Abstract
Merino sheep normally undergo a prolonged anestrous period during spring and summer, thus preventing the continuous production of lambs for the marketplace. To meet this challenge, it has been demonstrated that off-season estrus can be artificially induced by the delivery of exogenous hormones, including the intravaginal application of progestagen sponges in combination with pregnant mare serum gonadotropin (PMSG), and melatonin. However, questions about possible hormone persistence in lamb meat have resulted in the prohibition of such hormone treatments in the agricultural practices of many countries, including Germany. The development of a natural and safe method of estrus induction in sheep has been advanced by the discovery of the “ram” effect, in which the introduction of a ram to a group of anoestrous ewes induces estrus (Martin et al., 1986).
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References
Al-Merestani, M. R., 1989, Examinations to influence the endocrine function of reproduction during and outside the breeding season by pheromones, PhD thesis, University of Leipzig.
Atkinson, S., and Williamson, P., 1985, Ram-induced growth of ovarian follicles and gonadotrophin inhibition in anoestrous ewes, J. Reprod. Fert. 73:185–189.
Boland, M. P., Al-Kamali, A. A., Crosby, T. F., Haynes, N. B., Howies, C. M., Kelleher, D. L., and Gordon, I., 1985, The influence of breed, season and photoperiod on semen characteristics, testicular size, libido and plasma hormone concentrations in rams, Anim. Reprod. Sci. 9:241–252.
Braden, T. D., King, M. E., Odde, K. G., and Niswender, G. D., 1989, Development of preovulatory follicles expected to form short-lived corpora lutea in beef cows, J. Reprod. Fert. 85:97–104.
Claus, R., 1979, Pheromone bei Säugetieren unter besonderer Berücksichtigung des Ebergeruchsstoffes und seiner Beziehung zu anderen Hodensteroiden, Paul Paray, Verlag, München.
Cohen-Tannoudji, J., Einhorn, J. and Signoret, J. P., 1994, Ram sexual pheromone: First approach of chemical identification, Physiol. Behav. 56:955–961.
Croker, K. P., Butler, L. G., Johns, M. A., and McColm, S. C., 1982, Induction of ovulation and cyclic activity in anestrous ewes with testosterone treated wethers and ewes, Theriogenology 17:349–354.
D`Occhio, M. J., and Brooks, D. E., 1983, Seasonal changes in plasma testosterone concentration and mating activity in Border leicester, Poll Dorst, Romney and Suffolk rams, Austr. J. Exper. Agric. Anim. Husb. 13:248–253.
Fulkerson, W. J., Adams, N. R., and Gherardi, P. B., 1981, Ability of castrate male sheep treated with oestrogen or testosterone to induce and detected oestrus in ewes, Appl. Anim. Ethology 7:57–66.
Haynes, N. B., and Haresign, W., 1987, Endocrine aspects of reproduction in the ram important to the male effect, World Rev. Anim. Prod. 23:21–28.
Ichimaru, T., Takeuchi, Y., and Mori, Y., 1999, Stimulation of the GnRH pulse generator activity by continuous exposure to the male pheromones in the female goat, J. Reprod. Develop. 45:243–248.
Kaulfuß, K.-H., and Berger, E., 2000, Ultrasonic examination of the ovary activity in sheep before and after weaning, Reprod. Dom. Anim. 35:29.
Kaulfufß, K.-H., SuB, R. and Moritz., 1999, Examinations about the seasonality of reproduction in German Mutton Merino and German Blackheaded sheep, in: II. VDL-Fachtagung Forschung im Schafsektor, pp. 115–122.
Knight, T. W., 1983, Ram induced stimulation of ovarian and oestrous activity in anoestrous ewes - a review, Proc. New Zealand Soc. Anim. Prod. 43:7–11.
Knight, T. W., and Lynch, P. R., 1980a, Source of ram pheromones that stimulates ovulation in the ewe, Anim. Reprod. Sci. 3:133–136.
Knight, T. W., and Lynch, P. R., 1980b, The pheromone from rams that stimulates ovulation in the ewe, Proc. Aust. Soc. Anim. Prod. 13:74–76.
Knight, T. W., Tervit, H. R., and Fairclough, R. J., 1981, Corpus luteum function in ewes stimulated by rams, Theriogenology 15:183–190.
Martin, G. B., and Scaramuzzi, R. J., 1983, The induction of oestrus and ovulation in seasonally anovular ewes by exposure to rams, J. Steroid Biochem. 19:869 - 875.
Martin, G. B., Oldham, C. M., and Lindsay, D. R., 1980a, Increased plasma LH levels in seasonally anovular merini ewes following the introduction of rams, Anim. Reprod. Sci. 3:125 - 132.
Martin, G. B., Cognie, Y., Gayerie, F., Oldham, C. M., Poindron, P., Scaramuzzi, R. J., and Thierry, J. C., 1980b, The hormonal response of teasing, Proc. Aust. Soc. Anim. Prod. 13:77–79.
Martin, G. B., Oldham, C. M., Cognie, Y., and Pearce, D. T., 1986, The physiological responses of anovulatory ewes to the introduction of rams: a review, Livest. Prod. Sci. 15:219–247.
Opitz, H., 1991, Pheromones in mammals and the possibility of the application of ram pheromones to induce and stimulate oestrous, PhD thesis, University of Leipzig.
Over, R., 1992, Physiological reactions and operations to isolate pheromones of rams and he-goats, PhD thesis, University of Hohenheim.
Scaramuzzi, R. J., and Downing, J. A., 1999, Effect of progesterone on the GnRH-induced secretion of oestradiol and androstenedione from the autotransplanted ovary of the anoestrous ewe, J. Reprod. Pert. 116:127–132.
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Kaulfuß, KH., Süß, R., Schenk, P., Berger, E., von Borell, E. (2001). Hypothalamic and Ovarian Response to Pheromone Application in Seasonal Anoestrous German Mutton Merino Sheep. In: Marchlewska-Koj, A., Lepri, J.J., Müller-Schwarze, D. (eds) Chemical Signals in Vertebrates 9. Springer, Boston, MA. https://doi.org/10.1007/978-1-4615-0671-3_51
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DOI: https://doi.org/10.1007/978-1-4615-0671-3_51
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