Hostname: page-component-8448b6f56d-xtgtn Total loading time: 0 Render date: 2024-04-24T12:22:35.541Z Has data issue: false hasContentIssue false
  • English
  • Français

A comparison of methods for the estimation of the proportion of microbial nitrogen in duodenal digesta, and of correction for microbial contamination in nylon bags incubated in the rumen of sheep

Published online by Cambridge University Press:  09 March 2007

P. M. Kennedy ,
G. P. Hazlewood  and
L. P. Milligan
P. M. Kennedy
Affiliation:
Department of Animal Science, The University of Alberta, Edmonton, Alberta T6G 2P5, Canada
G. P. Hazlewood
Affiliation:
Department of Animal Science, The University of Alberta, Edmonton, Alberta T6G 2P5, Canada
L. P. Milligan
Affiliation:
Department of Animal Science, The University of Alberta, Edmonton, Alberta T6G 2P5, Canada
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. Four sheep, each fitted with cannulas in the rumen and proximal duodenum, were given two diets (1390 g dry matter (DM)/d) consisting of lucerne (Medicago sutiva) pellets (24.2 g nitrogen/kg DM) plus pelleted reed canary grass (Phaluris arundinacea; 14.1 g N/kg DM) or chopped hay (11.8 g N/kg DM) at intervals of 2 h. Flow of duodenal digesta measured by reference to the markers 51Cr-EDTA and 103Ru-phenanthroline indicated a net gain of 5.8–7.5 g non-ammonia-N (NAN) between mouth and duodenum.

2. The proportion of microbial N in duodenal digesta N was estimated using 15N and 35S incorporation into bacteria and digesta. Two methods of analysis for 35S content, the Bird & Fountain (1970; B&F method) and the Mathers & Miller (1980; M&M method), were used. (15NH4)2S04 and Na235S04 were infused into the rumen for 3.5 d before and 4.0 d during sampling. A bacterial fraction was prepared from the fluid phases of sampled duodenal digesta and rumen contents by differential centrifugation. In addition, samples of ground canary grass and of lucerne were incubated in nylon bags in the rumen for 3–48 h during the infusion.

3. Each of the 35S analytical methods yielded similar values of 35S content of isolated rumen or duodenal bacteria, but there was more (P < 0.05) incorporation of 15N into rumen than into duodenal bacteria. Relative to values obtained using the M&M method and 15N incorporation, the B&F method for S analysis yielded higher (P < 0.05) estimates of microbial content of duodenal digesta from sheep given chopped reed canary grass.

4. 35S activity associated with washed nylon-bag residues increased rapidly with time-period of incubation and was substantially greater (P < 0.05) when analysed by the B&F method compared with the M&M method. The 35S content (/g DM) of adherent bacteria removed from nylon-bag residues by homogenization in a second experiment vaned from 0.65 to 1.88 that of free-living bacteria isolated from rumen fluid by differential centrifugation.

5. The difference in 35S content in digesta and nylon-bag residues as measured using the two analytical methods was considered in relation to 35S-labelled extracellular material postulated to be produced by bacteria adherent to plant residues. Estimates of disappearance of dietary N from nylon bags after correction for microbial contamination indicated a disparity with estimates based on in vivo information.

Type
Papers on General Nutrition
Information
British Journal of Nutrition , Volume 52 , Issue 2 , September 1984 , pp. 403 - 417
Copyright
Copyright © The Nutrition Society 1984

References

Agricultural research council (1980). The Nutrient Requirements of Ruminant Livestock. Farnham Royal: Commonwealth Agricultural Bureau.Google Scholar
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
Bird, R. P. & Fountain, R. D. (1970). Analyst 95, 98–102.CrossRefGoogle Scholar
Chapman, P. G. & Norton, B. W. (1984). Animal Production in Australia 15, 286–289.Google Scholar
Cheng, K.-J., Fay, J. P., Howarth, R. E. & Costerton, J. W. (1980). Applied and Environmental Microbiology 40, 613–625.CrossRefGoogle Scholar
Costerton, J. W. & Cheng, K.-J. (1982). In Experimental Microbial Ecology, pp. 275–290 [Burns, R. G. and Slater, J. H., editors]. Oxford: Blackwell Scientific Publications.Google Scholar
Doyle, P. T. & Moir, R. J. (1979). Australian Journal of Biological Sciences 32, 65–76.CrossRefGoogle Scholar
Faichney, G. J. (1975). In Digestion and Metabolism in the Ruminant, pp. 277–291 [McDonald, I. W. and Warner, A. C. I., editors]. Armidale: University of new england publishing unit.Google Scholar
Faichney, G. J. (1980). Australian Journal of Agricultural Research 31, 1129–37.CrossRefGoogle Scholar
Fitzgerald, J. W. (1976). Bacteriological Reviews 40, 698–721.CrossRefGoogle Scholar
Forsberg, C. W. & Lam, K. (1977). Applied and Environmental Microbiology 33, 528–537.CrossRefGoogle Scholar
Gillett, J. A., Bater, D. B. & Bergen, W. G. (1983). Michigan Agricultural Experimental Station Research Report no. 444, 73–77.Google Scholar
Goering, H. K. & Van soest, P. J. (1970). Forage Fiber Analyses. USDA Agriculture Handbook, no. 37. Washington dc: United states Department of Agriculture.Google Scholar
Harrop, C. J. F. (1974). Journal of Agricultural Science, Cambridge 83, 249–257.CrossRefGoogle Scholar
Hogan, J. P. & Weston, R. H. (1967). Australian Journal of Agricultural Research 18, 803–819.CrossRefGoogle Scholar
Hume, I. D. (1974). Australian Journal of Agricultural Research 25, 155–165.CrossRefGoogle Scholar
Kennedy, P. M., Christopherson, R. J. & Milligan, L. P. (1982). British Journal of Nutrition 47, 521–535.CrossRefGoogle Scholar
Kennedy, P. M. & Milligan, L. P. (1978 a). British Journal of Nutrition 39, 65–84.CrossRefGoogle Scholar
Kennedy, P. M. & Milligan, L. P. (1978 b). British Journal of Nutrition 39, 105–117.CrossRefGoogle Scholar
Kennedy, P. M. & Milligan, L. P. (1980). Canadian Journal of Animal Science 60, 1029–1032.CrossRefGoogle Scholar
Leibholz, J. (1972). Australian Journal of Agricultural Research 23, 1073–1083.CrossRefGoogle Scholar
McDonald, I. (1981). Journal, of Agricultural Science, Cambridge 96, 251–252.CrossRefGoogle Scholar
Mackie, R. I., Therion, J. J., Gilchrist, F. M. C. & Ndhlovu, M. (1983). South African Journal of Animal Science 13, 52–54.Google Scholar
Macrae, J. C. & Reeds, P. J. (1980). In Protein Deposition in Animals, pp. 225–249 [Buttery, P. J. and Lindsay, D. B., editors]. London: Butterworths.CrossRefGoogle Scholar
Mathers, J. C. & Aitchison, E. M. (1981). Journal of Agricultural Science, Cambridge 96, 691–693.CrossRefGoogle Scholar
Mathers, J. C. & Miller, E. L. (1980). British Journal of Nutrition 43, 503–514.CrossRefGoogle Scholar
Mathison, G. W. & Milligan, L. P. (1971). British journal of Nutrition 25, 351–366.CrossRefGoogle Scholar
Merry, R. J. & McAllan, A. B. (1983). British Journal of Nutrition 50, 701–709.CrossRefGoogle Scholar
Pickering, F. S., Nolan, J. V. & Corbett, J. L. (1982). Proceedings of the Nutrition Society of Australia 7, 127–130.Google Scholar
Roy, A. B. & Trudinger, P. A. (1970). The biochemistry of inorganic compounds of sulphur. Cambridge: Cambridge university press.Google Scholar
Siddons, R. C., Beever, D. E. & Nolan, J. V. (1982). British Journal of Nutrition 48, 377–389.CrossRefGoogle Scholar
Tan, T. N., Weston, R. H. & Hogan, J. P. (1971). International Journal of Applied Radiation and Isotopes 22, 301–308.CrossRefGoogle Scholar