scholarly journals Effects of the antibiotic monensin and an inhibitor of methanogenesis on in vitro continuous rumen fermentations

1981 ◽  
Vol 45 (3) ◽  
pp. 567-578 ◽  
Author(s):  
G. Stanier ◽  
A. Davies
Keyword(s):  
Fatty Acids ◽  
Dilution Rate ◽  
Rate Control ◽  
Volatile Fatty Acids ◽  
High Dilution ◽  
In Vitro System ◽  
Practical Implications ◽  
High Dilution Rate

1. The effects of a methane inhibitor, ICI 111075, and a propionate enhancer, monensin, were studied using in vitro continuous fermenters.2. Both compounds increased the yield of substrate energy, carbon and hydrogen in volatile fatty acids (VFA). This was mainly due to an increase in the molar proportion of propionic acid.3. Improved yields of VFA were accompanied by reductions in methane production and microbial yield.4. Since published information showed that monensin reduced rumen dilution rate in vivo an analogous in vitro system was proposed in which a high dilution rate control fermenter was compared with a monensin treated fermenter set to run at a low dilution rate.5.Results showed that the general intrinsic microbial activity of the chemical manipulators was not affected by changes in dilution rate. Changing dilution rate in addition to chemical treatment however resulted in substantial modifications in the net effect on the fermentation.6. The practical implications of reducing rumen dilution rate as a side effect of chemically manipulating the rumen fermentation could involve changes in food intake, increased importance of secondary fermentations and a reduced effect of nutrients not degraded in the rumen.

A stringent test for the artificial rumen

1962 ◽  
Vol 13 (2) ◽  
pp. 343 ◽  
Author(s):  
FV Gray ◽  
RA Weller ◽  
AF Pilgrim ◽  
GB Jones
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Artificial Saliva ◽  
Two Systems ◽  
Stringent Test ◽  
Specific Activities

In each of three experiments the acetic, propionic, and butyric acids in the rumen of a sheep were labelled with 14C and a sample of the rumen contents was removed to an artificial rumen so that fermentations of the same substrates could be conducted simultaneously in vivo and in vitro. The in vitro fermentations were carried out in a specially designed artificial rumen of the "permeable" type in which the volume of the contents was kept constant while a continuous supply of artificial saliva was introduced. The relationships between the specific activities of the volatile fatty acids during a period of 2 to 3 hr indicated that the relative rates of formation of the acids were similar in the two systems, although in each experiment the fermentation appeared to proceed more slowly in vitro. It is considered that the procedure constitutes a stringent test for the correct functioning of an artificial rumen.

scholarly journals Influence of different morphological parts of buckwheat (Fagopyrum esculentum) and its major secondary metabolite rutin on rumen fermentation in vitro

2012 ◽  
Vol 57 (No. 1) ◽  
pp. 10-18 ◽  
Author(s):  
F. Leiber ◽  
C. Kunz ◽  
M. Kreuzer
Keyword(s):  
Fatty Acids ◽  
Phenolic Compounds ◽  
Dietary Protein ◽  
Dry Matter ◽  
Volatile Fatty Acids ◽  
In Vivo Studies ◽  
Ruminal Fermentation ◽  
Beneficial Effects

It was hypothesized that buckwheat, especially its flowers, influences foregut fermentation in ruminant animals because it is rich in phenolic compounds. The entire fresh aerial buckwheat herb, or its parts (leaves, stems, flowers and grain), were incubated for 24 h together with pure ryegrass (1:1, dry matter basis) in an in vitro ruminal fermentation system (Hohenheim Gas Test). Additionally ryegrass, supplemented with 0, 0.5, 5, or 50 mg rutin trihydrate/g dry matter, was incubated. Contents of extractable phenols (g/kg dry matter) were the highest in buckwheat flowers (88), followed by leaves (63), and the lowest in ryegrass (8). The levels of production of total gas and volatile fatty acids demonstrated that the nutritional value of buckwheat was slightly lower than that of ryegrass. Compared to ryegrass alone, ruminal transformation of dietary protein-N <br />into ammonia was lower with 50 mg rutin, buckwheat flowers and buckwheat leaves. Thus, these treatments appeared to have partly protected dietary protein from ruminal degradation. Rutin, at the highest level, buckwheat flowers and the total aerial fraction of the buckwheat plant suppressed methane per unit of total gas by &gt; 10%, either at elevated (rutin) or reduced total gas volume. This indicates that the ways of the influence on the ruminal fermentation pattern differed between pure rutin and buckwheat. In vivo studies have to confirm these potentially beneficial effects of buckwheat if used as forage for ruminants and clarify the role of further phenolic compounds present in buckwheat. Abbreviations: DM = dry matter, HGT = Hohenheim Gas Test, NDF = neutral detergent fibre, TEP = total extractable phenols, VFA = volatile fatty acids

scholarly journals The formation of volatile fatty acids in the rumen contents of cows in vivo and in vitro

1959 ◽  
Vol 31 (1) ◽  
pp. 315-320
Author(s):  
Martti Lampila ◽  
Ilmari Poijärvi
Keyword(s):  
Fatty Acids ◽  
Butyric Acid ◽  
Volatile Fatty Acid ◽  
Volatile Fatty Acids ◽  
Anterior Part ◽  
Fatty Acid Mixture ◽  
Acid Mixture ◽  
Sugar Beets

On a diet containing fodder sugar beets the proportion of butyric acid in the mixture of the volatile fatty acids of the rumen contents was found to be unusually high. When the rumen contents were incubated at different pH-levels in vitro, it was found that the proportion of butyric acid in the volatile fatty acid mixture produced increases when the pH decreases. Using polyethylene glycol as a reference substance, the transfer of fluid through the reticulo-omasal orifice was studied. The transfer of volatile fatty acids into the omasum is calculated on the basis of the fluid flow and on the acid concentrations of the fluid in the lower anterior part of the contents.

scholarly journals Variability of caecal parameters in rabbits

2019 ◽  
Vol 21 (91) ◽  
pp. 108-110
Author(s):  
O. Vozna ◽  
N. Motko
Keyword(s):  
Fatty Acids ◽  
Methane Production ◽  
Dry Matter ◽  
Volatile Fatty Acids ◽  
In Vitro Cultures ◽  
Molar Percentage ◽  
Hydrogen Recovery ◽  
Different Origin

Three groups of rabbits of different origin (29, 27 and 28 animals; 3 or 4–6 months of age) were slaughtered, their caecal contents analyzed and used for inoculation of in vitro cultures. Whereas the caecal pH, dry matter percentages and acetate molar proportions in caecal volatile fatty acids (VFA) were relatively stable, molar proportions of other VFA varied considerably. In in vitro incubations, caecal parameters varied somewhat less than in vivo. Methane production varied much more than total VFA production. No non-methanogenic rabbit, however, was found. The hydrogen recovery correlated Significantly with the methane production and, in two out of three groups of rabbits, also with the propionate molar percentage. The caecal pH was inversely related to VFA concentration.

scholarly journals Changes in the rumen metabolism of sheep given increasing amounts of linseed oil in their diet

1975 ◽  
Vol 34 (1) ◽  
pp. 25-44 ◽  
Author(s):  
J. W. Czerkawski ◽  
W. W. Christie ◽  
Grace Breckenridge ◽  
Margaret L. Hunter
Keyword(s):  
Fatty Acids ◽  
Dilution Rate ◽  
High Fat Diet ◽  
Volatile Fatty Acids ◽  
Linseed Oil ◽  
Diaminopimelic Acid ◽  
High Fat ◽  
Proportional Increase ◽  
Micro Organisms

1. Linseed oil was incorporated gradually into the diet of four sheep until the animals received 90 g additional fat/d. Attempts were made to measure changes in concentration of substances and rates of synthesis in the rumen directly, and by incubation of rumen contents in vitro (zero-time technique).2. The high-fat diet increased the dilution rate and the volume of rumen contents and decreased the synthesis of diaminopimelic acid in the rumen. The number of protozoa decreased and the number of bacteria increased in the rumen of animals receiving the high-fat diet.3. The concentration of volatile fatty acids (VFA) in the rumen decreased for sheep given the high-fat diet, but the capacity of rumen contents to produce VFA in vitro increased.4. The incorporation of radioactivity from [14C]acetate into lipids during incubation of rumen contents in vitro increased with the amount of linseed oil in the diet. The greatest proportional increase was with the bacterial fraction of rumen contents.5. In the group of four animals used, one animal showed consistent differences in the magnitude of the measured variables. This animal appeared to have a smaller rumen, a lower dilution rate and larger concentrations of some substances in the rumen. A higher proportion of fatty acids appeared to be synthesized by the micro-organisms from this animal.

scholarly journals Passage of protozoa and volatile fatty acids from the rumen of the sheep and from a continuous in vitro fermentation system

1974 ◽  
Vol 32 (2) ◽  
pp. 341-351 ◽  
Author(s):  
R. A. Weller ◽  
A. F. Pilgrim
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
In Vitro Fermentation ◽  
Fermentation System

1. A procedure for sampling digesta from within the omasal canal of sheep given a variety of roughage diets was used to enable comparison to be made of the composition of effluent from the reticulo-rumen with that of rumen fluid.2. Concentrations of protozoa in effluents, relative to a soluble marker continuously infused intraruminally, were usually less than 20% of corresponding rumen fluid concentrations. It was estimated that the amount of protozoal nitrogen leaving the rumen represented less than 2% of dietary N.3. Passage of volatile fatty acids (VFA) from the rumen in effluent was less than 75% of that indicated by rumen concentrations.4. A continuous, in vitro fermentation system was developed, in which outputs of protozoa were comparable with in vivo outputs.

scholarly journals Inhibition of a Glucose-Limited Sequencing Fed-Batch Culture ofSalmonella enterica Serovar Enteritidis by Volatile Fatty Acids Representative of the Ceca of Broiler Chickens

2001 ◽  
Vol 67 (4) ◽  
pp. 1979-1982 ◽  
Author(s):  
Paul W. J. J. van der Wielen ◽  
Steef Biesterveld ◽  
Len J. A. Lipman ◽  
Frans van Knapen
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Broiler Chickens ◽  
Volatile Fatty Acid ◽  
Volatile Fatty Acids ◽  
Sudden Increase ◽  
Fed Batch ◽  
In Vitro System ◽  
Fed Batch Culture

ABSTRACT The effects of concentrations of volatile fatty acids on an anaerobic, glucose-limited, and pH-controlled growing culture ofSalmonella enterica serovar Enteritidis were studied. Suddenly increasing volatile fatty acids to the concentrations representative of the ceca of 15-day-old broiler chickens caused washout of serovar Enteritidis. In contrast, a sudden increase to the volatile fatty acid concentrations representative of the ceca of younger broiler chickens caused a reduction in the biomass but not washout. Gradually increasing volatile fatty acids caused a gradual decrease in the biomass of serovar Enteritidis. We conclude that the concentrations of volatile fatty acids present in the ceca of broilers with a mature microflora can cause washout of serovar Enteritidis in an in vitro system mimicking cecal ecophysiology.

scholarly journals The Fermentation of Carbohydrates in the Rumen of the Sheep

1945 ◽  
Vol 22 (1-2) ◽  
pp. 51-62
Author(s):  
S. R. ELSDEN
Keyword(s):  
Fatty Acids ◽  
Acetic Acid ◽  
Lactic Acid ◽  
Volatile Fatty Acids ◽  
In Vitro Fermentation ◽  
Dietary History ◽  
History Of ◽  
Rumen Microflora

1. Acetic, propionic and butyric acids are the main volatile fatty acids in the rumen of the sheep. Acetic acid accounts for 55-75% of the total. 2. Cellulose, glucose and lactic acid are rapidly fermented in vitro by rumen contents with the production of acetic, propionic and butyric acids. Pro-pionic acid is the major component in all cases: very little if any butyric acid is formed from cellulose. 3. The in vitro fermentation of glucose closely resembles the in vivo. 4. The in vitro fermentation of dried grass yields the same three acids, but with acetic acid predominating. 5. Members of the genus Propionibacterium have been isolated from the rumen, and evidence is presented to show that these organisms are responsible for the production of the propionic acid found in the rumen. 6. The dietary history of the animal is shown to influence the rate at which glucose is fermented in the rumen, and the composition of the rumen microflora.

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