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Reproduction in young female sheep induced to breed at various ages

Published online by Cambridge University Press:  02 September 2010

R. M. H. Al-Wahab  and
M. J. Bryant
R. M. H. Al-Wahab
Affiliation:
Department of Agriculture and Horticulture, University of Reading, Earley Gate, Reading RG6 2AT
M. J. Bryant
Affiliation:
Department of Agriculture and Horticulture, University of Reading, Earley Gate, Reading RG6 2AT
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Abstract

Two hundred and thirteen Suffolk × (Cadzow Improver × Scottish Blackface) young female sheep were mated either after the natural occurrence of puberty or at 140, 182 and 224 days of age in Year 1 and 140 and 182 days of age in Year 2 after treatment with progestagen (MAP) and 750 i.u. PMS; 90 to 100% of sheep ovulated after hormone treatment. Few sheep were found with embryos or live lambs in Year 1, possibly because of inadequacies in artificial insemination. In Year 2, after natural mating, the incidences of cleaved ova, live embryos 26 days after mating and live lambs born were 82, 33 and 23% respectively for sheep mated at 140 days; 100, 31 and 23% respectively for sheep mated at 182 days; and 100, 62 and 31% respectively for sheep mated after puberty. The occurrence of a second post-treatment ovulation in sheep without embryos at 26 days increased with age at treatment.

Type
Research Article
Information
Animal Production , Volume 26 , Issue 3 , June 1978 , pp. 309 - 316
Copyright
Copyright © British Society of Animal Science 1978

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References

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