ISSN:
1432-136X
Keywords:
Key words Doubly labeled water
;
Energy expenditure
;
Japanese Quail Coturnix c. japonica
;
Growth
;
Fractional evaporative water loss
;
AbbreviationsCb isotope concentration of background
;
Cd isotope concentration of dose
;
Ci isotope concentration at start
;
Cf isotope concentration at end
;
DLW doubly labeled water
;
f1 fractionation factor
;
k fractional turnover rate
;
kd fractional turnover rate 2H
;
ko fractional turnover rate 18O
;
M average body mass
;
Mf body mass at end
;
Mi body mass at start
;
N amount of body water
;
Q dose of isotopes administered
;
rCO2 rate of CO2 production
;
rCO2-DLW rate of CO2 production measured with doubly labeled water
;
rCO2-IR rate of CO2 production measured with respiration gas analysis
;
Rdilspace ratio 2H and 18O body water dilution spaces
;
rG fractional evaporative water loss
;
RGR relative growth rate
;
rH2O water efflux rate
;
rH2O-uncorr water efflux rate uncorrected for fractionation effects
;
t time
;
TBW total amount of body water
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Abstract The Doubly Labeled Water (DLW) method was validated against respiration gas analysis in growing Japanese Quail chicks (between 1 week and 3 weeks of age) as well as in birds after having achieved sexual maturity (7 weeks of age). A comparison was made between a strain selected for high growth rates (P-strain, n=18), and a non-selected strain (C-strain, n=18). Relative growth rates of individual chicks during the measurement ranged from −13.8% day−1 to 23.1% day−1. When employing a single-pool model (eq. 34, Lifson and McClintock 1966), it was found that the relative error of the DLW method was sensitive to assumptions concerning fractional evaporative water loss. The best fit was obtained after taking a fractional evaporative water loss value of 0.33. When applying this value for all chicks, it was found that neither strain, relative growth rate of the chick during measurement, nor age significantly contributed to the explained variance. When employing two-pool models, it was found that the DLW method significantly underestimated the true rates of CO2 production at all assumed levels of fractional evaporative water loss. Based on an evaluation of DLW validation studies in growing shorebirds, terns, and quail we recommend Speakman's Eq. 7.17 (Speakman 1997) for general use in young birds.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s003600000112
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