetic efficiency of synthesis was calculated from the volatile fatty acids produced during incubation, as g N incorporated per kg organic matter fermented (g N/kg OMf).2. Defaunation decreased the proportions of acetate, butyrate and methane and increased those of propionate in fermentation end-products. Fermentation rate when expressed per mg microbial N was not affected by defaunation.3. Expressed per unit volume of rumen contents, Nnwas increased by defaunation whereas Nfremained unchanged. Thus, a decrease in degradation can be calculated. Energetic efficiences of total and net synthesis were increased from 35 and 13 to 47 and 30 g N/kg OMfrespectively.4. Specific rates of both total and net synthesis of microbial N were significantly increased by defaunation whereas the specific rate of degradation was not affected.

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 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.

scholarly journals Effects of monensin source on in vitro rumen fermentation characteristics and performance of Bos indicus beef bulls offered a high-concentrate diet

2019 ◽  
Vol 4 (1) ◽  
pp. 84-94 ◽  
Author(s):  
Daniel A A Teixeira ◽  
Bruno I Cappellozza ◽  
Juliano R Fernandes ◽  
Kaique S Nascimento ◽  
Lorena E L M Bonfim ◽  
...  
Keyword(s):  
Volatile Fatty Acids ◽  
Animal Health ◽  
Bos Indicus ◽  
Experimental Period ◽  
Biological Efficiency ◽  
Energetic Efficiency ◽  
Adaptation Period ◽  
Brachiaria Ruziziensis ◽  
And Performance

Abstract In Exp. 1, Brachiaria ruziziensis (11.1 % CP) was inoculated or not with two sources of monensin, resulting in three treatments: 1) no monensin inoculation (CONT), 2) 20 mg of monensin sodium-A/kg of DM (Elanco Animal Health; MON-A), and 3) 20 mg of monensin sodium-B/kg of DM (Shandong Qilu King-Phar Pharmaceutical Co. Ltd.; MON-B). Three rumen-fistulated Jersey steers were offered a cool-season forage-based diet and were used as the rumen inoculum donors. Volatile fatty acids concentrations were evaluated at 0, 6, 12, 24, 30, and 48 h after treatment inoculation. Overall, acetate and butyrate concentrations were reduced in MON-A vs. CONT (P ≤ 0.02), whereas both monensin products reduced Ac:Pr ratio vs. CONT (P ≤ 0.01); however, MON-A also (P = 0.05) reduced the Ac:Pr ratio vs. MON-B. A treatment × hour interaction was detected for rumen propionate concentration (P = 0.01), primarily because MON-A resulted in greater propionate than CONT and MON-B at 24 and 48 h (P ≤ 0.03), but no differences were observed between CONT vs. MON-B (P ≥ 0.27). In Exp. 2, 240 Nellore bulls (initial BW = 363.2 ± 40.9 kg) were ranked and blocked according to initial BW, and within blocks animals were allotted into pens (n = 10 pens/treatment). Pens were randomly assigned into one of three treatments: 1) corn-based diet with no monensin (CONT), 2) CONT plus 28 mg of MON-A/kg of DM, and 3) CONT plus 28 mg of MON-B/kg of DM. The CONT diet was composed of sugarcane bagasse, ground corn, DDGS, urea, and a mineral-vitamin mix. The experimental period lasted 106 d and was divided into a 21-d adaptation period and an 85-d finishing phase. During the adaptation phase, both monensin sources increased (P ≤ 0.01) BW change, ADG, and F:G, as well as reduced DMI variation (P = 0.02). When the entire experimental period was evaluated, no treatment effects were detected for final BW, DMI, and ADG (P ≥ 0.26). Nonetheless, DMI variation was reduced as monensin was included (P = 0.01) and only MON-A improved the efficiency by reducing F:G vs. CONT (P = 0.05) and biological efficiency vs. MON-B (P = 0.05). Additionally, carcass ADG tended (P = 0.10) to be greater for MON-A vs. MON-B, whereas no other differences in the carcass characteristics were observed (P ≥ 0.53). In summary, the source of monensin inoculated in vitro and offered to Nellore bulls during the feedlot phase significantly affected the energetic efficiency and the performance of the animals.

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
Keyword(s):  
Fatty Acids ◽  
Linoleic Acid ◽  
Volatile Fatty Acids ◽  
Vaccenic Acid ◽  
Acacia Cyanophylla ◽  
Total Conjugated Linoleic Acid ◽  
Branched Chain ◽  
Micro Organisms ◽  
Ruminal Biohydrogenation

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.

The use of pivalic acid as a reference substance in measurements of production of volatile fatty acids by rumen micro-organisms in vitro

1976 ◽  
Vol 36 (2) ◽  
pp. 311-315 ◽  
Author(s):  
J. W. Czerkawski
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Pivalic Acid ◽  
Reference Substance ◽  
Micro Organisms

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.

scholarly journals Effect of supplementing a fibre basal diet with different nitrogen forms on ruminal fermentation and microbial growth in an in vitro semi-continuous culture system (RUSITEC)

1999 ◽  
Vol 82 (2) ◽  
pp. 149-157 ◽  
Author(s):  
M. D. Carro ◽  
E. L. Miller
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Microbial Growth ◽  
Volatile Fatty Acids ◽  
Basal Diet ◽  
Ruminal Fermentation ◽  
Acid Detergent Fibre ◽  
Preferential Uptake ◽  
Microbial N

Incubation trials were carried out with the rumen simulation technique (RUSITEC) to study the effects of four forms of N on the growth of ruminal micro-organisms and the fermentation variables when an all-fibre basal diet was incubated. The basal diet consisted of 10 g neutral-detergent fibre (NDF) from grass hay plus 2 g NDF from sugarbeet pulp. N forms were isolated soyabean protein, soyabean peptides, amino acids blended to profile soyabean protein and NH3 as NH4Cl. Half of the daily N supply was infused as NH4Cl and the other half was infused as each of the four treatments described. Non-NH3 N (NAN) forms increased NDF (P = 0·006), acid-detergent fibre (P = 0·003) and cellulose (P = 0·015) disappearance after 48 h incubation, CO2 (P < 0·001), CH4 (P = 0·002) and total volatile fatty acids production (P < 0·001), as well as the molar percentages of isobutyrate, isovalerate and valerate, which reflected the fermentation of amino acid C skeletons. NAN treatments also increased microbial N flow (P < 0·001) compared with NH3, with peptides and protein supporting more (P = 0·036) than amino acids. The proportion of microbial N derived from NH3 decreased successively (P < 0·05) with NH3 > amino acids > peptides > protein treatments, indicating preferential uptake of peptides without passage through the NH3 pool. Microbial efficiency (g microbial N/kg organic matter apparent disappearance) was greater (P = 0·002) for the NAN forms than for the NH3 treatment, with peptides and protein treatments supporting higher (P = 0·009) values than amino acid treatment. These results indicate that N forms other than NH3 are required for optimal fibre digestion and microbial growth.

Effect of melamine onin vitrorumen microbial growth, methane production and fermentation of Chinese wild rye hay and maize meal in binary mixtures

2013 ◽  
Vol 152 (4) ◽  
pp. 686-696 ◽  
Author(s):  
H. J. YANG ◽  
H. ZHUANG ◽  
X. K. MENG ◽  
D. F. ZHANG ◽  
B. H. CAO
Keyword(s):  
Volatile Fatty Acids ◽  
Ammonia Nitrogen ◽  
Rumen Fermentation ◽  
Gas Production ◽  
Hydrogen Gas ◽  
Batch Cultures ◽  
Branched Chain ◽  
Micro Organisms ◽  
High Forage

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.

Effect of malate on in vitro (RUSITEC) rumen fermentation

1998 ◽  
Vol 22 ◽  
pp. 303-305 ◽  
Author(s):  
M. D. Carro ◽  
S. Lopez ◽  
C. Valdes ◽  
F. J. Ovejero
Keyword(s):  
Volatile Fatty Acids ◽  
Artificial Saliva ◽  
Rumen Fermentation ◽  
Disodium Salt ◽  
Antibiotic Resistant ◽  
Selenomonas Ruminantium ◽  
Alfalfa Hay ◽  
Micro Organisms ◽  
Electron Sink

In the last few years there has been an increasing concern regarding the use of antibiotics in ruminant feeding and the potential for selection of antibiotic-resistant pathogen micro-organisms. Some authors (Martin and Streeter, 1995; Callaway and Martin, 1996) suggested that organic acids (aspartate, fumarate, malate) potentially provide an alternative to currently used antimicrobial compounds. Several in vitro studies (Martin and Streeter, 1995; Callaway and Martin, 1996) showed that incorporation of DL-malate into fermentations with both Selenomonas ruminantium HD4 and with mixed ruminal micro-organisms resulted in changes in final pH, methane and volatile fatty acids (VFA) that are analogous to ionophore effects. Nisbet and Martin (1993) hypothesized that malate acted as an electron sink for hydrogen. However, the mechanism of action is not well known. Malate is a key intermediate in the succinate-propionate pathway and therefore could stimulate propionate production. The objective of this study was to study the effects of DL-malate and propionate on the in vitro rumen fermentation of a 50:50 foragexoncentrate diet.The study was carried out using the rumen simulation technique (RUSITEC) following the general incubation procedure described by Czerkawski and Breckenridge (1977). The complete unit consisted of eight vessels with an effective volume of 700 ml each. The vessels inocula (solid and liquid) were obtained from three ruminally fistulated ewes given a diet consisting of 700 g alfalfa hay and 300 g concentrate per kg dry matter (DM) (Table 1) and transferred to the RUSITEC system within 30 min of the 1st day of the experiment. The flow through the vessels was maintained by continuous infusion of artificial saliva at a rate of 533 ml/day. Each vessel received daily a nylon bag containing 7 g alfalfa hay, 7 g concentrate and 0·10 g vitaminsminerals mix. From the 1st day of incubation three vessels received daily 5·62 mmol DL-malate (disodium salt; Sigma-Aldrich Quimica, S.A., Spain), three vessels received 5·62 mmol of propionate (monosodium salt; Sigma-Aldrich Quimica, S.A., Spain) and two vessels received no addition (control). DL-malate and propionate were weighed into the nylon bags and carefully mixed with the food.

The in vitro production, by rumen micro-organisms, of volatile fatty acids from cellulose and hemicellulose labelled with 14C

1961 ◽  
Vol 56 (1) ◽  
pp. 131-136 ◽  
Author(s):  
I. H. Bath ◽  
M. J. Head
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
New Technique ◽  
In Vitro Production ◽  
End Products ◽  
A New Technique ◽  
Micro Organisms ◽  
Vitro Production

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.

The mechanism of cellulose digestion in the ruminant organism: IV. Further observations from in vitro studies of the behaviour of rumen bacteria and their bearing on the problem of the nutritive value of cellulose

1938 ◽  
Vol 28 (1) ◽  
pp. 43-63 ◽  
Author(s):  
H. E. Woodman ◽  
R. E. Evans
Keyword(s):  
Fatty Acids ◽  
Acetic Acid ◽  
Volatile Fatty Acids ◽  
Nutritive Value ◽  
Thermophilic Bacteria ◽  
Breakdown Product ◽  
Bacterial Fermentation ◽  
Bacterial Decomposition ◽  
Micro Organisms

Further studies of the behaviour of cellulose-splitting bacteria in artificial media have been made in an attempt to account for the manner in which cellulose is utilized for fat production in the ruminant. The behaviour of thermophilic bacteria, with an optimum temperature of fermentation in the neighbourhood of 65°C, has been compared with that of the micro-organisms capable of fermenting at 37°C. In both cases the cultures were obtained from the rumen contents of sheep.By the addition of toluene at the “head” stage of fermentation, it was possible to demonstrate, both at 37 and 65°C., the production of small amounts of glucose during subsequent incubation. Glucose is clearly a primary breakdown product in the bacterial fermentation of cellulose.An investigation has been made of the nature of the volatile fatty acids produced by bacterial decomposition of shredded filter paper. No consistent differences from this standpoint were noted between the reactions as carried out at 37 and 65°C., but the nature and proportions of the acids varied considerably from culture to culture. In some cases acetic acid was produced almost exclusively, whilst in others the fatty acids consisted of butyric and formic acids, with but traces of acetic acid. The findings in this regard apparently afford no clue to the manner in which cellulose is used for fat production, since propionic acid, the only recognized fat-former among the lower normal fatty acids, was not detected.

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