Hostname: page-component-586b7cd67f-2brh9 Total loading time: 0 Render date: 2024-12-04T19:52:35.086Z Has data issue: false hasContentIssue false
  • English
  • Français

A study of pre-natal growth and development in the sheep

Published online by Cambridge University Press:  27 March 2009

D. M. Joubert
D. M. Joubert
Affiliation:
School of Agriculture, University of Cambridge, and Department of Animal Husbandry, University of Pretoria
Get access Rights & Permissions [Opens in a new window]

Extract

1. The results are presented of an investigation in which the growth and development of forty single male sheep foetuses was examined. The material, obtained from slaughterhouses, included seventeen specimens of known age, while further details of the remainder were lacking. For these reasons, and the fact that the specimens were preserved in 10% formalin prior to dissection, relative, rather than absolute, trends were discussed. This had been achieved by expressing all values as percentages of those obtained from four single male lambs dissected at birth.

2. In order to age the experimental material with the greatest possible accuracy, data were collected from the literature on foetal weights and crownrump lengths of specimens of known age. Mean values were computed and normographs established for the pre-natal period between 18 days and fullterm. By employing the method of least squares, it was not possible to fit single curves to the data; in the case of both weight and crown-rump length the curves had to be divided into five segments in order to establish the relationships with age. Apart from a rather marked change in the rate of growth and development between the 109th and 110th days of gestation, the apparent ‘breaks’ in the curves were not considered important. It would seem that lack of data at certain stages, together with the heterogeneity of the population studied, were greatly responsible for the differential rates of growth and development recorded.

3. The data were inadequate to examine fully the effect of fixation on foetal weight; however, it would appear that whereas specimens weighing less than 200 g. and over 1200 g. lost weight during the course of preservation, foetuses intermediate between the above values gained weight. Since the causes could not be satisfactorily explained, the need for further investigation was emphasized.

4. Of the foetal measurements recorded, head length and, particularly, head width were shown to be earlier maturing than chest circumference and chest depth, while crown-rump length made even greater proportional increases during pre-natal life. In general, the results supported accepted theory that the retardation of rate of development proceeds in an anterior-posterior direction prior to birth.

5. By dissecting the head from the body and weighing each unit separately, it was shown that the head decreases in relative size throughout foetal life. Head:body ratio, however, was found to be unsuitable as a criterion of pre-natal age, since foetuses of equal age may differ appreciably in this respect. It was shown, for example, that a lamb at birth, though above the average in terms of absolute weight, may possess the conformation of a 120-day-old foetus on the basis of head: body ratio.

6. Dissections of the major constituent parts of the foetal body indicated the skinned head to be the earliest maturing, followed in order by the organs (weighed en masse), dressed carcass, total skin and, finally, the skinned feet and tail, which were latest maturing. The order in which these parts grow before birth appeared explicable primarily upon a basis of functional necessity.

7. The skull was shown to develop to a relatively lesser degree during foetal life than the mandibles, while skull measurements indicated the cranial portion to be earlier maturing than the facial. Linear measurements of the various vertebral regions at different stages of development did not yield entirely satisfactory results, but it was evident that the anterior cervical vertebrae are earlier maturing than those of the posterior extremity (caudal vertebrae).

8. Weights of the major units of both thoracic and pelvic limbs indicated the former to be slightly earlier maturing. In contrast to the direction of retardation of growth during post-natal life, in the foetus the gradient followed a proximo-distal direction; scapula and pelvis, for example, being earlier maturing than metacarpus and metatarsus.

9. Linear development of individual bones was shown to be earlier maturing than growth in weight. However, on the basis of length measurements, the course of development proceeded in a similar direction as the trends established in terms of weight, i.e. proximo-distally. Width of pelvis, on the contrary, was shown to be earlier maturing than width of scapula; this was explained in terms, particularly, of earlier developing cartilage in the former bone.

10. In terms of weight, m. longissimus dorsi appeared to be earlier maturing than m. rectus femoris and m. gastrocnemius lateralis; between the latter two muscles no marked difference in rate of growth could be established. The results indicated that these three muscles develop at much the same rate in respect of length and depth during pre-natal life, but m. longissimus dorsi showed relatively less development in width over the same period of time than the other muscles.

11. Of each of the above-mentioned muscles, the cross-diameter of fifty individual fibres was measured by means of an ocular micrometer. Again, a tendency was observed for fibres of m. longissimus dorsi to be earlier maturing than those of m. rectus femoris or m. gastrocnemius.

12. Development of muscle-fibre diameter during foetal life was examined further on the overall mean for the three muscles studied, i.e. the mean of 150 measurements per foetus. The results showed that whereas muscle-fibre diameter increased but slightly (approximately 19·5%) during the first two-thirds of pre-natal life, the increase thereafter was substantial; on the basis of a linear regression, the increase amounted to 113·2% from about 108 days to full-term. The data thus appears to support the accepted view that muscular growth occurs initially by an increase in the number of fibres, and in late foetal life primarily by hypertrophy.

13. The dispersion of muscle-fibre sizes, in absolute measure, was shown to increase with advancing foetal age, the range at birth being considerable. In accord with the results of other investigators, a small proportion of small fibres was observed between approximate ages of 61 and 68 days which, apparently, were not present at either earlier or later stages.

14. Measurement of fibres from muscles situated in different anatomical regions of the body indicated that the muscles of the head were earlier maturing than those of the trunk, and muscles of the thoracic limb earlier maturing than those of the pelvic limb. In agreement with the results obtained on bone weights and measurements, the retardation appeared to proceed in a proximo-distal direction, particularly in the case of the pelvic limb.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 47 , Issue 4 , August 1956 , pp. 382 - 428
Copyright
Copyright © Cambridge University Press 1956

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

Adams, R. D., Denny-Brown, D. & Pearson, C. M. (1953). Diseases of Muscle. London: Cassell.Google Scholar
Arey, L. B. (1946). Developmental Anatomy, 5th ed.Philadelphia: Saunders.Google Scholar
Asai, T. (1914). Arch. mikr. Anat. 86, 8. (Quoted by Arey, 1946.)CrossRefGoogle Scholar
Asdell, S. A. (1929). J. Agric. Sci. 19, 382.CrossRefGoogle Scholar
Asdell, S. A. (1946). Patterns of Mammalian Reproduction. New York: Comstock.Google Scholar
Assheton, B. (1906). Phil. Trans. B, 198, 143.Google Scholar
Barcroft, J. (1945). J. Physiol. 104, 32P.CrossRefGoogle Scholar
Barcroft, J. (1946). Researches on Pre-natal Life, vol. 1. Oxford: Blackwell.Google Scholar
Barcroft, J. & Kennedy, J. A. (1939). J. Physiol. 95, 173.CrossRefGoogle Scholar
Bardeen, C. R. (1900). Johns Hopk. Hosp. Rep. 9, 367. (Quoted by Arey, 1946.)Google Scholar
Benzie, D. (1950). Brit. Vet. J. 106, 231.CrossRefGoogle Scholar
Bhatia, D. (1931). Z. Zellforsch. 12, 430. (Quoted by Needham, 1942.)CrossRefGoogle Scholar
Blaxter, K. L. (1954). Ruminant Nutrition. Ch. 1 of Physiology of Farm Animals, vol. 1. Edited by Hammond, J.. London: Butterworths.Google Scholar
Bonsma, F. N. (1939). Publ. Univ. Pretoria. Agric. no. 48.Google Scholar
Brody, S. (1927). Res. Bull. Mo. Agric. Exp. Sta. no. 97.Google Scholar
Brody, S. (1928). An Analysis of the Course of Growth and Senescence. Ch. II of Growth. New Haven: Yale Univ. Press.Google ScholarPubMed
Brody, S. (1945). Bioenergetics and Growth. New York: Reinhold.Google Scholar
Carlyle, A. (1945). J. Physiol. 104, 34P.Google Scholar
Cloete, J. H. L. (1939). Onderstepoort J. Vet. Sci. 13, 417.Google Scholar
Colin, G. (1888). Traité de Physiologie comparée des Animaux, vol. 2. 3rd ed.Paris: Baillière. (Quoted by Needham, 1931.)Google Scholar
Craig, J. F. (1912). Fleming's Veterinary Obstetrics, 3rd ed.London: Baillière, Tindall and Cox.Google Scholar
Cuajunco, F. (1942). Contr. Embryol. Carneg. Instn, 30, no. 195, p. 127.Google Scholar
Curzon, H. H. & Malan, A. P. (1935). Onderstepoort J. Vet. Sci. 4, 481.Google Scholar
Curzon, H. H. & Quinlan, J. B. (1934). Onderstepoort J. Vet. Sci. 2, 657.Google Scholar
Donald, H. P. & McLean, J. W. (1935). N. Z. J. Sci. Tech. A, 17, 497.Google Scholar
Duerden, J. E. & Ritchie, M. I. F. (1924). S. Afr. J. Sci. 21, 480.Google Scholar
Eaton, O. N. (1952). Growth, 16, 175.Google Scholar
Eliot, T. S., Wiggington, R. C. & Corbin, K. B. (1943). Anat. Rec. 85, 307.Google Scholar
Ellenberger, H. B., Newlander, J. A. & Jones, C. H. (1950). Bull. Vt Agric. Exp. Sta. no. 558.Google Scholar
Galpin, N. (1935). J. Agric. Sci. 25, 344.CrossRefGoogle Scholar
Green, W. W. & Winters, L. M. (1945). Tech. Bull. Minn. Agric. Exp. Sta. no. 169.Google Scholar
Gurlt, O. (1847). Lehrbuch d. vergl. Physiol. d. Haussäugetiere. Berlin. (Quoted by Needham, 1931.)Google Scholar
Hamilton, W. J., Boyd, J. D. & Mossman, H. W. (1945). Human Embryology. Cambridge: Heffer.Google Scholar
Hammond, J. (1932). Growth and Development of Mutton Qualities in the Sheep. Edinburgh: Oliver and Boyd.Google Scholar
Hammond, J. (1936). Festschr. Prof. Duerst, p. 92. Bern.Google Scholar
Hammond, J. (1940). Farm Animals. London: Edward Arnold.Google Scholar
Hammond, J. & Appleton, A. B. (1932). Study of the Leg of Mutton. Pt. V of Growth and Development of Mutton Qualities in the Sheep. Edinburgh: Oliver and Boyd.Google Scholar
Hammond, J. & Marshall, F. H. A. (1952). The life cycle. Ch. 23 of Marshall's Physiology of Reproduction, vol. 2. 3rd ed. Edited by Parkes, A. S.. London: Longmans Green.Google Scholar
Hewer, E. E. (1927). J. Anat., Lond., 62, 72.Google Scholar
Hiner, R. L., Hankins, O. G., Sloane, H. S., Fellers, C. R. & Anderson, E. E. (1953). Food Res. 18, 364.CrossRefGoogle Scholar
Hirzel, R. (1939). Onderstepoort J. Vet. Sci. 12, 379.Google Scholar
Huggett, A. St G. & Widdas, W. F. (1951). J. Physiol. 114, 379.CrossRefGoogle Scholar
Hunter, G. L. (1954). Thesis, University of Cambridge.Google Scholar
Hunter, G. L., Adams, C. E. & Rowson, L. E. (1954). Nature, Lond., 174, 890.CrossRefGoogle Scholar
Iwanaga, I. (1925). Mitt. allg. Path. path. Anat. 2, 395. (Quoted by Arey, 1946.)Google Scholar
Jackson, C. M. (1928). Some aspects of Form and Growth. Ch. iv of Growth. New Haven: Yale Univ. Press.Google Scholar
Joubert, D. M. (1951). Fmg S. Afr. 26, 339.Google Scholar
Joubert, D. M. (1953). S. Afr. Jersey Oaz. 4, no. 7, p. 41.Google Scholar
Joubert, D. M. (1956). J. Agric. Sci. 47, 59.CrossRefGoogle Scholar
Joubert, D. M. & Hammond, J. (1954). Nature, Lond., 174, 647.CrossRefGoogle Scholar
Joubert, P. J. (1936). M.Sc. (Agric). Thesis, University of Pretoria.Google Scholar
Kislovsky, D. A. & Larchin, B. A. (1931). J. Agric. Sci. 21, 659.CrossRefGoogle Scholar
Latimer, H. B. & Aikman, J. M. (1931). Anat. Rec. 48, 1.CrossRefGoogle Scholar
Lee, D. H. K. (1953). F.A.O. Devel. Paper, Agric. no. 38.Google Scholar
MacCallum, J. B. (1898). Johns Hopk. Hosp. Bull. 9, 208. (Quoted by Adams et al. 1953.)Google Scholar
MacDonald, I. (1953). J. Obstet. Gynaec, Brit. Emp., 60, 61.CrossRefGoogle Scholar
MacDowell, E. C., Allen, E. & MacDowell, C. G. (1927). J. Gen. Physiol. 11, 57.CrossRefGoogle Scholar
Malan, A. P. & Curzon, H. H. (1936). Onderstepoort J. Vet. Sci. 7, 239.Google Scholar
Malan, A. P. & Curzon, H. H. (1937). Onderstepoort J. Vet. Sci. 8, 417.Google Scholar
McMeekan, C. P. (1940–1941). J. Agric. Sci. 30, 276; 31, 1.CrossRefGoogle Scholar
Meara, P. J. (1947). Onderstepoort J. Vet. Sci. 21, 329.Google Scholar
Meves, F. (1909). Anat. Anz. 34, 161.Google Scholar
Morpurgo, B. (1898). Anal. Anz. 15, 200.Google Scholar
Murray, J. A. (1921). J. Agric. Sci. 11, 258.CrossRefGoogle Scholar
Needham, J. (1931). Chemical Embryology, vol. 1. Cambridge University Press.CrossRefGoogle Scholar
Needham, J. (1942). Biochemistry and Morphogenesis. Cambridge University Press.Google Scholar
Palsson, H. (1939–1940). J. Agric. Sci. 29, 544; 30, 1.CrossRefGoogle Scholar
Palsson, H. & Verges, J. B. (1952). J. Agric. Sci. 42, 1.CrossRefGoogle Scholar
Paton, D. N., Watson, B. P. & Kerr, J. (1905). Trans. Roy. Soc. Edinb. 46, 71.CrossRefGoogle Scholar
Patten, B. M. & Philpott, R. (1921). Anat.Rec. 20, 393.CrossRefGoogle Scholar
Robinson, T. J. (1950–1951). J. Agric. Sci. 40, 275; 41, 6.CrossRefGoogle Scholar
Scammon, R. E. & Calkins, L. A. (1929). The Development and Growth of the External Dimensions of the Human Body in the Foetal Period. Minneapolis University Press.Google Scholar
Schäfer, E. A. (1912). Textbook of Microscopic Anatomy. London: Longmans Green.Google Scholar
Schiefferdecker, P. (1919). Pflüg. Arch. ges. Physiol. 173, 265.CrossRefGoogle Scholar
Schultz, A. H. (1919). Amer. J. Phys. Anthrop. 2, 35.CrossRefGoogle Scholar
Schultz, M. (1934). Biol. gen. 10, 49.Google Scholar
Schwartz, N. B. (1953). Growth, 17, 123.Google Scholar
Sisson, S. (1953). The Anatomy of the Domestic Animals, 4th ed. Revised by J. D. Grossman. Philadelphia: Saunders.Google Scholar
Starke, J. S. (1951). D.Sc. (Agric). Thesis, University of Pretoria.Google Scholar
Tello, J. F. (1917). Trab. Lab. Invest, biol. Univ. Madr. 15, 101. (Quoted by Tello, 1922.)Google Scholar
Tello, J. F. (1922). Z. ges. Anat. 1. Z. Anat. Entw-Gesch. 64, 348.CrossRefGoogle Scholar
Trautman, A. & Fiebiger, J. (1952). Fundamentals of the Histology of Domestic Animals. Translated and revised by Habel, R. E. & Biberstein, E. L.. New York: Comstook.Google Scholar
Wallace, L. R. (1948). J. Agric. Sci. 38, 93, 243.CrossRefGoogle Scholar
Weed, I. G. (1937). Z. Zellforsch. 25, 516.CrossRefGoogle Scholar
Weiss, P. (1949). Differential Growth. Ch. vii of The Chemistry and Physiology of Growth. Princeton University Press.Google Scholar
Winters, L. M. & Feuffel, G. (1936). Tech. Bull. Minn. Agric. Exp. Sta. no. 118.Google Scholar
Wohlfart, G. (1937). Acta psychiat., Kbh., Suppl. 12, 119. (Quoted by Adams et al. 1953.)CrossRefGoogle Scholar
Zuckerman, S. (1926). Proc. Zool. Soc. Lond. 56, pt. 2, p. 843.CrossRefGoogle Scholar