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

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).

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 249-250
Author(s):  
Andresa L Feliciano ◽  
Sérgio A G Pereira-Junior ◽  
Yury Granja-Salcedo ◽  
Livia Maria Sampaio Ferraz Sepini de Souza Grilo ◽  
Luís Felipe Arelaro Artioli ◽  
...  

Abstract The objective of this study was to determine the effects of supplementation of low-moisture, sugarcane molasses-based block (LMB) on steers fed low quality forage in the excretion of purine derivatives and in the synthesis of ruminal microbial protein. Six rumen cannulated Nellore steers steers (23 months, 350 ± 10 kg) were distributed in a 3 × 3 double Latin square design. The treatments were composed of Brachiaria brizantha ‘Marandu’ hay ad libtum as an exclusive source of bulky (93.65% DM, 3.97% CP and 81.76% NDF) and supplements: complete mineral blend with urea [UR, (urea, salt, mineral-vitamin premix)], a commercial protein supplement [PS, (corn grain, soybean meal, urea, salt and mineral-vitamin premix)] or low-moisture, cooked sugarcane molasses-based protein block [LMB, (cane molasses, cottonseed meal, soybean oil, urea, salt and mineral-vitamin premix)]. Each experimental period lasted 21 days (14 days of adaptation and 7 days of data collection). The total urinary volume was measured for five days in each experimental period. The urine was collected in rubber funnels fixed by elastic loops on the backs of the animals. The urine was conduct through hoses connected to a 20 L polyethylene bucket containing 250 mL of 20% H2SO4 solution. Every 24 hours, the collected urine was homogenized and the total excreted volume was measured. The data were analyzed using Software R, having as fixed effect the treatments and as animal random effect, period, Latin square and error. Supplementation with LMB lead to greater excretion of allantoin (P = 0.046), microbial nitrogen flow (P = 0.023) and higher microbial crude protein (P = 0.023) into the intestine compared to UR and PS. While no effect was observed on total purines and purines absorbed (P > 0.05). Thus, LMB supplementation for rumen cannulated Nellore steers fed low quality forage was effective to improve metabolizable protein supply.


2017 ◽  
Vol 95 (2) ◽  
pp. 884-891 ◽  
Author(s):  
G. V. Kozloski ◽  
C. M. Stefanello ◽  
L. Oliveira ◽  
H. M. N. Ribeiro Filho ◽  
T. J. Klopfenstein

Author(s):  
X. B. Chen ◽  
Adriana T. Mejia ◽  
D. J. Kyle ◽  
E. R. Ørskov

In ruminants, daily urinary excretion of purine derivatives (PD) reflects the absorption of microbial purines and can be used as an index of microbial protein supply (Chen, Ørskov and Hovell, 1991). The application could be extended to farm conditions if measurements based on spot urine samples or plasma could serve as an alternative index. The objective of this study was to examine whether PD concentrations in spot urine or plasma samples vary diurnally during a given feeding regime and if they reflect differences in daily PD excretion induced by varying feed intake.


1998 ◽  
Vol 1998 ◽  
pp. 80-80
Author(s):  
F. Herrera Gomez ◽  
F. D. Deb Hovell ◽  
C. A. Sandoval Castro

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.


2007 ◽  
Vol 2007 ◽  
pp. 216-216
Author(s):  
Yashar Vakil Faraji ◽  
Mojtaba Zahedifar ◽  
Jafari Khorshidi Kaveh

Rumen microbes are rich in nucleic acid: around 18% of total nitrogen is present on nucleic acids or 11% in purines. Rumen microbes constitue the major source of protein supply to the ruminant. The purines from the rumen microbes are metabolized and excreted in the urine as their end products: hypoxanthine, xanthine, uric acid and allantoin. In buffalo and cattle because of high xanthine oxidase activity in intestine and blood, hypoxanthine and xanthine convert to uric acid therefore only uric acid and allantoin excreted in urine way (Chen, X. B., Ørskov, E. R., 2003). This research carried out to use excretion of purine derivatives namely allantoin and uric acid as a parameter to estimate the microbial protein synthesis in the rumen of native swamp buffalo in north of iran, Mazandaran Province.


1998 ◽  
Vol 1998 ◽  
pp. 80-80
Author(s):  
F. Herrera Gomez ◽  
F. D. Deb Hovell ◽  
C. A. Sandoval Castro

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.


1998 ◽  
Vol 22 ◽  
pp. 158-160
Author(s):  
J. Dijkstra ◽  
J. France ◽  
S. Tamminga

In protein evaluation systems for ruminants, the microbial protein supply is calculated from the amounts of rumen degradable organic matter and nitrogen (N) using empirical equations. A variable part of the rumen synthesized microbial protein does not reach the duodenum but is recycled within the rumen (review Firkins, 1996). Since energy is required for its re-synthesis and degraded microbial protein is subject to deamination, the efficiency of substrate conversion into microbial protein in the rumen is affected by microbial recycling. Rumen protozoa have a major impact upon this recycling through engulfment of micro-organisms and autolysis. In vitro, bacterial protein breakdown is proportionately reduced by some 0·9 upon removal of protozoa (Wallace and McPherson, 1987). Defaunation of the rumen increases the efficiency of microbial protein synthesis in vivo significantly (review Jouany et al., 1988).


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