title: An ultrasonographic study of ovarian antral follicular dynamics in prepubertal gilts during the expected activation of the hypothalamo-pituitary-ovarian axis.
abstract: Daily transrectal ultrasonography was carried out in eight 4-5-month-old Polish Large White×Polish Landrace gilts for 42 days to monitor the growth of individual ovarian antral follicles≥2 mm in diameter. In total, 52.4±16.2 and 123.0±6.7 follicles per gilt (mean±SD) that grew to ≥4 mm were identified during the first and second 21-day study periods, respectively (P<0.01). Four follicular waves (defined as the synchronous growth of a group of follicles from 2-3 mm to ≥4 mm) emerged during the first period, and five waves emerged during the second period. The maximum diameters attained by the largest follicles of waves were 5.7±0.6 and 7.0±0.5 mm (first and second periods, respectively; P<0.01). The present results provide direct evidence for the rhythmic, wave-like pattern of antral follicle recruitment in prepubertal gilts. The number of follicles and maximum diameter they attain increase significantly during the expected activation of the hypothalamo-pituitary-ovarian axis in prepubescent gilts.
authors.affiliation: Department of Swine and Small Ruminant Breeding, University of Agriculture, 30-059 Cracow, Poland.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Schwarz
authors.forename: Maciej
authors.initials: M
authors.lastname: Murawski
authors.forename: Edward
authors.initials: E
authors.lastname: Wierzchoś
authors.forename: Paweł
authors.initials: P
authors.lastname: Bartlewski
mesh_terms: D000818:Animals; D005260:Female; D007030:Hypothalamo-Hypophyseal System / Q000000981:diagnostic imaging* / Q000502:physiology; D006080:Ovarian Follicle / Q000000981:diagnostic imaging* / Q000502:physiology; D010902:Pituitary Gland / Q000000981:diagnostic imaging* / Q000502:physiology; D013552:Swine / Q000502:physiology*; D014463:Ultrasonography