Endocrine, luteal and follicular responses after the use of the short-term protocol to synchronize ovulation in goats.
The effect of the so-called Short-Term Protocol (5-day progesterone treatment+PGF(2)alpha) on ovarian activity and LH surge was studied in goats. The goats received 250IU eCG at the time of device withdrawal (eCG group; n=7), or 200microg of EB (estradiol benzoate) 24h after device withdrawal (EB group; n=8), or received neither eCG nor EB (control group; n=8). The Short-Term Protocol induced greater (4.1+/-1.1ng/ml) progesterone serum concentrations at 24h after start of the treatment, that declined to 0.2+/-0.1ng/ml at 12h after device withdrawal. In all of the groups, the maximum concentration of estradiol-17beta was reached at about 36h after device withdrawal. Maximum concentration was greater in the EB group (76.9+/-24.6pmol/l) than in the control group (41.8+/-9.0pmol/l; P<0.01), with the eCG group showing intermediate concentration (70.3+/-32.5pmol/l; P=NS). The LH peak occurred earlier in the eCG group (38.4+/-2.0h after device withdrawal) and in the EB group (41.0+/-4.1h), than in the control group (46.3+/-5.1h; P<0.05). Ovulation occurred earlier in the eCG group (5/7) and in the EB group (8/8) (58.8+/-2.7h and 63.0+/-5.6h, respectively), than in the control group (7/8) (70.2+/-8.3h; P<0.05). In summary, the Short-Term Protocol induced similar concentrations of progesterone among treated goats. In addition, eCG or EB resulted in a similar increase in estradiol-17beta and a similar LH surge, which induced ovulation in most females (86.7%) in a consistent interval (about 60h) after the end of progesterone exposure.
Menchaca
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Departamento de Fisiología, Facultad de Veterinaria, Universidad de la República, Montevideo, Uruguay. alejomen@adinet.com.uy
Miller
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Salveraglio
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Rubianes
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E
D000818:Animals; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D003338:Corpus Luteum / Q000187:drug effects* / Q000502:physiology; D015237:Dinoprost / Q000494:pharmacology; D004958:Estradiol / Q000031:analogs & derivatives / Q000097:blood* / Q000494:pharmacology; D030762:Estrous Cycle / Q000187:drug effects* / Q000502:physiology; D005260:Female; D005300:Fertility Agents, Female / Q000494:pharmacology; D006041:Goats; D007315:Insemination, Artificial / Q000662:veterinary; D007986:Luteinizing Hormone / Q000097:blood*; D006080:Ovarian Follicle / Q000187:drug effects* / Q000502:physiology; D010060:Ovulation / Q000187:drug effects* / Q000502:physiology; D011374:Progesterone / Q000494:pharmacology; D013997:Time Factors
D006063:Chorionic Gonadotropin; D005300:Fertility Agents, Female; C074283:estradiol 3-benzoate; D011374:Progesterone; D004958:Estradiol; D007986:Luteinizing Hormone; D015237:Dinoprost