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The effect of artificial light, hormones, and rams on the reproductive performance of Finn-cross ewes during the seasonal anoestrus in Israel

Published online by Cambridge University Press:  27 March 2009

D. Amir
Affiliation:
Institute of Animal Science, Agricultural Research Organization, The Volcani Center, P.O. Box 6, Bet Dagan, Israel
H. Gacitua
Affiliation:
Institute of Animal Science, Agricultural Research Organization, The Volcani Center, P.O. Box 6, Bet Dagan, Israel

Summary

Adult Finn-cross ewes, pregnant from September matings, were kept under natural (control) or artificial photoperiod (experimental). The artificial photoperiod consisted of an abrupt increase in daylength to 18 h for 30 days in November, followed by a step wise decrease of 30 min every 10 days until May.

The ewes of the two groups were either exposed daily to rams after lambing in January-February or after weaning in March, or were kept isolated from the males until mating in April. Time of mating in the latter animals was determined by measuring the intra-vaginal electrical impedance. Hormone treatment for oestrus induction was given after weaning to a portion of the control and experimental ewes. The ovarian activity of the animals was determined by examining their plasma progesterone changes.

Daily teasing of the ewes from lambing to weaning and/or treatment with artificially decreasing daylength did not influence the ovarian activity during this period. All the ewes which were examined for ovulation, from both the control and experimental groups, ovulated 40–60 days after lambing, and 96% of the animals of the two groups which were not treated with hormones for oestrus induction exhibited spontaneous oestrus in March–May.

The lambing–first ovulation and the lambing–first spontaneous oestrus intervals were longer in the light-treated than in the control ewes, and in the animals kept isolated from the rams until mating than in those exposed to the males after lambing or weaning.

A conception rate of 70–100% and a high rate of cycle activity were obtained during the two consecutive years of the experiment in both control and experimental animals, treated or not with hormones and exposed or not to rams. In view of these results, no conclusions could be drawn about the effectiveness of the artificial photoperiod, ram effect and hormone treatment, alone or in combination, in inducing cycling activity and to increase the fertility of Finn-cross ewes during the seasonal anoestrus in Israel.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1985

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References

REFERENCES

Amir, D. (1984). Reproductive characteristics of Finn-cross ewes throughout the year in Israel. In The Reproductive Potential of Cattle and Sheep (ed. Ortavant, R. and Schindler, H.), pp. 159173. Les Colloques de l'INRA (Paris).Google Scholar
Amir, D., Rosenberg, M. & Schindler, H. (1984). Oestrous and ovarian activities of Finn-cross ewes during the post-partum and seasonal anoestrous periods. Journal of Agricultural Science, Cambridge 103, 155160.Google Scholar
Amir, D. & Schindler, H. (1977). [Induction of oestrus and fertility of ewes at the beginning and the end of the sexual season.] Hassadeh 57, 16631667 (in Hebrew).Google Scholar
Amir, D., Schindler, H., Rosenberg, M. & Folman, Y. (1980). The reproductive performance of Finn x German Mutton Merino and purebred German Mutton Merino ewes. Livestock Production Science 7, 4956.Google Scholar
Cognie, Y., Hernandez-Barreto, M. & Saumande, J. (1975). Low fertility in nursing ewes during the nonbreeding season. Annales de Biologie Animate, Biochimie Biophysique 15, 329343.CrossRefGoogle Scholar
Colas, G. (1981). Variations saisonniéres de la qualité du sperme chez le bélier Ile-de-France. II. Fécondance: rélation avec les critéres qualitatits in vitro. Reproduction Nutrition Développement 21, 399407.CrossRefGoogle Scholar
Ducker, M. J., Thwaites, C. J. & Bowman, J. C. (1970). Photoperiodism in the owe. 2. The effects of various patterns of decreasing day length on the onset of oestrus in Clun Forest ewes. Animal Production 12, 115123.Google Scholar
Evans, G. & Robinson, T. J. (1980). Reproductive potential and endocrinological responses of sheep kept under controlled lighting. I. Comparative reproductive performance of four breed types of ewe. Animal Reproductive Science 3, 2337.CrossRefGoogle Scholar
Eyal, E., Lawi, A., Folman, Y. & Morag, M. (1978). Lamb and milk production of a flock of dairy ewes under an accelerated breeding regime. Journal of Agricultural Science, Cambridge 91, 5969.CrossRefGoogle Scholar
Feldman, F., Aizinbud, E. & Schindler, H. (1976). [The electrical conductivity in the vagina of ewes during the synchronization of oestrus.] Zuchthygiene 11, 16 (in German).Google Scholar
Goot, H. (1969). Effect of light on spring breeding of Mutton Merino ewes. Journal of Agricultural Science, Cambridge 73, 177180.CrossRefGoogle Scholar
Hackett, A. J., Inskeep, E. K., Robertson, H. A., Shrestha, J. N. B. & Wolynetz, M. S. (1979). Comparison of artificial insemination and natural mating on reproductive performance of five strains of sheep during the anoestrous season in an intensive system. Canadian Journal of Animal Science 59, 675683.CrossRefGoogle Scholar
Lindsay, D. R., Cognie, Y. & Signoret, J. P. (1982). Méthode simplifée de maitrise de l'oestrus chez la brebis. Annales de Zootechnie 35, 7782.CrossRefGoogle Scholar
Martin, G. B. (1984). Factors affecting the secretion of luteinizing hormone in the ewe. Biological Reviews 59, 187.CrossRefGoogle ScholarPubMed
Riches, J. H. & Watson, R. H. (1954). The influence of the introduction of rams on the incidence of oestrus in Merino ewes. Australian Journal of Agricultural Research 5, 141147.CrossRefGoogle Scholar
Robinson, J. J., Fraser, C. & McHattie, I. (1975). The use of progestagens and photoperiodism in improving the reproductive rate of the ewe. Annales de Biologie Animate Biochimie Biophysique 15, 345352.CrossRefGoogle Scholar
Robinson, T. J., Salamon, S., Moore, N. W. & Smith, J. F. (1967). The evaluation of SC-9880-impregnated intravaginal sponges for the sychronization of oestrus for large-scale artificial insemination of Merino ewes in summer and autumn. In The Control of the Ovarian Cycle in the Sheep (ed. Robinson, T. J.), pp. 208236. Sydney: Sydney University Press.Google Scholar
Rosenberg, M., Hertz, Z., Davidson, M. & Folman, Y. (1977). Seasonal variations in post-partum plasma progesterone levels and conceptions in prirniparous and multiparous dairy cows. Journal of Reproduction and Fertility 51, 363367.CrossRefGoogle ScholarPubMed
Rougeot, J. (1969). Accélération du rythme de la reproduction chez le Mouflon de Corse(Ovis ammon musimon, Schreber, 1782) au moyen de cycles photoperiodiques semestriels. Annales de Biologie Animate Biochimie Biophysique 9, 441443.CrossRefGoogle Scholar
Schanbacher, B. (1980). Relationship of daylength and prolactin to resumption of reproductive activity in anoestrous ewes. Journal of Animal Science 50, 293297.CrossRefGoogle Scholar
Schindler, H. & Amir, D. (1983). The reproductive performance of a sheep flock on a mating schedule of three restricted periods a year. 34th Annual Meeting EAAP, Madrid 2, 712 (Abstract).Google Scholar
Thimonier, J. & Mauleon, P. (1969). Variations saisonnieres du comportement d'oestrus et des activites ovarienne et hypophysaire chez les ovins. Annales de Biologie Animate Biochimie Biophysique 9, 233250.CrossRefGoogle Scholar
Vesely, J. A. (1978). Application of light control to shorten the production cycle in two breeds of sheep. Animal Production 26, 169176.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, 143.CrossRefGoogle Scholar