Hostname: page-component-586b7cd67f-tf8b9 Total loading time: 0 Render date: 2024-11-27T23:13:07.689Z Has data issue: false hasContentIssue false

The effects of the protein content of the diet on the performance of lactating cows

Published online by Cambridge University Press:  01 June 2009

R. Paquay
Affiliation:
Department of Animal Physiology, Faculty of Veterinary Medicine, Cureghem, 1070-Brussels, Belgium
J. M. Godeau
Affiliation:
Department of Animal Physiology, Faculty of Veterinary Medicine, Cureghem, 1070-Brussels, Belgium
R. De Baere
Affiliation:
Department of Animal Physiology, Faculty of Veterinary Medicine, Cureghem, 1070-Brussels, Belgium
A. Lousse
Affiliation:
Department of Animal Physiology, Faculty of Veterinary Medicine, Cureghem, 1070-Brussels, Belgium

Summary

Four experiments were carried out with Friesian cows in different stages of lactation to determine the influence of the crude-protein content of the diet on the digestibility and utilization of dietary constituents and on the cow's performance and milk composition.

The rations were composed so that they met the energy requirements of the cows, but crude-protein content was widely variable.

Our findings on the digestibility of the dietary constituents were in agreement with the data given in the literature.

The utilization of dietary N for milk secretion was influenced by the level of N intake only when the crude-protein content of the diet was lower than a limiting value, which varied according to stage of lactation. When this value was not attained the daily milk production was affected, but not the protein content of the milk.

The optimal crude-protein content of the diet was 15–16% (dry-matter basis) when milk production exceeded 20 kg/d, 12–13% for a production of 15–17 kg/d and 11–12% for cows giving less than 10 kg of milk daily.

Type
Research Article
Copyright
Copyright © Proprietors of Journal of Dairy Research 1973

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

Agricultural Research Council (1965). The Nutrient Requirements of Farm Livestock. No. 2. Ruminants. London: H.M.S.O.Google Scholar
Armstrong, D. G. (1968). Proceedings of the Nutrition Society 27, 57.CrossRefGoogle Scholar
Armstrong, D. G. & Beever, D. E. (1969). Proceedings of the Nutrition Society 28, 121.CrossRefGoogle Scholar
Association of Offical Agricultural Chemists (1965). Official Methods of Analysis, 10th edn.Washington: A.O.A.C.Google Scholar
Blaxter, K. L. (1964). In Mammalian Protein Metabolism, vol. II, p. 173. (Ed. Munro, H. N.and Allison, J. B..) New York: Academic Press.CrossRefGoogle Scholar
Broster, W. H., Broster, V. J. & Smith, T. (1969). Journal of Agricultural Science 72, 229.CrossRefGoogle Scholar
Dorée, Ch. (1949). Les méthodes de la chimie de la cellulose. 2nd edn.Paris: Dunod.Google Scholar
Elliott, R. C. & Topps, J. H. (1963). British Journal of Nutrition 17, 549.CrossRefGoogle Scholar
Gardner, R. W. (1969). Journal of Dairy Science 52, 1973.CrossRefGoogle Scholar
Gordon, F. J. & Forbes, T. J. (1970). Journal of Dairy Research 37, 481.CrossRefGoogle Scholar
Gordon, F. J. & Forbes, T. J. (1971). Journal of Dairy Research 38, 381.CrossRefGoogle Scholar
Huber, J. T. & Thomas, J. W. (1971). Journal of Dairy Science 54, 224.CrossRefGoogle Scholar
Lister, E. E., Heaney, D. P. & Pigden, W. J. (1968). Journal of Dairy Science 51, 1946.CrossRefGoogle Scholar
Martz, F. A., Padgitt, D. D., Brown, J. R., Hilderbrand, E. S. & Marshall, R. T. (1971). Journal of Dairy Science 54, 662.CrossRefGoogle Scholar
Paquay, R., De Baere, R. & Lousse, A. (1972 a). Journal of Agricultural Science 78, 135.CrossRefGoogle Scholar
Paquay, R., De Baere, R. & Lousse, A. (1972 b). Journal of Agricultural Science 78, 141.CrossRefGoogle Scholar
Paquay, R., De Baere, R. & Lousse, A. (1972 c). Journal of Agricultural Science 79, 13.CrossRefGoogle Scholar
Rook, J. A. F. & Campling, R. C. (1965). Journal of Dairy Research 32, 45.CrossRefGoogle Scholar
Rook, J. A. F. & Line, C. (1961). British Journal of Nutrition 15, 109.CrossRefGoogle Scholar
Rook, J. A. F., Line, C. & Rowland, S. J. (1960). Journal of Dairy Research 27, 427.CrossRefGoogle Scholar
Thomas, J. W. (1971). Journal of Dairy Science 54, 1629.CrossRefGoogle Scholar
Van Niekerk, B. D. H., Smith, D. W. W. Q. & Oosthuysen, D. (1967). Proceedings of the South African Society of Animal Production 6, 108.Google Scholar
Weston, R. H. & Hogan, J. P. (1968). Australian Journal of Agricultural Research 19, 963.CrossRefGoogle Scholar
Wilson, L. L., Varela-Alvarez, H., Hess, C. E. & Rugh, M. C. (1971). Journal of Animal Science 33, 686.CrossRefGoogle Scholar