Hostname: page-component-78c5997874-j824f Total loading time: 0 Render date: 2024-11-08T07:46:17.883Z Has data issue: false hasContentIssue false
  • English
  • Français

Variations in the time of onset of the breeding season in Clun ewes

Published online by Cambridge University Press:  27 March 2009

J. L. Lees
J. L. Lees
Affiliation:
Department of Agriculture (Animal Husbandry), University College of Wales, Aberystwyth
Get access Rights & Permissions [Opens in a new window]

Extract

Variations in the time of onset of the breeding season in Clun ewes have been studied during the four years 1962-65. Differences within seasons were studied in 1963 and 1964 by scattering the lambing over the first 7 months of the year. The date of first service then appears to be very highly dependent on the date of previous lambing. Time of previous weaning appears to be less important.

Very highly significant differences have been found between seasonal means and these differences have been shown to be significantly related to the mean ambient temperature during a limited period between mid-summer and the mean date for the resumption of cyclic activity in the ewes. The higher this temperature the later the onset of breeding activity. Over the years individual ewes have tended to breed consistently either early or late.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 67 , Issue 2 , October 1966 , pp. 173 - 179
Copyright
Copyright © Cambridge University Press 1966

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

De Baca, R. C, Warnick, A. C, Hitchcock, G. H. & Bogart, R. (1954). Factors associated with the onset of oestrus in ewes. Stn tech. Bull. Ore. agric. Exp. Stn, no. 29.Google Scholar
Dutt, R. H. & Bush, L. F. (1955). The effect of low environmental temperature on the initiation of the breeding season and fertility in sheep. J. Anim. Sci. 14, 885–96.CrossRefGoogle 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
Hammond, J. Jn, (1944). On the breeding season in the sheep. J. agric. Sci., Camb. 34, 97–105.CrossRefGoogle Scholar
Hunter, G. L. (1962). Observations on oestrus in Merinos. Proc. S. Afr. Soc. Anim. Prod. no. 1, pp. 67–69. Pretoria.Google Scholar
Inkster, I. J. (1959). A study of fertilisation in sheep. Sheepfmg A., pp. 9–15.Google Scholar
Lees, J. L. (1964). Variations in the breeding season of sheep and their effects on subsequent productivity and performance. Anim. Prod. 6, 255–6 (abstr.).Google Scholar
Nalbandov, A. V. (1964). Reproductive Physiology, 2nd ed. p. 80. London and San Francisco: W. H. Freeman.Google Scholar
Radford, H. M. (1961). Photoperiodism and sexual activity in Merino ewes. Aust. J. agric. Res. 12, 139–53.CrossRefGoogle Scholar
Schäfer, H. (1964). Effect of environment on sheep fertility. Z. Tierzücht. ZüchtBiol. 80, 97–129.CrossRefGoogle Scholar
Smith, I. D. (1965). The influence of level of nutrition during winter and spring upon oestrous activity in the ewe. Wld Rev. Anim. Prod. no. 4, pp. 95–101.Google Scholar
Williams, S. M. (1954). Fertility in Clun Forest sheep. J. agric. Sci., Camb. 45, 202–28.CrossRefGoogle Scholar
Yeates, N. T. M. (1949). The breeding season of sheep with particular reference to its modification by artificial means using light. J. agric. Sci., Camb. 39, 1–43.CrossRefGoogle Scholar