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 HighWire Citing Articles via Google Scholar Google Scholar Articles by Ohlson, D. L. Articles by Davis, S. L. Search for Related Content PubMed PubMed Citation Articles by Ohlson, D. L. Articles by Davis, S. L.

Use of Active Immunization against Prolactin to Study the Influence of Prolactin on Growth and Reproduction in the Ram¹

University of Idaho, Moscow 83843

Abstract

An experiment was conducted to determine whether prolactin (PRL) is involved in the maintenance of reproductive tissue weights and body growth in yearling rams. Suppression of circulating PRL was achieved by active antibody production against bovine PRL. Free plasma PRL concentrations in immunized rams were decreased (P<.05) by 73% after 3 months of treatment and 91% after 10 months of treatment in relation to concentrations in control rams. Average daily gain and final body weight were lower (P<.05) for rams with suppressed circulating PRL (.042 kg/day and 67.0 kg for treatment rams and .060 kg/day and 72.7 kg for control rams). Although testes weights were 32% lower for the treated rams, antibody treatment did not affect (P>.05) the weights of the testes or accessory sex glands. No treatment effect was noted on plasma luteinizing hormone (LH), growth hormone (GH) or thyrotropin (TSH). Seasonal differences were observed in some variables of LH, GH and TSH secretion. Mean baseline LH for all animals was higher (P<.01) in December than in March, June or September. Overall and baseline concentrations of GH and TSH were highest (P<.01) in December. These data suggest that (1) PRL is involved in body growth of the yearling ram, and (2) PRL may have a role in the maintenance of reproductive tissue weights in the yearling ram.

¹ Idaho Agr. Exp. Sta. Pub. No. 8044.

² Current address: Dept. of Dairy Sci., Michigan State Univ., East Lansing.

³ Dept. of Anim. Sci.

⁴ The authors wish to thank Ms. Debbi Blann for excellent technical assistance; Dr. J. G. Pierce for purified TSH; Dr. L. E. Reichert for purified PRL and LH, and Dr. A. E. Wilhelmi for purified GH used for radio-iodinations. We are also indebted to NIH, National Pituitary Agency, for providing ovine hormone preparations used for reference standards.

This article has been cited by other articles:

				H. Tucker and R. Ringer Controlled photoperiodic environments for food animals Science, June 25, 1982; 216(4553): 1381 - 1386. [PDF]