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Studies on the breeding season of Icelandic ewes and ewe lambs

Published online by Cambridge University Press:  27 March 2009

Ø. R. Dýrmundsson
Ø. R. Dýrmundsson
Affiliation:
The Agricultural College, Hvanneyri, Iceland
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Summary

The paper reports on a study, conducted in four successive seasons, of sexual development and breeding activity in females of the Iceland breed, the only breed of sheep kept in the country. The ewe lambs normally attained puberty in their first year of life, on average at 7 months of age, with marked individual variation in both age and body weight at first oestrus. Ewe lambs always showed oestrus on average slightly later than mature ewes (2–9 years), the mean date of onset of the breeding season of the latter being 8 December, however, with considerable individual variation. Furthermore, ewe lambs had a shorter breeding season (1–4 months) than ewes (4–6 months) and they appeared to experience more silent heats resulting in less regular cyclic activity. There seemed to be a minor increase in the duration of the oestrous cycle with age and ewe lambs clearly exhibited shorter oestrus (heat) than ewes. With seasonal breeding activity ranging from November to May the mid-breeding season occurs some 4–7 weeks after the shortest day.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 90 , Issue 2 , April 1978 , pp. 275 - 281
Copyright
Copyright © Cambridge University Press 1978

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References

Dufour, J. J. (1974). The duration of the breeding season in four breeds of sheep. Canadian Journal of Animal Science 54, 389–92.Google Scholar
Dýrmundsson, Ó. R. (1972). Studies on the attainment of puberty and reproductive performance in Clun Forest ewe and ram lambs. Ph.D. thesis, University of Wales, U.K.Google Scholar
Dýrmundsson, Ó. R. (1973). Puberty and early reproductive performance in sheep. I. Ewe lambs. Animal Breeding Abstracts 41, 273–89.Google Scholar
Dýrmundsson, Ó. R. (1976). Breeding from ewe lambs – a common practice in Iceland. Bulletin No. 24, Research Institute, Nedri Ás, Hveragerdi, 12 pp.Google Scholar
Dýrmundsson, Ó. R. & Lees, J. L. (1972). Attainment of puberty and reproductive performance in Clun Forest ewe lambs. Journal of Agricultural Science, Cambridge 78, 39–45.CrossRefGoogle Scholar
Fraser, A. F. & Laing, A. H. (1968). The potential breeding season of Cheviot sheep. Scottish Agriculture 47, 1–4.Google 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. Jun (1944). On the breeding season in the sheep. Journal of Agricultural Science, Cambridge 34, 97–105.CrossRefGoogle Scholar
Keane, M. G. (1974). Effect of bodyweight on attainment of puberty and reproductive performance in Suffolk × ewe lambs. Irish Journal of Agricultural Research 13, 263–74.Google Scholar
Keane, M. G. (1975). The duration of the breeding season in Suffolk × Galway ewe lambs. Journal of Agricultural Science, Cambridge 85, 569–70.CrossRefGoogle Scholar
Land, R. B. (1970). A relationship between the duration of oestrus, ovulation rate and litter size of sheep. Journal of Reproduction and Fertility 23, 49–53.Google Scholar
Lees, J. L. (1966). Variations in the time of onset of the breeding season in Clun ewes. Journal of Agricultural Science, Cambridge 67, 173–9.CrossRefGoogle Scholar
Lees, J. L. (1969). The reproductive pattern and performance of sheep. Outlook on Agriculture 6, 82–8.CrossRefGoogle Scholar
Lees, J. L. (1971). Some aspects of reproductive efficiency in sheep. Veterinary Record 88, 86–95.Google Scholar
Maijala, K. & Oesterberg, Siv (1976). Productivity of pure Finnsheep in Finland and abroad. Proceedings of the 27th Annual Meeting, European Association for Animal Production, Zürich.Google Scholar
Mason, I. L. (1969). A World Dictionary of Breeds, Types and Varieties of Livestock. Technical Communication No. 8 (rev.) of the Commonwealth Bureau of Animal Breeding and Genetics, Edinburgh, and the Commonwealth Agricultural Bureaux, Famham Royal, England. London: Morrison and Gibb.Google Scholar
Osborne, H. G. (1970). The duration and intensity of oestrus in Finnsheep. Australian Veterinary Journal 46, 605.CrossRefGoogle ScholarPubMed
Pálsson, H. (1943). International sheep breeds (Iceland sheep). In The California Wool Grower (5th International Sheep Breeds Edition, 2 11), pp. 14–22.Google Scholar
Radford, H. M., Watson, R. H. & Wood, G. F. (1960). A crayon and associated harness for the detection of mating under field conditions. Australian Veterinary Journal 36, 57–66.Google Scholar
Ricordeau, G., Tchamitchian, L., Thimonier, J., Flamant, J. C. & Theriez, M. (1976). Performances de reproduction et d'élevage des brebis Romanov, Finnoises et croisées: premier bilan des résultats obtenus en France dans les troupeaux expérimentaux de l'lNRA et dans quelques troupeaux d'étude. Proceedings of the 27th Annual Meeting, European Association for Animal Production, Zürich.Google Scholar
Sadleir, R. M. F. S. (1969). The Ecology of Reproduction in Wild and Domestic Mammals. London: Methuen.Google Scholar
Schindler, H. & Amir, D. (1972). Length of oestrus, duration of phenomena related to oestrus, and ovulation time in the local fat-tailed Awassi ewe. Journal of Agricultural Science, Cambridge 78, 151–6.Google Scholar
Williams, H. Ll., Thwaites, C. J. & Fogarty, N. M. (1974). The relationship between liveweight and its components and the onset of the breeding season in Border Leicester ewes. British Veterinary Journal 130, 70–3.Google Scholar
Yeates, N. T. M. (1949). The breeding season of the sheep with particular reference to its modification by artificial means using light. Journal of Agricultural Science, Cambridge 39, 1–43.CrossRefGoogle Scholar