RUMINANT PHYSIOLOGY: Digestion, Metabolism, Growth and Reproduction Edited by P.B. Cronjé CABI Publishing RUMINANT PHYSIOLOGY Digestion, Metabolism, Growth and Reproduction Dedication This volume is dedicated to the memory of the late Dr F.M.C. Gilchrist. RUMINANT PHYSIOLOGY Digestion, Metabolism, Growth and Reproduction Edited by P.B. Cronjé Department of Animal and Wildlife Sciences University of Pretoria Pretoria South Africa Associate Editors E.A. Boomker P.H. Henning W. Schultheiss J.G. van der Walt CABI Publishing CABI Publishing is a division of CAB International CABI Publishing CAB International Wallingford Oxon OX10 8DE UK Tel: +44 (0)1491 832111 Fax: +44 (0)1491 833508 Email:
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[email protected] © CAB International 2000. All rights reserved. No part of this publication may be reproduced in any form or by any means, electronically, mechanically, by photocopying, recording or otherwise, without the prior permission of the copyright owners. A catalogue record for this book is available from the British Library, London, UK Library of Congress Cataloging-in-Publication Data Ruminant physiology : digestion, metabolism, growth, and reproduction / edited by P. Cronje ; assoc. editors, E.A. Boomker … [et al.]. p. cm. Includes bibliographical references and index. ISBN 0-85199-463-6 (alk. paper) 1. Ruminants--Physiology--Congresses. I. Cronjé, P. (Pierre) II. Boomker, E. A. QL737.U5 R868 2000 571.1¢963- - dc21 ISBN 0 85199 463 6 Typeset in 10/12pt Garamond by Columns Design Ltd, Reading Printed and bound in the UK by Biddles Ltd, Guildford and King’s Lynn 00–023661 Contents Contributors Foreword Part I Regulation of Feed Intake 1 Integration of Learning and Metabolic Signals into a Theory of Dietary Choice and Food Intake J.M. Forbes and F.D. Provenza 2 Mathematical Models of Food Intake and Metabolism in Ruminants A.W. Illius, N.S. Jessop and M. Gill 3 Control of Salivation and Motility of the Reticulorumen by the Brain in Sheep W.L. Grovum and J.S. Gonzalez Part II Rumen Microbiology and Fermentation ix xiii 1 3 21 41 59 4 Molecular Ecology and Diversity in Gut Microbial Ecosystems R.I. Mackie, R.I. Aminov, B.A. White and C.S. McSweeney 61 5 Microbial Adherence to the Plant Cell Wall and Enzymatic Hydrolysis C.W. Forsberg, E. Forano and A. Chesson 79 6 The Microbial Ecology and Physiology of Ruminal Nitrogen Metabolism M. Morrison 99 Part III Nutrient Absorption and Splanchnic Metabolism 7 Tissue, Cellular and Molecular Aspects of Peptide Absorption and Utilization K.E. Webb, Jr 115 117 v vi Contents 8 Influence of Gastrointestinal Metabolism on Substrate Supply to the Liver C.J. Seal and D.S. Parker 131 9 The Liver: Integrator of Nitrogen Metabolism G.E. Lobley, G.D. Milano and J.G. van der Walt 149 Part IV Tissue Maintenance and Utilization of Endogenous Body Reserves 169 10 Adipose Tissue: Beyond an Energy Reserve R.G. Vernon and K.L. Houseknecht 171 11 Regulation of Growth and Metabolism During Postnatal Development B.H. Breier, M.H. Oliver and B.W. Gallaher 187 12 Direct Effects of Photoperiod on Lipid Metabolism, Leptin Synthesis and Milk Secretion in Adult Sheep Y. Chilliard and F. Bocquier 20