Hostname: page-component-586b7cd67f-vdxz6 Total loading time: 0 Render date: 2024-11-30T14:35:15.609Z Has data issue: false hasContentIssue false
  • English
  • Français

Rebreeding activity in milking Awassi ewes under semi-arid conditions

Published online by Cambridge University Press:  02 September 2010

R. Kassem ,
J. B. Owen  and
I. Fadel
R. Kassem
Affiliation:
Kraim Centre for Sheep Breeding and Range Development, Salamieh, Syria
J. B. Owen
Affiliation:
Centre for Arid Zone Studies, School of Agricultural and Forest Sciences, University of Wales, Deiniol Road, Bangor LL57 2UW
I. Fadel
Affiliation:
Kraim Centre for Sheep Breeding and Range Development, Salamieh, Syria
Get access

Abstract

Post-partum interval to oestrus and conception was studied in relation to previous and current lactation (milk yield and lactation length), age of ewe and treatment with intravaginal sponges in a total of 186 Awassi ewes lambing in December/January. In the first trial, 62% of ewes, tested for oestrus twice a day with vasectomized rams until the end of May, showed oestrus between 1 and 170 days after lambing with a mean interval of 83 (s.d. 31·9) days. Neither current nor previous lactation had important effects on the rebreeding interval (P > 0·05). In another trial where ewes were exposed continuously to fertile rams until the end of March, 50% showed oestrus with a mean interval of 56 (s.d. 23·7) days (range 33 to 113 days). Of those showing oestrus, 86% conceived with a mean post-partum interval of 70 (s.d. 33·0) days (range 33 to 133 days). Lactation yield had no significant effect on the lambing-to-oestrus interval (P > 0·05) but ewes with longer lactations showed longer lambing-to-conception intervals (P > 0·01). Treatment with progesterone-impregnated vaginal sponges at 1, 2 and 3 months post partum showed an increase in the percentage of ewes showing oestrus from 35% to 75% and in those conceiving from 25% to 70% as the timing of treatment increased from 1 to 3 months post partum. It is concluded that lambing three times in 2 years is biologically feasible and that hormone treatment can facilitate its operation in practice.

Type
Research Article
Information
Animal Production , Volume 49 , Issue 1 , August 1989 , pp. 89 - 93
Copyright
Copyright © British Society of Animal Science 1989

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

Aboul-Naga, A. M. 1983. Lamb crop eight months from subtropical fat-tailed sheep. Proceedings of 5th World Conference on Animal Production, Tokyo, Vol. 2, pp. 147–148. Japanese Society of Zootechnical Science.Google Scholar
Barker, H. B. and Wiggins, E. L. 1964. Estrual activity in lactating ewes. Journal of Animal Science 23: 973–980.CrossRefGoogle Scholar
Eyal, E., Lawi, A., Folman, Y. and Morag, M. 1978 Lamb and milk production of a flock of dairy ewes under an accelerated breeding regime. Journal Agricultural Science, Cambridge 91: 69–79.CrossRefGoogle Scholar
Fadel, I., Owen, J. B. and Kassem, R. 1989. Economic assessment of Awassi ewe production systems under semi-arid conditions. Research and Development in Agriculture 6: 47–52.Google Scholar
Fadel, I., Owen, J. B., Kassem, R. and Juha, H. 1989. A note on the milk composition of Awassi ewes. Animal Production 48: 606–610.CrossRefGoogle Scholar
González-Stagnaro, C. and Perozo-Gory, F. 1985. [Effect of production status and suckling lambs on the reproductive efficiency and litter size in ewes in the tropics.] Memorias Asociación Latin Americana de Produccion Animal, 1983, 18: 136–137. [Animal Breeding Abstracts, 1987, 55: 618.]Google Scholar
Hafez, E. S. E. 1952. Studies on the breeding season and reproduction of the ewe. Part I. The breeding season in different environments. Part II. The breeding season in one locality. Part III. The breeding season and artificial light. Part IV. Studies on the reproduction of the ewe. Part v. Mating behaviour and pregnancy diagnosis. Journal of Agricultural Science, Cambridge 42: 189–199, 199-231, 232-241, 241-255, 255-265.CrossRefGoogle Scholar
Honmode, D. 1977. [Postpartum changes in the uterus of ewes.] Zhivotnovodstvo 3: 62–63. [Animal Breeding Abstracts 45: 384.]Google Scholar
Morag, M. and Eyal, E. 1971. Post partum conception in lactating Awassi and East Friesian × Awassi dairy ewes. Journal Agricultural Science, Cambridge 77: 109–116.CrossRefGoogle Scholar
Nie, N. H., Hull, C. H., Jenkins, J. G., Steinbrenner, K. and Bent, D. H. 1975. SPSS: Statistical Package for the Social Sciences. 2nd ed. McGraw-Hill, New York.Google Scholar
Solomonov, H. 1965. [The effect of milking ewes during the breeding season on their performance.] Zhivotnovodni Nauki, Sofija 2: 217–223. [Animal Breeding Abstracts 33: 575.]Google Scholar