scholarly journals Incorporation of nitrogen into rumen bacterial fractions of steers given protein- and urea-containing diets. Ammonia assimilation into intracellular bacterial amino acids

1983 ◽  
Vol 50 (3) ◽  
pp. 769-782 ◽  
Author(s):  
J. S. Blake ◽  
D. N. Salter ◽  
R. H. Smith
Keyword(s):  
Amino Acids ◽  
Cell Wall ◽  
Rumen Fluid ◽  
Free Cell ◽  
Ammonia Assimilation ◽  
Supernatant Fraction ◽  
Soluble Carbohydrate ◽  
Rumen Bacteria ◽  
Bacterial Protein ◽  
Cell Supernatant

1. Experiments were carried out in vivo to investigate the pathways of ammonia incorporation into rumen bacteria, bacterial fractions and free amino acids within the bacteria.2. Steers were alternately given two isoenergetic, isonitrogenous diets containing the nitrogen mainly as either urea or decorticated groundnut meal (DCGM). At the end of each period on a given diet, a solution of15NH4Cl was infused into the rumen and samples of rumen contents were removed at 2, 10, 20 and 90 min and 5, 10 and 24 h afterwards. Concentrations of ammonia and its15N enrichment were determined and samples of mixed rumen bacteria were prepared. Bacteria were disrupted ultrasonically and separated into bacterial protein, cell wall and protein-free cell supernatant fractions. Amino acids were separated after hydrolysis and their15N contents determined.3. A rumen fluid circulation pump was developed so that representative samples could be taken at very short time intervals after the introduction of the15N label.4. Rumen pH changes, rumen fluid dilution rates and patterns of rumen ammonia concentrations were consistent with normal rumen metabolism. Net bacterial synthesis (as calculated from the net outflow of bacteria from the rumen) was significantly (P< 0·05) greater with the DCGM diet (12·4 g bacterial N/d) than with the ureadiet (9·24 g bacterial N/d).5. With both diets the15N label rapidly left the rumen ammonia pool and entered the rumen bacteria. Analysis of the bacterial fractions indicated that the label appeared rapidly in the protein-free cell supernatant fraction and more slowly in the bacterial protein and cell wall fractions.6. With the DCGM diet bacteria apparently utilized intracellular label less efficiently than with the urea diet. The proportion of N in the protein-free cell supernatant was higher with the DCGM diet, suggesting increased levels of intracellular amino acids and peptides, following extracellular protein degradation.7. Levels of enrichment of the amino acids alanine and glutamate in the protein-free cell supernatant fraction suggested that the enzymes alanine dehydrogenase (EC1. 4. 1. 1) and glutamate dehydrogenase (EC1. 4. 1. 2 and 1. 4. 1. 4) may be the major enzymes for assimilating ammonia when concentrations of soluble carbohydrate and rumen ammonia are high in the rumen.8. The high levels of intracellular alanine are discussed with reference to publishedwork on the excretion of alanine by rumen bacteria.

Antibiotic activity of an isocyanide metabolite of Trichoderma hamatum against rumen bacteria

1985 ◽  
Vol 31 (9) ◽  
pp. 767-772 ◽  
Author(s):  
S. N. Liss ◽  
D. Brewer ◽  
A. Taylor ◽  
G. A. Jones
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Rumen Fluid ◽  
Cellulose Hydrolysis ◽  
Soluble Carbohydrate ◽  
Rumen Bacteria ◽  
Fermentation Products ◽  
Fluid Medium ◽  
Trichoderma Hamatum ◽  
Significant Depression

A metabolite of Trichoderma hamatum, 3-(3-isocyanocyclopent-2-enylidene)propionic acid, was tested for its effects on growth of and carbohydrate metabolism in 11 strains of functionally important rumen bacteria. To standardize the biological activity of this unstable metabolite, a rapid, aerobic disc diffusion assay was developed using Escherichia coli ATCC 11775. In an anaerobic broth dilution assay using a medium lacking rumen fluid and containing a soluble carbohydrate, the minimum inhibitory concentration of the metabolite which completely inhibited growth of the rumen bacteria for 18 h at 39 °C was generally < 10 μg∙mL−1; however, the minimum inhibitory concentrations for Megasphaera elsdenii B159 and Streptococcus bovis Pe18 were 10–25 and 25–64 μg∙mL−1, respectively. In general, the Gram-negative strains were more sensitive than the Gram positive. The minimum inhibitory concentration for Bacteroides ruminicola 23 grown with glucose was 1 μg∙mL−1; for B. ruminicola GA33 (glucose), B. succinogenes S85 (cellobiose), and Succinivibrio dextrinosolvens 24 (maltose), it was 2 μg∙mL−1. When added to a cellulose-containing rumen fluid medium, 1–4 μg∙mL−1 of the metabolite delayed cellulose hydrolysis by B. succinogenes S85, Ruminococcus albus 7, and R. flavefaciens FD1 for up to 4 days, and 6–7 μg∙mL−1 prevented hydrolysis for at least 1 month. In the presence of the metabolite, the proportion of acetate produced from soluble carbohydrate by the majority of strains increased, but with some strains net production of acetate decreased relative to production of other acidic fermentation products. If the metabolite gained entrance to the rumen, a concentration of as little as 1 μg∙mL−1 would probably cause a significant depression of the fermentation and result in nutritional deprivation of the animal.

The digestion of pasture plants by sheep. III. The digestion of forage oats varying in maturity and in the content of protein and soluble carbohydrate

1969 ◽  
Vol 20 (2) ◽  
pp. 347 ◽  
Author(s):  
JP Hogan ◽  
RH Weston
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Cell Wall ◽  
Organic Matter ◽  
Volatile Fatty Acids ◽  
Fertilizer Application ◽  
Feed Consumption ◽  
Soluble Carbohydrate ◽  
Fertilizer Treatment ◽  
Soluble Nitrogen

A comparison has been made of the composition, intake, and digestion of forage oats grown with and without the application of nitrogen fertilizer and harvested at three stages of maturity. The chemical composition of the forages showed the usual changes with maturity. Fertilizer application had little effect on the levels of cell wall constituents but, as expected, decreased the levels of soluble carbohydrate and increased those of total nitrogen, alcohol-soluble nitrogen, and nitrate. The digestibility of organic matter, cell wall constituents, and nitrogen declined with advancing maturity, all three parameters being little affected by the fertilizer treatment. Feed consumption declined only with the most mature diet and was not affected by the fertilizer treatment even though the high nitrogen (HN) diets supplied 4–5 g nitrate nitrogen per day and relatively small amounts of soluble carbohydrate. There was a loss of dietary nitrogen from the stomach with the HN diets and a gain with the low nitrogen (LN). The amount of nitrogen in the digesta leaving the stomach per unit intake of nitrogen increased with maturity. The quantities of protein leaving the stomach were too great to be accounted for as microbial protein, and hence appreciable quantities of plant protein must have passed through the stomach. The digestibility of crude protein in the intestines was not affected either by maturity of the forages or by fertilizer treatment. There was little effect of advancing maturity or fertilizer application on: (a) the extent of digestion of organic matter and the structural carbohydrates in the stomach relative to that occurring in the intestines; (b) the proportion of digestible organic matter derived from rumen volatile fatty acids and amino acids; � the potential value of the metabolizable energy from volatile fatty acids and amino acids to provide net energy for fattening; (d) most parameters associated with the movement of digesta through the stomach. Advancing maturity of the diets was associated with increased expenditure of time in chewing activities.

The in vitro digested cell wall and fermentation characteristics of grasses as affected by temperature and humidity during their growth

1977 ◽  
Vol 88 (1) ◽  
pp. 217-222 ◽  
Author(s):  
K. W. Moir ◽  
J. R. Wilson ◽  
G. W. Blight
Keyword(s):  
Cell Wall ◽  
Chemical Composition ◽  
Growth Temperature ◽  
Rumen Fluid ◽  
Gas Production ◽  
Total Cell ◽  
Grass Species ◽  
Rumen Bacteria ◽  
Temperature And Humidity

SUMMARYTotal cell wall, in vitro digested cell wall and fermentation-gas production were determined in the separated tops and stubble of five tropical and two temperate grass species grown under controlled temperatures and humidities. As the day/night temperatures increased from 18/10 to 25/17 °C the total cell wall and in vitro digested cell wall increased. With a further increase to 32/24 °C the total cell wall increased, but not the in vitro digested cell wall. In vitro digested cell-wall values were also calculated from a previously derived relationship between in vitro digested cell wall and total cell wall. The differences between observed and calculated values increased (negatively) with increasing growth temperature suggesting that the in vitro digested cell wall was depressed with increasing growth temperatures, but the extent of this depression was small.In vitro gas production from the fermentation of plant tops or stubble in buffered rumen fluid for 24 h was significantly affected by growth temperature and humidity, apparently because of changes in chemical composition induced by the treatments. The volume of gas produced between 24 and 48 h fermentation times was appreciably lower from stubble than from plant tops and this was thought to be due to a higher resistance of part of the cell wall of stubble to digestion by rumen bacteria. Gas production in this period was slightly lower in the tops of grasses grown at the lower temperatures, but this could have been an indirect effect from an associated decrease in the total cell wall.

scholarly journals Digestion of rumen bacteria in vitro

1983 ◽  
Vol 49 (1) ◽  
pp. 101-108 ◽  
Author(s):  
R. J. Wallace
Keyword(s):  
Rumen Fluid ◽  
Individual Species ◽  
Rumen Bacteria ◽  
Gram Negative Bacteria ◽  
Bacterial Protein ◽  
Gram Positive ◽  
Gram Negative ◽  
Pure Cultures ◽  
Mixed Bacteria

1. A pepsin + pancreatin method was used to assess the digestibility of pure cultures of rumen bacteria and mixed bacteria prepared from rumen fluid.2. Individual species of Gram-negative rumen bacteria were highly digestible, whereas Gram-positive species, especially cocci, were more resistant to digestion.3. A similar difference was observed microscopically with mixed rumen bacteria, but the influence of the relative proportions of Gram-positive and Gram-negative bacteria on the digestibility of bacterial protein in rumen fluid was small.

scholarly journals Ruminal Flora Studies in the Sheep V. the Amino Acid Composition of Rumen Bacterial Protein

1953 ◽  
Vol 6 (4) ◽  
pp. 637 ◽  
Author(s):  
P Holmes RJ Moir ◽  
EJ Underwood
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Paper Chromatography ◽  
Rumen Bacteria ◽  
Bacterial Protein

Fifteen amino acids were determined, by paper chromatography, on the protein preparations of each of two bulk samples of rumen bacteria from sheep fed under "dry" and "green" feed conditions.

The effect ofin saccorumen incubation of a grass silage upon the total and D-amino acid composition of the residual silage dry matter

1984 ◽  
Vol 102 (3) ◽  
pp. 695-702 ◽  
Author(s):  
J. A. Rooke ◽  
H. A. Greife ◽  
D. G. Armstrong
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Dry Matter ◽  
Similar Proportion ◽  
Rumen Bacteria ◽  
Bacterial Protein ◽  
Grass Silage

SummaryGrass silage was incubated in polyester bags in the rumens of Jersey heifers for 2, 12, 24 and 48 h. The total (D + L) and D-amino acid contents of the silage and of the silage residues remaining after rumen incubation were determined. In addition, the contamination of the silage residues by rumen bacterial protein was measured by using35S as a marker of rumen bacterial protein. The amino acid profile of the residual silage dry matter differed markedly after 2 h of rumen incubation from that of the original silage; thereafter progressive changes in the amino acid composition of the residual silage dry matter occurred between 2 and 48 h of rumen incubation. The D-alanine content of the original silage was higher than that of D-glutamic acid. Both these D-amino acids disappeared almost completely from the silage after 2 h rumen incubation; between 2 and 48 h rumen incubation the quantities of D-alanine and D-glutamic acid in the residual silage dry matter increased. The residual silage dry matter contained more D-glutamic acid than D-alanine and these acids were in a similar proportion to that found in rumen bacteria; thus it was concluded that D-amino acids in the residual silage dry matter resulted from contamination of the residues by rumen bacteria. Contamination of residual silage protein by rumen bacterial protein increased with length of rumen incubation; the extent of contamination was similar for each incubation time whether assessed using35S or D-amino acids as markers of rumen bacterial protein. However, this contamination by rumen bacterial protein did not markedly alter the degradability of silage protein calculated from the disappearance of silage N incubatedin sacco.

Herring silage as a protein supplement for young cattle

1991 ◽  
Vol 71 (4) ◽  
pp. 1187-1196 ◽  
Author(s):  
J. W. G. Nicholson ◽  
D. A. Johnson
Keyword(s):  
Amino Acids ◽  
Free Amino ◽  
Crude Protein ◽  
Fish Meal ◽  
Unsaturated Fatty Acids ◽  
Rumen Fluid ◽  
Potassium Sorbate ◽  
Protein Supplement ◽  
Young Cattle ◽  
True Protein

Fish silage made by grinding herring and adding formic acid, β-hydroxytoluene and potassium sorbate was evaluated as a protein supplement for young cattle. Only about 15% of the crude protein in the herring silage was true protein. Ammonia N accounted for 8% of the crude protein and most of the rest was peptides and free amino acids. The crude protein of herring silage was as resistant as fish meal to deamination when fermented in rumen fluid, and more resistant than soybean or casein. The herring silage was readily accepted by Holstein heifers fed hay or grass–legume silage with potatoes (7 kg d−1) and a supplement (1.5 kg d−1). Feed intake and weight gain were similar when the heifers were fed hay with either soybean meal or herring silage but were higher when forage silage replaced the hay. Rumen fluid NH3-N and blood urea levels were normal, even for cattle fed the high non-protein N diet of forage silage with herring silage. The herring silage depressed rumen fluid acetate levels and increased propionate in the heifers fed hay + potatoes, probably because of the unsaturated fatty acids in the herring. Well-made herring silage was a suitable protein supplement for young cattle fed forage and potato diets. Key words: Herring silage, fish silage, potatoes, cattle, protein degradation

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