Hostname: page-component-cd9895bd7-lnqnp Total loading time: 0 Render date: 2024-12-26T07:03:01.476Z Has data issue: false hasContentIssue false

Estimation of microbial nitrogen in nylon-bag residues by feed 15N dilution

Published online by Cambridge University Press:  09 March 2007

T. Varvikko
Affiliation:
Institute of Animal Husbandry, Agricultural Research Centre, SF-31600 Jokioinen, Finland
J. E. Lindberg
Affiliation:
Department of Animal Nutrition and Management, Swedish University of Agricultural Sciences, S-750 07 Uppsala, Sweden
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. Rapeseed (Brussicu nupus), barley grain, ryegrass (Loliurnperenne) and barley straw were labelled with 15N as an internal marker. The dilution of 15N was used to estimate microbial N (RMN15N) in the feed residues in nylon bags incubated in the rumen for 5, 12 and 24 h. For comparative purposes, diaminopimelic acid (DAP) content of the residues was also determined and rumen microbial N (RMNDAP-N) in the feed residues calculated using DAP as a bacterial marker. The influence of two bag pore sizes (20 μm and 40 μm) with different sample sizes (1 g and 5 g respectively) was also studied.

2. For all feeds, the average disappearance of 15N was faster than that of total N, the difference between N and 15N disappearance being marked with barley, ryegrass and barley straw. The disappearance of microbially corrected dry matter (DM; correction calculated from the 15N values) was, accordingly, always faster than the uncorrected DM disappearance. Except for the bag pore/sample size effect for N disappearance, significant (P < 0.01–0.001) feed, pore/sample size and incubation-time effects were always found for the disappearance values.

3. Errors (%) resulting from the microbial contamination (calculated from the 15N values) in N-loss measurement with rapeseed, barley, ryegrass and barley straw, at 5, 12 and 24 h in 20 μm bags were respectively: –1.8, –3.9, –0.9; –3.8, –22.4, –3.8; –7.2, –4.1, –2.9; –164.5, –146.3, –204.6. In 40 μm bags the corresponding errors were respectively: –4.4, –1.2, –0.7; –26.1, –10.5, –3.9; –13.2, –6.4, –5.5; –221.2, –310.1, –1284.6.

4. The largest residual proportions of RMN15N, RMNDAP-N and DAP-N (% of total N) were found in barley straw, followed by barley, ryegrass and rapeseed, in that order. RMN15N (g/kg residual DM) followed the descending order: barley, ryegrass, straw, rapeseed. RMNDAP-N, (g/kg residual DM) and DAP (mg/kg residual DM) followed the descending order: barley, ryegrass, rapeseed and barley straw. Feed, pore/sample size and incubation-time effects were always significant (P < 0.001).

5. With 40 μm bags RMN15N values of barley, ryegrass and barley straw (expressed as % of total N or g/kg residual DM) were substantially higher than those of RMNDAP-N With 20 μm bags the RMN15N and RMNDAP-N values were generally quite close for these feeds. With rapeseed residues, RMN15N was clearly lower than RMNDAP-N with 20 μm bags, but only small differences were found with 40 μm bags.

6. A more diverse microbial colonization of feed samples was indicated in the 40 μm bags compared with the 20 μm bags. It was also noticed, consequently, that in most cases larger error resulted from the microbial contamination in 40 μm bags.

Type
Papers on General Nutrition
Copyright
Copyright © The Nutrition Society 1985

References

REFERENCES

Akin, D. E. & Amos, H. E. (1975). Applied Microbiology 29, 692701.CrossRefGoogle Scholar
Akin, D. E., Amos, H. E., Barton, F. E. & Burdick, D. (1973). Agronomy Journal 65, 825828.CrossRefGoogle Scholar
Åman, P. (1979). Proceedings of the 5th International Rapeseed Conference, Malmö, 1978 2, 3844.Google Scholar
Baldwin, R. L. (1970). American Journal of Clinical Nutrition 23, 15081513.CrossRefGoogle Scholar
Bauchop, T. (1979). Applied and Environmental Microbiology 37, 12171223.CrossRefGoogle Scholar
Bauchop, T. (1981). Agriculture and Environment 6, 339348.CrossRefGoogle Scholar
Bryant, M. P. (1973). Federation Proceedings 32, 18091813.Google Scholar
Cheng, K.-J., Akin, D. E. & Costerton, J. W. (1977). Federation Proceedings 36, 193197.Google Scholar
Czerkawski, J. W. (1974). Journal of the Science of Food and Agriculture 25, 4555.CrossRefGoogle Scholar
Dufva, G. S., Bartley, E. E., Arambel, M. J., Nagaraja, T. G., Dennis, S. M., Galitzer, S. J. & Dayton, A. D. (1982). Journal of Dairy Science 65, 17541759.CrossRefGoogle Scholar
Latham, M. J., Broker, B. E., Pettipher, G. L. & Harris, P. J. (1978). Applied and Environmental Microbiology 35, 156165.CrossRefGoogle Scholar
Lindberg, J. E. (1981). Swedish Journal of Agricultural Research 11, 7176.Google Scholar
Lindberg, J. E., Clason, C., Ciszuk, P. & den Braver, E. (1982). Swedish Journal of Agricultural Research 12, 7782.Google Scholar
Lindberg, J. E., Kaspersson, A. & Ciszuk, P. (1984). Journal of Agricultural Science, Cambridge 102. 501504.CrossRefGoogle Scholar
Lindberg, J. E. & Varvikko, T. (1982). Swedish Journal of Agricultural Research 12, 163171.Google Scholar
McAllan, A. B. & Smith, R. H. (1983). British Journal of Nutrition 49, 119127.CrossRefGoogle Scholar
Mathers, J. C. & Aitchison, E. M. (1981). Journal of Agricultural Science, Cambridge 96, 691693.CrossRefGoogle Scholar
Mehrez, A. Z. & Ørskov, E. R. (1977). Journal of Agricultural Science, Cambridge 88, 645650.CrossRefGoogle Scholar
Rahnema, S., Theurer, B., Longo, A. J. & McCaughey, W. F. (1979). Journal of Animal Science 49 Suppl. 1, 339.Google Scholar
Rooke, J. A., Greife, H. A. & Armstrong, D. G. (1984). Journal of Agricultural Science, Cambridge 102, 695702.CrossRefGoogle Scholar
Ross, P. J. & Martin, A. E. (1970). Analyst 95, 817822.CrossRefGoogle Scholar
Setälä, J. (1983). Journal of the Scientifc Agricultural Society of Finland 55, 178.Google Scholar
Smith, R. H., McAllan, A. B., Hewitt, D. & Lewis, P. E. (1978). Journal of Agricultural Science, Cambridge 90, 557568.CrossRefGoogle Scholar
Theurer, B. (1982). Proceedings of an International Symposium at Oklahoma State University, 1980, pp. 1022.Google Scholar
Varvikko, T., Lindberg, J. E., Setälä, J. & Syrjälä-Qvist, L. (1983). Journal of Agricultural Science, Cambridge 101, 603612.CrossRefGoogle Scholar