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Studies of the large intestine of sheep

3. Nitrogen kinetics in sheep given chopped lucerne (Medicago sativa) hay*

Published online by Cambridge University Press:  24 July 2007

R. M. Dixon  and
J. V. Nolan
R. M. Dixon
Affiliation:
Department of Biochemistry and Nutrition, Faculty of Rural Science, University of New England, Armidale, NSW 2351, Australia
J. V. Nolan
Affiliation:
Department of Biochemistry and Nutrition, Faculty of Rural Science, University of New England, Armidale, NSW 2351, Australia
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Abstract

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1. A study was made of nitrogen kinetics in the large intestine of sheep given 800 g chopped lucerne (Medicago sativa) hay/d. Four sheepwere continuously infused with (15NH4)2SO4 into the caecum and three other sheep were infused intravenously with [15N]urea. A digesta marker, 51Cr complexed with EDTA (51Cr-EDTA), was infused into the rumen of each sheep to allow estimation of the rates of flow of digesta constituents. Infusions were continued until tracer concentrations reached plateaux in digesta and blood pools, after which the sheep were anaesthetized and slaughtered.

2. Pre-infusion samples and samples on plateau were obtained before slaughter for subsequent analysis to give plasma urea and rumen ammonia-N concentration and enrichment. At slaughter, digesta were obtained from the ileum and segments of the large intestine. These were analysed for 51Cr-EDTA content and concentration and enrichment of ammonia-N, microbial N and non-urea non-ammonia-N (NU-NAN).

3. N flows in segments of the large intestine were calculated and represented in a quantitative eight-pool model.

4. Transfer of plasma urea across the wall of the caecum and proximal colon was negligible but there was an input of 0·8 g endogenous NU-NAN/d.

5. Flow of urea plus ammonia-N in digesta from the ileum into the caecum contributed 1·0 g N/d to the caecal ammonia pool.

6. Proteolysis and deamination produced a further 3·0 g ammonia-N/d in the caecum and proximal colon.

7. The net absorption of N between the ileum and the rectum was 2·8 g N/d but 3·0 g ammonia-N/d was absorbed from the caecum and proximal colon and, in addition, at least 0·9 g ammonia-N/d from the distal colon and rectum.

8. Ammonia-N was incorporated into caecal microbes (0·6 g N/d) and approximately 57% of the NU-NAN in caecal digesta was microbial N. The majority of the microbial N flowing from the caecum was excreted in faeces.

9. The rate of irreversible loss of urea-N from plasma, measured by intravenous infusion of [15N]urea, was 13·6 g/d. On average 83 (SE 6·8)% of the 15NH3 apparently absorbed from the caecum was incorporated into plasma urea; caecal ammonia contributed 9–19% of the N in plasma urea and 0·2–3·1% of the N in rumen ammonia.

Type
Research Article
Information
British Journal of Nutrition , Volume 50 , Issue 3 , November 1983 , pp. 757 - 768
Copyright
Copyright © The Nutrition Society 1983

References

Beever, D. E., Harrison, D. G., Thomson, D. J., Cammell, S. B. & Osbourn, D. F. (1974). British Journal of Nutrition 32, 99–112.CrossRefGoogle Scholar
Beever, D. E., Thomson, D. J. & Cammell, S. B. (1976). Journal of Agricultural Science, Cambridge 86, 443–452.CrossRefGoogle Scholar
Beever, D. E., Thomson, D. J., Cammell, S. B. & Harrison, D. G. (1977). Journal of Agricultural Science, Cambridge 88, 61–70.CrossRefGoogle Scholar
Chalmers, M. I., Grant, I. & White, F. (1976). In Protein Metabolism and Nutrition, pp. 159–179 [Cole, D. J. A., Boorman, P. J., Buttery, P. J., Lewis, D., Neale, R. J. and Swan, H., editors]. London: Butterworths.Google Scholar
Dixon, R. M. & Nolan, J. V. (1982). British Journal of Nutrition 47, 289–300.CrossRefGoogle Scholar
Dixon, R. M., Nolan, J. V. & Milligan, L. P. (1982). British Journal of Nutrition 47, 301–309.CrossRefGoogle Scholar
Elsden, S. R., Hitchcock, M. W. S., Marshall, R. A. & Phillipson, A. T. (1946). Journal of Experimental Biology 22, 191–202.CrossRefGoogle Scholar
Engelhardt, W. Von & Hinderer, S. (1976). In Tracer Studies on Non-protein Nitrogen for Ruminants, vol. 3, pp. 57–58. Vienna: International Atomic Energy Agency.Google Scholar
Hecker, J. F. (1971 a). British Journal of Nutrition 25, 85–95.CrossRefGoogle Scholar
Hecker, J. F. (1971 b). British Journal of Nutrition 26, 135–145.CrossRefGoogle Scholar
Hoover, W. H. (1978). Journal of Animal Science 46, 1789–1799.CrossRefGoogle Scholar
Houpt, T. R. (1963). American Journal of Physiology 205, 1144–1150.CrossRefGoogle Scholar
Hume, I. D. (1974). Australian Journal of Agricultural Research 25, 155–165.CrossRefGoogle Scholar
Judson, G. J., Abdelsamie, R. & Bird, R. B. (1975). Australian Journal of Agricultural Research 26, 743–749.CrossRefGoogle Scholar
Kay, R. N. B. (1969). Proceedings of the Nutrition Society 28, 140–150.CrossRefGoogle Scholar
Kempton, T. J., Nolan, J. V. & Leng, R. A. (1979). British Journal of Nutrition 42, 303–315.CrossRefGoogle Scholar
Kennedy, P. M. & Milligan, L. P. (1977). Proceedings of the Nutrition Society 36, 53A.Google Scholar
Kennedy, P. M. & Milligan, L. P. (1980). Canadian Journal of Animal Science 60, 205–221.CrossRefGoogle Scholar
Nolan, J. V. (1975). In Digestion and Metabolism in the Ruminant, pp. 416–431 [McDonald, I. W. and Warner, A. C. I., editors]. Armidale, Australia: University of New England Publishing Unit.Google Scholar
Nolan, J. V. & Leng, R. A. (1972). British Journal of Nutrition 27, 177–194.CrossRefGoogle Scholar
Nolan, J. V. & Leng, R. A. (1974). Proceedings of the Nutrition Society 33, 1–9.CrossRefGoogle Scholar
Nolan, J. V., Norton, B. W. & Leng, R. A. (1976). British Journal of Nutrition 35, 127–147.CrossRefGoogle Scholar
Ørskov, E. R., Fraser, C., Mason, V. C. & Mann, S. O. (1970). British Journal of Nutrition 24, 671–682.CrossRefGoogle Scholar
Roberts, S. A. & Miller, E. L. (1969). Proceedings of the Nutrition Society 28, 32A.Google Scholar
Snedecor, G. W. & Cochran, W. G. (1967). Statistical Methods, 6th ed. Ames, Iowa, USA: Iowa State University Press.Google Scholar
Thornton, R. F., Bird, P. R., Somers, M. & Moir, R. J. (1970). Australian Journal of Agricultural Research 21, 345–354.CrossRefGoogle Scholar
Ulyatt, M. J., Dellow, D. W., Reid, C. S. W. & Bauchop, T. (1975). In Digestion and Metabolism in the Ruminant, pp. 119–133 [McDonald, I. W. and Warner, A. C. I., editors]. Armidale, Australia: University of New England Publishing Unit.Google Scholar
Williams, V. J. (1965). Australian Journal of Agricultural Research 16, 77–91.CrossRefGoogle Scholar
Yang, M. G., Bergan, W. G., Sculthorpe, A. E. & Michelsen, D. (1972). Proceedings of the Society of Experimental Biology and Medicine 139, 1312–1318.CrossRefGoogle Scholar