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The association of food conversion ratio, age at slaughter and carcass quality in pigs fed ad libitum

Published online by Cambridge University Press:  02 September 2010

J. B. Owen  and
J. R. Morton
J. B. Owen
Affiliation:
School of Agriculture, University of Cambridge
J. R. Morton
Affiliation:
School of Agriculture, University of Cambridge
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Summary

Data from a boar progeny testing scheme based on ad libitum feeding were analysed to test the hypothesis that the resultant correlations of food conversion ratio with related factors would differ from those found under conditions of restricted feeding.

The results support the hypothesis, showing that the primarily genetic correlations derived from boar effects for growth and conversion ratio, are lower than those reported elsewhere for restricted feeding. It was also shown that these primarily genetic correlations could vary between breeds, the leanness associated with rapid growth in Wessex not being found in Large White, and that the correlations due to residual effects containing a greater environmental component varied widely from test to test.

It is concluded that the parameters used in the design of a genetic improvement scheme should be derived specifically for each breed and feeding system. However, if the marked variability in phenotypic correlations noted here is generally applicable, this could present a difficult problem in the design of pig improvement programmes with multiple objectives.

Type
Research Article
Information
Animal Production , Volume 11 , Issue 3 , August 1969 , pp. 317 - 324
Copyright
Copyright © British Society of Animal Science 1969

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References

REFERENCES

Bartlett, M. S. 1934. The problem in statistics of testing several variances. Proc. Camb. phil. Soc. 30: 164–169.CrossRefGoogle Scholar
Duncan, D. B. 1955. Multiple range and multiple F tests. Biometrics 11: 1–42.CrossRefGoogle Scholar
Duncan, D. B. 1957. Multiple range tests for correlated and heteroscedastic means. Biometrics 13: 164–176.CrossRefGoogle Scholar
Falconer, D. S. 1960. Introduction to Quantitative Genetics. Oliver and Boyd, Edinburgh and London.Google Scholar
Fisher, R. A. 1921. On the ‘probable error’ of a coefficient of correlation deduced from a small sample. Metron Rovigo 1 (4): 3–32.Google Scholar
Harter, H. L. 1960. Critical values for Duncan's new multiple range test. Biometrics 16: 671–685.CrossRefGoogle Scholar
Jonsson, P. 1965. Analysis of characters in the Danish Landrace pig with a historical introduction. Beretn. forsøgslab., København, No. 350: 1–490.Google Scholar
Owen, J. B. and Ridgman, W. J. 1957. The effect of dietary energy content on the voluntary intake of pigs. Anim. Prod. 9: 107–113.Google Scholar
Owen, J. B. and Ridgman, W. J. 1968. Further studies of the effect of dietary energy content on the voluntary intake of pigs. Anim. Prod. 10: 85–91.CrossRefGoogle Scholar
Smith, C., King, J. W. B. and Gilbert, N. 1962. Genetic parameters of British Large White bacon pigs. Anim. Prod. 4: 128–143.Google Scholar
Smith, C. and Ross, G. J. S. 1965. Genetic parameters of British Landrace bacon pigs. Anim. Prod. 7: 291–301.Google Scholar
Sutherland, T. M. 1965. The correlation between feed efficiency and rate of gain, a ratio and its denominator. Biometrics 21: 739–749.CrossRefGoogle Scholar
Taylor, St C. S. and Young, G. B. 1966. Variation in growth and efficiency in twin cattle with live weight and food intake controlled. J. agric. Sci., Camb. 66: 67–85.CrossRefGoogle Scholar
Turner, H. N. 1959. Ratios as criteria for selection in animal or plant breeding, with particular reference to efficiency of food conversion in sheep. Aust. J. agric. Res. 10: 565–580.CrossRefGoogle Scholar
Wall's Reports 1962–67. Wall's progeny testing scheme reports. Wall's progeny testing station, Tring.Google Scholar