title: Effect of additional human chorionic gonadotrophin (hCG) on follicular growth and ovulation in gonadotrophin-treated gilts.
abstract: The objective of this study was to determine the effect of additional human chorionic gonadotrophin (hCG) on the ovarian response of gilts previously treated with 200 IU hCG combined with 400 IU equine chorionic gonadotrophin (eCG) (eCG/hCG). Seventy-one prepuberal gilts (105 ± 7.5 kg) were assigned to groups: i) eCG/hCG (hCG-0; n = 25); ii) eCG/hCG followed by 100 IU of hCG at 24 h (hCG-100; n = 24); iii) eCG/hCG followed by 200 IU hCG at 24 h (hCG-200; n = 10); and iv) controls (CON; n = 12). Ovulation response was assessed by ovarian dissection or real-time ultrasonography. Additional hCG did not significantly improve numbers of gilts ovulating. Numbers of corpora lutea increased with hCG, and was higher in hCG-200 (P < 0.01). Compared to hCG-0, the frequency of cysts in gilts was higher in hCG-100 (P < 0.05) and further increased in hCG-200 (P < 0.01). The number of cysts per gilt was dose-dependently increased by additional hCG. We conclude that supplemental hCG will increase the number of corpora lutea but will be associated with follicular cyst development in a dose dependent manner.
authors.affiliation: Department of Medicine, Surgery and Veterinary Anatomy, University of León, Spain (Manjarín, Garcia, Dominguez); Department of Population Medicine, University of Guelph, Guelph, Ontario, (Cassar, Friendship); School of Animal and Veterinary Sciences, University of Adelaide, Roseworthy, South Australia, Australia (Kirkwood).
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Manjarín
authors.affiliation: Department of Medicine, Surgery and Veterinary Anatomy, University of León, Spain (Manjarín, Garcia, Dominguez); Department of Population Medicine, University of Guelph, Guelph, Ontario, (Cassar, Friendship); School of Animal and Veterinary Sciences, University of Adelaide, Roseworthy, South Australia, Australia (Kirkwood).
authors.forename: Glen
authors.initials: G
authors.lastname: Cassar
authors.affiliation: Department of Medicine, Surgery and Veterinary Anatomy, University of León, Spain (Manjarín, Garcia, Dominguez); Department of Population Medicine, University of Guelph, Guelph, Ontario, (Cassar, Friendship); School of Animal and Veterinary Sciences, University of Adelaide, Roseworthy, South Australia, Australia (Kirkwood).
authors.forename: Robert M
authors.initials: RM
authors.lastname: Friendship
authors.affiliation: Department of Medicine, Surgery and Veterinary Anatomy, University of León, Spain (Manjarín, Garcia, Dominguez); Department of Population Medicine, University of Guelph, Guelph, Ontario, (Cassar, Friendship); School of Animal and Veterinary Sciences, University of Adelaide, Roseworthy, South Australia, Australia (Kirkwood).
authors.forename: José C
authors.initials: JC
authors.lastname: Garcia
authors.affiliation: Department of Medicine, Surgery and Veterinary Anatomy, University of León, Spain (Manjarín, Garcia, Dominguez); Department of Population Medicine, University of Guelph, Guelph, Ontario, (Cassar, Friendship); School of Animal and Veterinary Sciences, University of Adelaide, Roseworthy, South Australia, Australia (Kirkwood).
authors.forename: J Carlos
authors.initials: JC
authors.lastname: Dominguez
authors.affiliation: Department of Medicine, Surgery and Veterinary Anatomy, University of León, Spain (Manjarín, Garcia, Dominguez); Department of Population Medicine, University of Guelph, Guelph, Ontario, (Cassar, Friendship); School of Animal and Veterinary Sciences, University of Adelaide, Roseworthy, South Australia, Australia (Kirkwood).
authors.forename: Roy N
authors.initials: RN
authors.lastname: Kirkwood
mesh_terms: D000818:Animals; D006063:Chorionic Gonadotropin / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D006080:Ovarian Follicle / Q000187:drug effects* / Q000254:growth & development; D010060:Ovulation / Q000187:drug effects*; D013552:Swine / Q000502:physiology*
chemical_list: D006063:Chorionic Gonadotropin