Methane production in ruminants: Its effect on the doubly labeled water method

Journal Article · Fri Dec 01 00:00:00 EST 1989 · American Journal of Physiology; (USA)

OSTI ID:7168401

Midwood, A J; Haggarty, P; McGaw, B A; Robinson, J J ^[1]

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1. Rowett Research Institute, Aberdeen, Scotland (England)

The doubly labeled water (DLW) technique for measuring CO2 production (rCO2) in free-living animals requires an assessment of the elimination of both 2H and 18O from the body over a long period of time. To calculate rCO2, it is necessary to calculate water turnover (rH2O) from the 2H flux rate. In ruminant animals, the accuracy of this calculation is affected by the loss of 2H in methane. We have quantified the effect of methane production (rCH4) on the 2H flux rate, determined in four sheep given 2H2O. The methane produced was depleted in 2H relative to the urine. A relationship between the enrichment of the methane and urine was established. The ratio of urine to methane enrichment was found on average to be 0.6536, and this value was unaffected by the level of rCH4 but showed some dependence on the absolute concentration of 2H in urine. For this reason, the ratio value obtained from four sheep not given 2H2O was different, a mean of 0.6886 was measured, this ratio was unaffected by changes in the diet supplied to the animals. Computer modeling was used to illustrate the dependence of the isotopically derived value for rCO2 on not only rCH4 but also the magnitude of rCO2 itself. The effect of rCH4 on the DLW method can be predicted from the observed ratio of rCO2 to rCH4 and the value of 0.6536 obtained for the ratio of methane to urine enrichment. With the use of data from several studies at this Institute, a limited range of 10 to 20 was found for rCO2/rCH4 in animals fed at or above maintenance.

• OSTI ID: 7168401
• Journal Information: American Journal of Physiology; (USA), Vol. 257; ISSN 0002-9513
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
CARBON DIOXIDE
MEASURING METHODS
METHANE
BIOSYNTHESIS
BIOLOGICAL MODELS
COMPUTERIZED SIMULATION
DEUTERIUM
DOUBLE LABELLING
OXYGEN 18
SHEEP
TRACER TECHNIQUES
ALKANES
ANIMALS
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
DOMESTIC ANIMALS
EVEN-EVEN NUCLEI
HYDROCARBONS
HYDROGEN ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
LABELLING
LIGHT NUCLEI
MAMMALS
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
OXYGEN ISOTOPES
RUMINANTS
SIMULATION
STABLE ISOTOPES
SYNTHESIS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques