Hostname: page-component-745bb68f8f-kw2vx Total loading time: 0 Render date: 2025-01-27T22:54:28.886Z Has data issue: false hasContentIssue false
  • English
  • Français

The relation between animal gain and stocking rate: Derivation of the relation from the results of grazing trials

Published online by Cambridge University Press:  27 March 2009

R. J. Jones  and
R. L. Sandland
Get access Rights & Permissions [Opens in a new window]

Summary

Several models have been proposed in the literature relating gain per animal (Ya) and stocking rate (x) from grazing experiments. Results from an experiment in which tropical pasture species were grazed continuously by beef cattle at a number of stocking rates (Jones, 1974) were used to examine this relation. A simple linear model of the form y = a − bxfitted the data well. Production per hectare (Yh) was related to stocking rate by yh = ax − bx2.

Stocking rate for maximum gain per hectare (the optimum stocking rate) on each pasture could be calculated from the linear regression by a/2b.

Data from a number of stocking rate experiments in tropical and temperate environments were examined to see if this relation held for a wider range of stocking rates and pasture types. Results were expressed on a common basis by calculating the optimum stocking rate and relating ratios of gain to ratios of stocking rate relative to that at the optimum.

For gain per animal, the overall relation obtained: Ya = l·999–0·999x (r = –0·992; P < 0·001; n = 114) did not differ significantly from the expected linear relation: y = 2−x. Linearity was established over the range 0·18–2·0 times the optimum stocking rate. At rates greater than twice the optimum, animal gain was negative. When expressed as gain per hectare (Yh) the quadratic equation Yh = 2x − x2 gave a good fit to the data over this range.

It is suggested that, since the relation between production per animal and stocking rate (animals/ha) remains linear over a wide range of stocking rates, two rates of stocking (with replication) may be adequate for grazing experiments and these would not have to span the optimum stocking rate in order to predict gain at the optimum stocking rate.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 83 , Issue 2 , October 1974 , pp. 335 - 342
Copyright
Copyright © Cambridge University Press 1974

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

Alder, F. E., Cowlishaw, S. J., Newton, J. E. & Chambers, D. T. (1967). The effect of level of nitrogen fertilizer on beef production from grazed perennial ryegrass white clover pastures. 2. Animal production from irrigated swards. Journal of the British Grassland Society 22, 230–8.CrossRefGoogle Scholar
Bennett, D., Morley, F. H. W., Clark, K. W. & Dudzinski, M. L. (1970). The effect of grazing cattle and sheep together. Australian Journal of Experimental Agriculture and Animal Husbandry 10, 694–709.CrossRefGoogle Scholar
Connifee, D., Browne, D. & Walshe, M. J. (1970). Experimental design for grazing trials. Journal of Agricultural Science, Cambridge 74, 339–42.CrossRefGoogle Scholar
Conniffe, D., Browne, D. & Walshe, M. J. (1972). An example of a method of statistical analysis of a grazing experiment. Journal of Agricultural Science, Cambridge 79, 165–7.CrossRefGoogle Scholar
Cowlishaw, S. J. (1969). The carrying capacity of pastures. Journal of the British Grassland Society 24, 207–14.CrossRefGoogle Scholar
Evans, T. R. & Bryan, W. W. (1973). Effects of soils, fertilizers and stocking rate on pastures and beef production on the Wallum of South-eastern Queensland. 2. Animal response in terms of liveweight change and beef production. Australian Journal of Experimental Agriculture and Animal Husbandry 13 (in the Press).Google Scholar
Harlan, J. R. (1958). Generalized curves for gain per head and gain per acre in rates of grazing studies. Journal of Range Management 11, 140–7.CrossRefGoogle Scholar
Hart, R. H. (1972). Forage yield, stocking rate, and beef gains on pasture. Herbage Abstracts 42, 345–53.Google Scholar
Hull, J. L., Meyer, J. H. & Kromann, R. (1961). Influence of stocking rate on animal and forage production from irrigated pasture. Journal of Animal Science 20, 46–52.CrossRefGoogle Scholar
Hull, J. L., Meyer, J. H., Bonilla, S. E. & Weitkamp, W. (1965). Further studies on the influence of stocking rate on animal and forage production from irrigated pasture. Journal of Animal Science 24, 697–704.CrossRefGoogle ScholarPubMed
Humphreys, L. R. (1972). The interaction of pasture, stocking rate and fertilizer needs. Technical Bulletin No. 7, A.S.P.A.C. Fd 2 Fertilizer Technology Center, Taipei.Google Scholar
Jones, R. J. (1974). The relation of animal and pasture production to stocking rate on legume based and nitrogen fertilized sub-tropical pastures. Proceedings of the Australian Society of Animal Production 10.Google Scholar
Morley, F. H. W. & Spedding, C. R. W. (1968). Agricultural systems and grazing experiments. Herbage Abstracts 38, 279–87.Google Scholar
Mott, G. O. (1960). Grazing pressure and the measurement of pasture production. Proceedings of the 8th International Grassland Congress Reading, pp. 606–11.Google Scholar
Owen, J. B. & Ridgman, W. J. (1968). The design and interpretation of experiments to study animal production from grazed pasture. Journal of Agricultural Science, Cambridge 71, 327–35.CrossRefGoogle Scholar
Peterson, R. G., Lucas, H. L. & Mott, G. O. (1965). Relationship between rate of stocking and per animal and per acre performance on pasture. Agronomy Journal 57, 27–30.CrossRefGoogle Scholar
Riewe, M. E. (1961). Use of the relationship of stocking rate to gain of cattle in an experimental design for grazing trials. Agronomy Journal 53, 309–13.CrossRefGoogle Scholar
Scarisbrick, D. H. (1971). A note on the liveweight change of sheep grazing at three stocking rates and two levels of nitrogenous fertilizer. Journal of the British Grassland Society 26, 183–7.CrossRefGoogle Scholar
Yates, J. J., Edye, L. A., Davies, J. G. & Haydock, K. P. (1964). Animal production from a Sorghum almum pasture in south-east Queensland. Australian Journal of Experimental Agriculture and Animal Husbandry 4, 326–35.CrossRefGoogle Scholar