Hostname: page-component-78c5997874-s2hrs Total loading time: 0 Render date: 2024-11-09T16:01:55.292Z Has data issue: false hasContentIssue false
  • English
  • Français

Effect of various light regimes on lamb production by Rambouillet and Suffolk ewes

Published online by Cambridge University Press:  02 September 2010

J. A. Vesely  and
D. M. Bowden
J. A. Vesely
Affiliation:
Research Station, Agriculture Canada, Lethbridge, Alberta T1J 4B1, Canada
D. M. Bowden
Affiliation:
Research Station, Agriculture Canada, Lethbridge, Alberta T1J 4B1, Canada
Get access

Abstract

Six production cycles, each of 212 days' duration, were completed with Rambouillet and Suffolk ewes. One group of each breed was maintained under natural light conditions (control) and three groups of each breed were under the influence of various light treatments applied regularly in a rhythmic fashion within each production cycle. Comparison of conception rates between production cycles, breeds, and treatments showed that only in production cycle 2 (mating in June) were the conceptions in control ewes of both breeds significantly lower than those in ewes on altered light treatments. The most meaningful result was the effect of light treatments on prolificacy. Treatment 3 (106 days with 16-h light per day and 106 days with 8-h light per day) gave significantly higher prolificacy than control and treatments 1 (106 days with 8-h light per day starting 65 days before mating) and 2 (42 days with 16-h light per day, then light reduction at 21 min/week for 160 days). Rambouillet and Suffolk control ewes produced annually 179 and 174 lambs per 100 ewes exposed to rams. Corresponding productions were 200 and 197 for treatment 1, 193 and 226 for treatment 2, and 223 and 242 for treatment 3.

Type
Research Article
Information
Animal Production , Volume 31 , Issue 2 , October 1980 , pp. 163 - 169
Copyright
Copyright © British Society of Animal Science 1980

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

Ducker, M. J. 1971. Photoperiodism in the ewe. Ph.D. Thesis, Univ. Reading.Google Scholar
Dufour, J. J. 1974. The duration of the breeding season of four breeds of sheep. Can. J. Anim. Sci. 54: 389–392.Google Scholar
Dunstan, E. A., Cumming, I. A. and Findlay, J. K. 1977. Increasing ovulation rate in the ewe by changing photo-period. Theriogenology 8: 170.Google Scholar
Gordon, I. 1975. Hormonal control of reproduction in sheep. Proc. Br. Soc. Anim. Prod. (New Series) 4: 79–93.CrossRefGoogle Scholar
Hamner, K. C. and Hoshizaki, T. 1974. Photoperiodism and circadian rhythms: an hypothesis. Bio Science 24: 407–414.Google Scholar
Hanrahan, J. P. and Quirke, J. E. 1975. Repeatabilit y of the duration of oestrus and breed differences in the relationship between duration of oestrus and ovulation rate of sheep. J. Reprod. Fert. 45: 29–36.Google Scholar
Lincoln, G. A. and Davidson, W. 1977. The relationship between sexual and aggressive behaviour, and pituitary and testicular activity during the seasonal sexual cycle of rams, and the influence of photoperiod. J. Reprod. Fert. 49: 267–276.CrossRefGoogle ScholarPubMed
Robinson, J. J., Fraser, C. and McHattie, I. 1975. The use of progestagens and photoperiodism in improving the reproductive rate of the ewe. Annls. Biol. anim. Biochim. Biophys. 15: 345–352.Google Scholar
Thibault, C., Courot, M., Martinet, Lise, Mauleon, P., du Mesnil du Buisson, F., Ortavant, R., Pelletier, J. and Signoret, J. P. 1966. Regulation of breeding season and estrous cycles by light and external stimuli in some mammals. J. Anim. Sci. 25: Suppl., 119–142.CrossRefGoogle ScholarPubMed
Vesely, J. A. 1975. Induction of lambing every eight months in two breeds of sheep by light control with or without hormonal treatment. Anim. Prod. 21: 165–174.Google Scholar
Vesely, J. A. 1978. Application of light control to shorten the production cycle in two breeds of sheep. Anim. Prod. 26: 169–176.Google Scholar