Hostname: page-component-cd9895bd7-jn8rn Total loading time: 0 Render date: 2024-12-27T18:53:56.788Z Has data issue: false hasContentIssue false
  • English
  • Français

Influence of lambing date on subsequent ovarian cyclicity and ovulation rate in ewes

Published online by Cambridge University Press:  02 September 2010

L. M. Mitchell ,
M. E. King ,
R. P. Aitken  and
J. M. Wallace
L. M. Mitchell
Affiliation:
Scottish Agricultural College, The Ferguson Building, Craibstone Estate, Bucksburn, Aberdeen AB21 9YA
M. E. King
Affiliation:
Scottish Agricultural College, The Ferguson Building, Craibstone Estate, Bucksburn, Aberdeen AB21 9YA
R. P. Aitken
Affiliation:
Rowett Research Institute, Greenburn Road, Bucksburn, Aberdeen AB21 9SB
J. M. Wallace
Affiliation:
Rowett Research Institute, Greenburn Road, Bucksburn, Aberdeen AB21 9SB
Get access

Abstract

The effect of lambing date on the subsequent onset and duration of ovarian cyclicity in Mule (Bluefaced Leicester × Scottish Blackface) ewes was investigated. Nineteen ewes which had lambed in January (16 January 1993 (s.e. 3 days)) and been weaned in February-March and 22 comparable ewes which had lambed in May (14 May 1993 (s.e. 2 days)) and been weaned on 23 August were maintained at pasture as two isolated groups. A raddled vasectomized ram was continually present with each group from 14 July 1993 to 26 May 1994 and marked (oestrous) ewes were recorded twice weekly. Ovarian activity was assessed by measuring peripheral progesterone concentrations in blood samples collected twice weekly and by laparoscopic viewing of the ovaries of all ewes during October, January and March. The onset and duration of ovarian activity were significantly affected by the previous lambing date. For January and May lambing ewes, mean dates of onset were 5 September 1993 (s.e. 2 days) v. 25 September 1993 (s.e. 4 days) (P < 0·001) and of cessation were 5 April 1994 (s.e. 5 days) v. 10 April 1994 (s.e. 3 days). Mean durations of ovarian activity were 212 (s.e. 6) and 195 (s.e. 5) days (P < 0·05) during which 12·4 (s.e. 0·29) and 11·5 (s.e. 0·38) ovarian cycles respectively were recorded. Ovulation rate was not affected by previous lambing date but was significantly lower in March compared with October (January lambing ewes 1·7 (s.e. 0·1) v. 2·3 (s.e. 0·1) (P < 0·001); May lambing ewes 1·6 (s.e. 0·1) v. 2·1 (s.e. 0·1) (P < 0·01)). Results demonstrate that (i) Mule ewes have a potential breeding season of up to 8 months duration; (ii) the onset and duration of ovarian activity can be influenced by previous lambing date; and (Hi) a seasonal decline in ovulation rate may, in practical terms, result in a lower lambing percentage for animals bred towards the end of their natural breeding period.

Keywords

ewesovulation rateparturitionseasonality
Type
Research Article
Information
Animal Science , Volume 65 , Issue 1 , August 1997 , pp. 75 - 81
Copyright
Copyright © British Society of Animal Science 1997

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

Boyd, J. S. and Ducker, M. J. 1973. A method of examining the cyclic changes occurring in the sheep ovary using endoscopy. Veterinary Record 90: 40–43.CrossRefGoogle Scholar
Djahanbahkch, O., Swanston, I. A., Corrie, J. E. T. and McNeilly, A. S. 1981. Prediction of ovulation by progesterone. Lancet ii: 1164–1165.CrossRefGoogle Scholar
Donovan, A., O'Callaghan, D., Karsh, F. J., Boland, M. P. and Roche, J. F. 1992. Long days in spring signal the onset of the subsequent breeding season but also maintain current anoestrus in adult ewes. Proceedings of the 12th international congress on animal reproduction, The Hague, abstract number 597.Google Scholar
Ducker, M. J. and Boyd, J. S. 1974. The effect of daylength and nutrition on the oestrous and ovulatory activity of Greyface ewes. Animal Production 18:159–167.Google Scholar
Dutt, R. H. and Bush, L. E. 1955. The effect of low environmental temperature on the initiation of the breeding season in sheep. Journal of Animal Science 14:885–896.CrossRefGoogle Scholar
Follett, B. K. and Potts, C. 1990. Hypothyroidism affects reproductive refractoriness and the seasonal oestrous period in Welsh Mountain ewes. Journal of Endocrinology 127:103–109.CrossRefGoogle ScholarPubMed
Gunn, R. G. 1983. The influence of nutrition on the reproductive performance of ewes. In Sheep production (ed. Haresign, W.). Proceedings of the 35th Easter school in agricultural science, University of Nottingham, pp. 99–110. Butterworths, London.Google Scholar
Gwinner, E. 1986. Circannual rhythms. In Zoophysiology vol. 18. Circannual rhythms: annual clocks in the organisation of seasonal processes. Springer-Verlag, Berlin.CrossRefGoogle Scholar
Hafez, E. S. E. 1952. Studies on the breeding season and reproduction of the ewe. Journal of Agricultural Science, Cambridge 42:189–265.CrossRefGoogle Scholar
Hammond, J. Jr 1944. On the breeding season in the sheep. Journal of Agricultural Science, Cambridge 34:97–105.CrossRefGoogle Scholar
Haresign, W. 1992. The effect of implantation of lowland ewes with melatonin on the time of mating and reproductive performance. Animal Production 54: 31–39.Google Scholar
Haresign, W., Peters, A. R. and Staples, L. D. 1990. The effect of melatonin implants on breeding activity and litter size in commercial sheep flocks in the UK. Animal Production 50:111–121.Google Scholar
Hendy, C. R. C. and Bowman, J. C. 1974. The association between variation in the seasonal onset of oestrus and litter size in the ewe. Journal of Reproduction and Fertility 40: 105–112.CrossRefGoogle ScholarPubMed
Kennaway, D. J., Gilmore, T. A. and Seamark, R. F. 1982. Effect of melatonin feeding on serum prolactin and gonadotrophin levels and the onset of seasonal estrous cyclicity in sheep. Endocrinology 110:1766–1772.CrossRefGoogle ScholarPubMed
Lees, J. L. 1966. Variations in the time of onset of the breeding season in Clun ewes. Journal of Agricultural Science, Cambridge 67: 173–179.CrossRefGoogle Scholar
Luhman, C. M. and Slyter, A. L. 1986. The effect of photoperiod and melatonin feeding on reproduction in the ewe. Theriogenology 26: 721–732.CrossRefGoogle Scholar
Malpaux, B. and Karsh, F. J. 1990. A role for short days in sustaining seasonal reproductive activity in the ewe. Journal of Reproduction and Fertility 90: 555–562.CrossRefGoogle ScholarPubMed
Malpaux, B., Robinson, J. E., Wayne, N. L. and Karsh, F. J. 1989. Regulation of the onset of the breeding season of the ewe: importance of long days and of an endogenous reproductive rhythm. Journal of Endocrinology 122:269–278.CrossRefGoogle ScholarPubMed
Malpaux, B., Wayne, N. L. and Karsh, F. J. 1988. Termination of the breeding season in the Suffolk ewe: involvement of an endogenous rhythm of reproduction. Biology of Reproduction 39:254–263.CrossRefGoogle ScholarPubMed
Martin, G. B., Oldham, C. M., Cognie, Y. and Pearce, D. T. 1986. The physiological responses of anovulatory ewes to the introduction of rams — a review. Livestock Production Science 15: 219–247.CrossRefGoogle Scholar
Meat and Livestock Commission. 1983. Feeding before, during and after mating. In Feeding the ewe. Sheep Improvement Services, MLC, Milton Keynes.Google Scholar
Nett, T. M. and Niswender, G. D. 1982. Influence of exogenous melatonin on seasonality of reproduction in sheep. Theriogenology 17: 645–653.CrossRefGoogle Scholar
Robinson, J. J., Wallace, J. M., Aitken, R. P. and Wigzell, S. 1992a. Effect of duration of melatonin treatment on the onset and duration of oestrous cyclicity in ewes. Journal of Reproduction and Fertility 95: 709–717.CrossRefGoogle ScholarPubMed
Robinson, J. J., Wigzell, S., Aitken, R. P., Wallace, J. M., Ireland, S. and Robertson, I. S. 1991. The modifying effects of melatonin, ram exposure and plane of nutrition on the onset of ovarian activity, ovulation rate and the endocrine status of ewes. Animal Reproduction Science 26: 73–91.CrossRefGoogle Scholar
Robinson, J. J., Wigzell, S., Aitken, R. P., Wallace, J. M., Ireland, S. and Robertson, I. S. 1992b. Daily oral administration of melatonin from March onwards advances by 4 months the breeding season of ewes maintained under the ambient photoperiod at 57° N. Animal Reproduction Science 27:141–160.CrossRefGoogle Scholar
Russel, A. J. F., Doney, J. M. and Gunn, R. B. 1969. Subjective assessment of body fat in live sheep. Journal of Agricultural Science, Cambridge 72: 451–454.CrossRefGoogle Scholar
Scaramuzzi, R. J. and Radford, H. N. 1983. Factors regulating ovulation rate in the ewe. Journal of Reproduction and Fertility 69:353–367.CrossRefGoogle ScholarPubMed
Stellflug, J. N., Fitzgerald, J. A., Parker, C. F. and Bolt, D. 1988. Influence of concentration, duration and route of administration of melatonin on reproductive performance of spring-mated Polypay and Polypay-cross ewes. Journal of Animal Science 66: 1855–1863.CrossRefGoogle ScholarPubMed
Sweeney, T. and O'Callaghan, D. 1996. Breeding season and ovulation rate in ewes treated with long days in spring followed by a melatonin implant and exposure to a ram. Animal Science 62:507–512.CrossRefGoogle Scholar
Wheeler, A. G. and Land, R. B. 1977. Seasonal variation in oestrus and ovarian activity of Finnish Landrace, Tasmanian Merino and Scottish Blackface ewes. Animal Production 24: 363–376.Google Scholar
Worthy, K. and Haresign, W. 1983. Evidence that the onset of seasonal anoestrus in the ewe may be independent of increasing prolactin concentrations and daylength. Journal of Reproduction and Fertility 69:41–48.CrossRefGoogle ScholarPubMed