title: Factors affecting the success of oocyte transfer in a clinical program for subfertile mares.
abstract: Oocyte transfer is a potential method to produce offspring from valuable mares that cannot carry a pregnancy or produce embryos. From 2000 through 2004, 86 mares, 19.2 +/- 0.4 yr of age (mean +/- S.E.M.), were used as oocyte donors in a clinical program at Colorado State University. Oocytes were collected from 77% (548/710) of preovulatory follicles and during 96% (548/570) of cycles. Oocytes were collected 21.0+/-0.1h after administration of hCG to estrous donors and cultured 16.4 +/- 0.2 h prior to transfer into recipients' oviducts. At 16 and 50 d after transfer, pregnancies were detected in 201 of 504 (40%) and 159 of 504 (32%) of recipients, respectively, with an embryo-loss rate of 21% (42/201). Pregnancy rates were similar (P > 0.05) for cyclic and noncyclic recipients and for recipients inseminated with cooled, fresh or frozen semen. One or more recipients were detected pregnant at 16 and 50 d, respectively, for 80% (69/86) and 71% (61/86) of donors. More donors <20 than > or = 20 yr (mean ages +/- S.E.M. of 15.5 +/- 0.4 and 23.0 +/- 0.3 yr, respectively) tended (P = 0.1) to have one or more pregnant recipients at 50 d (36/45, 80%; 28/45, 62%, respectively). Results of the program confirm that pregnancies can consistently be obtained from older, subfertile mares using oocyte transfer.
authors.affiliation: Animal Reproduction and Biotechnology Laboratory, Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA. emc@colostate.edu
authors.forename: E M
authors.initials: EM
authors.lastname: Carnevale
authors.forename: M A
authors.initials: MA
authors.lastname: Coutinho da Silva
authors.forename: D
authors.initials: D
authors.lastname: Panzani
authors.forename: J E
authors.initials: JE
authors.lastname: Stokes
authors.forename: E L
authors.initials: EL
authors.lastname: Squires
mesh_terms: D000375:Aging; D000818:Animals; D001947:Breeding; D002478:Cells, Cultured; D006063:Chorionic Gonadotropin / Q000008:administration & dosage; D047108:Embryonic Development; D005187:Fallopian Tubes; D005260:Female; D006734:Horse Diseases / Q000628:therapy; D006736:Horses; D007247:Infertility, Female / Q000628:therapy / Q000662:veterinary*; D018587:Oocyte Donation / Q000662:veterinary*; D009865:Oocytes / Q000637:transplantation*; D011247:Pregnancy; D013396:Suction; D020858:Tissue and Organ Harvesting / Q000662:veterinary
chemical_list: D006063:Chorionic Gonadotropin