Hostname: page-component-cd9895bd7-gxg78 Total loading time: 0 Render date: 2024-12-25T06:08:59.546Z Has data issue: false hasContentIssue false
  • English
  • Français

A study of the development of the characters of the fleece during growth in the different regions of the body

Published online by Cambridge University Press:  27 March 2009

L. F. Thomasset
L. F. Thomasset
Affiliation:
Animal Nutrition Institute, School of Agriculture, University of Cambridge, and Instituto de Investigación Animal y Lanera, Molles, Uruguay
Get access Rights & Permissions [Opens in a new window]

Extract

1. A study has been made of the relative development of some regions in the fleece of twin lambs of a Suffolk ♂ × Suffolk (Border Leicester-Cheviot) ♀ cross during growth. The different regions develop in the following order: shoulder → leg → belly → tail. It is concluded that an improved animal is one in which the latest developing part of the fleece has the least possible number of undesirable fibres at the earliest possible age. The breeds of sheep begin their wool improvement by changes in the earliest developing regions (shoulder) and finish it in the latest (tail).

2. The properties of the fleece studied were the colour of the fibres, the medullated fibres, the fineness of the fibres, and uniformity of fibre size. In general a relationship is found between the stage and rapidity of development of the area, and the properties of the fibre. The intensity of the colour is stronger during the early active stages of development. There is a tendency to lose some kinds of coloured fibres, and to diminish the intensity of the colour in others as the development of each region in which the fibres grow proceeds.

The medullated fibres appeared in greatest quantities in the later developing regions, except the belly which presents few medullated fibres.

The staple is much finer at the first month of growth than in the later stages. Frequency curves of fibre size are of more value than average fibre size in estimating the value of the fleece.

3. It is suggested that the examination of the fleece of the lamb will give some idea of its genetic constitution and will reveal defects which would be concealed in the adult. Such a “phaeno-genetic” selection can be made best in a “late developing” area of the body such as the tail of the lamb at one month old.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 28 , Issue 4 , October 1938 , pp. 523 - 540
Copyright
Copyright © Cambridge University Press 1938

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

Duerden, J. E. & Ritchie, M. I. F. (1924). S. Afr. J. Sci. 21, 480.Google Scholar
Galpin, N. (1935). J. agric. Sci. 25, 344.CrossRefGoogle Scholar
Iljin, N. A. (1926). Trans. Lab. exp. Biol. Zoopark, Moscow, 1, 130–81.Google Scholar
Iljin, N. A. & Iljtn, V. N. (1930). J. Hered. 21, 309.Google Scholar
Iljin, N. A. (1936). J. Genet. 33, 305.CrossRefGoogle Scholar
Thomasset, L. F. (1936). Ann. Gembl. 42, 273.Google Scholar
Thomasset, L. F. (1937). Ann. Gembl. 43, 241.Google Scholar
Wildman, A. B. (1932). Proc. zool. Soc. Lond. 8 July.Google Scholar