Advanced SearchSearch Tips
A Method for Determination of Nitrogen in Ruminant Feedstuffs and Products
facebook(new window)  Pirnt(new window) E-mail(new window) Excel Download
 Title & Authors
A Method for Determination of Nitrogen in Ruminant Feedstuffs and Products
Islam, M.R.; Ishida, M.; Ando, S.; Nishida, T.; Yamada, T.;
  PDF(new window)
A method for the determination of nitrogen in ruminant feedstuffs, products and excreta (e.g. milk and urine) using a spectrophotometer is developed, where samples processed for P determination are also used to determine N. Samples are digested with sulphuric acid and subsequently with hydrogen peroxide in Kjeldahl tubes. Digested solutions along with phenol and buffered alkaline hypochlorite reagents are incubated in a water bath at for 30 min and presented in the spectrophotometer. The spectrophotometer set at 625 nm measures the concentration of N of each sample. Nitrogen in 261 of the samples was also determined by the classical Kjeldahl method in order to develop a relationship between N determined by the Kjeldahl method (Y) and the colorimetric method (X). The mean value of Y was as high as that of X (0.92 vs. 0.96; p>0.05). The colorimetric method predicted Kjeldahl N highly significantly (Y=0.985X-0.024, , p<0.001; or more simply Y=0.974X, , p<0.001). An analysis of regression found no difference (p>0.05; both t-test and F-test) between colorimetric (0.96% N) and adjusted (0.96% N) N. In comparison with the Kjeldahl method, the analytical capacity of N by colorimetric method increases greatly, where 200-300 determinations of N are possible in a working day. In addition, the system provides an opportunity to use not only the same digested solution for both N and P determination of a particular sample, but also uses the same spectrophotometer to assay both N and P. Therefore, the system may be attractive in situations where both elements of a sample are to be determined. In conclusion, the speed of N determination, low cost, efficient use of labour, time and reagents, fewer items of equipment, and the reduction of environmental pollution by reducing effluent and toxic elements are the advantages of this method of N determination.
Nitrogen;Phosphorus;Kjeldahl;Spectrophotometer;Feedstuffs;Phenol-hypochlorite Method;
 Cited by
Ammerman, C. B., J. E. Moore, P. R. Henry, S. M. Miller and F. G. Martin. 1982. Effect of age and sample preparation on mineral concentration of bermudagrass hay. J. Dairy Sci. 65:1329-1333.

AOAC. 1984. Official Methods of Analysis (14th ed.). Association of Official Analytical Chemists, Arlington, V.A.

Cameron, B. F. 1965. Determination of iron in heme compounds. II. Hemoglobin and myoglobin. Anal. Biochem. 11:164-168. crossref(new window)

Dumas, J. B. A. 1831. Procedes de l’analyse organique. Ann. Chim. Phys. 247:198-213.

Emanuele, S. M. and C. R. Staples. 1989. Ruminal release of minerals from six forage species. J. Anim. Sci. 68:2052-2060.

Fiske, C. H. and Y. Subbarow. 1925. The colorimetric determination of phosphorous. J. Biol. Chem. 66:375.

Harris, W. D. and P. Popat. 1954. Determination of the phosphorus content of lipids. Am. Oil Chem. Soc. J. 66:821.

Islam, M. R., M. Ishida, S. Ando and T. Nishida. 2002. In situ dry matter, nitrogen and phosphorous disappearance of different feeds for ruminants. Asian-Aust. J. Anim. Sci. 15:793-799.

Jones, J. B. Jr. 1991. Kjeldahl Method for Nitrogen Determination. Micro-Macro Publishing, Athens, GA.

Keonig, R. A. and C. R. Johnson. 1942. Colorimetric determination of phosphorous in biological material. Anal. Chem. 14:155-162.

Khorasani, G. R., R. A. Janzen, W. B. McGill and J. J. Kennely. 1997. Site and extent of mineral absorption in lactating cows fed whole-crop cereal grain silage or alfalfa silage. J. Anim. Sci. 75:239-248.

Kjeldahl, J. 1883. Neue methode zur bestimmung des stickstoffs in organischen korpern. Z. Anal. Chem. 22:366-382.

Martz, F. A., A. T. Belo, M. F. Weiss and R. L. Belyea. 1999. True absorption of calcium and phosphorus from corn silage fed to nonlactating, pregnant dairy cows. J. Dairy Sci. 82:618-622.

Mizuno, N. and M. Minami. 1980. Rapid pre-treatment method using sulphuric acid and hydrogen peroxide for determination of nitrogen, potassium, magnesium, calcium and manganese in crops (in Japanese). Jpn. J. Soil Plant. Nutr. 51:418-420.

Paik, I. K. 2003. Application of phytase, microbial or plant origin, to reduce phosphorous excretion in poultry production. Asian-Aust. J. Anim. Sci. 16: 124-135.

Revesz, R. N. and N. Aker. 1977. Automated determination of protein-nitrogen in cereals and grains. J. Assoc. Off. Anal. Chem. 60: 238-1242.

SAS. 1988. Statistical Analysis System. SAS Procedures Guide, Release 6.03 Edition, SAS Institute Inc., Cary, N.C.

Snedecor, G. W. and W. G. Cochran. 1980. Statistical Methods (7th Ed). The Iowa State University Press, Ames, Iowa, USA.

Witt, K. E. and F. N. Owens. 1983. Phosphorous: ruminal availability and effects on digestion. J. Anim. Sci. 4:930-937.

Steel, R. G. D. and H. T. Torrie. 1980. Principles and Procedures of Statistics: A Biomedical Approach (2nd ed). McGraw-Hill, Inc., USA.