title: Comparative follicular development in Meishan and Large White gilts during prepubertal periods and its relation to hormonal stimulation.
abstract: Changes in follicular development in the left ovary and ovarian response to hormonal injections (hCG or eCG and hCG) in the right ovary were studied in Meishan gilts (n = 36) at 3, 2, and 1 standard deviations (SD) before the mean age of puberty (51, 64, and 77 days of age) and in Large White gilts (n = 24) at 3 and 1 SD (140 and 166 days of age). Left ovaries were removed at the time of hormonal treatments and the remaining ovaries were removed 18 h after hCG was injected alone (hCG) or 72 h after eCG was injected (eCG-hCG). Both nonatretic and atretic (> 4 pyknotic bodies) antral follicles > 0.6 mm in diameter were identified in the left ovaries by histological techniques. LH-sensitive follicles were identified in the right ovaries by counting follicles with dispersed cumulus cells around the oocytes. All large White gilts showed the presence of antral follicles at both 3 and 1 SD before puberty while 6, 7, and 12 Meishan gilts had antral follicles > 0.6 mm at 3, 2, and 1 SD before puberty, respectively. In Large White gilts, the mean number of nonatretic antral follicles > 0.6 mm remained constant at 3 and 1 SD before puberty, while in Meishan gilts, the mean number increased as gilts got older. Mean percentage of class 1 nonatretic follicles (0.6-1.12 mm) of the total number of nonatretic follicles increased significantly with age in Meishan gilts (p < 0.02), while those of class 3 (2.01-3.56 mm) decreased significantly (p < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)
authors: Département de Zootechnie, Faculté des Sciences de l'Agriculture et de l'Alimentation, Université Laval, Québec, Canada.
authors: J J
authors: JJ
authors: Dufour
authors: J C
authors: JC
authors: Mariana
mesh_terms: D000375:Aging / Q000502:physiology; D000818:Animals; D006063:Chorionic Gonadotropin / Q000494:pharmacology*; D005260:Female; D006736:Horses; D007986:Luteinizing Hormone / Q000494:pharmacology; D006080:Ovarian Follicle / Q000187:drug effects / Q000502:physiology*; D010060:Ovulation / Q000502:physiology; D012741:Sexual Maturation / Q000502:physiology*; D013045:Species Specificity; D013552:Swine / Q000254:growth & development*
chemical_list: D006063:Chorionic Gonadotropin; D007986:Luteinizing Hormone