Embryo recovery from the oviduct in superovulated ewes: a method to improve MOET systems

Abstract

ABSTRACT:The efficiency of embryo recovery in a superovulatory treatment was studied by perfusing the oviduct or the uterine horn in 3.5 and 7 days after sponge withdrawal, respectively. Eighty-four and seventy ewes of Aragonesa breed were used as embryo donors and receptors, respectively. The donors were distributed in 3 replications. The oestrus was synchronized with the insertion of FGA intravaginal sponges (30 mg) for 13 days. Six intramuscular injections of 18 mg pFSH were applied in decreasing doses at 12 hour intervals starting 48 hours after sponge withdrawal. The recovery rate (RR) (83.2 vs. 75.8%), the viability rate (VR) (73.5 vs. 47.2%) and the number of viable embryos (VE) per donor ewe (5.9 ± 0.79 vs. 3.0 ± 0.37) were higher (P < 0.01) in ewes whose perfusion was done directly in oviducts. The interval from sponge withdrawal to oestrus had no influence on RR in any groups; however it had an effect on the VR in 3.5 and 7 days old embryos. Embryos from ewes showing the oestrus within 20 hours after sponge withdrawal had a higher viability. On the other hand, using morphologic criteria, 26.5% and 52.7% of 3.5 and 7 days old embryos, respectively, were discarded before transfer. The percentage of ewes in each group that became pregnant was similar in both groups. We conclude that in superovulated ewes the embryo recovery rate, viability and number of viable embryos are higher in embryos recovered from the oviduct compared to those recovered from the uterus, without decreasing the conception rate and the viability rate is higher in ewes that show the oestrus 20 hours before sponge withdrawal.

Superovulation, in vivo Embryo Recovery and Cryopreservation for Aoudad (Ammotragus Lervia) Females Using Osmotic Pumps and Vitrification: A Preliminary Experience and its Implications for Conservation

“…In addition, estrus detection in wild females can generate stress just before the moment of ovulation., We therefore decided to use a natural approach, only introducing the aoudad male with proven fertility, and to monitor the copulation behavior. We had a low embryo recovery rate in comparison with the same procedure in domestic ewes [12], which can be attributed to the low level of fertilization in vivo rather than a failure of the technique, because our procedure has an embryo recovery of more than 85% in domestic ewes when it is performed by the same surgeon [12]. Such sub-optimal fertilization can occur in domestic ewes due to changes in the cervical mucus that generate a deficient sperm transport; this difficulty can be avoided using intrauterine insemination [18].…”

“…Prior to the embryo collection, ovarian status was evaluated by endoscopy to determine whether surgery was necessary. The mini-laparotomy for the embryo collection was performed according to the technique described by Ramon-Ugalde et al [12]. The flushing medium used was TCM-199 with Hank's Salts containing L-glutamine, HEPES 25 mM (Gibco®, cat.…”

Response to FSH (Folltropin-V) and hCG treatment on superovulation and embryo production in sheep under sub-tropical climate

“…The embryo recovery percentage throughout this experiment ranged from 10-30 percent with an average of 21.79 percent, which is quite lower than the usual rates obtained under the traditional decreasing dose FSH protocols (D'Alessandro et al, 1996) [14] . Forcada et al (2012) [18] observed 50-60% recovery rate while Ramon-Ugalde et al (2008) [47] observed 70% recovery rate after uterus flusing in superovulated ewes. Very low recovery rate was observed by López-Saucedo et al (2013) [35] in wild Barbery sheep of Mexico.…”