HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Dufour, J. J. Articles by Matton, P. Search for Related Content PubMed PubMed Citation Articles by Dufour, J. J. Articles by Matton, P.

Relationship between Two Morphological Types of Ovaries and their Follicular Microscopic Population before Puberty and their Ensuing Follicular Development and Ovulation Rates at Puberty in Gilts^1,2

Agriculture Canada Research Station, Lennoxville, Quebec, J1M 1Z3

Abstract

A population of ovarian follicles was studied in 32 gilts with two morphological types at four physiological stages. Left ovaries were serially sectioned (10 µn), and follicles (> .19 mm) were counted and measured by histological techniques. In Exp. 1, prepuberal gilts that maintained the grape-type (GT) or other-type (OT) of ovaries at 140 and 160 d of age as determined by laparoscopy had their population of follicles studied at 165 d of age and compared with that on d 3 of the first puberal estrus in gilts that maintained the same ovarian type (GT or OT) at 140, 160 and 180 d of age. In Exp. 2, gilts that maintained the same ovarian types at 140, 160 and 180 d of age were compared at d 19 and 3 of the first and second puberal estrus, respectively. At 165 d of age, OT ovaries contained a greater number of classes 3 (.63 to 1.12 mm) and 4 (1.13 to 2.00 mm) nonatretic (< 4 pycnotic bodies) follicles than GT (P < .01), whereas at d 3 of the first puberal estrus, their mean number became comparable between the two ovarian types (P > .1) and similar to 165-d GT ovaries. At 165 d of age, atretic follicles formed 19.6% and 10.7% of the population of antral follicles in OT and GT ovaries (P < .05) whereas at puberty 17.5% and 19.6% atresia was observed in the same two groups, respectively (P > .10). Between d 19 and 3 of the estrous cycle no differences were detected in gilts that maintained the GT or OT ovaries during the prepuberal periods. Mean number of nonatretic follicles of classes 3 and 5 (2.01 to 3.56 mm) decreased between d 3 and 19 of the estrous cycle, whereas those of class 6 (3.57 to 5.70 mm) increased (P < .01). Likewise, the mean number of atretic follicles of classes 5 and 6 increased with the days of the estrous cycle studied (P < .01). Mean ovulation rates for gilts that maintained GT and OT ovaries throughout the prepuberal periods were 15.1 and 12.1, respectively, at puberty (P = .07). These results are in accordance with the suggestion that follicular development could be cyclic in prepuberal gilts. We suggest that atresia could be a key factor in this cyclicity and that, as puberty is reached, follicular development becomes influenced by days of the estrous cycle.

¹ Contribution no. 200.

² The authors wish to thank A. Bouchard for his contribution.

³ Dept. de Zootechnie, Faculté des Sciences de l'Agriculture et de l'Alimentation, Université Laval, Queéec, G1K 7P4.

⁴ Dept. de Biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, Québec, J1K 2R1.

⁵ Send reprint requests to this author.