Hostname: page-component-78c5997874-v9fdk Total loading time: 0 Render date: 2024-11-09T22:37:07.468Z Has data issue: false hasContentIssue false

A method for the estimation of dietary and microbial protein in duodenal digesta of ruminants

Published online by Cambridge University Press:  09 March 2007

D. E. Beever
Affiliation:
The Grassland Research Institute, Hurley, Maidenhead, Berkshire SL6 5LR
D. G. Harrison
Affiliation:
The Grassland Research Institute, Hurley, Maidenhead, Berkshire SL6 5LR
D. J. Thomson
Affiliation:
The Grassland Research Institute, Hurley, Maidenhead, Berkshire SL6 5LR
S. B. Cammell
Affiliation:
The Grassland Research Institute, Hurley, Maidenhead, Berkshire SL6 5LR
D. F. Osbourn
Affiliation:
The Grassland Research Institute, Hurley, Maidenhead, Berkshire SL6 5LR
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

1. A method is described for the estimation of the microbial and dietary protein entering the small intestine of sheep, based on an intraruminal infusion of [35S]sulphate, and isolation of the labelled microbial protein.

2. Samples of the microbial fraction contained in duodenal digesta were isolated by highspeed centrifugation and a scheme of analysis was devised for the determination of the specific activity of the methionine in the microbial fraction and the duodenal digesta.

3. In the absence of dietary methionine in duodenal digesta, it was postulated that the ratio of the specific activities of microbial methionine (M) and digesta methionine (D) should equal 1. Using two purified diets containing urea as the sole source of nitrogen, the M:D ratio was found to vary from 0·94 to 1·08 (mean 1·01 ± 0·01).

4. Addition of known quantities of dietary protein to labelled duodenal digesta obtained from one sheep fed on a non-protein diet increased the M:D ratio. Prediction of the dietary protein present from changes in the M:D ratio gave satisfactory agreement with the amounts of dietary protein known to be present (96–101% of known value, mean 98·4 ± 1·24%).

5. When animals were fed hourly the M:D ratio remained reasonably constant throughout 24 h. In contrast, with twice-daily feeding the M:D ratio varied markedly throughout the 24 h. However, summation of the estimates made of the flow of microbial and dietary protein into the duodenum in each 2 h period throughout 24 h agreed closely with the estimates made from samples withdrawn from the accumulated flow of digesta over the whole 24 h period.

6. The method was finally adapted to situations with either frequent or infrequent feeding patterns, and the need for a priming infusion period of 16 h before the collection and sampling of duodenal digesta was established.

Type
General Nutrition
Copyright
Copyright © The Nutrition Society 1974

References

REFERENCES

Armstrong, D. G. & Beever, D. E. (1969). Proc. Nutr. Soc. 28, 121.CrossRefGoogle Scholar
Ash, R. W. (1962). Anim. Prod. 4, 309.Google Scholar
Beever, D. E., Harrison, D. G. & Thomson, D. J. (1972). Proc. Nutr. Soc. 31, 61A.Google Scholar
Beever, D. E., Thomson, D. J., Pfeffer, E. & Armstrong, D. G. (1971). Br. J. Nutr. 26, 123.CrossRefGoogle Scholar
Brown, G. F., Armstrong, D. G. & MacRae, J. C. (1968). Br. vet. J. 124, 78.CrossRefGoogle Scholar
Corbett, J. L., Greenhalgh, J. F. D., McDonald, I. & Florence, E. (1960). Br. J. Nutr. 14, 289.CrossRefGoogle Scholar
Downes, A. M., Reis, P. J., Sharry, L. F. & Tunks, D. A. (1970). Br. J. Nutr. 24, 1083.CrossRefGoogle Scholar
Eadie, J. M. & Mann, S. O. (1970). In Physiology of Digestion and Metabolism in the Ruminant p. 335 [Phillipson, A. T., editor’. Newcastle upon Tyne: Oriel Press.Google Scholar
Harrison, D. G., Beever, D. E. & Thomson, D. J. (1972). Proc. Nutr. Soc. 31, 60A.Google Scholar
Henderickx, H. (1961). Archs int. Physiol. Biochim. 69, 449.Google Scholar
Hoeller, H. & Harmeyer, T. (1964). Zentbl. VetMed. A 11 (3), 244.Google Scholar
Hogan, J. P. & Weston, R. H. (1967). In Physiology of Digestion and Metabolism in the Ruminant p. 474 [Phillipson, A. T., editor’. Newcastle upon Tyne: Oriel Press.Google Scholar
Hungate, R. E. (1966). In The Rumen and Its Microbes. New York and London: Academic Press.Google Scholar
Hutton, K., Bailey, F. J. & Annison, E. F. (1971). Br. J. Nutr. 25, 165.CrossRefGoogle Scholar
Kay, R. N. B. (1969). Proc. Nutr. Soc. 28, 140.CrossRefGoogle Scholar
Leibholz, J. (1973). Aust. J. agric. Res. 23, 1073.CrossRefGoogle Scholar
Leng, R. A., Corbett, J. L. & Brett, D. J. (1968). Br. J. Nutr. 22, 57.CrossRefGoogle Scholar
Lennox, A. M., Lough, A. K. & Garton, G. A. (1968). Br. J. Nutr. 22, 237.CrossRefGoogle Scholar
McDougall, E. J. (1948). Biochem. J. 32, 99.CrossRefGoogle Scholar
Moore, S. (1963). J. biol. Chem. 238, 235.Google Scholar
Phillipson, A. T. (1964). In Mammalian Protein Metabolism Vol. I, p. 71 [Munro, H. N. and Allison, J. B., editors’. London: Academic Press.Google Scholar
Pounden, W. D., Fergusson, L. C. & Hibbs, J. W. (1950). J. Dairy Sci. 33, 565.Google Scholar
Roberts, S. A. & Miller, E. L. (1969). Proc. Nutr. Soc. 28, 32A.Google Scholar
Rose, A. H. (1968). Chemical Microbiology. London: Butterworth.Google Scholar
Smith, R. H. & McAllan, A. B. (1970). Br. J. Nutr. 24, 545.CrossRefGoogle Scholar
Smith, R. H. & McAllan, A. B. (1971). Br. J. Nutr. 25, 181.CrossRefGoogle Scholar
Stevenson, A. E. & de Langen, H. (1960). N.Z. Jl agric. Res. 3, 314.CrossRefGoogle Scholar
Virtanen, A. L. (1967). Ned. Melk-en Zuiveltijdschr. 21, 223.Google Scholar
Walker, D. J. & Nader, C. J. (1968). Appl. Microbiol. 16, 1124.CrossRefGoogle Scholar
Weller, R. A., Gray, F. V., Pilgrim, A. F. & Jones, G. B. (1967). Aust. J. agric. Res. 18, 107.Google Scholar