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A comparison of ovulation rate and late embryonic mortality in ewe lambs and ewes and the rôle of late embryo loss in ewe lamb subfertility

Published online by Cambridge University Press:  02 September 2010

N. F. G. Beck
Affiliation:
Welsh Institute of Rural Studies, University of Wales, Aberystwyth, Penglais, Aberystwyth, Dyfed SY23 3DD
M. C. G. Davies
Affiliation:
Welsh Institute of Rural Studies, University of Wales, Aberystwyth, Penglais, Aberystwyth, Dyfed SY23 3DD
B. Davies
Affiliation:
Welsh Institute of Rural Studies, University of Wales, Aberystwyth, Penglais, Aberystwyth, Dyfed SY23 3DD
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Abstract

An investigation was conducted to compare late embryonic losses in ewe lambs and ewes and to determine the effect of inducing embryonic mortality on day 15 of pregnancy on reproductive function in ewe lambs. Ovulation rate and embryo survival were determined, at 15 and 30 days after mating, in a total of 83 ewe lambs and 67 ewes. Ovulation rate was lower, at spontaneous oestrus, in ewe lambs (1·07) than in ewes (1·25; P < 0·05). There was no difference in embryo survival at day 15, as 79% of ewe lambs and 80% of ewes contained expanded conceptuses. However, embryo survival was lower in ewe lambs (69%) than ewes (88%) at day 30 (P < 0·05). Embryonic mortality was induced in an additional 18 ewe lambs with an intrauterine injection of colchicine on day 15 post mating. Four of these animals had normal length oestrous cycles, six had inter-oestrus intervals ranging from 22 to 35 days and eight did not return to oestrus. Overall, the results of this study demonstrate that low ovulation rate and late embryonic losses make a significant contribution to subfertility in ewe lambs. Moreover, conceptus death is associated with luteal persistence, which may reduce reproductive performance by preventing remating.

Type
Research Article
Copyright
Copyright © British Society of Animal Science 1996

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References

Al Wahab, R. M. H. and Bryant, M. J. 1978. Reproduction in young female sheep induced to breed at various ages. Animal Production 26: 309316.Google Scholar
Beck, N. F. G. and Davies, M. C. G. 1994. The effect of stage of breeding season or pre-mating oestrogen and progestagen therapy on fertility in ewe lambs. Animal Production 59: 429434.Google Scholar
Bryden, M. M., Evans, H. E. and Binns, W. 1972. Embryology of the sheep. 1. Extraembryonic membranes and the development of body form. Journal of Morphology 138:169186.CrossRefGoogle Scholar
Davies, M. C. G. 1988. Factors affecting embryo mortality in ewe lambs. Ph.D. thesis, University of Wales, Aberystwyth.Google Scholar
Davies, M. C. G. and Beck, N. F. G. 1992. Plasma hormone profiles and fertility in ewe lambs given progestagen supplementation after mating. Theriogenology 38: 513526.CrossRefGoogle ScholarPubMed
Davies, M. C. G. and Beck, N. F. G. 1993. A comparison of plasma prolactin, LH and progesterone concentrations during oestrus and early pregnancy in ewe lambs and ewes. Animal Production 57: 281286.Google Scholar
Downing, J. M. 1980. Studies on the attainment of puberty and reproductive performance in Clun Forest ewe lambs. Ph.D. thesis, University of Wales, Aberystwyth.Google Scholar
Dýrmundsson, Ó. R. 1973. Puberty and early reproductive performance in sheep. 1. Ewe lambs. Animal Breeding Abstracts 41: 272289.Google Scholar
Dýrmundsson, Ó. R. 1983. The influence of environmental factors on the attainment of puberty in ewe lambs. In Sheep production (ed. Haresign, W.) pp. 393408. Butterworths, London.Google Scholar
Edey, T. N. 1967. Early embryonic death and cycle length in the ewe. Journal of Reproduction and Fertility 13: 437443.CrossRefGoogle ScholarPubMed
Edey, T. N., Kilgour, R. and Bremner, K. 1978. Sexual behaviour and reproductive performance of ewe lambs at and after puberty. Journal of Agricultural Science, Cambridge 90:8391.CrossRefGoogle Scholar
Hare, L. and Bryant, M. J. 1985. Ovulation rate and embryo survival in young ewes mated either at puberty or second or third oestrus. Animal Reproduction Science 8: 4152.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: 263274.Google Scholar
Langford, G. A. 1986. Influence of body weight and number of inseminations on fertility of progestagen-treated ewe lambs raised in controlled environments. Journal of Animal Science 62:10581062.CrossRefGoogle Scholar
McMillan, W. H. and McDonald, M. F. 1985. Survival of fertilized ova from ewe lambs and adult ewes in the uteri of ewe lambs. Animal Reproduction Science 8: 235240.CrossRefGoogle Scholar
Moore, N. W. and Rowson, L. E. A. 1966. Egg transfer in sheep. Factors affecting the survival and development of transferred eggs. Journal of Reproduction and Fertility 1: 332349.CrossRefGoogle Scholar
Quirke, J. F. 1979. Control of reproduction in adult ewes and ewe lambs, and estimation of reproductive wastage in ewe lambs following treatment with progestagen treated sponges and PMSG. Livestock Production Science 6: 295305.CrossRefGoogle Scholar
Quirke, J. F. 1981. Regulation of puberty and reproduction in female lambs: a review. Livestock Production Science 8: 3753.CrossRefGoogle Scholar
Quirke, J. F. and Hanrahan, J. P. 1983. Comparison of the survival of fertilized eggs from adult ewes in the uteri of adult ewes and ewe lambs. Journal of Reproduction and Fertility 68: 289294.CrossRefGoogle ScholarPubMed
Quirke, J. F., Adams, T. E. and Hanrahan, J. P. 1983. Artificial induction of puberty in ewe lambs. In Sheep production (ed. Haresign, W.), pp. 409429, Butterworths, London.Google Scholar
Ryan, D. P., Rodriguez, H. F., Thomson, D. L., Saxton, A. M. and Godke, R. A. 1992. Luteal maintenance in cattle after conceptus death during the first trimester of pregnancy. Journal of Animal Science 70: 836840.CrossRefGoogle Scholar
Wilmut, I., Sales, D. I. and Ashworth, C. J. 1986. Maternal and embryonic factors associated with prenatal loss in mammals. Journal of Reproduction and Fertility 76: 851864.CrossRefGoogle ScholarPubMed