Prostaglandins (PGs) are critical lipid mediators involved in many reproductive processes including luteolysis, maternal recognition of pregnancy, and implantation in domestic animals. In pigs, PGs, especially PGE2 and PGF2α, are produced in the uterine endometrium. The actions of PGE2 and PGF2α are mediated by signaling receptors, PTGERs and PTGFR, respectively, but their expression in the uterine endometrium is not well elucidated. In this study, we determined expression of PTGERs and PTGFR in the uterine endometrium during the estrous cycle and pregnancy in pigs. Uterine endometrial tissue samples were collected from Day (D) 12 and D15 of the estrous cycle and from D12, D15, D30, D60, D90, and D114 of pregnancy. Temporal expression of all genes studied was analyzed by real-time RT-PCR. PTGERs except for PTGER1 were expressed in the uterine endometrium during the estrous cycle and pregnancy. Levels of PTGER2 and PTGER3 mRNA increased during early pregnancy and late pregnancy, respectively, and levels of PTGER4 mRNA were not changed during pregnancy. Levels of PTGFR mRNA were highest on D90 of pregnancy. Results of this study showed that expression of PG receptors was dynamically regulated in the uterine endometrium during pregnancy in pigs. These results indicate that actions of PGs are dependent on types of receptors and is critical to support the establishment and maintenance of pregnancy at the maternal-fetal interface in pigs.

The objective of this study was to determine the effect of administration of Prostaglandin F2α (PGF2α) on semen collection training and semen characteristics in sexually inexperienced boars. Boars were moved individually to a semen collection pen and were trained to mount dummy sow. During the first and second semen collection secessions, 4 out of 17 boars and 4 out of remaining 13 boars allowed collection of semen. The 9 boars that failed semen collection from first 2 attempts received immediately 15 mg of PGF2α i.m. (intramuscular injection) upon entering the collection pen for semen collection resulted in successful semen collection from all 9 boars. Total numbers of spermatozoa were higher in PGF2α treated boars but there was no significant difference in % motility kinematics characteristics between control and PGF2α treated groups during 72 hr period. Overall, administration of PGF2α in sexually inexperienced boars increased the sex drive and facilitated the mounting activity to the dummy sow for semen collection.