title: In vivo oocyte recovery and in vitro embryo production from bovine donors aspirated at different frequencies or following FSH treatment.
abstract: The effects of frequency of follicular aspiration and treatment of donor cattle with FSH on in vivo oocyte recovery and in vitro embryo production were studied. Simmental heifers (n = 24) formed 8 replicates of 3 treatments in which oocyte donors were aspirated 1) once a week, 2) twice a week, or 3) once a week following treatment with FSH for 3 d prior to aspiration. Oocytes were graded, washed, matured for 20 to 24 h and then inseminated with frozen/thawed semen from a single sire, followed by co-culture on granulosa cell layers. Embryo development was observed until Day 7 after insemination. Significantly fewer follicles per heifer per week were counted (14.7+/-2.3 vs. 27.4+/-3.1 vs. 23.1+/-2.8) and aspirated (12.0+/-2.0 vs. 21.8+/-2.7 vs. 20.1+/-2.6) in heifers on the once-weekly than twice-weekly aspiration treatment (P<0.01) or on the once-weekly aspiration after FSH treatment (P<0.05). There were no significant differences between treatments in the total number of oocytes recovered per week (5.6+/-1.2 vs. 8.9+/-1.5 vs. 6.1+/-1.2), but significantly more oocytes per heifer per week recovered from animals treated with FSH were graded Category 1 (2.8+/-0.4), i.e., >4 layers good cumulus with a clear, even cytoplasm, than from animals aspirated once (0.9+/-0.2; P<0.01) or twice a week (1.5+/-0.3; P<0.05). The number of transferable morulae plus blastocysts produced per heifer per week was higher from animals aspirated twice a week (2.4+/-0.4; P<0.05) or once a week following FSH treatment (2.1+/-0.4; P<0.05) than from animals aspirated once a week without FSH treatment (1.0+/-0.3). In conclusion, FSH treatment of bovine oocyte donors aspirated once a week enabled a similar number of transferable embryos to be produced per donor week as aspiration twice a week without FSH treatment. These 2 treatments produced twice as many transferable embryos per donor week as aspiration once a week without FSH treatment.
authors.affiliation: Scottish Agricultural College, Bucksburn, Aberdeen, UK.
authors.forename: K L
authors.initials: KL
authors.lastname: Goodhand
authors.forename: R G
authors.initials: RG
authors.lastname: Watt
authors.forename: M E
authors.initials: ME
authors.lastname: Staines
authors.forename: J S
authors.initials: JS
authors.lastname: Hutchinson
authors.forename: P J
authors.initials: PJ
authors.lastname: Broadbent
mesh_terms: D000818:Animals; D002417:Cattle / Q000196:embryology / Q000502:physiology*; D018920:Coculture Techniques; D005314:Embryonic and Fetal Development; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods / Q000662:veterinary*; D005640:Follicle Stimulating Hormone / Q000627:therapeutic use*; D007273:Injections, Intramuscular / Q000662:veterinary; D008297:Male; D018587:Oocyte Donation / Q000379:methods / Q000662:veterinary*; D009865:Oocytes / Q000502:physiology*; D006080:Ovarian Follicle / Q000502:physiology; D011897:Random Allocation
chemical_list: D005640:Follicle Stimulating Hormone