title: Miniature ponies: 1. Follicular, luteal and endometrial dynamics during the oestrous cycle.
abstract: Follicular dynamics were studied during 12 interovulatory intervals (IOIs) and 36 preovulatory periods in Miniature mares. The percentage of IOIs with the following follicle events was: ovulatory wave with only one follicle>or=10 mm (55%), diameter deviation similar to previous reports in larger mares (25%) and minor waves emerging before or after the ovulatory wave (55%). Follicle data were compared among Miniature ponies, large ponies and Breton horses (n=12 IOIs per breed). The IOI was longer (P<0.001) in Miniature ponies (23.3+/-0.9 days) and in large ponies (23.9+/-0.5 days) than in Breton horses (20.3+/-0.7 days). The Miniature ponies had fewer (P<0.0001) growing follicles>or=10 mm per ovulatory wave (1.5+/-0.3) and more (P<0.0004) ovulatory waves (6/11) with only one follicle>or=10 mm than large ponies (9.8+/-0.8 and 0/12) and horses (5.8+/-0.9 and 0/12). Maximum diameter of the preovulatory follicle was smaller (P<0.003) in the Miniature ponies (38.3+/-0.7 mm) than in the horses (44.5+/-1.4 mm), but the difference between breeds was slight (6%) compared with the difference in bodyweight (65%). Considering the small number of follicles per ovulatory wave, Miniature mares are a potential model for comparative studies in folliculogenesis within and among species.
authors.affiliation: Department of Pathobiological Sciences, University of Wisconsin, Madison, WI 53706, USA. egastal@svm.vetmed.wisc.edu
authors.forename: E L
authors.initials: EL
authors.lastname: Gastal
authors.forename: A P
authors.initials: AP
authors.lastname: Neves
authors.forename: R C
authors.initials: RC
authors.lastname: Mattos
authors.forename: B P L
authors.initials: BP
authors.lastname: Petrucci
authors.forename: M O
authors.initials: MO
authors.lastname: Gastal
authors.forename: O J
authors.initials: OJ
authors.lastname: Ginther
mesh_terms: D000818:Animals; D003338:Corpus Luteum / Q000000981:diagnostic imaging / Q000502:physiology*; D004717:Endometrium / Q000000981:diagnostic imaging / Q000502:physiology*; D030762:Estrous Cycle / Q000502:physiology*; D005260:Female; D005498:Follicular Phase / Q000502:physiology; D006736:Horses / Q000502:physiology; D008183:Luteal Phase / Q000502:physiology; D006080:Ovarian Follicle / Q000000981:diagnostic imaging / Q000502:physiology*; D014463:Ultrasonography