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 Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Kirkpatrick, R. L. Articles by Casida, L. E. Search for Related Content PubMed Articles by Kirkpatrick, R. L. Articles by Casida, L. E.

Effect of Estradiol-17ß on Follicular Development and Pituitary Potency in Gilts Fed 6-Methyl-17-Acetoxyprogesterone^1,2,

University of Wisconsin, Madison

Abstract

Forty Yorkshire and Duroc gilts received approximately 500 mg. of MAP per day orally beginning on day 13 of their respective estrual cycles and continuing for 12 days. An intravenous injection of 10 mg. of estradiol-17ß 3 days before slaughter at 4, 7, 10, 13, or 16 days after MAP withdrawal in half of the gilts (four on each day) had no significant effect on gonadotropic potency, follicular development, or the occurrence of estrus, ovulation, or luteinization of follicles. Follicular fluid weight and the average diameter of the four largest follicles increased significantly from 4 to 16 days after MAP withdrawal in both estradiol-treated and untreated gilts, with large cystic follicles being present at days 13 and 16. Although luteinization of follicles occurred in a large number of gilts and follicle size increased, neither FSH nor LH concentrations, nor relative total FSH potency changed during the experimental period, and neither FSH nor LH was significantly correlated with the ovarian changes within groups The correlation between FSH and LH concentrations was 0.52.

¹ Paper No. 919 from the Division of Genetics and No. 369 from the Department of Meat and Animal Science. Published with the approval of the Director of the Agricultural Experiment Station.

² This study was supported in part by grants from Oscar Mayer and Company, Jones Dairy Farm, Badger Breeders Cooperative, Consolidated Breeders Cooperative, East Central Breeders Cooperative, Tri-State Breeders Cooperative, and The Upjohn Company.