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Nutrient Requirements of Beef Cattle: Seventh Revised Edition, 1996 Nutrient Requirements of Beef Cattle Seventh Revised Edition, 1996 Subcommittee on Beef Cattle Nutrition Committee on Animal Nutrition Board on Agriculture National Research Council NATIONAL ACADEMY PRESS Washington, D.C. 1996
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Nutrient Requirements of Beef Cattle: Seventh Revised Edition, 1996 National Academy Press 2101 Constitution Avenue Washington, D.C. 20418 NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competencies and with regard for appropriate balance. This report has been reviewed by a group other than the authors according to procedures approved by a Report Review Committee consisting of members of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. This study was supported by the Agricultural Research Service of the U.S. Department of Agriculture, under Agreement No. 59–32U4–5–6, and by the Center for Veterinary Medicine, Food and Drug Administration of the U.S. Department of Health and Human Services, under Cooperative Agreement No. FD-U-000006–10. Additional support was provided by the American Feed Industry Association. The National Academy of Sciences is a private, nonprofit, self-perpetuating society of distinguished scholars engaged in scientific and engineering research, dedicated to the furtherance of science and technology and to their use for the general welfare. Upon the authority of the charter granted to it by the Congress in 1863, the Academy has a mandate that requires it to advise the federal government on scientific and technical matters. Dr. Bruce M.Alberts is president of the National Academy of Sciences. The National Academy of Engineering was established in 1964, under the charter of the National Academy of Sciences, as a parallel organization of outstanding engineers. It is autonomous in its administration and in the selection of its members, sharing with the National Academy of Sciences the responsibility for advising the federal government. The National Academy of Engineering also sponsors engineering programs aimed at meeting national needs, encourages education and research, and recognizes the superior achievements of engineers. Dr. Harold Liebowitz is president of the National Academy of Engineering. The Institute of Medicine was established in 1970 by the National Academy of Sciences to secure the services of eminent members of appropriate professions in the examination of policy matters pertaining to the health of the public. The Institute acts under the responsibility given to the National Academy of Sciences by its congressional charter to be an adviser to the federal government and, upon its own initiative, to identify issues of medical care, research, and education. Dr. Kenneth I.Shine is president of the Institute of Medicine. The National Research Council was organized by the National Academy of Sciences in 1916 to associate the broad community of science and technology with the Academy’s purposes of furthering knowledge and advising the federal government. Functioning in accordance with general policies determined by the Academy, the Council has become the principal operating agency of both the National Academy of Sciences and the National Academy of Engineering in providing services to the government, the public, and the scientific and engineering communities. The Council is administered jointly by both Academies and the Institute of Medicine. Dr. Bruce M.Alberts and Dr. Harold Liebowitz are chairman and vice chairman, respectively, of the National Research Council. Library or Congress Cataloging-in-Publication Data Nutrient requirements of beef cattle/Subcommittee on Beef Cattle Nutrition, Committee on Animal Nutrition, Board on Agriculture, National Research Council.—7th rev. ed. p. cm.—(Nutrient requirements of domestic animals) Includes bibliographical references and index. ISBN 0-309-06934-3 (alk. paper) 1. Beef cattle—Feeding and feeds. I. National Research Council (U.S.). Subcommittee on Beef Cattle Nutrition. II. Series: Nutrient requirements of domestic animals (Unnumbered) SF203.N88 1996 636.2'13–dc20 96–13244 CIP © 1996 by the National Academy of Sciences. All rights reserved. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the organizations or agencies that provided support for this project. Printed in the United States of America
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Nutrient Requirements of Beef Cattle: Seventh Revised Edition, 1996 SUBCOMMITTEE ON BEEF CATTLE NUTRITION JOCK G.BUCHANAN-SMITH, Chair, University of Guelph, Canada LARRY L.BERGER, University of Illinois CALVIN L.FERRELL, U.S. Department of Agriculture, Agricultural Research Service, Clay Center, Nebraska DANNY G.FOX, Cornell University MICHAEL L.GALYEAN, Clayton Livestock Research Center, Clayton, New Mexico DAVID P.HUTCHESON, Animal Agricultural Consulting, Inc., Amarillo, Texas TERRY J.KLOPFENSTEIN, University of Nebraska JERRY W.SPEARS, North Carolina State University COMMITTEE ON ANIMAL NUTRITION DONALD C.BEITZ, Chair, Iowa State University GEORGE C.FAHEY, University of Illinois DANNY G.FOX, Cornell University* RONALD L.HORST, U.S. Department of Agriculture, Agricultural Research Service, Ames, Iowa TERRY J.KLOPFENSTEIN, University of Nebraska AUSTIN J.LEWIS, University of Nebraska ALICE N.PELL, Cornell University GARY D.POTTER, Texas A&M University JERRY L.SELL, Iowa State University ROBERT P.WILSON, Mississippi State University KARIN M.WITTENBERG, University of Manitoba, Canada Staff MARY I.POOS, Project Director CHARLOTTE KIRK BAER, Program Officer JANET OVERTON, Editor DENNIS BLACKWELL, Senior Project Assistant * July 1, 1991, through June 30, 1994.
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Nutrient Requirements of Beef Cattle: Seventh Revised Edition, 1996 BOARD ON AGRICULTURE DALE E.BAUMAN, Chair, Cornell University JOHN M.ANTLE, Montana State University MAY R.BERENBAUM, University of Illinois, Urbana-Champaign LEONARD S.BULL, North Carolina University, Raleigh WILLIAM B.DELAUDER, Delaware State University RICHARD R.HARWOOD, Michigan State University T.KENT KIRK, U.S. Department of Agriculture, Madison, Wisconsin GEORGE E.SEIDEL, JR., Colorado State University CHRISTOPHER R.SOMERVILLE, Carnegie Institute of Washington JOHN R.WELSER, The Upjohn Company, Kalamazoo, Michigan Staff J.PAUL GILMAN, Executive Director CARLA CARLSON, Assistant Executive Director
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Nutrient Requirements of Beef Cattle: Seventh Revised Edition, 1996 Preface Among domestic livestock in North America, the range in type and condition of beef cattle as well as production environment is relatively extreme. Since the 1984 publication of Nutrient Requirements of Beef Cattle, Sixth Revised Edition, a great amount of effort in our universities and research stations has been put into defining the impact of cattle’s biological, production, and environmental diversities and variations on nutrient utilization and requirements. Variations in cattle type are reflected in the large number of cattle breeds. However, within breed groupings, for example, beef vs dairy, many breed effects on nutrient requirements can be accounted for by reference to animal mass, and this principle is adopted in the recommendations presented in this volume, with qualifications noted where necessary. Other animal variations relate to body condition, and this impacts on the ability of growing animals to make compensatory growth. A substantial amount of information has been published concerning the effects condition or finish in cows has on energy requirements. For this edition, effects of body condition and compensatory growth have been described more completely than has been done previously. Environmental variation can also have a significant effect on nutrient requirements, and our knowledge of this has grown substantially as well. In particular, the important effects of the environment and stress on food intake are documented. Calculating the effects of variation has benefitted from the development of mathematical models to predict and understand relationships between nutrient inputs and animal outputs and from experience in using them. For this edition, the subcommittee has evaluated modeling in concert with experimental data. This publication is not a revolution but only one step on the ladder to a more complete understanding of beef cattle and their nutrient requirements. To this end, and very early in the development of this edition, the subcommittee decided to include with the publication a computer model on diskette to formulate requirements at two modeling levels. The first level is more empirical and presented in a format similar to that provided with the previous edition. By defining some fundamental relationships concerning nutrient digestion, the second level is more mechanistic and provided for students of beef cattle nutrition, young and old, to provoke discussion and continuing evolution of knowledge in the subject. The goal at the first level is to obtain the greatest predictive accuracy; whereas the goal for the second level is less concerned with predictive accuracy than with developing an understanding of the process. The subcommittee expects that the two levels will often be compared. Where the second level can predict animal performance successfully, it could then be used for purposes other than those traditionally envisioned for nutrient requirement standards. For example, the model level 2 could be helpful in diagnosing why animal performance on a given diet is less than expected. For both levels, requirements are documented and summarized in equations. To facilitate adoption of requirements, examples are illustrated in the publication in tabular format. In addition, a table generator is provided with the computer models and all of these accompany this publication on a diskette, together with a user’s guide. There are specific aspects about feedstuffs and nutrient requirements that have been emphasized in the revision of the previous edition. There was a need to develop a data base on feed composition that is current and widely applicable. This was done by obtaining information from analytical laboratories throughout North America. Compositional data on feedstuffs have been summarized to show not only the average values but also their variances. Detailed information collected recently on development of the fetus and conceptus during pregnancy has been used to prescribe nutrient requirements of gestating cattle more precisely. The same was possible for lactation because of
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Nutrient Requirements of Beef Cattle: Seventh Revised Edition, 1996 a better understanding of factors affecting the level of milk production and the lactation curve in beef cows. Protein requirements have been established to reflect our current knowledge of nitrogen usage in ruminants; and the systems prescribed in this publication have been advanced to incorporate more recent developments, for example, host requirements for amino acids and microbial requirements in the rumen for nitrogen constituents in addition to ammonia. Revision of mineral and vitamin requirements has incorporated a significant body of new information on phosphorus, magnesium, and the B vitamins and vitamin E. The fact that trace mineral requirements for young cattle are not always identical to mature animals has been documented as well. A more complete documentation of water requirements is given in this publication and a table on water intake by beef cattle is included. As in previous editions, nutrient requirements are expressed on a per animal per day basis. To formulate diets and predict performance of cattle on any given feeding program, it is necessary to predict intake. The general relationship of liveweight and diet quality to intake, as presented in the sixth edition, has been retained in this publication; but the effect of diet quality and animal state has been defined more precisely. In undertaking its work, the subcommittee considered current issues in beef cattle production inasmuch as they affect nutrient requirements. One of these involves product quality and the trend toward carcasses containing more lean meat and less fat. The subcommittee has not attempted to define what level of fat is appropriate; however, users of this publication should be able to define nutrient requirements for feeding cattle to different levels of fatness more precisely than has been possible with previous editions. Another issue involves environmental awareness. Nutrient requirements bear only a peripheral role in this problem; however, the models presented can be used indirectly to predict the loss of nutrients—for example, nitrogen and phosphorus—in animal manure and promote responsible feeding to prevent pollution from beef cattle operations. The subcommittee would like to remind readers, when using the recommendations presented in this report, that animal observation can be as useful as direct adoption of what is recommended in this book. In the preparation of this report, the subcommittee acknowledges the assistance of many colleagues who have provided data on which recommendations are based or provided commentary. Without their input, this publication would not have been possible. Jock Buchanan-Smith, Chair Subcommittee on Beef Cattle Nutrition
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Nutrient Requirements of Beef Cattle: Seventh Revised Edition, 1996 Acknowledgments The Subcommittee on Beef Cattle Nutrition is grateful to the many individuals and organizations who provided specific input, data, and critiques of this revision during its development. In particular, appreciation is noted to the beef cattle specialists who provided input on changes needed from the previous edition, to the analytical laboratories that provided valuable information on nutrient composition of commonly used feeds, and to the many animal science students and graduate students of subcommittee members who served as test pilots for the model and provided feedback to increase its user friendliness. The subcommittee reserves a special acknowledgment and thanks to Michael C.Barry, Cornell University, for the many hours spent on software development, testing, and refinement and for his unfailing helpfulness in guiding the members through program installation and use. Without his able technological assistance, this major step forward in the evolution of predicting nutrient requirements of beef cattle would not have been possible.
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Nutrient Requirements of Beef Cattle: Seventh Revised Edition, 1996 Contents PREFACE vii ACKNOWLEDGMENTS ix OVERVIEW 1 1 ENERGY 3 Energy Units, 3 Requirements for Energy, 5 References, 12 2 PROTEIN 16 Microbial Protein Synthesis, 16 MP Requirements, 19 Conversion of MP to NP, 19 References, 20 3 GROWTH AND BODY RESERVES 22 Energy and Protein Requirements for Growing Cattle, 22 Energy and Protein Requirements for Breeding Herd Replacements, 32 Energy and Protein Reserves of Beef Cows, 33 References, 36 4 REPRODUCTION 40 Gestation, 40 Lactation, 43 Breeding Performance, 46 References, 49 5 MINERALS 54 Macrominerals, 55 Microminerals, 61 References, 69
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Nutrient Requirements of Beef Cattle: Seventh Revised Edition, 1996 6 VITAMINS AND WATER 75 Fat-Soluble Vitamins, 75 Water-Soluble Vitamins, 78 Water, 80 References, 82 7 FEED INTAKE 85 Factors Affecting Feed Intake, 85 Prediction of Feed Intake by Beef Cattle, 88 Special Considerations for All-Forage Diets, 94 References, 95 8 IMPLICATIONS OF STRESS 97 Energy, 97 Protein, 98 Minerals, 98 Vitamins, 99 References, 99 9 TABLES OF NUTRIENT REQUIREMENTS 102 Example Tables for Growing and Finishing Cattle, 103 Example Tables for Breeding Bulls, 106 Example Tables for Pregnant Replacement Heifers, 108 Example Tables for Beef Cows, 101 Table of Energy Reserves for Beef Cows, 111 Table of Maintenance Requirement Multipliers for Environmental Conditions, 112 10 PREDICTION EQUATIONS AND COMPUTER MODEL 113 Requirements for Both Levels, 114 Predicting Dry Matter Intake, 119 Supply of Nutrients, 119 Feed Composition Values for Use of the NRC Model, 127 References, 130 11 COMPOSITION OF SELECTED FEEDS 133 Effects of Processing Treatments, 133 References, 146 APPENDIX: NRC MODEL USER’S GUIDE 149 GLOSSARY 219 ABOUT THE AUTHORS 224 INDEX 225
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Nutrient Requirements of Beef Cattle: Seventh Revised Edition, 1996 Tables and Figures TABLES 3–1 Relationship of Stage of Growth and Rate of Gain to Body Composition, 24 3–2 Standard Reference Weights for Different Final Body Compositions, 26 3–3 Anabolic Agents Used for Growing and Finishing Cattle in North America, 27 3–4 Cow Condition Score, 35 3–5 Empty Body Chemical Composition at Different Condition Scores (CS), 36 3–6 Energy Reserves for Cows with Different Body Sizes and Condition Scores, 36 4–1 Estimated Birth Weight of Calves of Different Breeds or Breed Crosses, kg, 40 4–2 Estimates of Net Energy (NEm, Mcal/day) Required for Pregnancy, 43 4–3 Estimates of Available Net Protein Required for Pregnancy by Beef Cows, 43 4–4 Net Energy (NEm, Mcal/day) Required for Milk Production, 45 4–5 Net Protein (g/day) Required for Milk Production, 45 5–1 Mineral Requirements and Maximum Tolerable Concentrations, 54 5–2 Maximum Tolerable Concentrations of Mineral Elements Toxic to Cattle, 55 6–1 Approximate Total Daily Water Intake, 81 7–1 Relationship between Initial Weight on Feed and Dry Matter Intake in Two Sets of Commercial Feedlot Data, 90 7–2 Results of Regressing Predicted Dry Matter Intake on Actual Dry Matter Intake by Growing and Finishing Beef Cattle for Three Validation Data Sets, 91 7–3 Results of Regressing Predicted Dry Matter Intake on Actual Dry Matter Intake by Growing Beef Steers and Heifers and Beef Cows Fed All-Forage Diets for Two Validation Data Sets, 95 8–1 Dry Matter Intake of Newborn to 56-Day-Old Calves (% of body weight), 97 8–2 Suggested Nutrient Concentrations for Stressed Calves (dry matter basis), 99 9–1 Nutrient Requirements for Growing and Finishing Cattle, 104 9–2 Diet Evaluation for Growing and Finishing Cattle, 105 9–3 Nutrient Requirements for Growing Bulls, 106
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Nutrient Requirements of Beef Cattle: Seventh Revised Edition, 1996 9–4 Diet Evaluation for Growing Bulls, 107 9–5 Nutrient Requirements of Pregnant Replacement Heifers, 108 9–6 Diet Evaluation for Pregnant Replacement Heifers, 109 9–7 Nutrient Requirements of Beef Cows, 110 9–8 Diet Evaluation for Beef Cows, 111 10–1 Breed Maintenance Requirement Multipliers, Birth Weights, and Peak Milk Production, 115 10–2 Calcium and Phosphorus Requirements, 118 10–3 Other Mineral Requirements and Maximum Tolerable Concentrations and Vitamin Requirements, 118 10–4 Adjustment Factors for Dry Matter Intake, 119 10–5 Amino Acid Composition of Tissue and Milk Protein (g/100 g protein), 120 10–6 Utilization of Individual Absorbed Amino Acids for Physiological Functions (g/g), 120 10–7 Amino Acid Composition of Ruminal Microbial Cell Wall and Noncell Wall Protein (g/100 g protein), 126 10–8 Estimated eNDF Requirements, 129 11–1 Means and Standard Deviations for the Composition Data of Feeds Commonly Used in Beef Cattle Diets, 134 FIGURES 3–1 Empty body weight vs body fat in male castrate of British breeds, 23 3–2 Empty body weight vs body fat in Angus and Holstein cattle, 25 3–3 Comparison of the predicted and observed retained energy (Mcal/day) and protein (g/day) with the NRC model across all groups of animals, 30 3–4 Relationship of empty body weight, protein, ash, and fat (as percentage) of body condition score in mature cows, 34 4–1 Relationship of birth weight to cow condition score in mature cows of nine breeds, 41 4–2 Relationship of fetal weight to day of gestation in cattle, 42 4–3 Generalized lactation curves for cows producing 5, 8, 11, or 14 kg milk at peak milk production, 44 7–1 Relationship of dietary NEm concentration to NEm intake by beef cattle, 88 7–2 Comparison of dry matter intake predicted from the 1984 NRC equation with that predicted from the equation developed from a literature data set, 89 7–3 Relationship between initial body weight and dry matter intake, 90 7–4 Relationship of dietary NEm concentration to NEm intake by beef cows (nonpregnant, and middle and last third of pregnancy), 93 7–5 Comparison of dry matter intake by a 500 kg, pregnant beef cow predicted from the NRC 1984 and 1987 equations, 93 8–1 Changes in rate constants for infectious bovine rhinotracheitis virus (IBRV) infected calves, 98