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XXIII.—Sexual Maturity in Brown Leghorns. The Interactions of Genotype and Environment*

Published online by Cambridge University Press:  11 June 2012

Robert Osborne
Robert Osborne
Affiliation:
Poultry Research Centre, Edinburgh.
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Synopsis

In each of three years studied, the spring hatching period for a flock of Brown Leghorns has been divided into two sub-periods such that a number of matings are represented by offspring in each sub-period. Analysis of variance of age at sexual maturity reveals statistical interaction between family means and hatching period, the ranking of family means varying with date of hatch. Consequences of this are discussed with reference to current methods of correcting age at maturity for date of hatch, the method of multiple shift progeny testing, and the general question of improvement by selection in the presence of non-additive combinations of genetic and environmental effects.

Measurements of comb growth in maturing pullets reveal a seasonal retardation, possibly reflecting retardation in sexual maturity, and in line with environmental effects causing cessation of production in older birds. It is suggested that rapid changes in day length during September and October may play a large part in determining the retardtions and interactions displayed, and that measurements of comb growth may be of value in recognising consistently superior genotypes for age at sexual maturity.

Type
Research Article
Information
Proceedings of the Royal Society of Edinburgh, Section B: Biological Sciences , Volume 64 , Issue 4 , 1952 , pp. 445 - 455
Copyright
Copyright © Royal Society of Edinburgh 1952

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Footnotes

*

This paper was assisted in publication by a grant from the Carnegie Trust for the Universities of Scotland.

References

References to Literature

Bonnier, G., and Hansson, A., 1948. “Identical twin genetics in cattle,” Heredity, II, 1–27.CrossRefGoogle Scholar
Byerly, T. C., and Knox, C. W., 1946. “Date of hatch and day length affect age at first egg,” Poult. Sci., XXV, 587–592.CrossRefGoogle Scholar
Fisher, R. A., and Yates, F., 1949. Statistical Tables, 3rd ed., Oliver & Boyd, Edinburgh.Google Scholar
Greenwood, A. W., and Blyth, J. S. S., 1946. “Sexual maturity in Brown Leghorns,” Poult. Sci., XXV, 597–605.CrossRefGoogle Scholar
Haldane, J. B. S., 1946. “The interaction of nature and nurture,” Ann. Eugen. Camb., XIII, 197–205.CrossRefGoogle Scholar
Hogben, L., 1933. Nature and Nurture, Williams & Norgate, London.Google Scholar
Hutt, F. B., 1949. Genetics of the Fowl, McGraw-Hill, New York.Google Scholar
Lerner, I. M., 1950. Population Genetics and Animal Improvement, Cambridge University Press.Google Scholar
Lerner, I. M., and Taylor, L. W., 1940. “The use of the median as a measure of sexual maturity in White Leghorn pullets,” Poult. Sci., XIX, 216–218.CrossRefGoogle Scholar
Lerner, I. M., 1941. “Factors affecting the duration of the first annual rest,” Poult. Sci., XX, 490–495.CrossRefGoogle Scholar
Snedecor, G. W., 1946. Statistical Methods, 4th ed., Iowa State College Press.Google ScholarPubMed
Upp, C. W., and Thompson, R. B., 1927. “Influence of time of hatch on hatchability of the eggs, rate of growth of the chicks, and characteristics of the adult female,” Bull. Oklahoma Agric. Exp. Stn., CLXVII, 1–36.Google Scholar