Embryo Transfer in Anovulatory Recipient Mares Treated with Estradiol Benzoate and Long-Acting Progesterone

Hormone supplementation protocol using estradiol benzoate and long-acting progesterone is efficient in maintaining pregnancy of anovulatory recipient mares during autumn transitional phase

“…However, in the present research, administering exogenous progesterone to anovulatory mares during the transitional period led to improvements in pregnancy rates. Kaercher et al (2013) have observed that pregnancy rates in anovulatory and estrous cyclic mares were similar when the anestrous mares were given 400 mg of long-acting progesterone and the same estradiol benzoate dose used in the present study. In the present study, administering 1500 mg long-lasting progesterone and estradiol benzoate to anovulatory mares resulted in greater pregnancy rates than those observed for estrous cyclic mares.…”

“…In the present study, administering 1500 mg long-lasting progesterone and estradiol benzoate to anovulatory mares resulted in greater pregnancy rates than those observed for estrous cyclic mares. In addition, the present study was conducted in the autumn transitional phase, when serum progesterone concentrations are known to be less, and there were greater concentrations of progesterone achieved by treatments as compared with those in the research performed by Kaercher et al (2013). In previous studies it was reported that the administration of short or long-acting progesterone (Rocha-Filho et al, 2004) as well as long-acting progesterone associated with estradiol benzoate treatments (Kaercher et al, 2013) maintained pregnancy in anovulatory recipient mares after embryo transfer.…”

“…In addition, ovariectomized mare recipients are able to establish and maintain pregnancy when treated with progesterone until Day 100 of gestation (Hinrichs et al, 1987). For these reasons, hormonal protocols using progestins (Hinrichs et al, 1986;Shoemaker et al, 1989), progesterone (Hinrichs et al, 1987;Vanderwall et al, 2007), estradiol benzoate plus either progestins (Wiepz et al, 1988) or progesterone (Kaercher et al, 2013) have been used successfully to maintain pregnancy in anovulatory and ovariectomized embryo recipient mares. Thus, hormonal administration to anovulatory mares can make them suitable as embryo recipients, thereby reducing the problems associated to donor/recipient estrous synchronization and allowing the use of more recipients at the end of breeding season (Silva et al, 2014).…”

Likelihood of pregnancy after embryo transfer is reduced in recipient mares with a short preceding oestrus

“…This is confirmed by the successful use in practice of oestrogen administration followed by progesterone treatment to prepare anoestrous mares to receive embryos [11][12][13]. This is confirmed by the successful use in practice of oestrogen administration followed by progesterone treatment to prepare anoestrous mares to receive embryos [11][12][13].…”

Short communication: Establishment and maintenance of donkey-in-mule pregnancy after embryo transfer in a non-cycling mule treated with oestradiol benzoate and long-acting progesterone

“…Besides, intraspecific (Kaercher et al, 2013;Botelho et al, 2015) and interspecific (donkey-in-mare) (Allen et al, 1993;Peña-Alfaro et al, 2014) pregnancies have been established by ET in non-cycling mares. However, non-cycling recipient mules treated with oestradiol benzoate and progesterone before transfer of horse embryos failed to become pregnant (Camillo et al, 2003).…”