Hostname: page-component-586b7cd67f-rcrh6 Total loading time: 0 Render date: 2024-11-30T20:58:27.238Z Has data issue: false hasContentIssue false
  • English
  • Français

Photoperiodism in the ewe 5. An attempt to induce sheep of three breeds to lamb every eight months by artificial daylength changes in a non-light-proofed building

Published online by Cambridge University Press:  02 September 2010

M. J. Ducker  and
J. C. Bowman
M. J. Ducker
Affiliation:
Department of Agriculture, University of Reading, Reading, Berkshire
J. C. Bowman
Affiliation:
Department of Agriculture, University of Reading, Reading, Berkshire
Get access

Summary

An attempt to induce ewes to lamb at intervals of 8 months using high levels of artificial daylength applied in a non-light-proofed building was carried out over a period of 2½ years.

Thirty each of Dorset Horn, Clun Forest and Kerry Hill ewes were used. There were two different light regimes, both involving abrupt changes in daylength, all of which occurred at daylengths in excess of natural daylength. In both treatments the artificial daylength was abruptly increased to 22 hr at conception. In one treatment there was an abrupt decrease in daylength at parturition whilst the other treatment was an abrupt decrease in daylength approximately 50 days before parturition. The size of the daylength decrease possible was determined by the natural daylength at the time the decrease was applied and at the estimated time of onset of next oestrus.

The majority of ewes lambed four times in the 2½ year period, parturition occurring in March-April 1969, December 1969-January 1970, September-October 1970 and May 1971. The Clun Forest ewes produced 38, 29, 20 and 22 lambs at the four lambings, whilst the Dorset Horn ewes produced 41, 35, 26 and 25 lambs at the four lambings. Only 11 of the Kerry Hill ewes lambed throughout the whole experiment producing 3, 5,0 and 7 lambs at the four lambings. It is suggested that the changes in daylength at these high levels controlled the breeding activity of the ewes.

Type
Research Article
Information
Animal Production , Volume 14 , Issue 3 , June 1972 , pp. 323 - 334
Copyright
Copyright © British Society of Animal Science 1972

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

Averill, R. L. W. 1959. Ovulatory activity in mature Romney ewes in Otago. N.Z. agric. Res. 2: 575–583.CrossRefGoogle Scholar
Ducker, M. J. and Bowman, J. C. 1970a. Photoperiodism in the ewe. 3. The effects various patterns of increasing daylength on the onset of anoestrus in Clun Forest ewes. Anitn. Prod. 12: 465–471.Google Scholar
Ducker, M. J. and Bowman, J. C. 1970b. Photoperiodism in the ewe. 4. A note on the effect of onset of oestrus in Clun Forest ewes of applying the same decrease in daylength at two different times of the year. Anim. Prod. 12: 513–516.Google Scholar
Ducker, M. J., Thwaites, C. J. and Bowman, J. C. 1970a. Photoperiodism in the ewe. 1. The effect of long supplemented daylengths on the breeding activity of pregnant and non-pregnant Teeswater-Clun ewes. Anim. Prod. 12: 107–113.Google Scholar
Ducker, M. J., Thwaites, C. J. and Bowman, J. C. 1970b. Photoperiodism in the ewe. 2. The effects of various patterns of decreasing daylength on the onset of oestrus Clun Forest ewes. Anim. Prod. 12: 115–123.Google Scholar
Dutt, R. H., Dame, P. R. and Renfro, R. E. 1969. Influence of the photoperiod ovulation, fertility and embryo survival rates in ewes. Kentucky Anim. Sci. Res. Rep. Univ. Kentucky agric. Exp. Stn Prog. Rep. 181: 77–78.Google Scholar
Hafez, E. S. E. 1952. Studies on the breeding season and reproduction of the ewe. J. agric. Sci., Camb. 42: 189–265.CrossRefGoogle Scholar
Hulet, C. V. and Foote, W. C. 1964. Effects of variations in light on reproductive phenomena in ewes during the breeding season. J. Anim. Sci. 23: 907 (Abstr.).Google Scholar
Hulet, C. V., Price, D. A. and Foote, W. C. 1968. Effects of variation in light, month of year and nutrient intake on reproductive phenomena in ewes during the breeding season. J. Anim. Sci. 27: 684–690.CrossRefGoogle ScholarPubMed
Lees, J. L. 1966. Variations in the time of onset of the breeding season in Clun Forest ewes. J. agric. Sci., Camb. 67: 173–179.CrossRefGoogle Scholar
Marshall, F. R. and Potts, C. G. 1921. Flushing and other means of increasing lamb yields. Bull. U.S. Dep. Agric, No. 996.Google Scholar
Means, T., Andrews, F. N. and Fontaine, W. E. 1959. Environmental factors in the induction of oestrus in sheep. J. Anim. Sci. 18: 1388–1396.CrossRefGoogle Scholar
Mimura, K. and Asahida, Y. 1959. The environmental factors of lamb growth analytically studied with extra-seasonal lambs. 1. Extra-seasonal production of lambs by artificial light treatment. J. Fac. Fish. Anim. Husb. Hiroshima Univ. 2: 365–374.Google Scholar
Newton, J. E. 1969. Modern aspects of reproduction in sheep. Tech. Rep. Grassld Res. Inst., No. 7.Google Scholar
Newton, J. E. and Betts, J. E. 1967. Breeding performance of Dorset Horn ewes augmented by hormonal treatment. Expl Agric. 3: 307–313.CrossRefGoogle Scholar
Radford, H. M., Watson, R. H. and Wood, G. F. 1960. A crayon and associated harness for the detection of mating under field conditions. Aust. vet. J. 36: 57–66.CrossRefGoogle Scholar
Williams, H. L. 1967. The intensification of sheep production. Ph.D. Thesis, Univ. London.Google 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