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 Ziecik, A. Articles by Tilton, J. E. Search for Related Content PubMed PubMed Citation Articles by Ziecik, A. Articles by Tilton, J. E.

Porcine LH Levels during the Estrous Cycle, Gestation, Parturition and Early Lactation¹

University of Agriculture and Technology, 10718 Olsztyn, Poland and and North Dakota State University^,2, Fargo 58105

² Reprint requests to Dr. J. E. Tilton.

Abstract

Thirty-five sows were used in a study of plasma luteinizing hormone (LH) concentrations during the estrous cycle, including first and second estrus postweaning, during gestation, at parturition and during the first 5 d of lactation. After cannulation of the anterior vena cava via the cephalic vein, blood samples were collected four times daily for 2 d before estrus, during estrus and for 3 d after estrus and once daily at 1100 h throughout the rest of the estrous cycle. One sample was collected from each sow on alternate days (1100 h) during the gestation period. Four daily samples were obtained on d 60 through 68 of gestation and for 5 d after parturition. Preovulatory surges of LH occurred 8 to 32 h before standing estrus in four of seven sows during first estrus and in three of seven sows during second estrus. The mean preovulatory LH surge during the first estrus postweaning (3.00 ± .46 ng/ml) was lower than that during second estrus (4.24 ± .60 ng/ml). Throughout the first 12 d of gestation, LH concentrations were relatively high and variable, ranging from 1.2 to 2 ng/ml. They then decreased to a range of .42 to .62 ng/ml after d 24. Similar LH concentrations were noted throughout the remainder of gestation except for some slight fluctuations. Higher concentrations (P<.05) were noted with evening collections (1900 h, 1.17 ± .09 ng/ml) than in daytime collections (0700 h, .64 ± .08; 1100 h, .61 ± .06; 1500 h, .72 ± .06 ng/ml) during d 60 to 68 of gestation. Low plasma concentrations of LH (.3 to .5 ng/ml) were observed for the 5 d before and during parturition. After parturition, considerable variation of LH occurred, with rising concentrations observed on d 5 postpartum. Results of this study illustrate the occurrence of LH surges before behavioral estrus with increased plasma LH during implantation.

¹ Research supported in part by the Institute of Pathology and Therapy of Animals, Agriculture Academy, Wroclaw, as the Research Project at the Ministry of Higher Education, Science and Technology, Poland (MR-II-10).