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 McKinnie, M. R. Articles by Esbenshade, K. L. Search for Related Content PubMed PubMed Citation Articles by McKinnie, M. R. Articles by Esbenshade, K. L.

Ovarian Function and Hormone Secretion of Gilts Actively Immunized against Androstenedione^1,2,

North Carolina State University⁵, Raleigh 27695-7621

Abstract

Fifty crossbred gilts immunized against bovine serum albumin (BSA) or androstenedione conjugated to BSA (AD) were used in three experiments. Primary immunizations were given at 120 d of age and boosters at 148 and 176 d. Gilts were moved to pens containing four to five animals each and exposed to boars beginning at 180 d of age. Immunization against AD did not affect age at puberty, percentage of gilts exhibiting estrus or duration of first estrous cycle. Over the three experiments, ovulation rate was 24% greater for AD-immunized gilts than for controls, and the number of corpora lutea was related positively (r = .82) to the log of the antibody titer. Number of ovulations decreased as interval from booster immunization to onset of estrus increased. During diestrus of the first estrous cycle, gilts immunized against AD had more follicles 5 to 10 mm in diameter, more total ovarian follicles and more total ovarian structures (corpora lutea plus follicles) than controls. Immunization against AD increased the frequency of LH pulses on d 16 but not on d 17 or 18, of the estrous cycle. However, average serum concentrations of LH, FSH and estradiol from 5 d before until 2 d after expected estrus were not different between treatment groups. Concentrations of AD in follicles 4 to 6 and >7 mm in diameter were greater in gilts immunized against AD. Mean serum progesterone was higher on d 9 and 12 after mating in AD immunized gilts than in controls. Immunization against AD had no effect on maintenance of pregnancy or embryo survival rate.

¹ Paper No. 11464 of the Journal Series of the North Carolina ARS, Raleigh 27695-7601. The use of trade names in this publication does not imply endorsement by the North Carolina ARS of the products named or criticism of similar ones not mentioned.

² Acknowledgment is made to L. E. Reichert, Jr. for providing purified porcine LH (LER 786-3); G. D. Niswender for supplying antisera to luteinizing hormone; D. J. Bolt, USDA Hormone Program, for donating porcine FSH antisera and purified porcine FSH; N. R. Mason for supplying antisera to estradiol; Vickie Hedgpeth, Ruth Hand, and Tom E. Steffel for technical assistance; and Sue Mizelle for secretarial assistance. This research was supported in part by USDA grant 85-CRCR-1-1849.

³ Present address: North Carolina Agric. Ext. Program, North Carolina A&T State Univ., P.O. Box 21928, Greensboro 27420.

⁴ To whom reprint requests are to be sent.

⁵ Dept. of Anim. Sci.