Hostname: page-component-586b7cd67f-dsjbd Total loading time: 0 Render date: 2024-11-22T06:22:13.475Z Has data issue: false hasContentIssue false

The effect of constant long daily photoperiod upon the onset of puberty in ewes

Published online by Cambridge University Press:  27 March 2009

I. D. Smith
Affiliation:
University of Queensland, Brisbane, Australia

Extract

The effect upon the onset of reproductive activity of exposure of ewe lambs of three British breeds (Border Leicester, Southdown, Suffolk) to constant long daylight hours (16 h light/8 h dark) was studied.

Oestrus, ovulation and conception were depressed but not inhibited; however, only the incidence of conception was significantly less than in the control group. Athough the treatment retarded the onset of oestrous activity, the age at first oestrus was still within the normal age range for puberty.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1967

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

Allen, D. M. & Lamming, G. E. (1961). Some effects of nutrition on the growth and sexual development of ewe lambs. J. agric. Sci., Camb. 57, 8795.CrossRefGoogle Scholar
Ch'Ang, T. S. & Raeside, J. I. (1957). A study on the breeding season of Romney ewe lambs. Proc. N.Z. Soc. Anim. Prod. 17, 80–7.Google Scholar
Hafez, E. S. E. (1952). Studies on the breeding season and reproduction of the ewe. J. agric. Sci., Camb. 42, 189265.CrossRefGoogle Scholar
Hammond, J. Jr (1944). On the breeding season in the sheep. J. agric. Sci., Camb. 34, 97105.CrossRefGoogle Scholar
Hart, D. S. (1950). Photoperiodicity in Suffolk sheep. J. agric. Sci., Camb. 40, 143–9.CrossRefGoogle Scholar
Lamond, D. R. & Urquhart, E. J. (1961). Sheep laparotomy cradle. Aust. vet. J. 37, 430–1.CrossRefGoogle Scholar
Mckenzte, F. F. & Terrill, C. E. (1937). Estrus, ovulation and related phenomena in the ewe. Bull. Mo. agric. Exp. Sta. no. 264.Google Scholar
Radford, H. M. (1961a). Photoperiodism and sexual activity in Merino ewes. I. The effect of continuous light on the development of sexual activity. Aust. J. agric. Res. 12, 139–46.CrossRefGoogle Scholar
Radford, H. M. (1961b). Photoperiodism and sexual activity in Merino ewes. II. The effect of equinoctial light on sexual activity. Aust. J. agric. Res. 12, 147–53.CrossRefGoogle Scholar
Radford, H. M., Watson, R. H. & Wood, G. F. (1960). A crayon and associated harness for the detection of mating under field conditions. Aust. vet. J. 36, 5766.CrossRefGoogle Scholar
Schinckel, P. G. (1954). The effect of the ram on incidence and occurrence of oestrus in ewes. Aust. vet. J. 30, 189–95.CrossRefGoogle Scholar
Sinclair, A. N. (1950). A note on the effect of the presence of rams on the incidence of oestrus in maiden Merino ewes during spring mating. Aust. vet. J. 26, 37–9.CrossRefGoogle Scholar
Smith, I. D. (1966). The onset of the breeding season in Southdown ewes in subtropical Australia. J. agric. Sci., Camb. 66, 295–6.CrossRefGoogle Scholar
Watson, R. H. & Gamble, L. C. (1961). Puberty in the Merino ewe with special reference to the influence of season of birth upon its occurrence. Aust. J. agric Res. 12, 124–38.CrossRefGoogle Scholar
Watson, R. H. & Radford, H. M. (1955). A note on the hours of daylight associated with the seasonal increase in sexual activity in Merino ewes. Aust. vet. J. 31, 31–2.CrossRefGoogle Scholar
Yeates, N.T.M. (1949). The breeding season of the sheep with particular reference to its modification by artificial means using light. J. agric. Sci., Camb. 39, 142.CrossRefGoogle Scholar
Yeates, N. T. M. (1956). The effect of light on the breeding season, gestation and birthweight of Merino sheep. Aust. J. agric. Res. 7, 440–6.CrossRefGoogle Scholar