title: Effects of ovum pick-up frequency and FSH stimulation: a retrospective study on seven years of beef cattle in vitro embryo production.
abstract: The aim of this retrospective study was to compare the number of follicles, cumulus oocyte complexes (COCs) and cultured In Vitro Produced (IVP) embryos obtained from 1396 non-stimulated Ovum Pick-up (OPU) sessions on 81 donor animals in a twice weekly OPU scheme. Results were obtained from 640 sessions following FSH-LH superstimulation, on 112 donors subjected to OPU once every 2 weeks. The stimulation protocol started with the insertion of an ear implant containing 3 mg norgestomet (Crestar, Intervet, Belgium) 8 days before puncture (day -8). The dominant follicle was ablated by ultrasound-guided follicle puncture on day -6. On day -3 and day -2, cows were injected with FSH (Ovagen, ICP) twice daily (8 am to 8 pm), i.e. a total dose of 160 mug FSH and 40 mug LG per donor per stimulation cycle. Animals were punctured 48 h after the last FSH injection (day 0). Progesterone implants were removed the next day. Stimulated donor cows were treated with this protocol at 14-day intervals. Follicles were visualized with a Dynamic Imaging ultrasound scanner, equipped with a 6.5 MHz sectorial probe. Follicles were punctured with 55 cm long, 18 gauge needles at an aspiration pressure corresponding to a flow rate of 15 ml/min. Cumulus oocyte complexes were recovered and processed in a routine IVF set-up. Results demonstrate that, expressed per session, FSH stimulation prior to OPU increases production efficiency with significantly more follicles punctured and oocytes retrieved. However, when overall results during comparable 2-week periods are considered (four non-stimulated sessions vs one stimulated), more follicles are punctured and more oocytes are retrieved using the non-stimulated protocol. No significant differences in the number of cultured embryos could be detected, indicating that FSH/LH stimulation prior to OPU might have a positive effect on in vitro oocyte developmental competence as more embryos are cultured with less, presumably better-quality, oocytes.
authors.affiliation: Faculté de Médecine Vétérinaire, Service d'Obstétrique et de Pathologie de la Reproduction des ruminants, équidés et porcs, Université de Liège, Sart Tilman, Boulevard de Colonster 20, 4000 Liège, Belgium. rderoover@msn.com
authors.forename: R
authors.initials: R
authors.lastname: De Roover
authors.forename: J M N
authors.initials: JM
authors.lastname: Feugang
authors.forename: P E J
authors.initials: PE
authors.lastname: Bols
authors.forename: G
authors.initials: G
authors.lastname: Genicot
authors.forename: Ch
authors.initials: Ch
authors.lastname: Hanzen
mesh_terms: D000818:Animals; D002417:Cattle / Q000502:physiology*; D005260:Female; D005307:Fertilization in Vitro / Q000662:veterinary*; D005640:Follicle Stimulating Hormone / Q000008:administration & dosage*; D008460:Meat; D006080:Ovarian Follicle / Q000502:physiology*; D010062:Ovulation Induction / Q000662:veterinary*; D010063:Ovum / Q000502:physiology*; D012189:Retrospective Studies
chemical_list: D005640:Follicle Stimulating Hormone