dinoprost and estradiol-dipropionate

The induction of pseudopregnancy by the exogenous administration of estradiol dipropionate (EDP) was investigated in cyclic Microminipigs (MMpigs) and the effects of exogenous administration of prostaglandin (PG) F2α on estrus exhibition were assessed in pseudopregnant MMpigs. In experiment 1, ovariectomized MMpigs were given a single intramuscular injection of 0.5, 1.5, or 2.5 mg of EDP. The estradiol-17β level at each of these doses was significantly higher 1 to 3 days after EDP administration than on the day of the injection. In experiment 2, animals were given 1.5 mg of EDP once at 9 to 12 days after the end of estrus (D0) and then no (1.5 mg × 1 group), one (D0 and D4; 1.5 mg × 2 group), or two (D0, D4 and D7; 1.5 mg × 3 group) additional treatments. The pseudopregnancy rate was significantly higher in the 1.5 mg × 3 than in the 1.5 mg × 1 group. In experiment 3, PGF2α was administered twice between 26 and 28 days after EDP treatment to five pseudopregnant gilts with a 24-h interval between the two injections. Estrus after PGF2α treatment and LH surge were observed in 100% and 80% pseudopregnant MMpigs, respectively. The interval from the day of the first PGF2α treatment to the onset of estrus was 6.5 ± 0.2 days. These results indicate that multiple EDP treatments are required for induction of pseudopregnancy in MMpigs and estrus exhibition can be controlled in MMpigs by treatment with EDP and PGF2α.

Topics: Animals; Dinoprost; Estradiol; Estrus Synchronization; Female; Ovariectomy; Pseudopregnancy; Swine; Swine, Miniature

Utilization of estrus synchronization program in livestock industry would provide greater options for reproductive management in herd. To develop a convenient method for estrus synchronization in pigs, we determined the effective protocol using estradiol dipropionate (EDP) for the establishment of pseudopregnancy and investigated follicular development during the estrus synchronization with prostaglandin F2alpha (PGF2alpha) in association with reproductive hormone profiles in pseudopregnant sows.. In Experiment 1, the effective dose (0, 10, 20, or 30 mg) and timing (5, 8, 11 or 13 days after ovulation) of a single administration of EDP in cyclic pigs for the induction of pseudopregnancy were investigated. In Experiment 2, four pseudopregnant sows were treated with PGF2alpha twice at a 24-h interval between 24 and 28 days after EDP treatment. The changes in plasma concentrations of reproductive hormones were analyzed by time-resolved fluoroimmunoassay. Follicular development and ovulation following PGF2alpha administration were monitored by transrectal ultrasonography.. High efficiency (greater than 80%) of pseudopregnancy was achieved with a single treatment with 20 mg of EDP at 8 and 11 days after ovulation (equivalent to 9-13 days after the onset of estrus). Plasma estradiol-17beta concentrations in pseudopregnant sows were significantly higher between 12 h and 7 days than before EDP treatment. Total inhibin concentrations significantly decreased following EDP treatment and remained low for 14 days. The number of small follicles was increased from 6.3 +/- 2.6 at PGF2alpha treatment to 22.8 +/- 4.8 at 3 days later; this was associated with increased plasma concentrations of inhibin. Onset of estrus was detectable in all sows on 5.3 +/- 0.3 days after PGF2alpha treatment and the number of ovulated follicles was 15.5 +/- 1.4 detected at 7.6 +/- 0.2 days after the treatment.. This study has defined the effective dose and timing of EDP treatment for inducing pseudopregnancy in cyclic pigs. Our results also indicated that EDP caused a lowering of inhibin concentrations during pseudopregnancy and small numbers of follicles from 20 to 28 days after EDP. In contrast, EDP-induced pseudopregnancy appears to have no adverse effect on follicular development and subsequent ovulation following PGF2alpha administration.

Topics: Animals; Dinoprost; Estradiol; Estrus Synchronization; Female; Follicle Stimulating Hormone; Inhibins; Luteinizing Hormone; Ovarian Follicle; Progesterone; Pseudopregnancy; Swine