title: Effect of eCG superstimulation and buserelin on cumulus-oocyte complexes recovery and maturation in llamas (Lama glama).
abstract: The aim of the present study was two-fold. Experiment I: evaluate the effect of buserelin on llama's oocyte maturation after exogenous follicular activity suppression, followed by ovarian superstimulation with different doses of equine chorionic gonadotropin (eCG). Experiment II: compare the number of follicles aspirated and the number of cumulus-oocyte complexes (COCs) recovered according to different doses of eCG followed by buserelin. Experiment I consisted in a control group (without buserelin) and a treatment group (with buserelin), both subdivided according to eCG dose administered: A: 500 IU; B: 1000 IU; C: 1500 IU. The treatment group received a single i.v. dose of 8 microg of buserelin when two or more dominant follicles were found at ultrasound evaluation and 20 h later were subjected to surgery. In group A, 83% of the llamas did not respond to superstimulation. In groups B and C differences were observed between the control and the treatment groups for the degree of COCs maturation (p < 0.05). In experiment II animals were divided into two groups according to the eCG dose administered: 1000 and 1500 IU. Twenty hours before surgery females received a single i.v. dose of 8 microg of buserelin. Average number of follicles aspirated and COCs recovered was higher (p < 0.05) with the administration of 1500 IU of eCG. A larger number of expanded COCs were obtained from follicles > or =7 mm in diameter. We conclude that buserelin aids the recovery of a larger number of expanded COCs. Administration of 1500 IU of eCG produces a higher number of follicles for aspiration and number of COCs recovered.
authors.affiliation: Area de Teriogenología, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Buenos Aires, Argentina.
authors.forename: V L
authors.initials: VL
authors.lastname: Trasorras
authors.forename: M G
authors.initials: MG
authors.lastname: Chaves
authors.forename: M H
authors.initials: MH
authors.lastname: Miragaya
authors.forename: M
authors.initials: M
authors.lastname: Pinto
authors.forename: B
authors.initials: B
authors.lastname: Rutter
authors.forename: M
authors.initials: M
authors.lastname: Flores
authors.forename: A
authors.initials: A
authors.lastname: Agüero
mesh_terms: D000818:Animals; D002064:Buserelin / Q000008:administration & dosage*; D002161:Camelids, New World / Q000502:physiology*; D006063:Chorionic Gonadotropin / Q000008:administration & dosage*; D054885:Cumulus Cells / Q000187:drug effects / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005300:Fertility Agents, Female / Q000008:administration & dosage*; D006736:Horses; D009865:Oocytes / Q000187:drug effects / Q000254:growth & development*; D006080:Ovarian Follicle / Q000000981:diagnostic imaging; D010062:Ovulation Induction / Q000662:veterinary; D013396:Suction / Q000662:veterinary; D020858:Tissue and Organ Harvesting / Q000379:methods / Q000662:veterinary; D014463:Ultrasonography
chemical_list: D006063:Chorionic Gonadotropin; D005300:Fertility Agents, Female; D002064:Buserelin