title: Effect of duration of the growing phase of ovulatory follicles on oocyte competence in superstimulated cattle.
abstract: In the present study, we tested the hypotheses that oocyte competence is compromised by a longer duration of follicular growth and that it is not affected by FSH starvation. Cows were allocated to short FSH (n=14), FSH starvation (n=13) and long FSH (n=13) groups. The first two groups were given eight doses of FSH, whereas the third group was given 14 doses of FSH, starting from the day of wave emergence (Day 0). A progesterone-releasing device (controlled internal drug release; CIDR) was placed intravaginally at the start of the experiment in all groups. The short FSH group was given prostaglandin (PG) F2α on Day 3, whereas the two other groups received PGF2α on Day 6. In all cows, the CIDR was removed at the time of PGF treatment; porcine (p) LH was given 24h after CIDR removal and cows were inseminated 24 and 36 h later. Reproductive tracts were collected 4 days after insemination and ova and/or embryos were cultured for ≥6 days. The FSH starvation group had fewer ovulations (P=0.001), and ova and/or embryos (P<0.05). No difference in embryo quality was detected between long and short FSH groups at 7, 9 or 10 days after artificial insemination. In conclusion, oocyte competence was not altered by the duration of the follicular growth phase in superstimulated cows, whereas FSH starvation substantially reduced the ability of superstimulated follicles to ovulate.
authors: Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, SK S7N 5B4, Canada.
authors: F C F
authors: FC
authors: Dias
authors: E
authors: E
authors: Costa
authors: G P
authors: GP
authors: Adams
authors: R J
authors: RJ
authors: Mapletoft
authors: J
authors: J
authors: Kastelic
authors: O
authors: O
authors: Dochi
authors: J
authors: J
authors: Singh
mesh_terms: D000818:Animals; D002417:Cattle / Q000502:physiology*; D003433:Crosses, Genetic; D004477:Ectogenesis / Q000187:drug effects; D046149:Embryo Culture Techniques / Q000662:veterinary; D010064:Embryo Implantation / Q000187:drug effects; D005260:Female; D005300:Fertility Agents, Female / Q000008:administration & dosage* / Q000494:pharmacology; D005640:Follicle Stimulating Hormone / Q000008:administration & dosage / Q000494:pharmacology; D059471:In Vitro Oocyte Maturation Techniques / Q000662:veterinary; D007315:Insemination, Artificial / Q000662:veterinary; D009865:Oocytes / Q000166:cytology / Q000187:drug effects*; D009866:Oogenesis / Q000187:drug effects*; D006080:Ovarian Follicle / Q000166:cytology / Q000000981:diagnostic imaging / Q000187:drug effects*; D010060:Ovulation / Q000187:drug effects*; D011247:Pregnancy; D011897:Random Allocation; D012525:Saskatchewan; D013480:Superovulation / Q000187:drug effects*; D013997:Time Factors; D014463:Ultrasonography
chemical_list: D005300:Fertility Agents, Female; D005640:Follicle Stimulating Hormone