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The effect of route of dosing and method of estimation of tritiated water space on the determination of total body water and the prediction of body fat in sheep

Published online by Cambridge University Press:  27 March 2009

B. S. W. Smith  and
A. R. Sykes
B. S. W. Smith
Affiliation:
Moredun Research Institute, Edinburgh EH 17 7JH
A. R. Sykes
Affiliation:
Moredun Research Institute, Edinburgh EH 17 7JH
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Summary

Eight mature female sheep were offered a ration which maintained body weight constant during a 20-week period. During the final 10 weeks a comparison was made in each animal of the pattern of equilibration and urinary losses of tritiated water during 8 h after dosing by four different routes. These were intravenous, intraperitoneal, intraruminal and a combination of the intraperitoneal and intraruminal routes. Tritiated water spaces were calculated from (a) the 8-h plasma specific activity and (b) by extrapolation to zero time of the plasma specific activities during the 7 days after injection. At the end of the experiment the fat and water contents of the bodies of the sheep were determined directly.

Complete equilibration of tritiated water between plasma and rumen water was not achieved in all animals 8 h after intravenous or intraperitoneal injection but was when the rumen was primed by the combination of intraperitoneal and intraruminal dosing. After intraruminal dosing equilibration was not achieved in any animal within 8 h of dosing.

Urinary losses of marker were lower after intraruminal dosing but otherwise averaged 4–5 % of the dose/1 urine. This was equivalent to 0·3–6·7% of the dose for individual sheep.

Errors resulting from incomplete equilibration and urinary loss of marker did not influence the efficiency of prediction of total body water from tritiated water space. The multiple correlation coefficient relating body fat with empty body weight and its water content was very high (r = 0·99). Errors introduced into this relationship by the inclusion of gut water in the prediction equations were apparently of a similar magnitude to those resulting from the errors in the estimation of tritiated water space.

The extrapolation method for the determination of tritiated water space was shown to have the same accuracy as equilibration techniques under these controlled dietary conditions.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 82 , Issue 1 , February 1974 , pp. 105 - 112
Copyright
Copyright © Cambridge University Press 1974

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References

REFERENCES

Carnegie, A. B. & Tulloh, N. M. (1968). The in vivo determination of body water space in cattle using the tritium dilution technique. Proceedings of the Australian Society of Animal Production 7, 308–13.Google Scholar
Farrell, D. J. & Reardon, T. F. (1972). Undernutrition in grazing sheep. III. Body composition and its estimation in vivo. Australian Journal of Agricultural Research 23, 511–17.CrossRefGoogle Scholar
Keenan, D. M., MacManus, W. R. & Freer, M. (1969). Changes in the body composition and efficiency of mature sheep during loss and regain of live weight. Journal of Agricultural Science, Cambridge 72, 139–47.CrossRefGoogle Scholar
Kumar, I. & Berger, E. Y. (1968). Preparation of samples for liquid scintillation analysis of tritiated water. International Journal of Applied Radiation and Isotopes 19, 805–7.CrossRefGoogle Scholar
Panaretto, B. A. (1963). Body composition in vivo. III. The composition of living ruminants and its relation to the tritiated water spaces. Australian Journal of Agricultural Research 14, 944–52.CrossRefGoogle Scholar
Panaretto, B. A. (1968). Body composition in vivo. IX. The relation of body composition to the tritiated water spaces of ewes and wethers fasted for short periods. Australian Journal of Agricultural Research 19, 267–72.CrossRefGoogle Scholar
Panaretto, B. A. & Till, A. R. (1963). Body composition in vivo. II. The composition of mature goats and its relationship to the antipyrine, tritiated water, and N-acetyl-4-aminoantipyrine spaces. Australian Journal of Agricultural Research 14, 926–43.CrossRefGoogle Scholar
Searle, T. W. (1970). Body composition in lambs and young sheep and its prediction in vivo from tritiated water spaces and body weight. Journal of Agricultural Science, Cambridge 74, 357–62.CrossRefGoogle Scholar
Snedecor, G. W. (1956). Statistical Methods. Iowa, U.S.A.; Iowa State University Press.Google Scholar
Till, A. R. & Dowstes, A. M. (1962). Measurement of total body water in the sheep. Australian Journal of Agricultural Research 13, 335–42.CrossRefGoogle Scholar