Effect of different treatments at early postpartum period on uterine involution and subsequent reproductive performance in dairy cows

The objective of this study was to investigate the effectiveness of PGF2α and GnRH injections at early lactation on placental drop, uterine involution and subsequent reproductive performance in dairy cows. The study was conducted in El-Salhya dairy cattle breeding farm on 64 lactating dairy cows. Cows were assigned into the following groups: PGF2α treated group (18 cows), received PGF2α immediately after calving. GnRH treated group (17 cows), received GnRH analogue on 13-15 day postpartum (pp). PGF2α plus GnRH treated group (15 cows), received PGF2α immediately after calving and GnRH analogue on 13-15 day pp. Control group included 14 cows which were left without treatment. The reproductive tract of the cows was examined twice weekly by rectal palpation and transrectal ultrasound scanning to assess the postpartum uterine involution and the resumption of ovarian activity. Blood samples were obtained parallel with the reproductive examination for progesterone assay. Cows treated immediately after calving with PGF2α showed an earlier placental drop compared to the non treated ones. Cows treated immediately after calving with PGF2α showed an earlier uterine involution compared to those in the control and GnRH treated group. There was no significant difference in reproductive performance among control and treated groups. In conclusion, administration of PGF2α and GnRH during the early postpartum period did not significantly improve the reproductive performance; however, they slightly improve the time required for placental drop and uterine involution