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A new approach to the quantitative estimation of nitrogen metabolic pathways in the rumen

Published online by Cambridge University Press:  09 March 2007

Yoav Aharoni ,
Haim Tagari  and
Ray C. Boston
Yoav Aharoni
Affiliation:
Department of Animal Science, Faculty of Agriculture, Rehovot 76–100, Israel
Haim Tagari
Affiliation:
Department of Animal Science, Faculty of Agriculture, Rehovot 76–100, Israel
Ray C. Boston
Affiliation:
School of Mathematics and Physical Sciences, Murdoch University, Murdoch, WA6150, Australia
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Abstract

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Rumen nitrogen metabolism values were estimated by the use of a single injection of 15(NH4)2SO4 into the rumen of sheep and consecutive 15N enrichment measurements in the rumen ammonia pool, rumen non-NH3-N (NAN) pool, rumen purine pool and blood urea-N (BUN) pool for a period of 24 h. Synthesis and degradation of N compounds in the rumen and passage of N to and from the rumen were evaluated on a chemical rather than a microbial basis; microbial fractions were not separated. This model was examined in two experiments. In Expt 1 a ram (55 kg) was given a semi-synthetic diet (1067 g dry matter (DM), 22.8 g N) in which soya-bean meal provided over 90% of the N. In Expt 2, two rams (45 kg) were given in three consecutive periods a semi-synthetic basal diet containing: (1) roasted soya-bean meal (SBM, 725 g DM, 14.8 g N/d); or (2) fishmeal (FM, 728 g DM, 15.5 g N/d); or (3) raw soya-bean meal (RSBM, 724 g DM, 13.8 g N/d). In all these rations, the main protein source provided over 90% of the N. In Expt 1, 68.3% of N intake was degraded directly to NH3 in the rumen, 21.2% escaped rumen degradation and 10.5% was incorporated into stable N compounds in the rumen. Net NH3 transfer to the blood was 30.4%, NH3 flow from the rumen was 6.6% and rumen NAN output was 63% of N intake. In Expt 2, rumen NAN output was larger (7.67, 14.36 and 8.89 g N/d for diets containing SBM, FM and RSBM respectively; P < 0.05) and net NH3 loss to the blood was smaller (6.1, 0.39 and 4.17 g N/d for diets SBM, FM and RSBM respectively; P < 0.05) for diet FM as compared with the soya-bean diets. The percentage of rumen NAN that was synthesized from NH3 was larger for diet RSBM (36.4, 40.3 and 49.1 for diets SBM, FM and RSBM respectively; P < 0.05) than for the other two rations. NH3 pool sizes (g N) were 0.463, 0.385 and 0.301 for diets SBM, FM and RSBM respectively (P < 0.05), while their hourly turnover rates were 15.8, 26.1 and 5.12 for diets SBM, FM and RSBM respectively (P < 0.01), indicating no correlation between pool size and its turnover rate. The existence of a small and rapidly turning over NAN pool to which NH3 is first bound (SNAN1) was indicated by the difference in the shape of the NAN and purines 15N-enrichment curves in the first 3 h after label injection. The fact that the rate of NH3 initial binding to SNAN1 pool was related neither to ammonia pool size nor to SNAN1 pool size suggests the existence of an unknown control mechanism at this site.

Keywords

NitrogenMetabolic pathwaysRumen
Type
Nitrogen Metabolism
Information
British Journal of Nutrition , Volume 66 , Issue 3 , November 1991 , pp. 407 - 422
Copyright
Copyright © The Nutrition Society 1991

References

REFERENCES

Aharoni, Y. & Tagari, H. (1991). Use of nitrogen-15 determinations of purine nitrogen fraction of digesta to define nitrogen metabolism traits in the rumen. Journal of Dairy Science 74 (8), 2540–2547.CrossRefGoogle ScholarPubMed
Berman, M., Shahn, E. & Weiss, M. F. (1962). The routine fitting of kinetic data to models: a mathematical formalism for digital computers. Biophysical Journal 2, 275–287.CrossRefGoogle ScholarPubMed
Boston, R. C., Greif, P. C. & Berman, M. (1982). CONSAM (Conversational version of SAAM modeling program). In Lipoprotein Kinetics and Modelling [Berman, M., Grundy, S. M and Howard, B. V., editors]. New York: Academic Press.Google Scholar
Brosh, A. (1985). Metabolic effects of infrequent drinking and low quality feed on Beduin goats. PhD Thesis, Tel Aviv University.Google Scholar
Bruckental, I., Oldham, J. D. & Sutton, J. D. (1980). Glucose and urea kinetics in cows in early lactation. British Journal of Nutrition 44, 33–45.CrossRefGoogle ScholarPubMed
Bunting, L. D., Boling, J. A. & MacKown, C. T. (1989). Effect of dietary protein level of nitrogen metabolism in the growing bovine. I. Nitrogen recycling and intestinal protein supply in calves. Journal of Animal Science 67, 810–819.CrossRefGoogle ScholarPubMed
Chaney, A. L. & Marbach, E. P. (1962). Modified reagents for determination of urea and ammonia. Clinical Chemistry 8, 130–132.CrossRefGoogle ScholarPubMed
Conway, E. J. (1957). Microdiffusion Analysis and Volumetric Error. London: Crosby Lockwood & Son Ltd.Google Scholar
Cottrill, B. R., Beever, D. E., Austin, A. R. & Osbourn, D. F. (1982). The effect of protein- and non-proteinnitrogen supplements to maize silage on total amino acid supply in young cattle. British Journal of Nutrition 48, 527–541.CrossRefGoogle ScholarPubMed
Czerkawski, J. W. & Breckenridge, G. (1985). Metabolism of protein supplements studied by the rumen simulation technique (Rusitech). Archiv für Tierernahrung 35, 261–277.CrossRefGoogle Scholar
Dawson, J. M., Bruce, C. I., Buttery, P. J., Gill, M. & Beever, D. E. (1988). Protein metabolism in the rumen of silage-fed steers: effect of fishmeal supplementation. British Journal of Nutrition 60, 339–353.CrossRefGoogle ScholarPubMed
Feigenbaum, S. & Hadas, A. (1974). Method of sample preparation for 15N determination in soil extracts by emission spectrometry. Soil Science 117, 168–170.CrossRefGoogle Scholar
Goering, H. K. & Van Soest, P. J. (1975). Forage Fiber Analysis. Agricultural Handbook no. 379, Agriculture Research Survey. Washington, DC: US Department of Agriculture.Google Scholar
Harmeyer, J. & Guldenhaupt, H. (1980). Measurements of protein turnover in batch cultures of rumen microbes using isotopic markers. In Protein Metabolism and Nutrition, pp. 49–55 [Oflage, H. J. and Rohr, K., editors]. Proceedings of the 3rd EAAP Symposium. European Association for Animal Production, Publication no. 22. Braunschwerg, Germany: Information Center of Bundesforschungfanspalt.Google Scholar
Leng, R. A. & Nolan, J. V. (1984). Symposium: Protein nutrition of lactating dairy cows. Journal of Dairy Science 67, 1072–1089.CrossRefGoogle Scholar
Mazanov, A. & Nolan, J. V. (1976). Simulation of the dynamics of nitrogen metabolism in sheep. British Journal of Nutrition 35, 149–174.CrossRefGoogle ScholarPubMed
Nolan, J. V. & Leng, R. A. (1972). Dynamic aspects of ammonia and urea metabolism in sheep. British Journal of Nutrition 27, 177–194.CrossRefGoogle ScholarPubMed
Nolan, J. V., Norton, B. W. & Leng, R. A. (1976). Further studies of the dynamics of nitrogen metabolism in sheep. British Journal of Nutrition 35, 127–147.CrossRefGoogle ScholarPubMed
Salter, D. N., Denashvar, K. & Smith, R. H. (1979). The origin of nitrogen incorporated into compounds in the rumen bacteria of steers given protein- and urea-containing diets. British Journal of Nutrition 41, 197–209.CrossRefGoogle ScholarPubMed
Smith, R. H. (1975). Nitrogen metabolism in the rumen and the composition and nutritive value of nitrogen compounds entering the duodenum. In Digestion and Metabolism in the Ruminant, pp. 399–415 [McDonald, I. W. and Warner, A. C. I., editors]. Armidale, NSW: University of New England.Google Scholar
Titgemeyer, E. C., Merchen, N. R. & Berger, L. L. (1989). Evaluation of soybean meal, corn gluten meal, blood meal and fish meal as sources of nitrogen and amino acids disappearing from the small intestines of steers. Journal of Animal Science 67, 262–275.CrossRefGoogle ScholarPubMed
Zinn, R. A. & Owens, F. N. (1982). Rapid procedure for quantifying nucleic acids content of digesta. In Protein Requirements for Cattle: Symposium, pp. 26–30 [Owens, F. N., editor]. Stillwater, OK: Oklahoma State University.Google Scholar