Hostname: page-component-8448b6f56d-cfpbc Total loading time: 0 Render date: 2024-04-18T10:01:01.263Z Has data issue: false hasContentIssue false
  • English
  • Français

Responses to supplements by weaned lambs when grazing mature pasture or eating hay cut from the same pasture

Published online by Cambridge University Press:  27 March 2009

M. Freer ,
H. Dove ,
A. Axelsen  and
J. R. Donnelly
M. Freer
Affiliation:
CSIRO Division of Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia
H. Dove
Affiliation:
CSIRO Division of Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia
A. Axelsen
Affiliation:
CSIRO Division of Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia
J. R. Donnelly
Affiliation:
CSIRO Division of Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia
Get access Rights & Permissions [Opens in a new window]

Summary

Weaned cross-bred lambs either grazed mature pasture or were confined to yards where they were offered material cut from ungrazed areas of the same pasture. A 1:2 mixture (on an air-dry basis) of sunflower meal and oat grain was offered for 81 days at 0, 200, 400 or 600 g/head or ad libitum. Individual estimates of intake of pasture and supplement by grazing sheep at four levels of supplementation were made on four adjacent plots.

Weight gain increased from –30 to 178 g/day in the grazing animals as supplement intake increased up to 1030 g D.M./day and from –25 to 142 g/day in the yarded animals as supplement intake increased to 1076 g D.M./day. Growth of greasy wool increased from 4·5 to 11·7 g/day for grazing animals and from 4·5 to 10·2 g/day for those kept in yards.

At levels of supplement intake below 400 g D.M./day, the intake of grazed pasture increased by up to 58% compared with unsupplemented animals. However, when the intake of supplement was increased to about 650 g D.M./day, pasture intake fell, with an estimated substitution rate of 1·1 g D.M. pasture per g D.M. supplement. At all levels of supplementation, the intake of hay by the yarded lambs was less than half the intake of herbage in the field. However, at levels of supplement intake between 300 and 500 g D.M./day, the substitution rate was similar to that measured in the grazing animals, suggesting that this is an attribute of roughage quality, rather than differential eating behaviour between grazing and yarded animals.

The wastage, w (g D.M./day), of supplement was linearly related to the amount offered, s (g D.M./day), by the equation

w = 0·263s − 38·8; R2 = 0·89

Variability in supplement intake between individual grazing lambs was not affected by the level of supplementation but the coefficient of variation of supplement intake was considerably greater than that of the intake of unsupplemented pasture. Variability in the intake of pasture increased with the level of supplementation but variability in the total intake of food was similar at each level of supplement, indicating some degree of individual compensation in the intake of the two components.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 110 , Issue 3 , June 1988 , pp. 661 - 667
Copyright
Copyright © Cambridge University Press 1988

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

Agricultural Research Council (1980). The Nutrient Requirements of Ruminant Livestock. Farnham Royal: Commonwealth Agricultural Bureaux.Google Scholar
Allden, W. G. (1981). Energy and protein supplements for grazing livestock. In Grazing Animals (ed. Morley, F. H. W.), World Animal Science Bl, pp. 289–307. Amsterdam: Elsevier.Google Scholar
Corbett, J. L., Freer, M. & Graham, N. McC. (1987). A generalised equation to predict the varying maintenance metabolism of sheep and cattle. In Energy Metabolism of Farm Animals (ed. Moe, P. W., Tyrrell, H. F. and Reynolds, P. J.), EAAP Publication No. 32, pp. 62–65. Totowa, N. J.: Rowman & Littlefield.Google Scholar
Corbett, J. L., Freer, M. & Nolan, J. V. (1987). Present situation of the modern protein systems: Australia. In Feed Evaluation and Protein Requirement Systems for Ruminants (ed. Jarrige, R. and Alderman, G.), pp. 69–79. Luxembourg: Office for Official Publications of the European Communities.Google Scholar
Dove, H. (1984). Gypsum labelled with tritiated water as a marker for estimating supplement intake by individual sheep fed in groups. Australian Journal of Experimental Agriculture and Animal Husbandry 24, 484–493.CrossRefGoogle Scholar
Dove, H. & Freer, M. (1986). The use of tritiated gypsum for estimating individual intakes of pelleted or unpelleted supplement by lambs fed individually or in groups. Australian Journal of Experimental Agriculture 26, 19–22.CrossRefGoogle Scholar
Foot, J. Z., McIntyre, J. S. & Heazlewood, P. G. (1983). Supplements for Merino weaner sheep grazing mature pastures in summer and autumn. Australian Journal of Experimental Agriculture and Animal Husbandry 23, 374–382.CrossRefGoogle Scholar
Freer, M., Dove, H., Axelsen, A., Donnelly, J. R. & McKinney, G. T. (1985). Responses to supplements by weaned lambs grazing mature pasture or eating hay in yards. Australian Journal of Experimental Agriculture 25, 289–297.CrossRefGoogle Scholar
Goering, H. K. & Van Soest, P. J. (1970). Forage Fiber Analyses, Handbook No. 379. Washington: U.S. Department of Agriculture.Google Scholar
Heaney, D. P., Pritchard, G. I. & Pigden, W. J. (1968). Variability in ad libitum forage intakes by sheep. Journal of Animal Science 27, 159–164.CrossRefGoogle ScholarPubMed
Lobato, J. F. P., Pearce, G. R. & Tribe, D. E. (1980). Measurement of the variability in intake by sheep of oat grain, hay and molasses-urea blocks using chromic oxide as a marker. Australian Journal of Experimental Agriculture and Animal Husbandry 20, 413–416.CrossRefGoogle Scholar
Ministry of Agriculture, Fisheries and Food (1975). Energy Allowances and Feeding Systems for Ruminants. Technical Bulletin 33. London: Ministry of Agriculture, Fisheries and Food.Google Scholar
Morley, F. H. W., Bennett, D. & Clark, K. W. (1964). The estimation of pasture yield in large grazing experiments. CSIRO Australia, Division of Plant Industry Field Station Record 4, 43–47.Google Scholar
Williams, C. H., David, D. J. & Iismaa, O. (1962). The determination of chromic oxide in faeces samples by atomic absorption spectrophotometry. Journal of Agricultural Science, Cambridge 59, 381–385.CrossRefGoogle Scholar