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A note on the reproductive activity of Hampshire and Suffolk ewes outside the breeding season

Published online by Cambridge University Press:  02 September 2010

L. L. Bellinger  and
V. E. Mendel
L. L. Bellinger
Affiliation:
Department of Animal Science, University of California, Davis 95616, USA
V. E. Mendel
Affiliation:
Department of Animal Science, University of California, Davis 95616, USA
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Summary

The present study investigated the intensity of the anoestrous period in 36 Hampshire and Suffolk ewes as influenced by the photoperiod and the presence of the ram. The study began on 4 April and terminated on 11 June. Ewes kept under natural light in the absence of the ram (Group I) exhibited a limited amount of ovarian activity as determined by cervical smear. Ewes kept under natural light, but in the presence of a ram (Group II) showed an increased amount of cycling (P < 0·05) when compared to that in Group I. Two ewes from Group II mated during the so-called anoestrous period and subse-quently lambed. Ten of 12 ewes, subjected to a decreased photoperiod (Group HI), increased ovarian activity within a few days of light reduction. Five ewes in this group lambed.

Type
Research Article
Information
Animal Production , Volume 19 , Issue 1 , August 1974 , pp. 123 - 126
Copyright
Copyright © British Society of Animal Science 1974

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References

REFERENCES

Cole, H. H. and Miller, R. F. 1935. Changes in the reproductive organs of the ewe with some data bearing on their control. Am. J. Anat. 57: 39–97.CrossRefGoogle Scholar
Cole, H. H., Hart, G. H. and Miller, R. F. 1945. Studies on the hormonal control of estrus phenomena in the anestrus ewe. Endocrinology 36: 370–380.CrossRefGoogle Scholar
Grant, R. 1933. Occurrence of ovulation without heat in the ewe. Nature, Lond. 131:802.CrossRefGoogle Scholar
Hafez, E. S. 1951a. Inhibitory action of artificial light on the sexual season of the ewe. Nature, Lond. 168:336.CrossRefGoogle ScholarPubMed
Hafez, E. S. 1951b. Reproduction in sheep and the response to artificial light. Experientia 7: 423CrossRefGoogle ScholarPubMed
Hart, D. S.1950. Photoperiodicity in Suffolk sheep. J. agric. Sci., Camb. 40:143–149.Google Scholar
Mckenzie, F. F. and Terrill, C. E. 1937. Estrus, ovulation and related phenomena in the ewe. Res. Bull. Mo. agric. Exp. Stn., No. 264.Google Scholar
Raeside, J. I. and Mcdonald, M. F. 1959. Arborization of cervical mucus in the ewe. J. Endocr. 18: 350–358.Google Scholar
Robinson, T. J. 1950. The control of fertility in sheep. I. Hormonal therapy in the induction of pregnancy in the anestrus ewe. J. agric. Sci., Camb. 40: 275–307.Google Scholar
Schinckel, P. G. 1954. The effect of the ram on the incidence and occurrence of oestrus in ewes. Aust. vet. J. 30: 189–195.Google Scholar
Yeates, N. T. M. 1947. Influence of variation in length of day upon the breeding season in sheep. Nature, Lond. 160: 429–430.CrossRefGoogle ScholarPubMed
Yeates, N. T. M. 1949. The breeding season of the sheep with particular reference to its modification by artificial means. J. agric. Sci., Camb. 39: 1–43.Google Scholar