title: FSH injections and intrauterine insemination in protocols for superovulation of ewes.
abstract: In Exp. 1, five injections of crude FSH (20 mg total), starting 36 h before removal of progestin pessaries or injection of prostaglandin F2 alpha (PGF2 alpha), were found to be as effective for superovulation of ewes as seven injections starting 72 h before removal of pessaries. Seven injections caused superovulation (more than three ovulations) in 13 of 15 ewes with an average (all ewes) of 12 +/- 2.3 ovulations. Five injections caused superovulation in 17 of 19 ewes with an average of 11.5 +/- 1.6 ovulations after pessary-regulated estrus in 12 of 16 ewes with an average of 12.4 +/- 2.2 ovulations after PGF2 alpha injection. In Exp. 2, intrauterine artificial insemination (IUAI) of naturally mated ewes provided ovum fertilization rates of 75.3% with an embryo recovery rate of 39.4%, whereas mating alone (MATED) provided fertilization rates of 64.2% with an embryo recovery rate of 72.1%. However, subsequent replications of the MATED protocol (MATED2) resulted in a low fertilization rate (34.2%). In Exp. 3, surgical IUAI at 22 h after removal of pessaries resulted in a low rate of superovulation (5 of 12 ewes), presumably as the result of pentobarbital anesthesia. Conducting IUAI at 46 h after removal of pessaries resulted in a high rate of superovulation (14 of 16 ewes) but a low embryo recovery rate (30.7%). In two subsequent trials, IUAI at 40 h after removal of pessaries resulted in most ewes superovulating (33 of 35 in April/May and 16 of 17 in September) with acceptable embryo recovery (65.2% and 71.3%) and high fertilization rates (82.8% and 96.4%).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Livest. and Poult. Sci. Inst. ARS, Beltsville, MD 20705.
authors.forename: C E
authors.initials: CE
authors.lastname: Rexroad
authors.forename: A M
authors.initials: AM
authors.lastname: Powell
mesh_terms: D000818:Animals; D005260:Female; D005306:Fertilization / Q000187:drug effects; D005640:Follicle Stimulating Hormone / Q000008:administration & dosage*; D007267:Injections / Q000662:veterinary; D007315:Insemination, Artificial / Q000662:veterinary*; D010570:Pessaries; D011372:Progestins / Q000008:administration & dosage; D012756:Sheep / Q000502:physiology*; D013480:Superovulation / Q000187:drug effects*
chemical_list: D011372:Progestins; D005640:Follicle Stimulating Hormone