Administración posmonta de acetato de fluorogestona en ovejas donadoras de embriones / Posmating administration of fluorogestone acetate in ambryo donor ewes

De dos estudios realizados con ovejas donadoras de embriones tratadas posmonta con acetato de fluorogestona se analizaron el número de cuerpos lúteos normales o en regresión y el número de ovocitos o embriones recolectados. La sincronización de los estros se realizó con esponjas intravaginales impregnadas con 40 mg de acetato de fluorogestona (FGA) y para la superovulación se utilizaron 200 UI de hormona folículo estimulante en esquema decreciente. A las hembras en estro se les dio monta mientras permanecieron receptivas y doce horas después de finalizada la última monta, en la mitad de las ovejas del primer estudio y en todas las del segundo, se colocaron otras esponjas intravaginales con FGA que se retiraron el día de la recolección embrionaria. En cada oveja se clasificaron los cuerpos lúteos como normales o en regresión de acuerdo con su morfología y producción de progesterona. De las ovejas del primer trabajo tratadas con FGA se recolectaron más embriones que de las no tratadas (7.66 vs 3.87, P<0.05). Las menores concentraciones promedio de progesterona se encontraron en las ovejas con cuerpos lúteos en regresión (0.62 ng/mL). De acuerdo con los niveles de progesterona la regresión prematura de los cuerpos lúteos ocurrió al día 3.7 posestro. De las ovejas del segundo experimento que presentaron cuerpos lúteos en regresión y que fueron tratadas con FGA se recolectaron en promedio 8.0 embriones. En conclusión, la administración posmonta de FGA incrementó el número de embriones recolectados en las donadoras con regresión lútea prematura.

Peripheral serum progesterone and estradiol B17 hormone concentrations in saanen goats during synchronization of estrus with vaginal sponge

Estrus in saanen goats was synchronized using vaginal sponge during breeding and non breeding seasons. In the breeding season, the treated goats received 400 IU equine chorionic gonadotropin [eCG] at the day of the sponge removal, while in non breeding season the goats received 600 IU eCG two days before sponge removal. Serum progesterone and estradiol B17 were determined one day before, at day of, one day after and two days after sponge removal in both groups. The results revealed that during the breeding season all goats exhibited estrus 24 hours after sponge removal. The mean concentrations of progesterone were 5.43 +/- 0.83 and 5.31 +/- 0.37 ng/ml, respectively at one day before sponge removal and at the day of sponge removal. The level of progesterone sharply decreased to [0.26 + 0.08 ng/ ml one day after sponge removal and remained low two days after sponge removal [0.43 +/- 10.18 ng/ml]. The mean serum estradiol B17 was low before and at sponge removal. The maximum peak of serum estradiol B 17 [50.5 +/- 6.49 pg/ml] was observed 24 hours after sponge removal. The level of estradiol B 17 dropped abruptly and reached to 14.2 +/- 2.59 pg/ml 48 hours after sponge removal. On the other hand, in the non breeding season, the treated goats showed signs of estrus 20-24 hours after sponge removal. Mean serum progesterone concentration was found low in all goats. However, the mean estradiol serum levels increased after eCG injection and the maximum peak [60.8 +/- 11.2 pg/ml] was observed 24 hours after sponge removal. Forty eight hours after sponge removal, the estrediol level declined to 17.5 +/- 2.2 pg/ml. During breeding season, in control animals the serum progesterone was higher than 1 ng/ml at day 16 of the cycle, then started to decrease. The estradiol B 17 showed a steady increase at day 19 of the cycle. In non breeding season, the control goats had no ovarian activity along with constant low level of hormones. It could be suggested that the levels of progesterone and estradiol hormone were altered around time of induced estrus, as a result of a positive effect of eCG injection on estradiol 17 B production and a negative effect on progesterone and hence insure a high degree of synchronization

Use of Chronogest implants and Folltropin for estrus synchronization and superovulation in goats.

Six Barbari goats each were assigned randomly to treatments 1,2 or 3, comprising im injections of FSH (folltropin) at 12, 14 or 16 mg dose level respectively. Estrus was synchronized with intravaginal sponge impregnated with flugestone acetate (30 mg; chronogest) inserted for 12 days and cloprostenol (125 micrograms) im at the insertion as well as at removal of sponge. FSH treatment started 48 hr before the sponge removal as 4-day declining dose scheme. Estrus could be effectively synchronized in all goats under the study, with significant difference (P less than 0.05) in the onset of estrus between the treatment groups. All goats were administered with 750 IU hCG i.v. at estrus. Recording of ovarian response and embryo recovery was done 45 hr after the onset of estrus. The prime aim of superovulation was effectively achieved in Barbari goats with the use of chronogest implants and folltropin. There was no difference (P greater than 0.05) between the treatment groups in recovery of transferable embryos, however, 14 mg folltropin appeared to be near optimal dose. There was no adverse effect on the quality of recovered embryos with high doses of folltropin.