Estrus synchronization in microminipig using estradiol dipropionate and prostaglandin F-2 alpha

摘要

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) F-2 alpha 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-17 beta 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 x 1 group), one (D0 and D4; 1.5 mg x 2 group), or two (D0, D4 and D7; 1.5 mg x 3 group) additional treatments. The pseudopregnancy rate was significantly higher in the 1.5 mg x 3 than in the 1.5 mg x 1 group. In experiment 3, PGF(2 alpha) 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 PGF(2 alpha) treatment and LH surge were observed in 100% and 80% pseudopregnant MMpigs, respectively. The interval from the day of the first PGF(2 alpha) 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 PGF(2 alpha).