Hostname: page-component-84b7d79bbc-2l2gl Total loading time: 0 Render date: 2024-07-25T14:31:36.514Z Has data issue: false hasContentIssue false
  • English
  • Français

Some comments on the shape of the gain–stocking rate curve

Published online by Cambridge University Press:  27 March 2009

J. Connolly
J. Connolly
Affiliation:
Statistics Department, An Foras Taluntais (The Agricultural Institute), 19, Sandymount Avenue, Dublin 4
Get access Rights & Permissions [Opens in a new window]

Summary

In this paper the method proposed by Jones & Sandland (1974) for testing the linearity of the animal gain–stocking rate relationship is examined. It is shown that the method cannot be used to establish such linearity. An examination of the biases in estimation of optimum stocking rate and gain per animal and per unit area at the optimum stocking rate arising out of assuming linearity where the true relationship was quadratic led to the following conclusions. Quite large biases can arise. Selection of stocking rates straddling the true optimum reduces these biases. If experimental stocking rates are lower than the true optimum stocking rate the optimum stocking rate is overestimated and the animal gain at optimum is underestimated and vice versa if the experimental stocking rates exceed the true optimum rate.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 86 , Issue 1 , February 1976 , pp. 103 - 109
Copyright
Copyright © Cambridge University Press 1976

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

Conniffe, D., Browne, D. & Walshe, M. J. (1970). Experimental design for grazing trials. Journal of Agricultural Science, Cambridge 74, 339–42.CrossRefGoogle Scholar
Conniffe, D. (1972). The design and analysis of grazing experiments. Ph.D. thesis, University of Dublin.Google Scholar
Cowlishaw, S. J. (1969). The carrying capacity of pastures. Journal of the British Grassland Society 24, 207–14.CrossRefGoogle Scholar
Harlan, J. R. (1958). Generalised curves for gain per head and gain per acre in rates of grazing studies. Journal of Range Management 11, 140–7.CrossRefGoogle Scholar
Jones, R. J. & Sandland, R. L. (1974). The relation between animal gain and stocking rate. Journal of Agricultural Science, Cambridge 83, 335–42.CrossRefGoogle 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