ENDOCRINE CAUSES OF SEASONAL AND LACTATIONAL ANESTRUS IN FARM ANIMALS

ENDOCRINE CAUSES OF SEASONAL AND LACTATIONAL ANESTRUS IN FARM ANIMALS

CURRENT TOPICS IN VETERINARY MEDICINE AND ANIMAL SCIENCE Control of Reproduction in the Cow, edited by J.M. Sreenan Patterns of Growth and Development in Cattle, edited by H. de Boer and J. Martin Respiratory Diseases in Cattle, edited by W.B. Martin Calving Problems and Early Viability of the Calf, edited by B. Hoffmann, 1.L. Mason and J. Schmidt The Future of Beef Production in the European Community, edited by LC. Bowman and P. Susmel Diseases of Cattle in the Tropics: Economic and Zoonotic Relevance, edited by M. Ristic and 1. Mcintyre Control of Reproductive Functions in Domestic Animals, edited by W. Jiichle and D.R. Lamond The Laying Hen and its Environment, edited by R. Moss Epidemiology and Control of Nematodiasis in Cattle, edited by P. Nansen, R.L J0rgensen and E.LL. Soulsby The Problem of Dark-Cutting in Beef, edited by D.E. Hood and P.V. Tarrant The Welfare of Pigs, edited by W. Sybesma The Mucosal Immune System, edited by F.J. Bourne Laboratory Diagnosis in Neonatal Calf and Pig Diarrhoea, edited by P.W. de Leeuw and P.A.M. Guinee Advances in the Control of Theileriosis, edited by A.D. Irvin, M.P. Cunningham and A.S. Young Fourth International Symposium on Bovine Leukosis, edited by O.C. Straub Muscle Hypertrophy of Genetic Origin and its Use to Improve Beef Production, edited by J.W.B. King and F. Menissier Aujeszky's Disease, edited by G. Wittman and S.A. Hall Transport of Animals Intended for Breeding, Production and Slaughter, edited by R. Moss Welfare and Husbandry of Calves, edited by J.P. Signoret Factors Influencing Fertility in the Postpartum Cow, edited by H. Karg and E. Schallenberger Beef Production from Different Dairy Breeds and Dairy Beef Crosses, edited by G.J. More O'Ferrall The Elisa: Enzyme-Linked Immunosorbent Assay in Veterinary Research and Diagnosis, edited by R.C. Wardley and LR. Crowther Indicators Relevant to Farm Animal Welfare, edited by D. Smidt Farm Animal Housing and Welfare, edited by S.H. Baxter, M.R. Baxter and J.A.D. MacCormack Stunning of Animals for Slaughter, edited by G. Eikelenboom Manipulation of Growth in Farm Animals, edited by LF. Roche and D. O'Callaghan Latent Herpes Virus Infections in Veterinary Medicine, edited by G. Wittmann, R.M. Gaskell and H.-J. Rziha Grassland Beef Production, edited by W. Holmes Recent Advances in Virus Diagnosis, edited by M.S. McNulty and J.B. McFerran The Male in Farm Animal Reproduction, edited by M. Courot Endocrine Causes of Seasonal and Lactational Anestrus in Farm Animals, edited by F. Ellendorff and F. Elsaesser

ENDOCRINE CAUSES OF SEASONAL AND LACTATIONAL ANESTRUS IN FARM ANIMALS A Seminar in the CEC Programme of Co-ordination of Research on Livestock Productivity and Management, held at the Institut fur Tierziicht und Tierverhalten, Mariensee, Bundesforschungsanstalt fur Landwirtschaft (FAL), October 2-3, 1984 Sponsored by the Commission of the European Communities, Directorate-General for Agriculture, Co-ordination of Agricultural Research Edited by F. Ellendorff, F. Elsaesser Institut filr Tierzilcht und Tierverhalten, Mariensee Federal Republic of Germany 1985 MARTINUS NIJHOFF PUBLISHERS ~. a member of the KLUWER ACADEMIC PUBLISHERS GROUP II DORDRECHT / BOSTON / LANCASTER for THE COMMISSION OF THE EUROPEAN COMMUNITIES

Distributors jor the United States and Canada: Kluwer Academic Publishers, 190 Old Derby Street, Hingham, MA 02043, USA jor the UK and Ireland: Kluwer Academic Publishers, MTP Press Limited, Falcon House, Queen Square, Lancaster LAI lrn, UK jor all other countries: Kluwer Academic Publishers Group, Distribution Center, P.O. Box 322, 3300 AH Dordrecht, The Netherlands Library of Congress Cataloging in Publication Data Main entry under title: Endocrine causes of seasonal and lactational anestrus in farm animals. (Current topics in veterinary medicine and animal science) 1. Anestrus--Congresses. 2. Veterinary endocrinology--congresses. I. Ellendorff, F. II. Elsaesser, F. III. C.E.C. Programme of Coordination of Research on Livestock Productivity and Management. IV. Commission of the European Communities. Coordination of Agricultural Research. V. Series. SF768.3.E54 1985 636.089'8172 85-10646 ISBN-13: 978-94-010-8726-1 DOl: 10.1007/978-94-009-5026-9 e-isbn-13: 978-94-009-5026-9 EUR 9554 EN Book information Publication arranged by: Commission of the European Communities, Directorate-General Information Market and Innovation, Luxembourg Copyright/legal notice 1985 by ECSC, EEC, EAEC, Brussels-Luxembourg. Softcover reprint of the hardcover 1 st edition 1985 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, mechanical, photocopying, recording, or otherwise, without prior written permission of the publishers, Martinus Nijhoff Publishers, P.O. Box 163, 3300 AD Dordrecht, The Netherlands. Neither the Commission of the European Communities nor any person acting on behalf of the Commission is responsible for the use which might be made of the following information.

v CONTENTS PREFACE Page 1 SESSION I: SEASONAL ANESTRUS IN THE EWE SEASONAL ANESTRUS - PROBLEMS AND PERSPECTIVES G.E. Lamming ENDOCRINE BASIS OF SEASONAL ANESTRUS IN SHEEP W. Haresign, B.J. McLeod, G.M. Webster, K. Worthy GENETICS AND PHYSIOLOGY OF FOLLICLE RECRUITMENT AND MATURATION DURING SEASONAL ANESTRUS R. Webb, I.K. Gauld BREED DIFFERENCES IN THE BREEDING SEASON IN SHEEP J.F. Quirke, J.P. Hanrahan LIGHT CONTROL OF REPRODUCTION IN THE EWE J. Thimmonier, R. Ortavant EFFECTS OF MELATONIN ON THE TIME OF ONSET OF THE BREEDING SEASON IN DIFFERENT BREEDS OF SHEEP J.F. Roche, J.P. Hanrahan, J.F. Quirke, E. Ronayne INDUCTION OF OVULATION IN ANESTROUS EWES USING GONADOTROPHINS A.A. McNeilly, J.M. Wallace and D.T. Baird 3 6 19 29 44 55 66 INDUCED BREEDING IN ANESTROUS MILKING EWES OF DAIRY 76 BREEDS: COMPARISON OF NORGESTOMET, MEDROXYPROGESTERONE AND FLUOROGESTONE IN TWO REGIMES OF PMSG T. Alifakiotis SESSION II: SEASONAL ANESTRUS IN THE SOW AND MARE STIMULATION OF OVARIAN ACTIVITY IN THE PONY MARE DURING WINTER ANESTRUS B. Bour, E. Palmer, M.A. Driancourt PRACTICAL CONTROL OF ANESTRUS IN THOROUGHBRED BROODMARES W.A. Allen SEASONAL ANESTRUS IN WILD SOWS R. Mauget PHOTOPERIOD AND FERTILITY IN THE PIG C. Claus, U. Weiler, R. Hahn 83 85 98 108 119 131

VI Page SESSION III: LACTATIONAL ANESTRUS IN THE PIG HYPOTHALAMIC-PITUITARY-OVARIAN RESPONSES TO WEANING - 133 RETROSPECTIVE EVIDENCE FOR THE CAUSE OF LACTATIONAL ANESTRUS? G.R. Foxcroft ENDOCRINE INTERACTIONS DURING LACTATIONAL ANESTRUS IN SOWS F. E11endorff, F. E1saesser, N. Parvizi, D. Smidt RELEVANCE OF PROLACTIN TO LACTATIONAL AND POST WEANING ANESTRUS IN THE SOWS D.F.M. van de Wie1, P. Booman, A.H. Willemse and M.M. Bevers EFFECTS OF BROMOCRIPTINE TREATMENT DURING LACTATIONAL ANESTRUS IN PIGS E. Mattioli, E. Seren 145 154 165 179 SESSION IV: POST PARTUM ANESTRUS POST PARTUM ANESTRUS, PROBLEMS AND PERSPECTIVES H. Karg COMPARATIVE ASPECTS OF THE POSTPARTUM PERIOD IN DOMESTIC ANIMALS M. Vandeplassche REPRODUCTIVE POTENTIAL DURING THE POST PARTUM PERIOD IN COWS M. Terqui ENDOCRINE MECHANISMS CONTRIBUTING TO POST PARTUM ANESTRUS IN DAIRY AND BEEF CATTLE E. Schallenberger, D.L. Walters STUDIES ON THE ENDOCRINE AND ENVIRONMENTAL FACTORS INFLUENCING POST PARTUM ACYCLICITY IN DAIRY COWS BASED ON PROGESTERONE PROFILES J. Henriksen, A. Mikel Jensen GENERAL CONCLUSIONS LIST OF PARTICIPANTS 181 186 199 206 221 233 234 236