Intravaginal SC-9880-progesterone treatments in the synchronization of oestrus in cyclic sheep

Gordon, Ian; Maher, P. G.

doi:10.1017/s0021859600069288

Cited by 4 publications

(1 citation statement)

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“…Estrous synchronization has been a valuable tool in regulating the estrous cycle and ovulation in a variety of species. Early studies showed that progesterone and(or) progestogens administered by injection (Dutt and Casida, 1948;Cullen and Shearer, 1964), intravaginal sponge Gorden and Maher, 1971) or orally (Evans et al, 1962;Lindsay et al, 1967) could be effective in synchronization. However, progestogen administration was shown to reduce fertility at first post-treatment estrus (Curl et al, 1967;Ruttle and Menzies, 1975).…”

Section: Introductionmentioning

confidence: 99%

Reproductive Responses, Progesterone Profiles and Ovarian Characteristics of Cycling, Fine-Wool Ewes Treated with an Inhibitor of Progesterone Synthesis (Epostane)

et al. 1986

Journal of Animal Science

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In Exp. 1, 45 fine-wool ewes received (sc) either 0, 50 or 100 mg epostane (3-beta-hydroxysteroid dehydrogenase inhibitor) to examine effects on return to estrus and conception rates. Treatments were imposed on d 10 of an estrous cycle (estrus = d 0) and jugular blood samples were collected once daily on d 8 and 9, twice daily on d 10 through 13 and once daily from d 14 until first post-treatment estrus or d 20 (15 ewes/treatment). Intensive samples were obtained hourly for 6 h after treatment (d 10; five ewes/treatment). Serum progesterone (P4) before treatment was similar among groups; but by 2 h after treatment, epostane-treated ewes had lower (P less than .10) values than controls. By 6 h post-treatment, serum P4 in ewes receiving 50 (1.0 ng/ml) and 100 (.9 ng/ml) mg epostane was well below control values (3.2 ng/ml). By 7 d after treatment, 93.3% of ewes treated with 50 mg epostane had recycled compared with 66.7 and 33.3% of those receiving 100 and 0 mg, respectively (P less than .10). Similarly, 93.3, 53.3 and 26.7% of ewes receiving 50, 100 or 0 mg epostane, respectively, lambed to breeding within 7 d of treatment (P less than .05). Overall conception rates during a 34-d breeding season were similar among groups. Preweaning performance of offspring did not differ among maternal treatments.(ABSTRACT TRUNCATED AT 250 WORDS)

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Section: Introductionmentioning

confidence: 99%