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Effects of sex and gonadectomy on the growth and development of Southdown × Romney cross lambs. Part I. Effects on live–weight growth and components of live weight

Published online by Cambridge University Press:  27 March 2009

K. E. Jury
Ruakura Agricultural Research Centre, Private Bag, Hamilton, New Zealand


The influence of sex and gonadectomy on liveweight growth and its components was examined in a comparative slaughter experiment using Southdown – Romney cross lambs run under New Zealand pastoral feeding conditions.

Twenty ram lambs were castrated and 20 ewe lambs spayed at docking, at approximately 4 weeks of age. Ten ram and 10 ewe lambs were killed at this age and 5 lambs from each of the four ‘sexes’ (entire and gonadectomized, male and female) were killed 4, 8,12 and 24 weeks after docking.

Live-weight gain was higher for males than females and higher for entire than gonadectomized lambs, with some evidence of a greater depression in growth associated with castration than spaying. Effects on carcass weight followed those on live weight; weights for entire rams, wethers, entire and spayed ewes were 16.92, 14.72, 14.02 and 12.46 kg. respectively at approximately 7 months of age.

Research Article
Copyright © Cambridge University Press 1966

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Barton, R. A. (1957). Sheepfarming Annual, pp. 6173. Massey Agricultural College, New Zealand.Google Scholar
Bogart, R., Lasley, J. F. & Mayer, D. T. (1944). Endocrinology, 35, 173.CrossRefGoogle Scholar
Bogart, R., Sperling, G., Burnes, L. L. & Asdell, S. A. (1940). Amer. J. Physiol. 128, 355.Google Scholar
Brody, S. (1945). Bioenergetics and Growth. New York: Reinhold.Google Scholar
Callow, E. H. (1944). J. Agric. Sci. 34, 177–89.CrossRefGoogle Scholar
Casida, L. E., Andrews, F. H., Bogart, R., Clegg, M. T. & Nalbandov, A. B. (1959). Hormonal Relationships and Applications in the Production of Meats, Milk and Eggs. Nat. Aead. Sei.—Nat. Res. Coun., Publication no. 714, 153.Google Scholar
Cole, H. H. & Hart, G. H. (1938). Amer. J. Physiol. 123, 589–97.Google Scholar
Davidson, J. (1960). J. Roy. Agric. Soc. 121, 192199.Google Scholar
Donald, H. P. (1962). Anim. Prod. 4, 369–77.CrossRefGoogle Scholar
Everitt, G. C. (1961a). Proc. Ruakura Farmers' Conf. pp. 85102.Google Scholar
Everitt, G. C. (1961b). Bull. Inst. Meat, 31, 2; 32, 2; 33, 3.Google Scholar
Everitt, G. C. (1962). Proc. Aust. Soc. Anim. Prod. 4, 7989.Google Scholar
Everitt, G. C. (1964a). Beef carcass appraisal by jointing. Proc. Aust.C.S.I.R.O. Tech Conf. on Carcass Composition and Appraisal of Meat Animals, Melbourne, August 1963, Section 16, 112.Google Scholar
Everitt, G. C. (1964b). Nature, Lond., 201, 1341–2.CrossRefGoogle Scholar
Freudenburger, C. B. & Clausen, E. W. (1937). Aust. Rec. 68, 133.Google Scholar
Gramlich, H. T. (19261927). Proc. Amer. Soc. Anim. Prod. pp. 213–16.Google Scholar
Gramlich, H. J. & Thalman, R. R. (1930). Nebraska Agric. Exp. Sta. Bull. no. 252, 155.Google Scholar
Hammond, J. (1932). Growth and the Development of Mutton Qualities in the Sheep. Edinburgh: Oliver & Boyd.Google Scholar
Hart, G. H. & Cole, H. H. (1939). Proc. Soc. Exp. Biol., N.Y., 41, 310–13.CrossRefGoogle Scholar
Hart, G. H., Guilbert, H. R. & Cole, H. H. (1940). Bull. Calif. Agric. Exp. Sta. no. 645, 119.Google Scholar
Hartsook, E. W. & Magruder, N. D. (1957). Amer. J. Physiol. 190, 255.Google Scholar
Hemingsen, A. M. (1934). Nutr. Abstr. Rev. 3, 1051.Google Scholar
Holdas, A. S. (1960). Anim. Breed. Abstr. 29, 315.Google Scholar
Hunt, W. E., Meade, D. & Carmichael, B. E. (1938). Maryland Agric. Exp. Sta. Bull. no. 417, 259–78.Google Scholar
Joubert, D. M. (1959). Anim. Prod. 1, 163–5.CrossRefGoogle Scholar
Kempthorne, O. (1952). The Design and Analysis of Experiments. New York: John Wiley and Sons.Google Scholar
Lamming, G. E. (1961). Endocrinology and ruminant nutrition. In Digestive Physiology and Nutrition in the Ruminant (ed. Lewis, D.), pp. 249–61. London: Butterworths.Google Scholar
Medawar, P. B. (1950). Proc. Roy. Soc. B, 137, 474–9.CrossRefGoogle Scholar
Minkin, T. S., Gatin, P. P. & Varnikov, V. V. (1962). Anim. Breed. Abstr. 30, 1800.Google Scholar
Mott, C. R. (1945). Proc. Soc. Exp. Biol., N.Y., 58, 349–50.CrossRefGoogle Scholar
Meatprod, N.Z. BD. (1963). Annual Rep., New Zealand Meat Producers' Board, pp. 172.Google Scholar
Pálsson, H. (1955). Conformation and body composition, chap. 10, pp. 30–542. In Progress in the Physiology of Farm Animals (ed. Hammond, J.), ch. 10, pp. 430542. London: Butterworths.Google Scholar
Pálsson, H. & Verges, J. B. (1952). J. Agric. Sci. 42, 1149.CrossRefGoogle Scholar
Pomeroy, R. W. (1955). Live-weight growth. In Progress in the Physiology of Farm Animals (ed. Hammond, J.), chap. 9, pp. 395429. London: Butterworths.Google Scholar
Preston, R., Cheng, E. & Burroughs, W. (1956). Proc. Iowa Acad. Sci. 63, 423.Google Scholar
Scholl, D. A. (1950). Proc. Roy. Soc. B, 137, 470–4.CrossRefGoogle Scholar
Starke, J. S., Smith, J. B. & Joubert, D. M. (1958). Dep. Agric. Sth Afr. Sci. Bull. no. 382, 128.Google Scholar
Stephenson, S. K. & Lambourne, L. J. (1960). Aust. J. Agric. Res. 2, 1044–63.CrossRefGoogle Scholar
Stotsenberg, J. M. (1960). Anat. Rec. 3, 233.Google Scholar
Tang, Y. Z. (1941). Anat. Rec. 80, 1332.CrossRefGoogle Scholar
Tanner, J. M. (1963). Nature, Lond., 199, 845–50.CrossRefGoogle Scholar
Tulloh, N.M. (1963). Nature, Lond., 197, 809–10.CrossRefGoogle Scholar
Turton, J. F. (1962). Anim. Breed. Abstr. 30, 447–56.Google Scholar
Walker, D.E.K. (1950). N.Z. J. Sci. Tech A, 32, 30–9.Google Scholar
Wallace, L. R. (1944). Proc. N.Z. Soc. Anim. Prod. 4, 6470.Google Scholar
Yates, F. (1950). Proc. Roy. Soc. B, 137, 479–88.CrossRefGoogle Scholar