Hostname: page-component-586b7cd67f-2brh9 Total loading time: 0 Render date: 2024-11-26T14:54:12.876Z Has data issue: false hasContentIssue false

Evaluation of the use of the purine derivative: creatinine ratio in spot urine and plasma samples as an index of microbial protein supply in ruminants: studies in sheep

Published online by Cambridge University Press:  27 March 2009

X. B. Chen
Affiliation:
Rowett Research Institute, Bucksburn, Aberdeen AB2 9SB, UK
A. T. Mejia
Affiliation:
Rowett Research Institute, Bucksburn, Aberdeen AB2 9SB, UK
D. J. Kyle
Affiliation:
Rowett Research Institute, Bucksburn, Aberdeen AB2 9SB, UK
E. R. Ørskov
Affiliation:
Rowett Research Institute, Bucksburn, Aberdeen AB2 9SB, UK

Summary

In ruminants, the urinary excretion of purine derivatives (PD) reflects the absorption of microbial purines and can be used as an index of microbial protein supply. The objective of this study, carried out in Aberdeen, 1992, 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. Sixteen sheep were offered ad libitum one of four diets (fresh weight basis, the rest of each diet being minerals and vitamins): (1) 99·9% lucerne (pelleted); (2) 50% hay, 30% barley, 9% fishmeal and 10% molasses; (3) 72% straw, 7% molasses and 20% molassed sugarbeet pulp; and (4) 97% barley. Measurements were made for 1 week after a 2-week adaptation period. Urine was collected daily on days 1–4 and hourly on days 5–7. Hourly urine collection was achieved using a fraction collector. Plasma samples were collected hourly from 09·00 to 17·00 h on day 4. Feed intake varied considerably (347–1718 g DM/day) between diets and between animals. Daily excretion of PD (7·1–22·6 mmol/day) was linearly related to DM intake (r = 0·85, n = 16), and so was the microbial N supply (3·9–19·5 g N/day) estimated from daily PD excretion (r = 0·87). In hourly urine samples, the ratio of PD:creatinine concentrations showed no significant difference between sampling times, and was linearlycorrelated with the daily PD excretion (r = 0·92). Similarly, plasma PD concentration also showed little diurnal fluctuation. Glomerular filtration rate (GFR) increased with feed intake. Plasma PD was not well correlated with daily PD excretion in urine (r = 0·57). The tubular load of PD (plasma PD × GFR) was better correlated with the daily excretion (r = 0·80). It appears that when sheep are fed ad libitum, PD in spot urine may provide a practical indicator of microbial protein supply status.

Type
Animals
Copyright
Copyright © Cambridge University Press 1995

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Agricultural Research Council (1984). The Nutrient Requirements of Ruminant Livestock, Supplement No. 1, pp. 318. Slough: Commonwealth Agricultural Bureaux.Google Scholar
Association Of Official Analytical Chemists (1965). Official Methods of Analysis of the Association of Official Analytical Chemists, 10th Edn, pp. 327328. Washington DC: AOAC.Google Scholar
Balcells, J., Fondevila, M., Guada, J. A., Castrillo, C. & Surra, J. C. E. (1993). Urinary excretions of purine derivatives and nitrogen in sheep given straw supplemented with different sources of carbohydrates. Animal Production 57, 287292.Google Scholar
Chen, X. B., Mathieson, J., Hovell, F. D. Deb. & Reeds, P. J. (1990). Measurement of purine derivatives in urine of ruminants using automated methods. Journal of the Science of Food and Agriculture 53, 2333.CrossRefGoogle Scholar
Chen, X. B., Kyle, D. J., Ørskov, E. R. & Hovell, F. D. Deb. (1991). Renal clearance of plasma allantoin in sheep. Experimental Physiology 76, 5965.CrossRefGoogle ScholarPubMed
Chen, X. B., Chen, Y. K., Franklin, M. F., Ørskov, E. R. & Shand, W. J. (1992 a). The effect of feed intake and body weight on purine derivative excretion and microbial protein supply in sheep. Journal of Animal Science 70, 15341542.CrossRefGoogle ScholarPubMed
Chen, X. B., Grubic, G., Ørskov, E. R. & Osuji, P. (1992 b). Effect of feeding frequency on diurnal variation in plasma and urinary purine derivatives in steers. Animal Production 55, 185195.Google Scholar
Davidson, J., Mathieson, J. & Boyne, A. W. (1970). The use of automation in determining nitrogen by the Kjeldahl method with final calculations by computer. Analyst 95, 181193.CrossRefGoogle ScholarPubMed
Dewhurst, R. J. (1989). Studies on energy and nitrogen metabolism in the rumen – investigation of less invasive techniques for these studies. PhD thesis, University of Bristol.Google Scholar
Dewhurst, R. J. & Webster, A. J. F. (1992 a). Effects of diet, level of intake, sodium bicarbonate and monensin on urinary allantoin excretion in sheep. British Journal of Nutrition 67, 345353.CrossRefGoogle ScholarPubMed
Dewhurst, R. J. & Webster, A. J. F. (1992 b). A note on the effect of plane of nutrition on fractional outflow rates from the rumen and urinary allantoin excretion by wether sheep. Animal Production 54, 445448.Google Scholar
Hovell, F. D. Deb., Ørskov, E. R., Kyle, D. J. & MacLeod, N. A. (1987). Undernutrition in sheep. Nitrogen repletion by N-depleted sheep. British Journal of Nutrition 57, 7788.CrossRefGoogle ScholarPubMed
Larsen, K. (1972). Creatinine assay by Reaction-kinetic Principle. Clinica Chimica Ada 41, 209217.CrossRefGoogle ScholarPubMed
Lindberg, J. E. & Jacobsson, K.-G. (1990). Nitrogen and purine metabolism at varying energy and protein supplies in sheep sustained on intragastric infusion. British Journal of Nutrition 64, 359370.CrossRefGoogle ScholarPubMed
Lindberg, J. E., Bristav, H. & Manyenga, A. R. (1989). Excretion of purines in the urine of sheep in relation to duodenal flow of microbial protein. Swedish Journal of Agricultural Research 19, 4552.Google Scholar
Owens, F. N. & Goetsch, A. L. (1986). Digesta passage and microbial protein synthesis. In Control of Digestion and Metabolism in Ruminants (Eds Milligan, L. P., Grovum, W. L. & Dobson, A.), pp. 196226. Englewood Cliffs, New Jersey: Prentice Hall.Google Scholar
Rys, R., Antoniewicz, A. & Maciejewicz, J. (1975). Allantoin in urine as an index of microbial protein in the rumen. In Tracer Studies on Non-protein Nitrogen for Ruminants II, pp. 9598. Vienna: IAEA.Google Scholar
Udén, P., Rounsaville, T. R., Wiggans, G. R. & Van Soest, P. J. (1982). The measurement of liquid and solid digesta retention in ruminants, equines and rabbits given timothy (Phleum pratense) hay. British Journal of Nutrition 48, 329339.CrossRefGoogle ScholarPubMed