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Effect of light on spring breeding of mutton merino ewes

Published online by Cambridge University Press:  27 March 2009

H. Goot
H. Goot
Affiliation:
The Volcani Institute of Agricultural Research, Rehovot, Israel
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Summary

Mutton Merino ewes, all of which had lambed in the preceding in-season, were divided into two groups some 30 days after lambing.

The ‘light’ group was subjected, over 84 days, to a simulated decrease in daylength, achieved by first adding artificial light to the daylight and then stepping down the light at weekly intervals, from approximately 17 h, on 22 January, to natural daylength (13 ¾ h), on 20 April 1967. The control group was exposed to the normally increasing daylength.

Starting on 1 March, the ewes in both groups were ‘teased’ and hand-service commenced on 20 April.

The breeding activity (oestrus, ewes lambing, lambs born and twin births) as well as the length of gestation and birth weight appeared to be unaffected by the light.

It would appear that the ‘short-day’ photoperiodic theory is not applicable to all breeds of sheep, and it is suggested that in sheep with a long sexual season genetic heterozygosity may be responsible for regulating the breeding season by allowing other environmental stimuli, besides light, to trigger-off sexual activity.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 73 , Issue 2 , October 1969 , pp. 177 - 180
Copyright
Copyright © Cambridge University Press 1969

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References

Fraser, A. F. & Laing, A. H. (1966). A preliminary report on the induction of oestrus in sheep with fixed periods of dark-housing. Vet. Rec. 78, 430–1.Google Scholar
Goot, H. (1967). Some data on out-of-season lambing in Mutton Merino ewes. Israel J. agric. Res. 17, 219—24.Google Scholar
Goot, H. & Schindler, H. (1969). The use of vaginal sponges in spring breeding of Mutton Merino and crossbred ewes. J. agric. Sci., Camb. 72. 445—9.CrossRefGoogle Scholar
Hafez, E. S. E. (1952). Studies on the breeding season and reproduction of the ewe. J. agric. Sci., Camb. 42, 189–245.Google Scholar
Hafez, E. S. E. (1954). Oestrus activity in Fat-tailed sheep during the longest day. Experientia, 10, 338–40.CrossRefGoogle Scholar
Hammond, J., Jun, . (1944). On the breeding season in sheep. J. agric. Sci., Camb. 34, 97–105.CrossRefGoogle Scholar
Hart, D. S. (1950). Photoperiodicity in Suffolk sheep. J. agric. Sci., Camb. 40, 143–9.CrossRefGoogle Scholar
Ortavant, R., Mauleon, P. & Thibault, C. (1964). Photoperiodic control of gonadal and hypophyseal activity in domestic mammals. Ann. N.Y. Acad. Sci. 117, 157–92.CrossRefGoogle ScholarPubMed
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. (1966). Regulation of the breeding season in mammals. Proc. Aust. Soc. Anim. Prod. 6, 19–31.Google Scholar
Schafer, H. (1964). The dependence of fertility on the environment in sheep under natural conditions of management. Z. Tierzücht. ZüchtBiol. 80, 97–129.Google Scholar
Symington, R. B. & Oliver, J. (1966). Observations on the reproductive activity of tropical sheep in relation to the photoperiod. J. agric. Sci., Camb. 67, 7–12.CrossRefGoogle Scholar
Watson, R. H. & Radford, H. M. (1955). A note on the hours of daylight associated with the seasonal increase in the sexual activity in Merino sheep. Aust. vet. J. 31, 31–2.CrossRefGoogle Scholar
Wodzicka-Tomaszewska, M., Hutchinson, J. C. D. & Bennett, J. W. (1967). Control of the annual rhythm of breeding in ewes: effect of an equatorial daylength with reversed thermal season. J. agric. Sci., Camb. 68, 61–7.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, 1–43.CrossRefGoogle Scholar
Yeates, N. T. M. (1956). The effect of light on the breeding season, gestation and birth weight of Merino sheep. Aust. J. agric. Res. 7, 440–6.CrossRefGoogle Scholar