Effect of day of transfer and treatment administration on the recipient on pregnancy rates after equine embryo transfer

摘要

Donor-recipient synchronization has a major influence on the outcome of an equine ET program: To achieve optimal results recipients should ovulate between 1 day earlier and 3 after the donor (McKinnon and Squires 1988). Recipients’ selection performed on the 5th day of diestrous allowed pregnancy rates close to 75 % (Carnevale et al. 2000; Squires et al. 2004). A post-surgical-ET-like treatment resulted in pregnancy rates over 80 % (Foss et al. 1999). Equine embryos (Hinrichs et al. 1985; McKinnon et al. 1988; Hinrichs et al. 1989; Lagneaux and Palmer 1989; Carnevale et al. 2000; Pessoa et al. 2004) or oocytes (Carnevale et al. 2005) have been succesfully transferred to acyclic ovariectomized and asynchronous recipients treated with estrogens or/and progestins. The aim of this study was to analyze the influence of the treatment day post ovulation, and of pharmacological treatment after ET in horse recipients.