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Determination of protein degradation rates using a rumen in vitro system containing inhibitors of microbial nitrogen metabolism*

Published online by Cambridge University Press:  09 March 2007

Glen A. Broderick
Glen A. Broderick
Affiliation:
US Department of Agriculture, Agricultural Research Service, US Dairy Forage Research Center, 1925 Linden Drive West, University of Wisconsin, Madison, Wisconsin, 53706, USA
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Abstract

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1. A previously reported rumen in vitro system (Broderick, 1978) was modified to include chloramphenicol (CAP) with hydrazine sulphate (HS) to give quantitative recovery of protein breakdown products. Degradation rates were determined by regression v. time of log proportion remaining undegraded (computed by subtracting from added nitrogen the amount of N recovered as ammonia and amino acids). Concentrations of reagents giving optimal N recoveries and estimated degradation rates for casein and expeller soya-bean-meal (SBM) were: 1.0 mM-HS, 30 μg CAP/ml, 20 mM-mercaptoethanol, 3.3 mg maltose/ml, when protein was added at 0125 mg N/ml.

2. Digestion of azo-casein and azo-albumin, solubilization of radioactivity from 14C-labelled casein, ovalbumin and bovine serum albumin (BSA), and hydrolysis of benzoyl-L-tyrosine p-nitroanilide and benzoyl-L-arginine p-nitroanilide were not significantly decreased by HS and CAP. This suggests that the inhibitors did not reduce microbial proteolysis.

3. Mean fractional degradation rates (/h) were: 0395 casein, 0.135 BSA, 0.159 solvent-SBM, 0.045 expeller-SBM, 0.061 meat meal, 0070 lucerne (Medicago sativa) hay. Extents of protein escape, estimated assuming rumen passage of 0.06/h, were 13, 28, 56 and 40% for casein, solvent-SBM, expeller-SBM and lucerne hay respectively. This method appears more reliable for assessing rumen degradability than buffer N solubility and protein digestibility with ficin protease.

4. Azo-dye treatment slowed the rate of casein degradation, measured by ammonia plus amino acid release, but did not alter digestion of BSA.

5. The validity of the inhibitor in vitro method for estimating protein degradability, as well as potential problems in its application, are discussed. The complete procedure may be limited to laboratories with automated analytical equipment, but a simplified version of the method may be more generally applicable.

Type
General Nutrition papers
Information
British Journal of Nutrition , Volume 58 , Issue 3 , November 1987 , pp. 463 - 475
Copyright
Copyright © The Nutrition Society 1987

References

REFERENCES

Agricultural Research Council (1984). The Nutrient Requirements of Ruminant Livestock, Suppl. 1. Slough: Commonwealth Agriculture Bureaux.Google Scholar
Annison, E. F. (1956). Biochemical Journal 64, 705–714.CrossRefGoogle Scholar
Association of Official Analytical Chemists (1980). Official Methods of Analysis, 13th ed. Washington, DC: Association of Official Analytical Chemists.Google Scholar
Appel, W. (1974). In Methods of Enzymatic Analysis, 2nd ed., pp. 949–978 [Bergmeyer, H. U., editor]. New York: Academic Press.CrossRefGoogle Scholar
Broderick, G. A. (1978). Journal of Nutrition 108, 181–190.CrossRefGoogle Scholar
Broderick, G. A. (1982). In Protein Requirements for Cattle: Symposium, pp. 72–80 [Owens, F. N., editor]. Stillwater, Oklahoma: Oklahoma State University.Google Scholar
Broderick, G. A. (1984). Canadian Journal of Animal Science 64, suppl., 31–32.CrossRefGoogle Scholar
Broderick, G. A. (1986). Journal of Dairy Science 69, 2948–2958.CrossRefGoogle Scholar
Broderick, G. A. & Balthrop, J. E. Jr (1979). Journal of Animal Science 49, 1101–1111.CrossRefGoogle Scholar
Broderick, G. A. & Craig, W. M. (1980). Journal of Nutrition 110, 2381–2389.CrossRefGoogle Scholar
Broderick, G. A. & Kang, J. H. (1980). Journal of Dairy Science 63, 64–75.CrossRefGoogle Scholar
Cotta, M. A. & Hespell, R. B. (1986). In Control of Digestion and Metabolism in Ruminants, pp. 122–136 [Milligan, L. P., Grovum, W. P. and Dobson, A., editors]. Englewood Cliffs, New Jersey: Prentice-Hall.Google Scholar
Craig, W. M. & Broderick, G. A. (1981). Journal of Dairy Science 64, 769–774.CrossRefGoogle Scholar
Craig, W. M., Hong, B. J., Broderick, G. A. & Bula, R. J. (1984). Journal of Dairy Science 67, 2902–2909.CrossRefGoogle Scholar
Eliman, M. E. & Ørskov, E. R. (1984). Animal Production 38, 45–51.Google Scholar
Gale, E. F. & Folkes, J. P. (1953). Biochemical Journal 53, 493–498.CrossRefGoogle Scholar
Hartnell, G. F. & Satter, L. D. (1979). Journal of Animal Science 48, 381–392.CrossRefGoogle Scholar
Hungate, R. E. (1969). In Methods in Microbiology, vol. 3B, pp. 117–132 [Norris, J.R. and Ribbons, D. W., editors]. New York: Academic Press.Google Scholar
Krishnamoorthy, U., Sniffen, C. J., Stern, M. D. & Van Soest, P. J. (1983). British Journal of Nutrition 50, 555–568.CrossRefGoogle Scholar
McDonald, I. (1981). Journal of Agricultural Science, Cambridge 96, 251–252.CrossRefGoogle Scholar
McDonald, I. W. & Hall, R. J. (1957). Biochemical Journal 67, 400–405.CrossRefGoogle Scholar
McDougall, E. I. (1948). Biochemical Journal 43, 99–109.CrossRefGoogle Scholar
Mahadevan, S., Erfle, J. D. & Sauer, F. D. (1979). Journal of Animal Science 48, 947–953.CrossRefGoogle Scholar
Mahadevan, S., Erfle, J. D. & Sauer, F. D. (1980). Journal of Animal Science 50, 723–728.CrossRefGoogle Scholar
Mahler, H. R. & Cordes, E. H. (1966). Biological Chemistry, pp. 810–811. New York: Harper & Row.Google Scholar
Mangan, J. L. (1972). British Journal of Nutrition 27, 261–283.CrossRefGoogle Scholar
National Research Council (1985). Ruminant Nitrogen Usage. Washington, DC: National Academy Press.Google Scholar
Ørskov, E. R. & McDonald, I. (1979). Journal of Agricultural Science, Cambridge 92, 499–503.CrossRefGoogle Scholar
Poos-Floyd, M., Klopfenstein, T. & Britton, R. A. (1985). Journal of Dairy Science 68, 829–839.CrossRefGoogle Scholar
Raab, L., Cafantaris, B., Jilg, T. & Menke, K. H. (1983). British Journal of Nutrition 50, 569–582.CrossRefGoogle Scholar
Siddons, R. C., Beever, D. E. & Kaiser, A. G. (1982). Journal of the Science of Food and Agriculture 33, 609–613.CrossRefGoogle Scholar
Wallace, R. J. (1983). British Journal of Nutrition 50, 345–355.CrossRefGoogle Scholar