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Relation between body size and muscle fibre diameter in the newborn lamb

Published online by Cambridge University Press:  27 March 2009

D. M. Joubert
Affiliation:
School of Agriculture, University of Cambridge and Department of Animal Husbandry, University of Pretoria

Extract

1. An investigation is reported in which the relationship was examined between body size and muscle fibre size of nineteen newborn lambs and including twelve males and seven females. Body size was measured in terms of the dead body weight and that of the dressed carcass, while muscle fibre size was estimated on the basis of the mean crossdiameter of 150 fibres per lamb.

2. It was shown that the dressing (or carcass) percentage tends to increase with an increase in body weight, from 42·26% at a body weight of 2000 g. to 49·04% at 7000 g.

3. Of the 2850 cross-diameters recorded, the majority (33·8%) of the fibres measured between 8·0 and 9·6 μ, while individual fibres varied in size from 1·6 to 22·4 μ.

4. Highly significant, positive correlations were shown to exist between both body (r = 0·996) and carcass (r = 0·946) weight, and mean muscle fibre diameter, indicating that differences in size between the lambs may be accounted for largely by corresponding variations in the size of individual muscle fibres.

5. Of the three muscles sampled m. gastrocnemius had the largest mean fibre diameter (10·38μ), followed in decreasing order by m. rectus femoris (9·72 μ) and m. longissimus dorsi (9·09 μ). These inter-muscle differences were significant at the 1% level of probability.

6. Ram lambs had significantly thicker muscle fibres (10·32 μ) than ewe lambs (8·72 μ), but also weighed the heavier and produced heavier dressed carcasses. Some evidence was produced, however, in support of the theory that at comparable weights males possess thinner individual, and therefore a greater number of fibres than females.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1956

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References

REFERENCES

Alpatov, W. W. (1930). Biol. Bull., Woods Hole, 58, 85.CrossRefGoogle Scholar
Badreldin, A. L. (1951). Agric. Bull. Fouad I Univ. Cairo, no. 3.Google Scholar
Bonsma, F. N. (1939). Publ. Univ. Pretoria Agric. no. 48.Google Scholar
Conklin, E. G. (1912). J. Morph. 23, 159.CrossRefGoogle Scholar
Donald, H. P. & McLean, J. W. (1935). N.Z. J. Sci. Tech. A, 17, 497.Google Scholar
Hammond, J. (1932). Growth and Development of Mutton Qualities in the Sheep, London: Oliver and Boyd.Google Scholar
Hammond, J. & Appleton, A. B. (1932). Study of the Leg of Mutton. Pt. v, Growth and Development of Mutton Qualities in the Sheep. London: Oliver and Boyd.Google Scholar
Hansson, N. (1927). Medd. Cent Anst. Försöksv. Jordbr., Stockh., no. 314.Google Scholar
Illing, G. (1905). Anat. Anz. 26 (quoted by Kaufman, 1924).Google Scholar
Joubert, D. M. (1956 a). J. Agric. Sci. 47, 59.CrossRefGoogle Scholar
Joubert, D. M. (1956 b). J. Agric. Sci. (in the Press).Google Scholar
Kaufman, L. (1924). Bull. int. Acad. Cracovie (Acad. pol. Sci.), B, 281.Google Scholar
Mehner, A. (1938). Z. Züchl. B, 40, 1.Google Scholar
Murray, J. A. (1921). J. Agric. Sci. 11, 258.CrossRefGoogle Scholar
Palsson, H. & Verges, J. B. (1952). J. Agric. Sci. 42, 1.CrossRefGoogle Scholar
Phillips, R. W. & Dawson, W. M. (1937). Proc. Amer. Soc. Anim. Prod. p. 296.Google Scholar
Rabl, C. (1899). Z. wiss. Zool. 67 (quoted by Thompson, 1942).Google Scholar
Rohrbacher, H. (1927). Inaug. Diss., Karlsruhe.Google Scholar
Starke, J. S., Smith, J. B. & Joubert, D. M. (1956). Fmg S. Afr. (in the Press).Google Scholar
Thompson, D. W. (1942). On Growth and Form, 2nd ed.Cambridge University Press.Google Scholar
Young, T. (1845). Natural Philosophy, p. 466 (quoted by Thompson, 1942).Google Scholar