final approved cover art

isbn 978-0-8138-0534-4

SustainableSwine

NutritionE d i t E d b y

Lee i. Chiba

9 780813 805344

Swine nutrition is a constantly evolving field. As demand for pork products continues to grow globally and competition for grain and other feed sources becomes steep, it is increasingly important that researchers

continue to explore new sustainable approaches to efficiently and effectively provide energy and key nutrients needed for healthy swine growth and development. Sustainable Swine Nutrition provides readers with the latest advances in the field while paying close attention to issues of sustainability.

Sustainable Swine Nutrition brings together the work of some of the world’s leading swine nutrition experts and looks at the latest advances that will allow for responsible and sustainable swine production now and in the future. The book is divided into two sections. Section I covers fundamental elements of swine nutrition. The second section of chapters applies these fundamentals to sustainable strategies and practices. Combined, these sections bring together valuable basic nutritional and physiological science and provide the reader with practical tools to implement sustainable approaches to swine production.

Essential information for both animal scientists and the animal agriculture industry, Sustainable Swine Nutrition, is an invaluable single volume resource on the latest advances in sustainable nutrition.

E d i t o rLee i. Chiba is Professor of Animal Sciences in the Department of Animal Sciences at Auburn University.

r E L at E d t i t L E sEnvironmental Physiology of LivestockEdited by R. J. Collier with J. L. CollierISBN: 9780813811765

Sustainable Swine NutritionEditEd by LEE i. Chiba

Sustainable Swine N

utritionC

hib

aLivestock EpigeneticsEdited by Hasan KhatibISBN: 9780470958599

chiba_9780813805344_cover.indd 1 10/23/12 3:35 PM

Sustainable Swine Nutrition

Sustainable Swine Nutrition

EditorLee I. ChibaAuburn University

Department of Animal SciencesAuburn, Alabama

A John Wiley & Sons, Inc., Publication

This edition first published 2013 © 2013 by John Wiley & Sons, Inc.

Wiley-Blackwell is an imprint of John Wiley & Sons, formed by the merger of Wiley’s global Scientific, Technical andMedical business with Blackwell Publishing.

Editorial Offices2121 State Avenue, Ames, Iowa 50014-8300, USAThe Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, UK9600 Garsington Road, Oxford, OX4 2DQ, UK

For details of our global editorial offices, for customer services and for information about how to apply for permissionto reuse the copyright material in this book please see our website at www.wiley.com/wiley-blackwell.

Authorization to photocopy items for internal or personal use, or the internal or personal use of specific clients, isgranted by Blackwell Publishing, provided that the base fee is paid directly to the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923. For those organizations that have been granted a photocopy license by CCC, aseparate system of payments has been arranged. The fee codes for users of the Transactional Reporting Service areISBN-13: 978-0-8138-0534-4/2013.

Designations used by companies to distinguish their products are often claimed as trademarks. All brand names andproduct names used in this book are trade names, service marks, trademarks or registered trademarks of theirrespective owners. The publisher is not associated with any product or vendor mentioned in this book. This publicationis designed to provide accurate and authoritative information in regard to the subject matter covered. It is sold on theunderstanding that the publisher is not engaged in rendering professional services. If professional advice or otherexpert assistance is required, the services of a competent professional should be sought.

Library of Congress Cataloging-in-Publication Data

Sustainable swine nutrition / edited by Lee I. Chiba.pages cm

Includes bibliographical references and index.ISBN 978-0-8138-0534-4 (hardback : alk. paper) – ISBN 978-1-118-48582-8 (mobi) (print) –

ISBN 978-1-118-48583-5 (epdf/ebook) (print) – ISBN 978-1-118-48585-9 (epub) (print) – ISBN 978-1-118-49145-4(obook) (print) 1. Swine–Nutrition. 2. Swine–Feeding and feeds. I. Chiba, Lee, editor of compilation.

SF396.5.S87 2013636.4–dc23

2012030223

A catalogue record for this book is available from the British Library.

Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not beavailable in electronic books.

Cover design by Matt Kuhns

Set in 10.5/12 pt Times by Aptara R© Inc., New Delhi, India

DisclaimerThe publisher and the author make no representations or warranties with respect to the accuracy or completeness ofthe contents of this work and specifically disclaim all warranties, including without limitation warranties of fitness fora particular purpose. No warranty may be created or extended by sales or promotional materials. The advice andstrategies contained herein may not be suitable for every situation. This work is sold with the understanding that thepublisher is not engaged in rendering legal, accounting, or other professional services. If professional assistance isrequired, the services of a competent professional person should be sought. Neither the publisher nor the author shallbe liable for damages arising herefrom. The fact that an organization or Website is referred to in this work as a citationand/or a potential source of further information does not mean that the author or the publisher endorses theinformation the organization or Website may provide or recommendations it may make. Further, readers should beaware that Internet Websites listed in this work may have changed or disappeared between when this work was writtenand when it is read.

1 2013

Dedication

This book is dedicated with appreciation to my wife, Shoko. Her continuoussupport, patience, and willingness to give me “space” to take on challenges suchas this are forever cherished!

Contents

Contributors ixPreface xiiiEditor xv

Part I Fundamental Nutrition

Chapter 1 Water in Swine Nutrition 3John F. Patience

Chapter 2 Energy and Energy Metabolism in Swine 23Jean Noblet and Jaap Van Milgen

Chapter 3 Lipids and Lipid Utilization in Swine 59Xi Lin, Mike Azain, and Jack Odle

Chapter 4 Amino Acids and Amino Acid Utilization in Swine 81Nathalie L. Trottier and Rodrigo Manjarı́n

Chapter 5 Carbohydrates and Carbohydrate Utilization in Swine 109Knud Erik Bach Knudsen, Helle Nygaard Lærke, and Henry Jørgensen

Chapter 6 Vitamins and Vitamin Utilization in Swine 139J. Jacques Matte and Charlotte Lauridsen

Chapter 7 Minerals and Mineral Utilization in Swine 173Gretchen M. Hill

Chapter 8 Nutrition and Gut Health in Swine 197Benjamin P. Willing, Gita Malik, and Andrew G. Van Kessel

Part II Nutrition for Successful and Sustainable Swine Production

Chapter 9 Diet Formulation and Feeding Programs 217Sung Woo Kim and Jeffrey A. Hansen

vii

viii CONTENTS

Chapter 10 Alternative Feedstuffs in Swine Diets 229Ruurd T. Zijlstra and Eduardo Beltranena

Chapter 11 Fiber in Swine Nutrition 255Pedro E. Urriola, Sarah K. Cervantes-Pahm, and Hans H. Stein

Chapter 12 Enzymes and Enzyme Supplementation of Swine Diets 277Oluyinka A. Olukosi and Olayiwola Adeola

Chapter 13 Feed Additives in Swine Diets 295Gary L. Cromwell

Chapter 14 Bioavailability of Amino Acids, Lipids, and Carbohydrates in Feedstuffs 317Dong Y. Kil, Sarah K. Cervantes-Pahm, and Hans H. Stein

Chapter 15 Bioavailability of Minerals and Vitamins in Feedstuffs 341David H. Baker and Hans H. Stein

Chapter 16 Swine Nutrition and Environment 365Ming Z. Fan

Chapter 17 Swine Nutrition and Pork Quality 413Jason K. Apple

Chapter 18 Feeding Growing and Breeding Swine 439Lee J. Johnston, Mark H. Whitney, Samuel K. Baidoo,and Joshua A. Jendza

Index 465

Contributors

Olayiwola Adeola, Ph.D. Dept. of Animal SciencesPurdue UniversityWest Lafayette, Indiana

Jason K. Apple, Ph.D. Dept. of Animal ScienceUniversity of ArkansasFayetteville, Arkansas

Michael J. Azain, Ph.D. Dept. of Animal and Dairy ScienceUniversity of GeorgiaAthens, Georgia

Knud Erik Bach Knudsen, Ph.D. Dept. of Animal ScienceAarhus UniversityDK-8830 Tjele, Denmark

Sam K. Baidoo, Ph.D. Southern Research and Outreach CenterUniversity of MinnesotaWaseca, Minnesota

David H. Baker, Ph.D. (Deceased) Dept. of Animal SciencesUniversity of IllinoisUrbana, Illinois

Eduardo Beltranena, Ph.D. Ag Research DivisionAlberta Agriculture and Rural DevelopmentEdmonton, Alberta, Canada

Sarah K. Cervantes-Pahm, Ph.D. Schillinger GeneticsDes Moines, Iowa

Gary L. Cromwell, Ph.D. Dept. of Animal and Food SciencesUniversity of KentuckyLexington, Kentucky

Ming Z. Fan, Ph.D. Dept. of Animal and Poultry ScienceUniversity of GuelphGuelph, Ontario, Canada

ix

x CONTRIBUTORS

Jeffrey A. Hansen, Ph.D. Murphy-Brown, LLCWarsaw, North Carolina

Gretchen M. Hill, Ph.D. Dept. of Animal ScienceMichigan State UniversityEast Lansing, Michigan

Joshua A. Jendza, Ph.D. Southern Research and Outreach CenterUniversity of MinnesotaWaseca, Minnesota

Lee J. Johnston, Ph.D. West Central Research and Outreach CenterUniversity of MinnesotaMorris, Minnesota

Henry Jørgensen, Ph.D. Dept. of Animal ScienceAarhus UniversityDK-8830 Tjele, Denmark

Dong Y. Kil, Ph.D. Dept. of Animal Science and TechnologyChung-Ang UniversityAnseong-si, Gyeonggi-do, Republic of Korea

Sung Woo Kim, Ph.D. Dept. of Animal ScienceNorth Carolina State UniversityRaleigh, North Carolina

Helle Nygaard Lærke, Ph.D. Dept. of Animal ScienceAarhus UniversityDK-8830 Tjele, Denmark

Charlotte Lauridsen, Ph.D. Dept. of Animal ScienceAarhus UniversityDK-8830 Tjele, Denmark

Gita Malik, Ph.D. Dept. of Animal and Poultry ScienceUniversity of SaskatchewanSaskatoon, Saskatchewan, Canada

Rodrigo Manjarı́n, Ph.D. Dept. of Animal ScienceMichigan State UniversityEast Lansing, Michigan

J. Jacques Matte, Ph.D. Dairy & Swine Research & Development CentreAgriculture and Agri-Food CanadaSherbrooke, Quebec, Canada

Jean Noblet, Ph.D. INRAF-35590 Saint-GillesFrance

CONTRIBUTORS xi

Jack Odle, Ph.D. Dept. of Animal ScienceNorth Carolina State UniversityRaleigh, North Carolina

Oluyinka A. Olukosi, Ph.D. Dept. of Animal SciencesPurdue UniversityWest Lafayette, Indiana

John F. Patience, Ph.D. Dept. of Animal ScienceIowa State UniversityAmes, Iowa

Hans H. Stein, Ph.D. Dept. of Animal SciencesUniversity of IllinoisUrbana, Illinois

Nathalie L. Trottier, Ph.D. Dept. of Animal ScienceMichigan State UniversityEast Lansing, Michigan

Pedro E. Urriola, Ph.D. Cargill Animal NutritionElk River, Minnesota

Andrew G. Van Kessel, Ph.D. Dept. of Animal and Poultry ScienceUniversity of SaskatchewanSaskatoon, Saskatchewan, Canada

Jaap van Milgen, Ph.D. INRAF-35590 Saint-GillesFrance

Mark H. Whitney, Ph.D. University of Minnesota ExtensionUniversity of MinnesotaMankato, Minnesota

Benjamin P. Willing, Ph.D. Dept. of Animal and Poultry ScienceUniversity of SaskatchewanSaskatoon, Saskatchewan, Canada

Lin Xi, Ph.D. Dept. of Animal ScienceNorth Carolina State UniversityRaleigh, North Carolina

Ruurd T. Zijlstra, Ph.D. Dept. of Animal, Food and Nutritional ScienceUniversity of AlbertaEdmonton, Alberta, Canada

Preface

Swine nutrition is a dynamic and rapidly changing science. New information is generated and addedto the field of swine nutrition continuously, expanding the fundamental knowledge base. Obviously,all the information would be extremely important for successful and sustainable commercial swineproduction. To utilize the information effectively, all those recent developments or current advancesin swine nutrition must be put into a proper context simply because of the diversity of suchinformation. We have many books that cover various aspects of swine nutrition, but, unfortunately,there are not many books that are specifically designed to address pertinent issues necessary for“successful and sustainable swine production.” I am hoping that this book will fill the void and makecontributions to the development of environmentally friendly feeding strategies for successful andsustainable swine production.

In commercial swine production, the main objective of diet formulation and feeding strategy isto maximize profits, which does not necessarily imply maximal animal performance. To maximizethe economic efficiency, therefore, it is advantageous to supply energy and indispensable nutrientsas close as possible to meeting but not exceeding the requirements of the pig. Such optimumfeeding strategies would contribute greatly to the efficiency of energy and nutrient utilization,which helps ensure continuous availability of quality sources of energy and nutrients for futureswine production, and produce a positive impact on today’s environmentally conscious society byreducing the excretion of unutilized nutrients. The development of such feeding strategies involvesconsideration of a multitude of factors such as genetic variations in the pig, variability, availability,and stability of nutrients in feed ingredients, interactions among nutrients and non-nutritive factors,voluntary feed intake, physical and social environment, and others, and thorough, comprehensivereviews on some of those factors are, obviously, warranted.

The competition between humans and animals for quality sources of energy and nutrients is likelyto increase continuously in the future because of ever-increasing world population and an increase inthe economic development of both newly industrialized and less economically developed countries.Clearly, it is important for us to find alternative sources of energy and nutrients for swine production.Alternative feed ingredients have different feeding values because of variations in nutrient contentand other factors such as bioavailability and stability, anti-nutritional factors, interactions amongthe nutrients and possibly with non-nutritive factors, and palatability. To utilize potential alternativesources effectively or efficiently can be, therefore, challenging, and we obviously need all thefundamental and applied nutritional information to accomplish such a daunting task. Furthermore,satisfying consumer demands for healthy and nutritious food and alleviating public concerns on theenvironmental issues are an integral part of successful and sustainable swine production. Therefore,addressing not only the nutritional issues associated with maximizing growth performance and the

xiii

xiv PREFACE

utilization of energy and nutrients but also the issues associated with the carcass and pork qualityand impacts of swine production on the environment are extremely important.

As a comprehensive book on swine nutrition, it is, obviously, important to cover some basic orfundamental aspects of nutrition, i.e., water, protein or amino acids, lipids, carbohydrates, energymetabolism, vitamins, minerals, and also nutrition and immunology. The emphasis of the presentbook is, however, on recent developments or current advances or some pertinent issues in each ofthose major areas. Therefore, some fundamental aspects will be reviewed briefly, and the focusof review is on the latest up-to-date information. Then, the remaining book is dedicated to thediscussion of some specific, pertinent issues that may contribute to the ultimate goal or theme of thebook, that is, to provide a comprehensive review on each pertinent area necessary for “successfuland sustainable swine production.”

It is with the deepest sorrow to acknowledge the loss of Dr. David H. Baker, one of the contributingauthors. Dr. Baker was Professor Emeritus of Nutritional Sciences and Animal Sciences at theUniversity of Illinois at Urbana-Champaign. He was elected to membership in the National Academyof Sciences in 2005, which is considered as one of the highest and most prestigious honors thatcan be accorded to a scientist, in 2005. Dr. Baker received six major awards from the AmericanSociety of Animal Science, five major awards from the Poultry Science Association, and two majorawards from the American Society of Nutrition. In addition, along with countless others, Dr. Bakerreceived USDA Distinguished Service Award in Research and Charles A. Black Award from theCouncil for Agricultural Science and Technology. Dr. Baker published almost 600 peer-reviewedjournal articles, a record that is not approached by anyone in the field today. Dr. Baker was a Fellowof the American Society of Animal Science, the Poultry Science Association, and the AmericanSociety of Nutrition. His legacy will certainly continue to inspire further research in the field ofnonruminant nutrition and beyond.

This book would not have been possible without the help of my colleagues, and I would like tothank our contributors for their willingness to participate in this endeavor. I sincerely appreciatetheir time and dedicated effort on this book project. Also, I would like to thank my graduate students,Sean D. Brotzge and Chhabi K. Adhikari, for their assistance in reviewing and (or) formatting areference section for each chapter.

Editor

Lee I. Chiba is a professor of animal science in the Department of Animal Sciences at AuburnUniversity, Auburn, Alabama. He received his B.S. in animal science and M.S. and Ph.D. innonruminant nutrition from the University of Nebraska, Lincoln, Nebraska. Dr. Chiba teachesundergraduate courses in animal nutrition and swine production and graduate courses in nonruminantnutrition and vitamin and mineral metabolism. His research interests are in the areas of dietarymanipulations to improve leanness and efficiency of growing pigs and organoleptic quality of porkand also nutritional management to improve reproductive performance of sows. Dr. Chiba has servedas a member of the Editorial Board for three terms and an associate editor of the Journal of AnimalScience for two terms. He is currently serving his second term as a division editor of the Journal ofAnimal Science and a section editor of the Livestock Science.

xv

Part IFundamental Nutrition

1 Water in Swine NutritionJohn F. Patience

Introduction

Water is a critical component of the pig’s diet. Therefore, it seems incongruous that water receivesso little attention, either in the popular press or in the scientific literature. It has earned the title ofthe “forgotten nutrient” because it rarely attracts attention unless problems arise. The classic phraseexpressing the importance of water to the body can be attributed to Maynard (1979) who stated,“The body can lose practically all of its fat and over half of its protein and yet live, while a loss often percent of its water results in death.”

In most major pork-producing regions of the world, water is abundant, inexpensive, and not tradedcommercially, making it a rare focus of research (Fraser et al., 1990). This helps to explain the dearthof information on a topic of such importance, relative to many other nutrients. However, to givecredit to the research community, water is also a particularly difficult nutrient to study. Classicalapproaches to the study of energy, amino acids, minerals, and vitamins are extremely difficult, ifnot impossible, to apply to water.

Water is also surprisingly difficult to measure in the laboratory. The water in feed, fecal, urine, orcarcass samples is in continuous exchange with the surrounding air, such that samples may eitheraccumulate or lose substantial quantities of water over time. Furthermore, methods to determinethe dry matter content of a sample may remove not only water but also volatile compounds, suchas ammonia and short-chained fatty acids, introducing yet another source of error. Whereas themeasurement of dry matter requires the simplest of laboratory equipment, its determination isanything but simple. For such a simple molecule, water is a very complicated nutrient to study!

Water Content of the Body

The water molecule is by far the most abundant in the pig’s body, representing some 99% of thetotal (Shields et al., 1983). By weight, water ranges from about 82.5% at birth to 53% of the bodyat market weight; the difference is explained largely by declining lean and increasing lipid in thecarcass (Shields et al., 1983). Water in the body is distributed among three pools: the intracellularspace, representing about 69% of the total; the interstitium, representing about 22% of the total;and the remainder, which is found in the vascular system (Mroz et al., 1995). Maintaining proper

Sustainable Swine Nutrition, First Edition. Edited by Lee I. Chiba.C© 2013 John Wiley & Sons, Inc. Published 2013 by John Wiley & Sons, Inc.

3

4 WATER IN SWINE NUTRITION

water balance for the total body, as well as within cells and tissues, is a critical requirement of lifein terrestrial species. This is intimately related to electrolyte balance within and among cells andorgans, another essential homeostatic process (Patience et al., 1989).

Regulation of drinking in the pig is not well understood. Although hypovolemia and hypertonicityappear to be involved, other signals related to food consumption must also exist (Mroz et al., 1995).Furthermore, behavioral stimulation is well known in the pig, leading to luxury consumption ofwater during periods of boredom, hunger, and other stressors (Fraser et al., 1990).

Water is absorbed from, and secreted into, all sections of the intestinal tract, except the stomach.Absorption occurs by both active and passive processes (Argenzio, 1984). As the chyme passesprogressively through the small and large intestines, the osmotic gradient increases, allowing forremoval of most water by the terminal colon. The osmotic balance can be disturbed, for example,by the presence of large quantities of osmotically active ions in the intestine. This is the cause ofthe diarrhea (Fraser et al., 1990).

Water as a Nutrient

Functional Properties of Water

There are few processes in the body that do not involve water directly or indirectly. It is nocoincidence that water is central to all living things. Its unique structure elegantly matches itschemistry with its role in physiology, biochemistry, and nutrition.

Its high specific heat makes it ideally suited to its role in thermal homeostasis. For example, theheat of vaporization of water is 540 cal/g, more than double that of other liquids like alcohols andfive times that of solvents such as hexane and benzene (Lehninger, 1982). This high specific heatis also 2.5 times that of the dry matter in the body. Under heat-stress conditions, water can absorbmuch larger quantities of heat energy than other liquids or solids with less consequent change intemperature. In this way, it effectively contributes to constant internal body temperature. Becauseof its heat of vaporization, it also serves an essential role in the dissipation of heat from the body,through evaporation from the lungs.

Water also plays a central role in acid–base homeostasis. The pH of water is 7, very close to theideal physiological pH of most tissues. Furthermore, water is an integral part of the bicarbonatebuffer system, whereby CO2 and H2O are in equilibrium with H+ and HCO−

3:

H+ + HCO−3 = H2CO3 = H2O + CO2

In this way, water participates in the mechanism responsible for excreting the greatest quantity ofacid produced by normal metabolism in the body, namely, through CO2. The bicarbonate system, inassociation with hemoglobin in the blood, supports removal of an otherwise toxic molecule, CO2,with little damage to tissues and little change in venous pH. In this respect, water plays two roles,the chemical one illustrated previously and that of the solute carrying the molecules throughout thebody.

As a solvent, water is the major transportation medium for the exchange of nutrients, chemicalenergy, metabolites, and waste products among cells and among organs. It also supports movementof hormones from their site of production or release to the target cells or organs or both. Its successas a solvent lies in its unique chemical structure, namely, the dipolar character of the molecule. As

FUNDAMENTAL NUTRITION 5

Table 1.1 Estimated water balance of a 45-kg grower pig.

Intake, mL/d Excretion, mL/d

Drinking water1 5,552 Feces4 672Water from metabolism2 788 Urine4 2,839Water in feed2 252 Digestion5 185Tissue synthesis3 74 Other6 2,335

Total water excreted 6,031

Retained with body weight gain7 635

Total water supply 6,666 Total water excreted or retained 6,666

1 The pig weighs 45 kg, consumes 2.1 kg feed/d, gains 0.98 kg/d, and drinks 5.55 kg water/d(Shaw et al., 2006). Although not measured, it was assumed that the protein accretion rate was160 g/d, ash accretion was 35 g/d, and lipid accretion was 150 g/d (Oresanya et al., 2008).2 The diet contains 12% moisture, 5% ether extract (85% of 5% ether extract/lipids are digested,and also the efficiency of depositing digestible ether extract/lipids as body lipids is 90%), 18%crude protein [of which 80% is digested and 80% is actual protein (20% is non-protein nitrogen)and 35% of digestible protein is retained and the rest is catabolized]. This results in 9 g lipid,157 g protein, and 1,260 g carbohydrate being oxidized per day, generating 1,190, 450, and560 mL water/kg, respectively (NRC, 1981).3 From Schiavon and Emmans (2000).4 Assumes diet digestibility of 82% and fecal moisture of 64%.5 From Schiavon and Emmans (2000).6 Water lost that is not accounted for by the model, the majority of which will be evaporation.7 Tissue accretion rates: 150 g lipid, 35 g ash, and 160 g protein for a total of 345 g/d; totalbody weight gain was 980 g/d, resulting in 635 g water/d.

an example, simple salt readily dissolves in water, but it is nearly insoluble in other liquids such asbenzene or chloroform (Lehninger, 1982).

Water is the basis for chemical reactions in the body such as oxidation and hydrolysis. Oxidationis involved in the degradation of dietary amino acids not used in synthetic processes, and of dietarycarbohydrates and lipids not directly deposited into the body. Because about two-thirds of dietaryprotein is not retained in the body and most of the dietary carbohydrate is oxidized, this representsa substantial source of metabolic water, which we have estimated at about 12% of total daily waterbalance in the growing pig (Table 1.1). The exact portion of dietary lipid that is oxidized will behighly dependent on the physiological and nutritional state of the pig at any point in its growthcurve. It can, therefore, be seen that water is not only ideally suited to its central role in the body,but also essential to so many facets of life.

Water Balance

Water Intake

Although drinking represents the most important way for the pig to obtain water, it is by no meansthe only source. Feed contains free water, which is obligatorily ingested during meals. Oxidationof amino acids, carbohydrates, and lipids also contributes a substantial portion of the pig’s daily

6 WATER IN SWINE NUTRITION

needs. However, understanding drinking behavior has proven to be a very complex topic becausethere are so many factors that influence the pig’s need and demand for water (Fraser et al., 1990).These factors include the need to satisfy physiological, biochemical, and nutrition requirements,which themselves are influenced by environment, health, diet, and the quality of the drinking water.However, the pig will also use water to satisfy a variety of behavioral needs, if water is freelyavailable to it.

Schiavon and Emmans (2000) have proposed a simplified model to predict water intake of thegrowing pig. The model indicates that water intake will be increased by the quantity of water neededto support digestive processes, the quantity lost via the feces and urine, and the amount retained dur-ing growth. In turn, water intake will be reduced by water obtained from the feed, water produced byoxidative processes, and water released during protein and lipid synthesis. However, the authors con-cluded that additional experimentation was required to refine estimates of, for example, the quantityof water required to excrete excess nitrogen and electrolytes from the body, the partitioning of min-eral excretion between urine and feces, and the water required for osmotic regulation, among others.

Drinking Water in GeneralThe largest source of daily water intake for the pig is derived from drinking. Indeed, many publica-tions indicate that the only management required in the supply of water is to ensure that it is readilyavailable and of good quality. It is widely viewed that under such conditions, the pig will correctlyregulate its own water supply according to its need. However, as Fraser et al. (1990) have pointedout, this is definitely not the case, as pigs will exhibit considerable drive to consume additionalwater beyond that required for physiological need (Vermeer et al., 2009). However, the main factorsaffecting drinking-water intake are body weight, feed intake, and temperature (Mroz et al., 1995).

It is critically important to the body that water balance remains under tight control, becausedehydration and overhydration are both fatal. The hypothalamic region of the brain is consideredto be the center for the control of thirst and drinking behavior (Koeppen and Stanton, 2001).Osmoreceptors located in the hypothalamus detect changes in the osmolality of extracellular fluids,and a rise in plasma osmolality of only 10 mOsm/kg is sufficient to induce the sensation of thirst,which results in drinking (Anderson and Houpt, 1990). Hypovolemia also serves as a signal for thirst,such that a 6–7% fall in blood volume also induces thirst (Anderson and Houpt, 1990). However,based on drinking patterns, other signals must be involved. Mroz et al. (1995) have suggestedmucosal blood flow, vascular stretch or distention, and dryness of the mouth as possibilities.

The literature contains many estimates of the drinking-water intake of pigs under ad libitum condi-tions. These estimates sometimes refer to water “disappearance” opposed to water intake because noallowance is made for waste. Wasted drinking water has substantial financial implications, especiallyas it relates to manure volumes and annual slurry hauling costs. Consequently, the selection of drinkerdesign and location is generally given considerable weight to minimize wastage (Brumm, 2010).

Factors Affecting Water IntakeThe primary influences on the pig’s water intake are body weight, the thermal environment, and feedintake. Like all nutrients, as the pig grows, its daily requirement for water increases. Unfortunately,there are insufficient data in the literature to develop a credible relationship between body weightand water requirement. Schiavon and Emmans (2000) reported that the R2 between body weight andwater intake was only 0.45; this was measured under highly controlled conditions, and one wouldreasonably assume that under commercial conditions, the relationship would be even less powerful.Thus, there are numerous other influences affecting the pig’s free-choice water consumption.

FUNDAMENTAL NUTRITION 7

Intuitively, elevated environmental temperatures increase water intake. Schiavon and Emmans(2000) suggested that for every 1◦C increase in the air temperature, water intake increased by0.12 L/d. Vandenheede and Nicks (1991) reported that water intake increased from 2.2 to 4.2 L/din finishing pigs when the temperature increased from 10◦C to 25◦C, a difference that supports therelationship established by Schiavon and Emmans (2000). Mount et al. (1971) reported that raisingthe temperature from 12◦C–15◦C to 30◦C–35◦C increased water consumption by 57% in 33.5-kgpigs, whereas Straub et al. (1976) reported a 63% increase in 90-kg pigs. Yang et al. (1981) observedthat total body water remained constant, whereas water turnover increased when the temperaturerose from 27◦C to 35◦C.

It should be noted that during periods of heat stress, pigs tend to increase the amount of timespent playing with waterers, thereby increasing water wastage. That could cause an exaggeration ofwater requirements during periods of thermal stress.

Estimates of the water-to-feed ratio vary widely in the literature, from as little as 1.5:1 to morethan 5:1. Although some of the variation may be explained by environmental conditions, the natureof the diets, or behavioral influences, experimental procedures for such studies also differ widely.However, when the growing pig is housed in thermoneutral conditions, free of behavioral influences,and fed typical commercial diets, the ratio will typically be about 2.5:1 (Shaw et al., 2008); thisratio will be lower in the finisher pig (perhaps 2:1).

Sometimes, failure to account for wastage increases apparent intake. Thus, one should be carefulabout terminology because water intake refers to the quantity actually consumed by the pig, whereaswater disappearance refers to water that leaves the water delivery system. For example, wastage ofwater dispensed by a wall-mounted nipple drinker can typically range from 25% to 50%, or evenhigher (Li et al., 2005).

It is widely held that water intake increases as dietary protein increases. This is supported bynumerous reports in the literature (Suzuki et al., 1998; Pfeiffer et al., 1995) and makes sensephysiologically, because excess protein in the diet places demands on the kidney to excrete greaterquantities of urea. However, there is also a body of literature that indicates the relationship betweendietary protein level and water intake is not linear (Albar and Granier, 1996; Tachibana and Ubagai,1997; Shaw et al., 2006). Therefore, it may be concluded from the literature that lowering dietaryprotein as a means of conserving water may not be successful, and that dietary protein only elevateswater intake when it is present in substantial excess (Shaw et al., 2006). Mroz et al. (1995) havesuggested that many studies relating water intake and dietary protein content were confounded byconcurrent changes in dietary mineral levels.

It is also well known that increasing the salt concentration in the diet will result in elevated waterconsumption (Seynaeve et al., 1996). Interestingly, pigs also consume greater quantities of waterwhen the water itself is high in minerals (Maenz et al., 1994).

As occurs in many species, hunger will induce increases in water consumption. For example,Yang et al. (1984) reported that providing restrictively fed pigs with increasing amounts of feedreduced the observed water-to-feed ratio from 5.1:1 to 3.3:1.

It is widely accepted that pigs consume luxury amounts of water for play or because of hunger-induced or stress-induced polydipsia, such that simply measuring water disappearance may introduceerrors into the estimation of water requirements (Fraser et al., 1990; Vermeer et al., 2009).

Feed WaterThe pig obtains a certain amount of water from the feed. The actual amount consumed withfeed would be a function of the quantity of feed eaten and of the percent moisture in that feed.

8 WATER IN SWINE NUTRITION

Quantitatively, this is not a large portion of the pig’s daily intake, representing something less than5% of the total.

Metabolic WaterThe oxidation of 1 g of lipid, protein, or carbohydrate, on average, releases 1.10, 0.44, and 0.60 gof water, respectively. Of course, the exact quantity will be a function of the structure of the specificfatty acid, amino acid, or carbohydrate (Patience, 1989).

Water Released by Tissue SynthesisWater is released by the synthesis of body constituents. Thus, 1 g of protein retained in the bodyreleases 0.16 g water, whereas 1 g of lipid releases 0.07 g water (Schiavon and Emmans, 2000).

Water Excretion

Renal ExcretionThe quantity of water eliminated from the body via urine will be a function of the solutes presentin the urine and the ability of the kidney to concentrate the urine, which has been estimated at1 mOsm/L in the pig (Brooks and Carpenter, 1990). The solutes of greatest importance in thisregard will be nitrogen (primarily but not exclusively as urea), calcium, phosphorus, sodium,chloride, magnesium, and potassium. These fixed cations and anions will be accompanied bymetabolizable anions and cations, respectively (Patience, 1989).

The permeability of the renal tubules is under the influence of the antidiuretic hormone (ADH),which is released from the pituitary gland. The ADH is released when receptors in the atria ofthe heart detect a decrease in blood volume. In response to ADH, the kidney reabsorbs morewater, thus returning blood volume to a desirable level (Berdanier, 1995). In addition to ADH, therennin-angiotensin system plays a role in maintaining fluid volume by stimulating ADH and aldos-terone release, enhancement of sodium and chloride resorption, and vasoconstriction. Aldosteroneis secreted by the adrenal glands and serves to conserve sodium and chloride reserves (Berdanier,1995).

Fecal ExcretionWater lost with the feces can be estimated in a number of ways. The simplest, but least precise, isto assume a typical moisture content of feces (Table 1.1). More sophisticated approaches look atthe individual constituents of the feces and determine the quantity of moisture associated with each.Unfortunately, there are insufficient data available to undertake this approach with any reasonabledegree of precision (Schiavon and Emmans, 2000).

Water Balance

One cannot simply feed graded levels of water to the pig and define requirement as the level thatoptimizes performance. Because the pig possesses such a large and dynamic pool of water in theintracellular, intercellular, and extracellular spaces, any growth study would require a quantitativemeasurement of both sources of water supply to the pig, including drinking water, water in the feed,water generated by metabolism, and excretion of water from the body via feces, urine, respiration,and sweat. The difference would, of course, be water accumulated as a consequence of growth.

FUNDAMENTAL NUTRITION 9

Measuring so many water “pools” would be extremely difficult, and, based on the literature, ithas never been attempted. However, Schiavon and Emmans (2000) have attempted to model waterintake in the pig, accounting for water required for digestion, fecal excretion, urinary excretion,evaporation, and growth.

Table 1.1 demonstrates an attempt to quantify water balance in a typical growing pig housed in athermoneutral environment and fed a typical commercial diet ad libitum, which is based on experi-mental data reported by Shaw et al. (2006). From this determination of the water balance of a growingpig, it is readily apparent that water generated by metabolism of dietary fat, protein, and carbohy-drates represents a substantial portion (12%) of the total daily water supply. Conversely, moisture inthe feed represents a modest 4% of the total. In terms of excreted water, urine is only slightly greaterthan “other” losses (47% versus 39%); the latter will consist mainly of water lost by evaporation, acomponent that obviously would be greatly affected by ambient environmental temperature. Fecallosses of water, representing 11% of the total, will vary somewhat by diet composition, but willobviously be impacted by the presence of gastrointestinal pathologies such as diarrhea.

Water Requirement

Numerous approaches to the study of water requirements are available (Fraser et al., 1990). Theclassical approach of providing graded levels of the nutrient in the daily diet and then evaluatingperformance outcomes is difficult to apply to water, because the results will be influenced by manyfactors such as environmental temperature, the nature of the diet (e.g., levels of protein and minerals),and the portion of gain that is lean or lipid.

A second approach is to provide water to the pig on an ad libitum basis, and select the level ofintake associated with optimum gain. This is a particularly troubling approach, although it has beenused all too often in the literature, because there is no assurance that the pig’s intake is established byphysiological need. It is well known that pigs, as well as other species, engage in “luxury intake” ofwater because of factors such as stress and hunger (Patience et al., 1987). In one experiment, wherewater was provided ad libitum to 40-kg pigs, daily intake varied from 1.70 to 16.8 L/d (Patienceet al., 1987), revealing how inadequate this approach to defining requirements can be.

A third approach is to define the level of intake that prevents specific pathologies—in this case,dehydration. However, the pig will resort to metabolically costly means of preventing dehydration,such as excreting hyperosmotic urine, to conserve water balance. Although one can argue thathyperosmotic urine is produced only when blood volume declines, such mechanisms are extremelyprecise and would be very difficult to detect in a simple study of water intake.

It has been suggested that the water requirement of the pig can be defined as a ratio of water-to-feedintake (Brumm et al., 2000), but this ignores the impact of body weight, environmental temperature,and diet composition as key factors influencing water intake (Mroz et al., 1995). However, suchratios provide a useful practical tool, provided their limitations are well understood by the user. Byunderstanding that recommended water-to-feed ratios are defined in a thermoneutral environment,one can suggest the following standard: 2.5:1 for early growing pigs and 2.0:1 for the late finishingpig. In some instances, water-to-feed ratios, as low as 1.5:1, have been reported in late finishing.From this, one can suggest that the average water intake in a thermoneutral environment will beabout 3.2 L for a 25-kg pig, increasing to 5.5 L at a market weight of 130 kg. However, it mustbe reemphasized that specific requirements will vary among farms because of widely varying feedintake, changes in the thermal environment (Mroz et al., 1995), and the unique behavioral demandsof different populations of pigs (Fraser et al., 1990).

10 WATER IN SWINE NUTRITION

Water Delivery to the Pig

There are a number of issues associated with the proper delivery of water to swine (Gonyouand Zhou, 2000; Brumm et al., 2000). Inadequate water impairs pig performance and in casesof severe restriction reduces feed digestibility (Mroz et al., 1995). Excess water leads to wasteand unnecessarily increases manure volumes. This, in turn, increases manure hauling costs whenapplied to the land. Excessive water waste also leads to increased medication costs, if medicationsare supplied via the drinking water. Fecal contamination of drinkers can lead to reduced intake andimpaired performance. Consequently, the selection of the correct drinker is an important decisionin pig management.

Nipple Drinkers

Water can be delivered to the pig using a number of different approaches. Traditionally, nippledrinkers have been mounted on or near the rear wall of the pen to provide water ad libitum.Water wastage is an important issue with such systems; 25% of the water delivered by a typicalnipple drinker is wasted by the pig and unnecessarily leads to excessive manure volumes that mustbe removed from the barn (Li et al., 2005). In the study by Li et al. (2005), water flow rate was set atthe manufacturer’s recommended level and the height of the drinker was adjusted as the pigs grew.The authors suggested that under more typical commercial practice, where nipple-drinker heightis fixed and flow rates often exceed that required by the drinking device, wastage can approach50–60%. It is recommended that the bottom of the nipple drinker be located 50 cm above theshoulder of the smallest pig in the pen (Gill and Barber, 1990), which itself can be calculated as 150× BW0.33 (Petherick, 1983). Excessive flow rates will also increase water wastage.

Although excessive water flow rates of nipple drinkers should be avoided to minimize wastage,inadequate flow rates can also be a serious concern. For example, in the nursery, salt poisoning hasbeen reported in newly weaned piglets because they were unable to consume adequate water toremove dietary salt from their systems. Neinable and Hahn (1984) reported that flow rates adequateat low temperatures can be inadequate when pigs are heat stressed. Table 1.2 presents typicalrecommendations for nipple-drinker flow rates, which balance the need to avoid excessive wastagewhile ensuring adequate water intake.

A variant of the wall-mounted nipple drinker is the swinging nipple drinker, which is suspendedfrom the ceiling of the barn. It reduces the amount of water wasted by the pig, although theexact amount has not been quantified. Brumm et al. (2000) reported a 11% reduction in water

Table 1.2 Recommended nipple drinker flow rates forvarious classes of swine.

Recommended flow rate, mL/min

Class Minimum Maximum

Gestation 500 1,000Lactation 1,000 2,000Weanling 750 1,000Grower–finisher 750 1,000

FUNDAMENTAL NUTRITION 11

disappearance with the use of swinging drinkers compared to wall-mounted drinkers, but waste wasnot measured.

Dish Drinkers

Wall-mounted dish drinkers tend to waste very little water if correctly adjusted, but their heightmust be increased as the pigs grow. Otherwise, they may be fouled and this leads to reduced waterintake. Dish drinkers should not be located close to pen corners, as this increases the risk of fouling.Brumm et al. (2000) reported 25% less water disappearance from bowl drinkers than swingingnipple drinkers.

Wet–Dry Feeders

Wet–dry feeders are another alternative method to provide drinking water. They allow pigs theopportunity to eat feed either in dry form or wetted (hence, their name). Wet–dry feeders reducewater wastage by 35%, compared to wall-mounted nipple drinkers. In temperature climates, anadditional source of water is not required, but in warmer climates, where heat stress is a commonoccurrence, additional drinkers are recommended. The selection of drinker type will determine ifwater wastage will be a concern. Table 1.2 provides recommended flow rates for nipple drinkers fordifferent classes of swine (Patience et al., 1995).

Liquid Feeding

Liquid feeding offers numerous advantages over conventional dry feeding of pigs. These includeimproved growth rates or improved feed efficiency or both (Hurst et al., 2008). However, theseadvantages may be more noticeable when the diet contains wheat and barley as compared to corn(De Lange et al., 2006). There is increasing interest in fermented liquid feeding to improve piglethealth, and also to improve the bioavailability of phytate-bound phosphorus in many feedstuffs ofplant origin.

There is a lack of agreement in the literature on the most appropriate water-to-feed ratios toapply to liquid feeding systems. Minimum water is required for mechanical purposes to ensurethe adequate flow of feed from the mixer to the pigs, but beyond that, recommendations vary. Forexample, it has been shown that dry matter intake increases as the water-to-feed ratio increases to3:1 or 3.5:1 (Barber et al., 1991a,b), but further increases up to 6:1 lowered dry matter intake. Incurrent commercial practice, water-to-feed ratios tend to fall within the range of 2.5:1 to 3.5:1.

Water Management

Gestating Sows

Water intake in gestating sows is greatly influenced by behavioral factors, notably hunger-inducedpolydipsia. Like many other species, pigs overconsume water when their appetite for food is not fullysatisfied. Consequently, water intake values reported in the literature for gestating sows vary widely.

12 WATER IN SWINE NUTRITION

Examples include 5.6 L/(d kg) feed (Lightfoot and Armsby, 1984) and 2.5 L/(d kg)(Friend, 1971),14.9 L/d (Bauer, 1982), 17.2 L/d (Madec et al., 1986), and 25.8 L/d (Kuperus, 1988). Where rangeswere reported, they were very large; for example, Pollman et al. (1979) reported a range in dailywater intake from 3.4 to 46.2 L/d. It is very difficult to assign a specific intake need for the dry sow,because hunger-induced polydipsia is a legitimate consideration. Therefore, the recommendationfor dry sows is fresh water supplied ad libitum throughout the day.

Lactating Sows

A common question in nursing sow management relates to water and whether insufficiency of waterintake impairs lactation performance, at least in some instances. Most studies on lactational waterintake have simply measured intake, without attempting to determine its adequacy. In a survey ofmany such studies, Fraser et al. (1990) summarized the results from twelve different reports. Theonly reasonable conclusion was that intake varied widely, both within and among studies. Meanintake among studies ranged from 8.1 to 25.1 L/d.

Fraser and Phillips (1989) presented interesting data that indicated that low water intake duringthe first five days postfarrowing was correlated with reduced piglet growth rates. Sows with lowwater intakes nursed piglets with low gains and sows with high water intakes were the opposite. Itis impossible to assign cause and effect in such studies, but it seems that paying attention to waterintake in the early nursing period is critical to good piglet growth.

Paying attention to water intake during the first five days postfarrowing seems to be very important.This means making it as easy as possible for sows to access drinkers, whether they are standing orlying, because postpartum lethargy may be important. Because sow’s milk is about 81% water, theneed to optimize water intake is self-evident.

Nursing Piglets

There is no agreement on the need for supplemental water by the nursing piglet, especially duringthe first one to two weeks after birth. Fraser et al. (1990) have suggested that early water intake inpiglets ranges from nil to more than 100 mL/d. Deligeorgis et al. (2006) reported that piglets visitedthe drinker, on average, 16 hours after birth; pigs that visited the drinker weighed more 48 hoursafter birth than those that did not, and placement of the drinker affected water intake.

Because sow milk production, thermal environment, and creep feed consumption all influencewater intake by suckling pigs, it is generally recommended to make water available to piglets fromthe time of birth. As weaning ages in North America increase from less than 21 days to 25 daysor higher, it will become increasingly important to provide a continuous supply of fresh drinkingwater in the farrowing crate to encourage creep feed consumption.

Weaning Pigs

During the late nursing period, a pig will be consuming 700 mL to more than 1.0 L of water perday in the form of milk. Yet, immediately after weaning, water intake follows an unusual patternof decline from about 1.0–1.5 L/d on the first day of weaning to 0.4–1.0 L/d around the fourth daypostweaning (McLeese et al., 1992; Maenz et al., 1993, 1994; Torrey et al., 2008). This indicates