Hostname: page-component-848d4c4894-5nwft Total loading time: 0 Render date: 2024-05-21T06:28:03.425Z Has data issue: false hasContentIssue false

Studies in grazing management V. Further determination of the nutrient intake of dairy cows under close-folding and rotational methods of grazing

Published online by Cambridge University Press:  27 March 2009

R. Waite
Affiliation:
The Hannah Dairy Research Institute, Kirkhill, Ayr
W. Holmes
Affiliation:
The Hannah Dairy Research Institute, Kirkhill, Ayr
J. Boyd
Affiliation:
The Hannah Dairy Research Institute, Kirkhill, Ayr

Extract

1. The experiments started in 1949 to determine the weight and chemical composition of the herbage dry matter eaten by two groups of dairy cows grazing under a rotational and a close-folding system of management have been continued in 1950.

2. Good-quality herbage was fed in adequate quantity to both groups for 20 weeks, in four fiveweekly periods allowing a double change-over system for the groups. The weights of protein, fibre, other extractives, lignin and minerals eaten daily by the close-folded group were determined. Difficulty in obtaining truly representative herbage samples from the rotational paddock made such detailed analyses for the rotationally grazed cattle not worth while.

3. The weight of dry matter eaten by the closefolded cows was remarkably constant, the mean was 26 lb./cow/day and the standard deviation ±2·7 lb. The weight eaten by the rotationally grazed cows was more difficult to measure and appeared to vary considerably, the average being 31 lb. dry matter/ cow/day, and the standard deviation ±3·1 lb. Reasons are suggested why this figure of 31 lb. may be at least 5% too high.

4. The relationship between the chemical composition of herbage as cut for sampling and the probable composition of the herbage as eaten by the grazing animal is discussed. Correction curves are given to convert the protein and fibre contents of herbage as cut in these experiments to values corresponding to those in the herbage as eaten.

5. An attempt has been made to provide a balance sheet, in terms of D.C.P. and S.E., of animal production against nutrient intake. A deficiency of both protein and energy existed during the first spring period in both 1949 and 1950 (according to presentday standards), and although the protein balance became positive later in the season, the energy provided by the grass eaten was still barely adequate.

6. Mineral balances calculated for the closefolded cows showed deficiencies of both calcium and phosphorus during the period of high milk yield, with the balances becoming positive later in the grazing season.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1952

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

Freus, A. M. & Bosch, S. (1950). Netherl. Milk Dairy J. 4, 288.Google Scholar
Holmes, W., Waite, R., Fergusson, D. L. & Campbell, Jean I. (1950). J. Agric. Sci. 40, 381.CrossRefGoogle Scholar
Holmes, W., Waite, R., Fergusson, D. L. & MacLusky, D. S. (1952). J. Agric. Sci. 42, 304.CrossRefGoogle Scholar
Linehan, P. A. & Lowe, J. (1946). J. Brit. Grassl. Soc. 1, 7.CrossRefGoogle Scholar
Linehan, P. A., Lowe, J. & Stewart, R. H. (1947). J. Brit. Grassl. Soc. 2, 145.CrossRefGoogle Scholar
Mackintosh, J. (1938). Bull. Minist. Agric. no. 42.Google Scholar
Mitchell, H. H. (1942). J. Anim. Sci. 1, 159.CrossRefGoogle Scholar
New Zealand Dept. Agric., Animal Res. Div., Ann. Rep. 19481949.Google Scholar
Reid, J. T., Woolfolk, P. G., Richards, C. R., Kaufmann, R. W., Loosli, J. K., Turk, K. L., Miller, J. I. & Blaser, R. E. (1950). J. Dairy Sci. 33, 60.CrossRefGoogle Scholar
Wagner, R. E., Hein, M. A., Shepherd, J. B. & Ely, R. E. (1950). Agron. J. 42, 487.CrossRefGoogle Scholar
Waite, R., Holmes, W., Campbell, Jean I. & Fergusson, D. L. (1950). J. Agric. Sci. 40, 392.CrossRefGoogle Scholar
Waite, R., MacDonald, W. B. & Holmes, W. (1951). J. Agric. Sci. 41, 165.CrossRefGoogle Scholar
Woodman, H. E. (1948). Bull. Minist. Agric. no. 48.Google Scholar