scholarly journals Determination of rumen microbial-nitrogen production in sheep: a comparison of urinary purine excretion with methods using 15N and purine bases as markers of microbial-nitrogen entering the duodenum

1996 ◽  
Vol 75 (5) ◽  
pp. 699-709 ◽  
Author(s):  
J. F. erez ◽  
J. Balcells ◽  
J. A. Guada ◽  
C. Castrillo
Keyword(s):  
Urinary Excretion ◽  
Basal Diet ◽  
Barley Grain ◽  
Rumen Content ◽  
Purine Derivatives ◽  
Flow Measurements ◽  
Mean Values ◽  
Purine Bases ◽  
Microbial Nitrogen ◽  
Microbial N

The present study compares estimates of rumen microbial-N production derived from duodenal flow measurements (15N and purine bases) with those from measurements of the urinary excretion of purine derivatives. Four Rasa Aragonesa ewes fitted with simple cannulas in the rumen and proximal duodenum were used. Four diets consisting of 550 g lucerne (Medicago sativa) hay/d as sole feed or supplemented with 220, 400 and 550 g rolled barley grain/d were given in a 4 x 4 random factorial arrangement. Duodenal digesta flows were determined by the dual-phase marker technique during continuous intraruminal infusions of Co-EDTA and Yb-acetate. Microbial contribution to the non-NH3N (NAN)flow was estimated from 15N enrichment and purines: N ratio in duodenal digesta and bacterial fractions isolated from the rumen content. Whole tract organic matter (OM) digestibility and duodenal flow of OM and NAN increased (P<0·001) with the level of barley supplementation. Digestible OM intake ranged from 19·0 to 42·7 g/kg metabolic weight (W0·75) and the duodenal flow of purine bases and the urinary excretion of allantoin increased Linearly (P < 0·001) from minimum values of 7·47 (SD 1·524)and 4·65 (SD 0·705) mmol/d respectively on the basal diet to 18·20 (SD 1·751) and 11·62 (SD 0·214) mmol/d on the 400 g barley diet; a further increase in barley supplementation decreased both variables (13/50 (SD 2/334) and 8/77 (SD 0/617) mmol/d respectively). Urinary excretion of uric acid and hypoxanthine showed a slight but significant increase (P < 0·05) over all levels of barley. Molar recoveries of duodenal purine bases as purine derivatives or allantoin in the urine were 0·78 (SD 0·156) and 0·65 (SD 0·130) respectively. The increase on barley supplementation significantly augmented microbial-N, but large differences between microbial markers employed were observed. Mean values of microbial-N estimated from the duodenal purine bases or urinary allantoin excretion were on average 18 and 29% lower than those measured by 15N.

Rumen microbial production estimated either from urinary purine derivative excretion or from direct measurements of 15N and purine bases as microbial markers: effect of protein source and rumen bacteria isolates

1997 ◽  
Vol 65 (2) ◽  
pp. 225-236 ◽  
Author(s):  
J. F. Pérez ◽  
J. Balcells ◽  
J. A. Guada ◽  
C. Castrillo
Keyword(s):  
Organic Matter ◽  
Urinary Excretion ◽  
Fish Meal ◽  
Soya Bean ◽  
Purine Derivatives ◽  
Sunflower Meal ◽  
Purine Bases ◽  
Direct Measurements ◽  
Digestible Organic Matter ◽  
Microbial N

AbstractFour ewes fitted with ruminal and duodenal T-piece cannulae were each given six diets in a 6 × 4 factorial design. Diets or experimental treatments consisted of two ratios of forage: concentrate (700:150 (LC) and 400: 600 (HO). Forage was ammonia-treated straw and the concentrate was formulated with barley supplemented with one of three protein sources: sunflower meal, soya-bean meal or fish meal. Duodenal flows ofdigesta were estimated by the dual-phase technique using Co-EDTA and Yb acetate as liquid and solid markers. Microbial nitrogen (N) was estimated from the digesta flow of purine bases and 15N enrichment using as reference samples, bacterial isolates from the liquid (LAB) or solid (SAB) phase of rumen digesta.Duodenal flow of purine bases (mmol/day) was lower on LC (12·9) than HC (17·7) diets but in both treatments it was depressed by fish meal (12·3) compared with either soya-bean (17·3) or sunflower meal (16·3) as supplements (s.e. 1·13). Urinary excretion of purine derivatives showed a similar trend, 8·6 v. III mmol/day in LC and HC respectively and 8·8 v. 10·4 and 10·5 mmol/day in fish meal, soya-bean and sunflower meal diets (s.e. 0·56), respectively. Variation in excretion of urinary purine derivatives was mainly associated with digestible organic matter intake with an average ratio of 1·7 (s.e. 0·11) mmol per 100 g digestible organic matter intake. Irrespective of the microbial marker used, microbial yield was higher in animals offered HC than in those offered LC and with soya-bean or sunflower meal compared with fish meal supplemented diets. The microbial purine bases/N (mmol/g) ratio varied between LAB (1·99, s.e. 0·092) and SAB (1·69, s.e. 0·071) isolates leading to different estimates of microbial-N yield (g) from duodenal purine bases (7·76 (s.e. 2·84) v. 9·13 (s.e. 3·24)), urinary excretion of allantoin (5·57 (s.e. 2·0) v. 6·57 (s.e. 2·03)) or total purine derivatives (6·43 (s.e. 2·39) v. 7·56 (s.e. 2·77)). Urinary excretion of allantoin or total purine derivatives provided consistently lower estimates of duodenal microbial-N than duodenal purine bases or 15N, although it closely reflected the pattern observed in direct measurements.

Validation of use of purine bases as a microbial marker by15N labelling in growing lambs given high-concentrate diets: effects of grain processing, animal age and digesta sampling site

2005 ◽  
Vol 81 (1) ◽  
pp. 57-65 ◽  
Author(s):  
A. R. Askar ◽  
J. A. Guada ◽  
J. Balcells ◽  
A. de Vega ◽  
C. Castrillo
Keyword(s):  
Sampling Site ◽  
Barley Grain ◽  
Barley Straw ◽  
Purine Bases ◽  
Rumen Degradation ◽  
Grain Processing ◽  
Microbial Nitrogen ◽  
The Difference ◽  
Endogenous Contamination ◽  
Microbial N

AbstractThe origin of post-ruminal purine bases (PB) was studied in 24 growing lambs that were given a pelleted concentrate plus barley straw (C) or whole barley grain plus protein supplement (WB). Six lambs from each treatment were slaughtered at 10 and 30 days post weaning after15N labelling of microbial nitrogen (N) and PB. Microbial contribution to digesta non-ammonia N (NAN) and PB was lower (P< 0·01) when estimated from duodenal rather than abomasal samples (0·36 v. 0·52 (s.e.d. 0·021) for NAN and 0·47 v. 0·77 (s.e.d. 0·029) for PB) as a result of endogenous contamination. In comparison with15N, total PB/N led to higher estimates (P< 0·01) of microbial contribution to abomasal NAN in WB treatment (0·62 v. 0·46 s.e.d. 0·049). The difference was removed after correcting for microbial PB, while this effect was not observed with < the C diet, resulting in a marker by diet interaction (P< 0·05). Abomasal PB flow increased (P< 0·1) from 10 to 30 days after weaning mainly due to the higher proportion of microbial PB (0·70 v. 0·81 (s.e.d. 0·047)). Rumen apparent PB degradation did not differ between diets in older lambs, but it was proportionally 0·39 lower for WB treatment (P< 0·05) in younger lambs. When the microbial PB flow was estimated indirectly from labelled microbial N and the PB/N ratio of bacterial extracts the estimates were in agreement with those derived from PB-15N in the WB treatment but resulted in unrealistic values in lambs on diet C. Results suggest that significant proportions of dietary PB can escape rumen degradation which may lead to overestimation of microbial contribution to abomasal NAN when the PB/N ratio is used as marker. The extent of the overestimation is affected by the lamb age and grain processing.

scholarly journals Excretion of endogenous and exogenous purine derivatives in sheep: effect of increased concentrate intake

1998 ◽  
Vol 79 (3) ◽  
pp. 237-240 ◽  
Author(s):  
J. F. Pérez ◽  
J. Balcells ◽  
J. A. Cebrián ◽  
S. M. Martín-Orúe
Keyword(s):  
Organic Matter ◽  
Uric Acid ◽  
Urinary Excretion ◽  
Isotope Dilution ◽  
Basal Diet ◽  
Barley Grain ◽  
Dual Phase ◽  
Purine Derivatives ◽  
Marker System ◽  
Digestible Organic Matter

The present study examined the endogenous urinary excretion of purine derivatives (PD; allantoin, uric acid and xanthine plus hypoxanthine) in fed animals. Four Rasa Aragonesa ewes fitted with simple cannulas in the rumen and proximal duodenum were used. Animals were given a lucerne (Medicago sativa) hay diet, as sole feed (A) or supplemented, respectively, with 220 (B), 400 (C), and 550 (D) g rolled barley grain/d following a 4 × 4 random factorial design. Duodenal flow of purine bases (PB) was determined by the dual-phase marker system. 15N was infused continuously into the rumen to label exogenous or microbial PB. Duodenal PB flow and urinary excretion of PD increased with digestible organic matter intake showing a constant recovery of duodenal PB. The isotope dilution of PD in urine samples confirmed the presence of an endogenous fraction, originating from tissues, that increased from 115.2 (SE 5.84) μmol/kg W0.75 for the basal diet to 304.2 (SE 7.6) μmol/kg W0.75 at the highest level of duodenal PB.

The relationship between microbial N synthesis and urinary excretion of purine derivatives in Dorper×thin-tailed Han crossbred sheep

2013 ◽  
Vol 112 (1-3) ◽  
pp. 49-55 ◽  
Author(s):  
Tao Ma ◽  
Kaidong Deng ◽  
Chenggang Jiang ◽  
Yan Tu ◽  
Naifeng Zhang ◽  
...  
Keyword(s):  
Urinary Excretion ◽  
Purine Derivatives ◽  
The Relationship ◽  
Microbial N

Urinary recovery of allantoin in normally fed steers

1998 ◽  
Vol 1998 ◽  
pp. 80-80
Author(s):  
F. Herrera Gomez ◽  
F. D. Deb Hovell ◽  
C. A. Sandoval Castro
Keyword(s):  
Urinary Excretion ◽  
Recovery Factor ◽  
Purine Derivatives ◽  
Urinary Recovery ◽  
Host Animal ◽  
N Supply ◽  
Normal Feeding ◽  
The Relationship ◽  
Infusion Technique ◽  
Microbial N

Studies in the use of the purine derivatives technique in ruminants have been stimulated by the possible use of this technique as an estimator of the rumen microbial-N supplied to the host animal. The recovery factor influences the estimation of the total purines absorbed and therefore the microbial-N supply. The relationship between exogenous purine input and urinary excretion and recovery has been studied using cattle maintained with the intragastric infusion technique (Orskov et al., 1979). The urinary recovery of exogenous purines has been estimated to be 0.77-0.85 (Chen et al., 1990a, Verbic et al., 1990), and this relationship has been assumed to be applicable to normal feeding situations. To our knowledge there is no data to support or reject this approach. This study examined the urinary recovery of exogenous allantoin input in steers under normal feeding conditions.

The simultaneous use of ribonucleic acid, 35S, 2,6-diaminopimelic acid and 2-aminoethylphosphonic acid as markers of microbial nitrogen entering the duodenum of sheep

1978 ◽  
Vol 39 (1) ◽  
pp. 165-179 ◽  
Author(s):  
J. R. Ling ◽  
P. J. Buttery
Keyword(s):  
Fish Meal ◽  
Barley Grain ◽  
Soya Bean ◽  
Diaminopimelic Acid ◽  
Estimation Methods ◽  
Mean Values ◽  
Advantages And Disadvantages ◽  
Bean Meal ◽  
Soya Bean Meal ◽  
Microbial N

1. Three sheep, each fitted with a ruminal cannula and duodenal re-entrant cannulas were given three isonitrogenous, isoenergetic diets in a Latin-Square design. Each diet contained (/kg) approximately 400 g N as white fish meal, soya-bean meal or urea and approximately 600 g dry matter (dm) was barley grain. The diets were fed continuously and supplied about 28 g N/d.2. Total duodenal digesta was collected manually for 72 h and the proportions of microbial N in that digesta were simultaneously estimated for all sheep using RNA, radioactive sulphur (35S), diaminopimelic acid (DAPA) and aminoethylphosphonic acid (AEPA) as markers.3. Three of the estimation methods showed that the variable source of dietary N had the greatest (RNA P < 0.05, 35S P < 0.005, DAPA P < 0.1) effect on the proportions of microbial N in duodenal digesta, though differences between sheep accounted for some variation.4. These methods also ranked the diets in the order: urea > soya-bean meal > fish meal with respect to the proportions of digesta N that were microbial in origin; the respective mean values for these diets with the different markers were: RNA 0.98, 0.70, 0.56; 35S 0.92, 0.64, 0.54; DAPA 0.80, 0.47, 0.42.5. AEPA was found to be present in substantial quantities not only in isolated rumen protozoa, but also in dietary and bacterial material; an observation that invalidated its further use as a protozoal marker.6. Calculations using values obtained from the 35S procedure showed that the proportions of dietary N degraded within the rumen were 0.38, 0.43 and 0.89 for the white fish meal, soya-bean meal and barley respectively.7. The marker methods are compared and their advantages and disadvantages (real and apparent) are discussed. It is concluded that where microbial N estimates of a more general and comparative nature are required, the use of RNA as a marker is probably adequate. Where information for more exacting purposes is required, the use of 35S appears to be more appropriate.

Urinary recovery of allantoin in normally fed steers

1998 ◽  
Vol 1998 ◽  
pp. 80-80
Author(s):  
F. Herrera Gomez ◽  
F. D. Deb Hovell ◽  
C. A. Sandoval Castro
Keyword(s):  
Urinary Excretion ◽  
Recovery Factor ◽  
Purine Derivatives ◽  
Urinary Recovery ◽  
Host Animal ◽  
N Supply ◽  
Normal Feeding ◽  
The Relationship ◽  
Infusion Technique ◽  
Microbial N

Studies in the use of the purine derivatives technique in ruminants have been stimulated by the possible use of this technique as an estimator of the rumen microbial-N supplied to the host animal. The recovery factor influences the estimation of the total purines absorbed and therefore the microbial-N supply. The relationship between exogenous purine input and urinary excretion and recovery has been studied using cattle maintained with the intragastric infusion technique (Orskov et al., 1979). The urinary recovery of exogenous purines has been estimated to be 0.77-0.85 (Chen et al., 1990a, Verbic et al., 1990), and this relationship has been assumed to be applicable to normal feeding situations. To our knowledge there is no data to support or reject this approach. This study examined the urinary recovery of exogenous allantoin input in steers under normal feeding conditions.

Purine derivatives excretion and urinary nitrogen losses as influenced by the source of dietary carbohydrates supplementation

1992 ◽  
Vol 1992 ◽  
pp. 214-214
Author(s):  
J. Balcells ◽  
M. Fondevila ◽  
J.A. Guada ◽  
J. A. Carriedo
Keyword(s):  
Urinary Excretion ◽  
Latin Square ◽  
Experimental Period ◽  
Barley Grain ◽  
Barley Straw ◽  
Purine Derivatives ◽  
Negative Effect ◽  
Beet Pulp ◽  
Suitable Index ◽  
Urinary Nitrogen

Utilization of low quality roughages is limited fundamentally by the low energy cont and low DM intake when fed to the ruminant animal. Supplementation with concentrates can al improved energy supply although their inclusion can lead to a negative effect upon rough intake and ruminal cellulolitic activity. Urinary excretion of purine derivatives, urea and may constitute a suitable index to detect possible effects on rumen fermentation.The objective of this study was to determine the effect of changes in rumen fermentat: upon urinary excretion of these compounds induced by dietary supplementation of straw v differents sources of carbohydrates.Twelve Rasa Aragonesa ewes (44±0.45 Kg) were fed “ad libitum” with urea-supplemer barley straw and allocated at random to 3 groups of 4 animals. Each group was supplemented barley grain, sugar beet pulp and grass hay, respectively, at 4 levels of supplementation (: 300, 450 and 600 g/d) in a 4 x 4 latin square design. Each 42-d experimental period compr: 35 days of adjustment period followed by a 7 days measurement period.

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).

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