Hostname: page-component-586b7cd67f-t8hqh Total loading time: 0 Render date: 2024-11-26T11:34:08.166Z Has data issue: false hasContentIssue false
  • English
  • Français

Genetical studies on growth and form in the fowl 1. Phenotypic variation in the relative growth pattern of shank length and body-weight

Published online by Cambridge University Press:  14 April 2009

A. G. Cock
A. G. Cock
Affiliation:
Agricultural Research Council Poultry Research Centre, King's Buildings, Edinburgh 9
Rights & Permissions [Opens in a new window]

Extract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Body-weight and shank length from 2 weeks of age to adult (and from 8 weeks onwards, shank width) have been measured on 154 fowls all hatched on the same date, belonging to two F1 breed crosses: White Leghorn × Rhode Island Red (L × R) and Indian Game × Light Sussex (G × S). After logarithmic transformation the data have first been analysed cross-sectionally (analysis of the age-means for each sex and cross). A longitudinal analysis (fitting a regression line to the data of each individual) has then been made of the approximately linear portions of the curves. The following conclusions are drawn.

(1) Growth in shank length relative to body-weight between 2 and 10 weeks conforms closely to simple allometry. The coefficient of ontogenetic allometry (heter-auxesis), k, is approximately 0·4, being 0·02 higher in L × R than in G × S and 0·05 higher in males than in females. In females k declines (eventually to zero) after 10 weeks; the decline occurs about 4 weeks later in males. For shank width relative to body-weight k is about 0·25.

(2) At a given body-weight males have longer and thicker shanks than females; L × R have longer but thinner shanks than G × S.

(3) Within sexes and crosses there is highly significant individual variation in k, but the allometry lines do not pass, within the limits of error, through any single point. This implies that variation in relative shank length is complex in its ontogenetic origin.

(4) There is no appreciable correlation within sexes and crosses between shank width and shank length at a given body-weight; this implies (as does (2)) that variation is also complex anatomically.

(5) Differences in shape and rate-of-change of shape contribute only a small part of the total variation within sexes and crosses; most is due to differences in general size and general growth rate.

(6) Shank width at a given body-weight is positively correlated with body-weight at a given age (r = + 0·36 within sexes and crosses). This agrees with the finding that the coefficient of static allometry (allomorphosis) for shank width is much higher than the ontogenetic coefficient. For shank length the ontogenetic and static coefficients are approximately the same.

Type
Research Article
Information
Genetics Research , Volume 4 , Issue 2 , July 1963 , pp. 167 - 192
Copyright
Copyright © Cambridge University Press 1963

References

REFERENCES

Clark, W. E. le Gros & Medawar, P. B. (eds.) (1945). Essays on Growth and Form. Oxford Univ. Press.Google Scholar
Cock, A. G. (1962). Genetical Studies on Growth and Form in the Fowl. Ph.D. Thesis, Edinburgh.Google Scholar
Gilbreath, J. C. & Upp, C. W. (1952). The growth pattern of the Cornish fowl. Bull. La agric. Exp. Sta. 464.Google Scholar
Jaap, R. G. (1943). Body form in growing chickens. II. Growth of Cornish bantams. Poult. Sci. 22, 11–19.CrossRefGoogle Scholar
Kermack, K. A. & Haldane, J. B. S. (1950). Organic correlation and allometry. Biometrika, 37, 30–41.CrossRefGoogle ScholarPubMed
Kidwell, J. F., Gregory, P. W. & Guilbert, H. R. (1952). A genetic investigation of allometric growth in Hereford cattle. Genetics, 37, 158–174.CrossRefGoogle ScholarPubMed
Kidwell, J. F. & Williams, E. (1956). Allometric growth of the Dark Cornish fowl. Growth, 20, 275–293.Google Scholar
Landauer, W. (1934). Studies on the creeper fowl. VI. Skeletal growth of creeper chickens, with especial reference to growth of the long bones. Bull. Storrs agric. Exp. Sta. 193.Google Scholar
Lerner, I. M. (1936). Heterogony in the axial skeleton of the creeper fowl. Amer. Nat. 70, 595–598.Google Scholar
Lerner, I. M. (1937). Relative growth and hereditary size limitation in the domestic fowl. Hilgardia, 10, 511–560.Google Scholar
Lerner, I. M. & Burmester, B. R. (1937). A measuring device for shank length of living birds. Poult. Sci. 16, 211–212.Google Scholar
Lerner, I. M. (1938). Growth ratio of the fowl's tarsometatarsus. Growth, 2, 135–144.Google Scholar
Medawar, P. B. (1945). Size, shape and age. In: Clark & Medawar (1945).Google Scholar
Reeve, E. C. R. (1940). Relative growth in the snout of anteaters. Proc. zool. Soc. Lond. A110, 47–80.CrossRefGoogle Scholar
Reeve, E. C. R. & Huxley, J. S. (1945). Some problems in the study of allometric growth. In: Clark & Medawar (1945), 125–156.Google Scholar
Richards, O. W. & Kavanagh, A. J. (1945). The analysis of growing form. In: Clark & Medawar (1945), 188–230.Google Scholar
Tanner, J. M. (1951). Some notes on the reporting of growth data. Human Biol. 23, 93–159.Google ScholarPubMed
Tanner, J. M. (1962). Growth at Adolescence. 2nd edn.Oxford: Blackwell.Google Scholar
Teissier, G. (1948). La relation d'allometrie, sa signification statistique et biologique. Biometrics, 4, 14–52.CrossRefGoogle Scholar
Kelley, T. L. (1947). Fundamentals of Statistics. Harvard Univ. Press.Google Scholar
Williams, E. J. (1953). Tests of significance for concurrent regression lines. Biometrika, 40, 297–305.Google Scholar