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Studies on reproduction in prolific ewes. 3. The development in size and shape of the foetal skeleton

Published online by Cambridge University Press:  27 March 2009

I. McDonald
Affiliation:
The Rowett Research Institute, Buckburn, Aberdeen, AB2 9SB
G. Wenham
Affiliation:
The Rowett Research Institute, Buckburn, Aberdeen, AB2 9SB
J. J. Robinson
Affiliation:
The Rowett Research Institute, Buckburn, Aberdeen, AB2 9SB

Summary

Measurements of 21 bone lengths and breadths were made on radiographs of 215 foetuses of known gestational ages ranging from 50 to 145 days obtained from 80 Finnish Landrace x Dorset Horn ewes. Number of foetuses per ewe varied from 1 to 5, but the main statistical analyses were based on the 22 sets of twins, 34 of triplets and 11 of quadruplets. Equations were fitted to relate each of the linear measurements to foetal weight alone, to foetal age alone, to foetal age together with number of foetuses, and to foetal age together with foetal weight. It was found that there were significant differences between the twins, triplets, and quadruplets in the lengths their bones attained at any specified weight or at any specified age but not when both weight and age were fixed. The relationships to weight and age jointly were significantly closer than to either of them alone even after allowing for number of foetuses. The mathematical model that fitted best was a modified Gompertz equation of the form

where ywas the measured length, w was the number of days prior to expected parturition, w was foetal weight, wu was an estimate of the expected foetal weight at time u, and P, Q, R and Dwere fitted constants.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1977

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References

Boyd, E. (1935). The Growth of the Surface Area of the Human Body, pp. 1145. Milford: University of Minnesota Press.Google Scholar
Everitt, G. C. (1968). Prenatal development of uniparous animals, with particular reference to the influence of maternal nutrition in sheep. In Qrowth and Development of Mammals(ed. Lodge, G. A. and Lamming, G. E.), pp. 131–57. London: Butterworth.Google Scholar
Hight, G. K. & Jury, K. E. (1969). Lamb mortality in hill country flocks. Proceedings of the New Zealand Society of Animal Production 29, 219–32.Google Scholar
Joubert, D. M. (1956). A study of prenatal growth and development in the sheep. Journal of Agricultural Science, Cambridge 47, 382428.CrossRefGoogle Scholar
Laird, A. K. (1966). Dynamics of embryonio growth. Growth 30, 263–75.Google ScholarPubMed
Laird, A. K., Barton, A. D. & Tyler, S. A. (1968).Growth and time: An interpretation of allometry. Growth 32, 347–54.Google ScholarPubMed
Laird, A. K., Tyler, S. A. & Barton, A. D. (1965). Dynamics of normal growth. Growth 29, 233–48.Google ScholarPubMed
Lascelles, A. K. (1959). The time of appearance of ossification centres in the peppin-type merino. Australian Journal of Zoology 7, 7986.Google Scholar
Leitch, I. (1976). Change in shape of the human body. Progress in Food and Nutrition Science 2, 99141.Google ScholarPubMed
Medawar, P. B. (1945). Size, shape and age. In Essays on Growth and Form (ed. Clark, W. E. Le Gross and Medawar, P. B.), pp. 157–87. Oxford: Clarendon Press.Google Scholar
Reeve, E. C. R. & Huxley, J. S. (1945). Some problems in the study of allometrio growth. In Essays on Growth and Form (ed. Clark, W. E. Le Gross and Medawar, P. B.), pp. 121–56. Oxford: Clarendon Press.Google Scholar
Richardson, C., Hebert, C. N. & Terlecki, S. (1976). Estimation of the developmental age of the ovine foetus and lamb. Veterinary Record 99, 22–6.CrossRefGoogle ScholarPubMed
Robinson, J. J., McDonald, I., Fraser, C. & Crofts, R. M. J. (1977). Studies on reproduction in prolific owes. 1. Growth of the products of conception. Journal of Agricultural Science, Cambridge. 88, 539–52.Google Scholar
Stephenson, S. K. (1962). Pre-natal growth in Romney x Southdown cross and Australian Merino sheep. II. Carcass conformation in the two breed groups. Australian Journal of Agricultural Research 13, 733–67.CrossRefGoogle Scholar
Stephenson, S. K. & Lambourne, L. J. (1960). Pre-natal growth in Romney x Southdown cross and Australian Merino sheep. I. Introduction and external growth patterns in the two breeds. Australian Journal of Agricultural Research 11, 1044–63.CrossRefGoogle Scholar
Wallace, L. R. (1948). The growth of lambs before and after birth in relation to the level of nutrition. Journal of Agricultural Science, Cambridge 38, 243302, 367–401.CrossRefGoogle Scholar
Wenham, G. (1977). Studies on reproduction in prolific ewes. 2. A radiographic study of the primary and secondary ossification centres in the foetus. Journal of Agricultural Science, Cambridge. 88, 553–66.CrossRefGoogle Scholar
Wenham, G., Fowler, V. R. & McDonald, I. (1973). A radiographic study of skeletal growth and development in the pig. Temporal pattern of growth. Journal of Agricultural Science, Cambridge 80, 125–33.CrossRefGoogle Scholar
Wenham, G., McDonald, I. & Elsley, F. W. H. (1969). A radiographic study of the development of the skeleton of the foetal pig. Journal of Agricultural Science, Cambridge 72, 123–30.Google Scholar