Folliculogenesis, Embryo Parameters, and Post-Transfer Recipient Pregnancy Rate in eFSH-Treated Donor Mares

摘要

Equine follicle-stimulating hormone (eFSH) treatment increases embryo-recovery rate in donor mares. Recipient pregnancy rates per donor cycle were similar between eFSH-treated mares and non–eFSH-treated progesterone- and estradiol-synchronized donormares. Embryo transfer offers distinct advantages to own-ers who wish to increase the number of foals born from valuable mares. It is also useful for mares where pregnancy is not desirable, such as in perf or-mance mares or in cases where medical issuespre-clude carrying a foal to term. However, the high cost of equine embryo transfer dictates that only genetically superior animals should be used as donors. Contributing to the expense of embryo transfer are the unique biological features and technicalproblems that must be overcome in mares. Currently, single-embryo recovery attempts are common in equine-em-bryo transfer. A 50% embryo-recovery rate per ovu-lation and a 50–65% pregnancy rate per transferred embryo is expected in commercial embryo-transfer op-erations. Economically, there is a need to increase the success rate with embryo transfer.