Influence of Estrus Synchronization of Prepubertal Gilts on Embryo Quality

Abstract

Abstract. Synchronization and superovulation are commonly used to obtain large numbers of embryos for experimental and practical purposes. This study compared the number, quality, and in vitro development of embryos recovered from gilts following single or double estrus synchronization and superovulation. Prepubertal gilts from the single synchronization group were injected with 1500 I.U. PMSG and 1000 I.U. hCG 72 h later. The double synchronized group of gilts was treated with 750 I.U. PMSG and 500 I.U. hCG 72 h later. After 17 days, 1500 I.U. PMSG followed by 1000 I.U. hCG was administered. Five days after insemination embryos were recovered and cultured for 6 days. Both single and double hormonal stimulation schedules resulted in recovery of elevated numbers of embryos (28.4 and 23.4 vs. 11.3; p<0.01and p≤0.05, respectively) with a higher percentage of embryos classified as degenerated (39.2% and 43.1%, respectively) compared to the non-stimulated, control group (5.1%). The number of embryos destined for culture did not differ between the single and double synchronized groups. The highest percentage of hatched embryos was observed in the control group. In conclusion, the single synchronization and superovulation schedule is sufficient to obtain high numbers of embryos, however, both synchronization methods resulted in the recovery of considerable numbers of degenerated embryos. A higher number and percentage of hatched embryos after culture was found among embryos from the control group compared to gonadotropinstimulated gilts.

Factors of importance when selecting sows as embryo donors

“…Unlike in sows Martinez et al, 2014), superovulation treatments in prepubertal gilts and synchronized mature gilts yield high proportions (25% to 50%) of unfertilized oocytes and degenerated embryos (Guthrie et al, 1974;Holt and Schlieper, 1991;Wallenhorst and Holtz, 2002;Ziecik et al, 2005), which makes the use of this these females as embryo donors inadvisable. We had only selected multiparous sows due to their high accessibility on-farm and because they usually have farrowing rates and litter sizes higher than those in primiparous sows.…”

Synchronization and superovulation of mature cycling gilts for the collection of pronuclear stage embryos

“…Embryos obtained from pigs having naturally occurring estrous cycles are developmentally superior to those when superovulation treatments are used (Ziecik et al, 2005). However, due to problems inherent to collecting adequate numbers of stage-specific embryos for the procedure, it is not generally feasible to produce transgenic pigs via microinjection using naturally ovulated embryos.…”

Ovarian stimulation with human chorionic gonadotropin and equine chorionic gonadotropin affects prostacyclin and its receptor expression in the porcine oviduct

“…Our previous study revealed that ovarian stimulation with equine chorionic gonadotropin (eCG) and human chorionic gonadotropin (hCG) to induce ovulation and evoke superovulation completely changed the synthesis of PGE 2 and PGF 2a [17]. Therefore, we propose that disturbances of proper embryo development and viability, which were documented after administering hCG/eCG [18] may be connected with alterations in PGI 2 production and expression of its receptor in porcine oviducts. The present study was undertaken to examine, for the first time, whether insemination by itself and with hCG/eCG affect PGI 2 synthesis in the porcine oviduct on day 3 post coitus (p.c.…”

“…Małysz-Cymborska, A. Andronowska / Domestic Animal Endocrinology 53 (2015)[17][18][19][20][21][22][23][24][25] …”