Hostname: page-component-8448b6f56d-tj2md Total loading time: 0 Render date: 2024-04-16T13:48:06.697Z Has data issue: false hasContentIssue false
  • English
  • Français

Observations on the reproductive activity of tropical sheep in relation to the photoperiod

Published online by Cambridge University Press:  27 March 2009

R. B. Symington  and
J. Oliver
R. B. Symington
Affiliation:
Department of Agriculture, University College of Rhodesia and Nyasaland, Salisbury, Rhodesia
J. Oliver
Affiliation:
Department of Agriculture, University College of Rhodesia and Nyasaland, Salisbury, Rhodesia
Get access Rights & Permissions [Opens in a new window]

Extract

A study has been made of the effect of a progressive increase in the hours of light each day on the sexual activity of German Merino, Persian Blackhead and indigenous ‘Native’ ewes.

Incidence of oestrous tended to be greater in ewes subjected to extended daylight than in ewes subjected to the natural photoperiod. This was particularly true during the latter stages of the study. Duration of oestrus was unaffected by the extended daylight but varied temporarily in both groups of ewes. The effect of extended daylight on duration of the oestrous cycle and on the incidence of oestrous cycles of normal or abnormal duration was not marked and differed between breeds. Extension of daylight to 19 hr. each day apparently did not prevent reproduction since several light-treated ewes inadvertently conceived, gave birth to and reared a healthy lamb after a gestation period of normal length.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 67 , Issue 1 , August 1966 , pp. 7 - 12
Copyright
Copyright © Cambridge University Press 1966

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

Anderson, J. (1949). Cited Hafez (1952) 2nd International Congress Fertility and Reproduction.Google Scholar
Bedford, Duke of & F. H. A., Marshall. (1942). Proc. Roy. Soc. B, 130, 396.Google Scholar
Duerden, J. E. & Boyd, E. (1930). Bull. Dept. Agric, S.Afr. no. 82.Google Scholar
Elliott, R. C. & Folkersten, K. (1961). J. Rhod. Agric. 58, 186–7.Google Scholar
Finci, M. (1957). Bull. Res. Counc. Israel, 6B, no. 1, pl.Google Scholar
Hafez, E. S. E. (1952). J. Agric. Sci. 42, 189.CrossRefGoogle Scholar
Hafez, E. S. E. (1954). Experientia, 10, 358.CrossRefGoogle Scholar
Hammond, J. (1952). Proc. 6th Int. Congr. Anim. Husb. Sec. 3, 38.Google Scholar
Howell, C. E. & Rollins, W. C. (1951). J. Anim. Sci. 10, 789.CrossRefGoogle Scholar
Hunter, G. L. (1959). J. Agric. Sci. 52, 282.CrossRefGoogle Scholar
Kelley, R. B. (1937). Bull. 112, C.S.I.R.O. Aust.Google Scholar
Kelley, R. B. & Shaw, H. E. B. (1943). Bull. 166, C.S.I.R.O. Aust.Google Scholar
Kupfer, M. (1928). The oestrus cycle of female domesticated animals. 13th and 14th Rep. D.V.E.R., S.Afr.Google Scholar
Labuschagne, J. (1948). Fmg. S. Afr. 23, 77.Google Scholar
Lall, H. K. (1956). Indian Coun. Agric. Res. Misc. Bull. no.75.Google Scholar
Maincourity, L. (1959). Personal communication.Google Scholar
Quinlan, J. & Mare, G. S. (1931). The physiological changes in the ovary of the Merino Sheep. 17th Rep. D.V.E.R., S. Afr.Google Scholar
Radford, H. M. & Watson, R. H. (1955). Aust. J. Agric. Res. 6, 431.CrossRefGoogle Scholar
Roux, L. L. (1936). Onderstepoort J. Vet. Sci. Anim. Ind. 6, 465.Google Scholar
Symington, R. B. (1960). Ph. D. thesis, London University.Google Scholar
Symington, R. B. (1963). Ann. Rep. Div. Animal Physiology, C.S.I.R.O., Aust.Google Scholar
Watson, R. H. & Radford, H. M. (1955). Aust. Vet. J. 31, 31.CrossRefGoogle Scholar
Yeates, N. T. M. (1954). ‘Progress in the Physiology of Domestic Animals’. London: Butterworth.Google Scholar
Yeates, N. T. M. (1956). Aust. J. Agric. Res. 7, 440.CrossRefGoogle Scholar