Hostname: page-component-cd9895bd7-fscjk Total loading time: 0 Render date: 2024-12-25T06:11:34.106Z Has data issue: false hasContentIssue false

Magnesium metabolism in the dairy cow. II. Metabolism during the spring grazing season

Published online by Cambridge University Press:  27 March 2009

J. A. F. Rook
Affiliation:
National Institute for Research in Dairying, Shinfleld, near Reading
C. C. Balch
Affiliation:
National Institute for Research in Dairying, Shinfleld, near Reading

Extract

1. Three experiments are reported in which magnesium metabolism trials were carried out with milking cows that had been changed abruptly from typical winter rations to herbage cut freshly from swards at an early or at a more mature stage of growth and fed in the stall.

2. The intake of herbage magnesium by individual animals varied from 9·5 to 15·2 g./day. Much of this variation was, however, associated more with differences in the palatability and dry-matter content of the herbage offered than with individual differences in appetite.

3. The mean proportion of the ingested herbage magnesium excreted in the faeces was similar in all three experiments, being 82·3, 83·0 and 82·4% respectively. With any given sward there were, however, wide variations between individual animals in their utilization of herbage magnesium.

4. The supply of ‘available’ magnesium to animals fed cut herbage in the stall varied from 0·5 to 4·2 g./day, as compared with values of from 2·6 to 10·5 g./day obtained previously (Rook et al. 1958) with cattle fed typical winter rations. In spite of this lower intake of ‘available’ magnesium, the animals maintained a positive magnesium balance.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1958

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

Balch, C. C., Bartlett, S. & Johnson, V. W. (1951). J. Agric. Sci. 41, 98.CrossRefGoogle Scholar
Balch, C. C., Head, M. J., Line, C., Rook, J. A. F. & Rowland, S. J. (1956). Proc. Nutr. Soc. 15, x.Google Scholar
Bartlett, S., Brown, B. B., Foot, A. S., Head, M. J., Line, C., Rook, J. A. F., Rowland, S. J. & Zundel, G. (1957). J. Agric. Sci. 49, 291.CrossRefGoogle Scholar
Bartlett, S., Brown, B. B., Foot, A. S., Rowland, S. J., Allcroft, R. & Parr, W. H. (1954). Brit. Vet. J. 110, 3.CrossRefGoogle Scholar
Blaxter, K. L. & McGill, R. F. (1956). Vet. Rev. & Annot. 2, 35.Google Scholar
Blaxter, K. L. & Rook, J. A. F. (1954). J. Comp. Path. 64, 176.CrossRefGoogle Scholar
Brouwer, E. (1952). Brit. Vet. J. 108, 123.CrossRefGoogle Scholar
Cox, C. P., Foot, A. S., Hosking, Z. D., Line, C. & Rowland, S. J. (1956). J. Brit. Grassl. Soc. 11, 107.CrossRefGoogle Scholar
Cunningham, I. J. (19361937). N.Z. J. Sci. Tech. 18, 424.Google Scholar
Davidson, J. (1952). Analyst. 77, 263.CrossRefGoogle Scholar
Head, M. J. & Rook, J. A. F. (1956). Proc. Nutr. Soc. 16, 25.CrossRefGoogle Scholar
Hosking, Z. D. & Line, C. (1956). J. Brit. Grassl. Soc. 11, 190.CrossRefGoogle Scholar
McCance, R. A. & Widdowson, E. M. (1942). J. Physiol. 101, 350.CrossRefGoogle Scholar
Rook, J. A. F., Balch, C. C. & Line, C. (1958). J. Agric. Sci. 51, 189.CrossRefGoogle Scholar
Sjollema, B. (1932). Tijdschr. Diergeneesk. 59, 57 and 329.Google Scholar
Sjollema, B. (1933). Acta vet. neerl. 1.Google Scholar
Swan, J. B. & Jamieson, W. D. (1956). N.Z. J. Sci. Sci. Tech. (A), 38, 363.Google Scholar