scholarly journals A comparison of methods for the estimation of microbial nitrogen in duodenal digesta of sheep

1982 ◽  
Vol 48 (2) ◽  
pp. 377-389 ◽  
Author(s):  
R. C. Siddons ◽  
D. E. Beever ◽  
J. V. Nolan
Keyword(s):  
Dry Matter ◽  
Diaminopimelic Acid ◽  
Comparison Of Methods ◽  
Isotopic Labelling ◽  
Grass Silage ◽  
Microbial Nitrogen ◽  
Ruminal Degradation ◽  
Amino Acid Profiles ◽  
Micro Organisms ◽  
Microbial N

1. Six sheep, each fitted with a rumen cannula and re-entrant cannulas in the proximal duodenum and distal ileum, were given two diets (600 g dry matter (DM)/d) consisting of either grass silage (32·1 g nitrogen/kg DM) or dried grass (18·3 g N/kg DM). A net loss of N occurred between mouth and duodenum with the silage diet, indicating extensive ruminal degradation of dietary N, compared with a net gain on the dried-grass diet. Consequently, despite higher N intakes when silage was given, N flow at the duodenum was similar for both diets.2. The proportion of microbial N in duodenal digesta N was estimated using diaminopimelic acid (DAPA), [35S]methionine (35S), 15N-enriched non-ammonia-N (15NAN) and amino acid profiles (AAP) as microbial markers. Isotopic labelling of rumen micro-organisms was achieved by intraruminal infusions of Na235SO4 and (15NH4)2SO4.3. A comparison of all methods was made based on the marker concentrations in microbial fractions isolated by differential centrifuagation of strained rumen contents. With both diets, DAPA gave the highest estimates and AAP the lowest. Estimates based on 35S and 15NAN were intermediate and did not differ significantly (P > 0·05).4. For the 15NAN, 35S and AAP methods, the effect of site of sampling of the microbial fraction, i.e. from rumen contents or duodenal digesta, was examined and in all instances mean estimates based on duodenally-derived microbes were higher. However, the differences were significant for only 15NAN with both diets (P < 0·001), for 35S with the dried grass (P < 0·05), and for AAP with the silage (P < 0·05). Estimates based on duodenally-derived microbes were higher (P < 0·05) using 15NAN than those obtained using 35S with both diets.5. Depending on the method used for estimating microbial N, estimates of the efficieny ofmicrobial N synthesis in the rumen (g microbial N flow at duodenum/kg organic matter apparently digested in the rumen) ranged between 16 and 38 for the silage diet and 10 and46 for the dried grass diet. Similarly, estimates of feed N degradability in the rumen ranged between 0·62 and 0·97 for the silage and 0·00 and 0·93 for the dried grass.

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.

Comparison of methods for the measurement of microbial protein supply in sheep

1997 ◽  
Vol 1997 ◽  
pp. 125-125
Author(s):  
M.A. Samaniego ◽  
X.B. Chen ◽  
F.DeB. Hovell ◽  
J.C. MacRae ◽  
R. W. Mayes
Keyword(s):  
Surgical Intervention ◽  
Dual Phase ◽  
Comparison Of Methods ◽  
Microbial Protein ◽  
Purine Derivatives ◽  
Flow Rates ◽  
N Supply ◽  
Microbial Nitrogen ◽  
Protein Supply ◽  
Microbial N

The excretion of purine derivatives (PD) in urine has been used as an index for the estimation of microbial nitrogen (N) supply in ruminants. This method is simple and does not require surgical intervention of the animal. However, there have been few attempts to compare the results of this method with other methods for the measurement of microbial N supply. In the present study, two experiments were performed. The main experiment (Experiment 2) compared the estimated duodenal microbial N flow based on urinary PD excretion, with the more direct measurement based on duodenal RNA flow rates obtained from cannulated sheep using n-alkanes as the digesta flow marker. However, a preliminary experiment (Experiment 1) was needed to validate the use of alkane as a digesta marker in comparison with the commonly accepted dual phase marker method of Faichney (1975).

Nucleic Acids in Grass and Grass Silage

1988 ◽  
Vol 1988 ◽  
pp. 86-86
Author(s):  
A B McAllan ◽  
G D Braithwaite
Keyword(s):  
Nucleic Acid ◽  
Nucleic Acids ◽  
Protein Content ◽  
Ribonucleic Acid ◽  
Protein Fraction ◽  
Dry Matter ◽  
Deoxyribonucleic Acid ◽  
Total N ◽  
Grass Silage ◽  
Microbial N

Little attention has been directed at defining the ‘protein’ fraction of silages. This component is normally estimated by fractionation based on solubility characteristics and under the conditions most commonly used, nucleic acids (ribonucleic acid (RNA) and deoxyribonucleic acid (DNA)) would appear in the protein fraction. Grasses and legumes can contain appreciable amounts of nucleic acids ranging from 11-29 and 19-53 g/kg dry matter respectively (McAllan, 1982). No information is available as to the effects of ensilage on these nucleic acids. Microbes also contain appreciable amounts of nucleic acids which can account for 150-200 gN/kg total-N of the cell and these amounts may vary according to the stage of growth. It has been suggested (Ullrich, 1982) that microbial-N contribution to the total-N content of silage is as much as 220-280 g/kg. Thus the total amount of silage ‘protein-N’ present in the form of nucleic acid-N (from both plant and microbes) could be appreciable leading to a considerable overestimation of the ‘protein’ content of the silage.

Comparison of methods for isolation of protozoa from ruminal fluid

1996 ◽  
Vol 76 (3) ◽  
pp. 481-483 ◽  
Author(s):  
L. Neill ◽  
M. Ivan
Keyword(s):  
Key Words ◽  
Dry Matter ◽  
Bacterial Contamination ◽  
Diaminopimelic Acid ◽  
Comparison Of Methods ◽  
Ruminal Fluid ◽  
Sedimentation Method ◽  
Isolation Methods ◽  
Polyester Monofilament

Isolation of protozoa from ruminal fluid taken from the same cow on five different days was carried out by three methods based on sedimentaton or on filtration using 10-μm mesh (PMB-10) or 20-μm mesh (PMB-20) polyester monofilament bags. Differences among means for percentage recoveries of protozoal numbers for the three isolation methods were statistically significant (P = 0.007), but those for dry matter and diaminopimelic acid (DAPA) recoveries were not (P > 0.1). The sedimentation method produced the lowest recovery of protozoa as well as the highest recovery of DAPA, which indicated the highest bacterial contamination. Among the filtration-based methods PMB-10 produced higher recoveries of protozoal numbers and dry matter than PMB-20, but with somewhat larger bacterial contamination. Among the three methods compared, filtration with PMB-10 was considered as the most suitable. Key words: Ruminal fluid, protozoal isolation, sedimentation, filtration

The effect of animal species on the ruminal degradation of dry matter and nitrogen fractions in urea-treated whole-crop wheat

1998 ◽  
Vol 22 ◽  
pp. 326-328
Author(s):  
A. T. Adesogan ◽  
A. L. Abdalla ◽  
M. S. Dhanoa ◽  
D. I. Givens ◽  
E. Owen ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Dry Matter ◽  
Animal Species ◽  
Nutritive Value ◽  
Food Composition ◽  
Nitrogen Fractions ◽  
Grass Silage ◽  
Food Composition Tables ◽  
Ruminal Degradation ◽  
Target Rates

At maintenance at least, the whole tract digestibility of several foods in sheep and cattle is similar, consequently much of the information on the nutritive value of dairy cow foods in food composition tables is derived from studies conducted in sheep. However, Adesogan (1996) reported that in whole-crop wheat (WCW), starch digestibility is higher in sheep than in dairy cows. This study examined the validity of using sheep to model the ruminal degradation of WCW in cows by comparing the degradability of dry matter (DM) and nitrogen (N) of urea-treated WCW in both species.Winter wheat (cv.Hussar) was harvested at 540 g DM per kg and conserved following urea application at target rates of 20 or 40g/kg DM (WCW2 and WCW4 respectively). The degradability of the forages was examined in dairy cows given 6 kg dairy concentrate and grass silagead libitumand in wethers given 2.4 kg/day of grass silage supplemented with 0.36kg/day of rolled, mineralized barley.

scholarly journals Influence of stage of maturity of grass silages on protein digestion and microbial protein synthesis in the rumen

1994 ◽  
Vol 42 (3) ◽  
pp. 203-215
Author(s):  
M.W. Bosch ◽  
J. Van Bruchem ◽  
L.J.G.M. Bongers ◽  
S. Tamminga
Keyword(s):  
Cell Wall ◽  
Crude Protein ◽  
Dry Matter ◽  
Degradation Rate ◽  
Matter Content ◽  
Dry Matter Content ◽  
Protein Digestion ◽  
Significant Relation ◽  
Ruminal Degradation ◽  
Amino Acid Profiles

In four change-over experiments, wilted grass silages, differing in growth stage at harvesting and as a consequence in cell wall content, were fed ad libitum to dairy cows in early and late lactation. Ruminal degradation rate of the crude protein fraction of the silages was investigated using nylon bag incubations. No significant relation between the degradation rate (%h-1) and the cell wall content of the silages was found. The soluble and undegradable fractions of the crude protein both increased with an increase in silage cell wall content. The soluble fraction was more closely related to dry matter content and date of harvesting than to cell wall content of the silages. The fraction of dietary protein escaping rumen fermentation increased with cell wall content.In duodenal protein, the fraction originating from the diet, estimated using amino acid profiles of dietary, microbial and duodenal protein, decreased with cell wall content.

scholarly journals The nutritive value of silages Digestion of nitrogenous constituents in sheep receiving diets of grass silage and grass silage and barley.

1980 ◽  
Vol 43 (3) ◽  
pp. 469-479 ◽  
Author(s):  
P. C. Thomas ◽  
D. G. Chamberlain ◽  
N. C. Kelly ◽  
M. K. Wait
Keyword(s):  
Amino Acids ◽  
Organic Matter ◽  
Small Intestine ◽  
Crude Protein ◽  
Dry Matter ◽  
Nutritive Value ◽  
Diaminopimelic Acid ◽  
Total N ◽  
Marked Influence ◽  
Grass Silage

Two experiments were conducted to study the digestion of nitrogenous constituents in the rumen, small intestine and caecum and colon of sheep given diets of grass silage or grass silage and barley. Three silages were used. One was made from first-harvest grass in the spring and the others from regrowth grass cut in either early autumn or late autumn. All were of perennial ryegrass (Lolium perenne) and were preserved with formic acid.Expt 1 involved a comparison between the spring silage given alone (644 g dry matter (DM)/d) and the spring silage supplemented with barley (151 g DM/d). The intakes (g/d) of total nitrogen for the silage diet and for the supplemented diet were 14.89 and 17.36. Corresponding values (g/d) for N passage were 15.55 and 18.53 (P < 0.01) at the duodenum, 6.01 and 7.09 at the ileum and 5.06 and 5.52 in the faeces. The barley supplement had no significant (P < 0.05) effect on rumen ammonia-N- concentration.Expt 2 involved a comparison between the two autumn-cut silages each offered at a level of feeding of approximately 700 g DM/d. The intakes (g/d) of total N for the early-cut silage and for the late-cut silage were 21.67 and 15.62 respectively. Corresponding values (g/d) for N passage were 17.10 and 16.96 at the duodenum, 6.65 and 6.80 at the ileum and 4.5 and 5.22 in the faeces. The concentration of NH3-N in the rumen was significantly (P < 0.001) higher with the early-cut silage than with the late-cut silage.In both experiments the rates of bacterial crude protein (N × 6.25) synthesis in the rumen, estimated using α, ε-diaminopimelic acid as a marker, were low, 142 and 161 g crude protein/kg organic matter apparently digested in the rumen for the spring silage and the spring silage and barley diets respectively, and 68 and 103 g crude protein/kg organic matter apparently digested in the rumen for the early-cut autumn silage and the late-cut autumn silage respectively. For all diets there was a relatively low contribution of bacterial crude protein to the duodenal passage of crude protein and the amounts of individual amino acids ingested in the diets had a marked influence on the amino acids passing to the duodenum and as a consequence on the mixture of amino acids taken up from the small intestine.The results are discussed in relation to the nutritive value of silage N for ruminants.

scholarly journals Digestion of alfalfa and grass silages in sheep. 2. Digestion of protein in reticulorumen and intestines.

1988 ◽  
Vol 36 (4) ◽  
pp. 365-374
Author(s):  
J. van Bruchem ◽  
A.K. Kies ◽  
R. Bremmers ◽  
M.W. Bosch ◽  
H. Boer ◽  
...  
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Small Intestine ◽  
Amino Acid ◽  
Milk Protein ◽  
Diaminopimelic Acid ◽  
Microbial Protein ◽  
Grass Silage ◽  
Amino Acid Profiles ◽  
Limiting Amino Acids

Wilted lucerne and grass silages were given to mature wethers. Estimates of degradability of proteins in the reticulorumen were lower with diaminopimelic acid (38-71%) than those based on amino acid profiles of dietary, microbial and duodenal proteins (64-87%). Microbial protein synthesis was related to extent of organic matter fermentation in the reticulorumen. Efficiency of protein synthesis was not different between silages. Apparent digestibility of protein and amino acids in the small intestine was lower for lucerne silage (54%) than for grass silage (60-63%), probably caused by a higher DM passage in the small intestine of lucerne silage. Relative to the amino acid profiles of milk protein and beef, histidine and methionine were the first limiting amino acids. (Abstract retrieved from CAB Abstracts by CABI’s permission)

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