Hostname: page-component-78c5997874-4rdpn Total loading time: 0 Render date: 2024-11-03T05:34:24.805Z Has data issue: false hasContentIssue false

The value of urea as a substitute for protein in the rations of dairy cattle: I. Field trials with dairy cows*

Published online by Cambridge University Press:  27 March 2009

S. Bartlett
Affiliation:
National Institute for Research in Dairying, University of Reading
K. L. Blaxter
Affiliation:
National Institute for Research in Dairying, University of Reading

Extract

1. A large-scale experiment with 274 dairy cows has been carried out to determine whether urea can be a substitute for part of the protein requirement of the lactating. dairy cow.

2. It has been emphasized that any proteinsparing effect of urea or other sources of non-protein nitrogen can only be determined in the proteindeficient animal and one of the experimental treatments was therefore designed to supply well below that minimum requirement of protein compatible with milk production.

3. The addition of protein to such a ration increasing the percentage of crude protein in the production rations from 12·9 to 17·9 and the protein equivalent from 9·5 to 14·5 resulted in a significant increase in milk production. This gave ample confirmation of the protein deficiency of the low protein ration.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1947

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Bartlett, M. S. (1937). J. Roy. statist. Soc. Suppl. 4, 137.Google Scholar
Bartlett, S. & Cotton, A. G. (1938). J. Dairy Res. 9, 263–72.CrossRefGoogle Scholar
Bartlett, S., Foot, A. S., Huthnance, S. L. & Mackintosh, J. (1940). J. Dairy Res. 11, 121–35.CrossRefGoogle Scholar
Benesch, R. (1941). Nature, Lond., 147, 531.CrossRefGoogle Scholar
Blaxter, K. L. & Price, H. A. (1946). J. Agric. Sci. 36, 301.CrossRefGoogle Scholar
Gluschke, A. (1929). Tierärtzl. Rdsch. 35, 781–9.Google Scholar
Halnan, E. T. (1929). J. Dairy Res. 1, 334.CrossRefGoogle Scholar
Harris, L. E. & Mitchell, H. H. (1941). J. Nutrit. 22, 167.CrossRefGoogle Scholar
Hart, E. B., Bohstedt, S., Deobald, H. J. & Wegner, M. I. (1939). J. Dairy Sci. 22, 785.CrossRefGoogle Scholar
Krebs, H. A. (1937). Biederm. Zbl. B, Tiernährung, 9, 394.Google Scholar
Mitchell, H. H. & Hamilton, T. S. (1929). “The Biochemistry of the Amino Acids.” The Chemical Catalog Company, Inc., N.Y.Google Scholar
Møllgarde, H. (1929). “Futterungslehre des Milchvieh's.” Verlaz, von N. & Schaper, M. Hanover. P. 153.Google Scholar
Nutrit. Rev. (Sept. 1943), 1, 11, 322.Google Scholar
Nutrit. Rev. (Jan. 1944), 2, 1, 22.CrossRefGoogle Scholar
Owen, E. C. (1941). J. Dairy Res. 12, 214.CrossRefGoogle Scholar
Scheunert, A., Klein, W. & Steuber, M. (1922). Biochem. Z. 133, 137.Google Scholar
Smith, J. A. B. & Baker, F. (1944). Biochem. J. 38, 5, 496.CrossRefGoogle Scholar
Van der Walt, S. J. & Steyn, D. G. (1941). Onderstepoort J. vet. Sci. 17, 1 & 2, 201.Google Scholar
Woodman, H. E. (1939). “Rations for Live Stock.” H.M.S.O., London.Google Scholar