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Purine nitrogen index, potentially a new parameter for rapid feed evaluation in ruminants

Abstract

The concept of a new parameter `Purine Nitrogen Index (PNI)` for feed evaluation in ruminants is discussed. PNI refers to the ratio of purine derivative (PD) nitrogen to total nitrogen in urine. It is suggested that PNI can potentially be used as an indicator of the efficiency with which degradable dietary nitrogen is converted to microbial protein in the rumen. The excretion of PD in the urine provides an estimation of the intestinal flow of microbial protein, and therefore, PNI effectively corresponds to the amount of microbial protein produced in the rumen relative to the nitrogen loss in the urine. If a diet or a dietary regime has a high conversion efficiency, proportionally more rumen degradable nitrogen is converted to microbial protein and less nitrogen is excreted in the urine, resulting in a high PNI. Conversely, if a diet has a poor conversion efficiency, proportionally less dietary nitrogen is converted to microbial protein and more is excreted in the urine, resulting in a low PNI. Preliminary data from six experiments involving 34 sheep confirmed a positive correlation between PNI and the nitrogen conversion efficiency, and suggested that a dietary regime with a PNI lower than 0.08 for sheep appeared to  More>>
Authors:
Chen, X B; Oerskov, E R; [1]  Subba, D B; [2]  Jayasuriya, M C.N. [3] 
  1. Rowett Research Institute, Bucksburn, Aberdeen (United Kingdom)
  2. Pakhribas Agricultural Centre, Dhankuta, Kathmandu (Nepal)
  3. International Atomic Energy Agency, Animal Production and Health Section, Vienna (Austria)
Publication Date:
Jun 01, 1999
Product Type:
Conference
Report Number:
IAEA-TECDOC-1093; CONF-9808104-
Reference Number:
SCA: 553005; PA: AIX-30:033613; EDB-99:076039; SN: 99002119810
Resource Relation:
Conference: 2. research co-ordination meeting on development, standardization and validation of nuclear based technologies for measuring microbial protein supply in ruminant livestock for improving productivity, Vienna (Austria), 24-28 Aug 1998; Other Information: DN: 15 refs, 5 figs, 4 tabs; PBD: Jun 1999; Related Information: Is Part Of Nuclear based technologies for estimating microbial protein supply in ruminant livestock. Proceedings of the second research co-ordination meeting of a co-ordinated research project (phase 1); PB: 119 p.
Subject:
55 BIOLOGY AND MEDICINE, BASIC STUDIES; ANIMAL FEEDS; DOMESTIC ANIMALS; EVALUATION; EXCRETION; MATHEMATICAL MODELS; MICROORGANISMS; NITROGEN; PROTEINS; PURINES; QUANTITATIVE CHEMICAL ANALYSIS; RUMINANTS; TRACER TECHNIQUES; URINE
OSTI ID:
363476
Research Organizations:
Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, Vienna (Austria)
Country of Origin:
IAEA
Language:
English
Other Identifying Numbers:
Journal ID: ISSN 1011-4289; Other: ON: DE99627388; TRN: XA9951068033613
Availability:
INIS; OSTI as DE99627388
Submitting Site:
INIS
Size:
pp. 97-110
Announcement Date:
Aug 31, 1999

Citation Formats

Chen, X B, Oerskov, E R, Subba, D B, and Jayasuriya, M C.N. Purine nitrogen index, potentially a new parameter for rapid feed evaluation in ruminants. IAEA: N. p., 1999. Web.
Chen, X B, Oerskov, E R, Subba, D B, & Jayasuriya, M C.N. Purine nitrogen index, potentially a new parameter for rapid feed evaluation in ruminants. IAEA.
Chen, X B, Oerskov, E R, Subba, D B, and Jayasuriya, M C.N. 1999. "Purine nitrogen index, potentially a new parameter for rapid feed evaluation in ruminants." IAEA.
@misc{etde_363476,
title = {Purine nitrogen index, potentially a new parameter for rapid feed evaluation in ruminants}
author = {Chen, X B, Oerskov, E R, Subba, D B, and Jayasuriya, M C.N.}
abstractNote = {The concept of a new parameter `Purine Nitrogen Index (PNI)` for feed evaluation in ruminants is discussed. PNI refers to the ratio of purine derivative (PD) nitrogen to total nitrogen in urine. It is suggested that PNI can potentially be used as an indicator of the efficiency with which degradable dietary nitrogen is converted to microbial protein in the rumen. The excretion of PD in the urine provides an estimation of the intestinal flow of microbial protein, and therefore, PNI effectively corresponds to the amount of microbial protein produced in the rumen relative to the nitrogen loss in the urine. If a diet or a dietary regime has a high conversion efficiency, proportionally more rumen degradable nitrogen is converted to microbial protein and less nitrogen is excreted in the urine, resulting in a high PNI. Conversely, if a diet has a poor conversion efficiency, proportionally less dietary nitrogen is converted to microbial protein and more is excreted in the urine, resulting in a low PNI. Preliminary data from six experiments involving 34 sheep confirmed a positive correlation between PNI and the nitrogen conversion efficiency, and suggested that a dietary regime with a PNI lower than 0.08 for sheep appeared to be a less efficient in the production of microbial protein and have a greater loss of nitrogen in the urine. PNI can theoretically be determined in spot urine samples, and has the potential to serve as a `dipstick` method for the rapid evaluation of ruminant feeds. However, more research with a mathematical modelling approach is required to evaluate and develop the concept further. (author) 15 refs, 5 figs, 4 tabs}
place = {IAEA}
year = {1999}
month = {Jun}
}