Hostname: page-component-cd9895bd7-gbm5v Total loading time: 0 Render date: 2024-12-27T18:54:53.709Z Has data issue: false hasContentIssue false
  • English
  • Français

The effect of daylength and nutrition on the oestrous and ovulatory activity of Greyface ewes

Published online by Cambridge University Press:  02 September 2010

M. J. Ducker  and
J. S. Boyd
M. J. Ducker
Affiliation:
Departments of Animal Husbandry and Veterinary Anatomy, Glasgow University Veterinary School, Bearsden, Glasgow
J. S. Boyd
Affiliation:
Departments of Animal Husbandry and Veterinary Anatomy, Glasgow University Veterinary School, Bearsden, Glasgow
Get access

Summary

The onset and duration of oestrous and ovulatory activity in 26 Greyface ewes receiving natural daylength changes were determined. Precise ovulation data were obtained by endoscopy and repeated observations of the ovaries of all ewes were made on 10 occasions from 15 July 1971 to 27 June 1972. The natural breeding season for these Greyface ewes was, on average, 22 September 1971 to 18 February 1972. There were significant seasonal changes in the mean ovulation rate of the ewes which appeared to be inversely related to seasonal changes in natural daylength.

An abrupt decrease in artificial daylength of 11 -43 hr applied on 22 June 1971 to 28 similar Greyface ewes advanced their mean onset of oestrous activity by 23 days. The decrease in artificial daylength also advanced the occurrence of ovulation in these ewes. The highest mean ovulation rate of the ewes receiving the decrease in artificial daylength was at least as high as the peak mean ovulation rate measured in the control ewes.

At most stages of the experiment, the plane of nutrition had no significant effect on either oestrous or ovulatory activity in the ewes.

Type
Research Article
Information
Animal Production , Volume 18 , Issue 2 , April 1974 , pp. 159 - 167
Copyright
Copyright © British Society of Animal Science 1974

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

Boyd, J. S. and Ducker, M. J. 1973. A method of examining the cyclic changes occurring in the sheep ovary using endoscopy. Vet. Rec. 93: 40–43.CrossRefGoogle ScholarPubMed
Dermody, W. C., Foote, W. C. and Hulet, C. 1966. Effects of season of year and progesterone synchronisation on ovulation rate. J. Anim. Sci. 25: 585.Google Scholar
Ducker, M. J. 1971. Photoperiodism in the ewe. Ph.D. Thesis, Univ. Reading.Google Scholar
Ducker, M. J. and Bowman, J. C. 1972. Photoperiodism in the ewe. 5. An attempt to induce sheep of three breeds to lamb every eight months by artificial daylength changesin non-light-proofed buildings. Anim. Prod. 14: 323–334.Google Scholar
Ducker, M. J. and Boyd, J. S. 1972. The successful use of etorphine hydrochloride/diprenorphine hydrochloride in sheep. Vet. Rec. 91: 458–459.CrossRefGoogle ScholarPubMed
Ducker, M. J., Thwaites, C. J. and Bowman, J. C. 1970. Photoperiodism in the ewe. 2. The effect of various patterns of decreasing daylength on the onset of oestrus in Clun Forest ewes. Anim. Prod. 12: 115–123.Google Scholar
Gerring, J. C. 1954. Flushing of ewes in fat lamb production. N.Z. Jl Agric. 88: 25–27.Google Scholar
Hafez, E. S. E. 1952. Studies on the breeding season and reproduction of the ewe. J. agric. Sci., Comb. 42: 189–265.CrossRefGoogle Scholar
Hammond, J. Jr. 1944. On the breeding season in sheep. J. agric. Sci., Camb. 34: 97–105.CrossRefGoogle Scholar
Hendy, C. R. C. and Bowman, J. C. 1971. The effect of the interaction of date of onset of oestrus with the number of previous oestrous periods on lambing percentage. Anim. Prod. 13: 395–396 (Abstr.).Google Scholar
Hutchinson, J. S. M. and Robertson, H. A. 1966. The growth of the follicle and corpus luteum in the ovary of the sheep. Res. vet. Sci. 7: 17–24.CrossRefGoogle ScholarPubMed
Kammlade, W. G. Jr, Welch, J. A., Nalbandov, A. V. and Norton, H. W. 1952. Pituitary activity of sheep in relation to the breeding season. J. Anim. Sci. 11: 646–655.CrossRefGoogle Scholar
Land, R. B., Dickinson, A. G. and Read, J. L. 1969. The influence of seasonal variation on fertility and early body growth in sheep. Anim. Prod. 11: 251–257.Google 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
Underwood, E. J. and Shier, F. L. 1941. The effect of nutritional flushing upon fertility. J. Dep. Agric. W. Aust. 18: 13–21.Google Scholar
Wallace, L. R. 1953. Management of the fat lamb flock. N.Z. J. Agric. 87: 529–535.Google 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