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THE ROLES OF AMINO ACID CHELATES

IN ANIMAL NUTRITION

THE ROLES OF

AMINO ACID CHELATES

IN ANIMAL NUTRITION

Edited by

H. DeWayne Ashmead

Albion Laboratories, Inc.

Clearfield, Utah

Reprint Edition

NOYES PUBUCATIONS

Westwood, New Jersey, U.S.A.

Copyright © 1993 by Noyes Publications

No part of this book may be reproduced or utilized in

any form or by any means, electronic or mechanical,

including photocopying, recording or by any informa￾tion storage and retrieval system, without permission

in writing from the Publisher.

Library of Congress Catalog Card Number: 92-25242

ISBN: 0-8155-1312-7

Printed in the United States

Published in the United States of America by

Noyes Publications

Fairview Avenue, Westwood, New Jersey 07675

1098 7 6 5 432

Library of Congress Cataloging-in-Publication Data

92-25242

CIP

1992

The Roles of amino acid chelates in animal nutrition / edited by H.

DeWayne Ashmead.

p. em.

Includes bibliographical references (p. ) and indexes.

ISBN 0-8155-1312-7

1. Amino acid chelates in animal nutrition. 1. Ashmead, H.

DeWayne.

SF98.A38R64

636.08'52--dc20

INTRODUCTION

Th i s book wi 11 be of great interest to anyone concerned with animal feeds and feeding programs whether

one is studying bovine, porcine, equine, avian or lower

vertebrate (fish and eel) nutrition. This information

is critical to the success of an animal feeding program.

Somet imes the di fference between a successful and a

failing program can be traced to mineral deficiencies

which cause either abnormal growth, reduced milk

production, interrupted fertility and breeding, compromised immune system integrity and/or decrement in

normal hemoglobin concentration. Increased

morbidity/mortality rates can make a profitable animal

feeding program into a financial failure overnight when

the replacement costs for a prize animal are considered.

These abnormalities, and others, are addressed in the

pages that follow.

From 25 controlled studies by 42 different authors

in five different countries a diverse array of data is

presented. These data val idate the effect iveness of

mineral nutrients presented as amino acid chelates when

compared with the ionic forms derived from the inorganic

sal ts. These stud i es further support the resul ts of

numerous laboratory experiments showing increased

absorption, assimilation and reduced toxicity of the

forms of minerals chelated to amino acids. With little

cost and effort animals can be supplemented with amino

acid chelates which will promote, with little risk of

overdose, a fuller genetic potential achievement as far

as mineral requirements are concerned. Results of this

supplementation are reflected in increased growth,

immunological integrity, and more consistent

reproduction (increased ovulation and conception after

first service) as a result of increased bioavailability of these chelated forms.

v

VI Introduction

Of novel interest are the reports showing a

protein sparing as a result of amino acid chelate

supp1ementation. In the face of dwi ndl i ng protei n

sources for animal feeds, this effect of chelated

minerals needs further scrutiny in feeding programs in

other species.

Darrell J. Graff, Ph.D.

Weber State University Ogden, Utah, U.S.A.

A NOTE TO THE READER

In the late 1800's, many of the fundamental

concepts of che1ation chemi stry were evo1vi ng. Chemi sts

began to recognize that certain atoms could exist in

more than one valence state, but could not comprehend how atoms with more than one valence could form a highly stable compound.

Alfred Werner, a German chemist, was the first to

break with traditional thinking and propose an entirely

new molecular structure to describe these highly stable

molecules. He noted that certain structural entities,

which he called "complexes", remained intact through a

series of chemical transformations. In 1893, Werner

wrote, "If we think of the metal ion as the center of

the whole system, then we can most simply place the

mo1ecul es bound to it at the corners of an

octahedron."(1) For the first time a chelate had been

described.

Werner further refined this revolutionary concept in the succeeding years. He concluded that a metal ion

was characterized by two valences. The first, which he

called the "principal valency", is now termed the

oxidation state, or oxidation number, of the metal. The

second valency, which he called the "auxiliary valency",

represents the number of ligand atoms associated with

the central metal atom. This is the same as the

coord inat ion number of the metal. (2-7) Werner's concepts

were fundamental to the comprehension of chelates.

The term, "chelate", was finally used by Morgan and Drew, in 1920, to describe the molecular structure

discovered by Werner. As noted above, the fi rst

chelating molecules that had been discovered were those

VII

VIII A Note to the Reader

with two points of attachment. It was this caliper-like mode of attaching the ligand (the chelating molecule) to

the metal atom that led Morgan and Drew to suggest the

word "chelate" to describe the molecule.(8) The word is

derived from the Greek word "chele", meaning lobster's

claw. The word, IIchelate ll

, was originally used as an

adjective. It later became a more versatile word and

today i s used as an adj ect i ve, adverb, or noun. The

ligands are chelating agents, and the complexes they

form are metal chelates.

Because the claw, or ligand, held the cation, the

metal was no longer free to enter into other chemical

reactions. Thus it quickly became evident that when a

metal was che1ated, the chemi cal and physi cal

characteristics of the constituent metal ion and ligands

were changed. This had far reaching consequences in the

realms of chemistry and general biology. In spite of

the knowledge of what chelation could do to and for a

metal ion, it was not until the early 1960's that anyone thought seriously about using this molecule for

nutritional purposes.

At that period, a handful of investigators, independent of each other, each conceived the idea that

if a metal ion could be chelated before feeding it to

animals, the ligand would sequester the cation and

prevent it from entering into various absorption inhibiting chemical reactions in the gut. The

theoretical consequence was greater nutritional uptake

of the ions.

Two schools of thought quickly developed. One,

led by the pioneering research of Albion Laboratories,

Inc., proposed that amino acid chelates were the proper

chelates to enhance mineral absorption. As attested by

a large number of research reports, lectures, and

publications based on the research efforts both

A Note to the Reader IX

coordinated and conducted by this organization, the use

of amino acid chelates in animal nutrition were both

positive and highly encouraging. At that point in time

these amino acids were called "metal proteinates"

instead of chelates.

Concurrently, with the development of the amino

acid chelates, a second school of thought approached animal nutrition with synthetic chelates based on

ethylenediaminetetraacetic acid (EOTA). The theory was

the same as before. The EOTA ligand would chelate the

cation and protect it from chemical reactions in the

gut. While it successfully accomplished its mission in

terms of protect ion, it genera11 y fa i1ed to enhance

mineral nutrition because it formed chelates that were

too stable. The biological ligands in the animals'

bodies were incapable of extracting the cations from the

EOTA chelates, even after they were absorbed into the

blood. Thus, the EOTA chelates were returned to the

lower bowels or excreted into the urine still protecting

the cations that the animal s were supposed to have

utilized. As Bates, et li., concluded, even though

chelation plays a dominant role in mineral absorption, "chelation does not, in itself, insure efficient uptake because the absorption of the ferric chelates of EOTA,

NTA, and gluconate were not significantly different than

that of ferrous sul fate. ,,(9)

These synthetic chelates were heavily promoted in

the decade of the 60's and the early part of the 70's.

When they could not deliver the enhanced mineral

nutrition promised by the chelation concept, all

nutritional products using the word "chelation" lost

favor with most animal nutritionists. The "c" word

became a word to avoid if one wished to amicably discuss

animal nutrition.

x A Note to the Reader

It was for this reason metal proteinates became a

favored description for the amino acid chelates. As a

term, the words evolved out of the concept of complexing metal s wi th protei n. Metal protei nates became

acceptable terminology because they successfully avoided

mention of the "ell word. There was a problem with that

approach, however. There was no official definition to

describe a metal proteinate.

By 1970, Albion Laboratories, Inc. had supplied the necessary research to allow the American Association

of Feed Control Officials (AAFCO) to officially define

metal protei nates as the product resul t i ng from the

chelation or complexing of a soluble salt with amino

acids and/or hydrolyzed protein.

As greater numbers of manufacturers began capital izing on the metal proteinate definition, it

became evident that this definition was too broad to

accurately define Qllly those minerals that research had

proven were efficacious. Many companies were not making chelates, but could still have their products defined as

metal proteinates. Other companies, who may have been

making chelates, were not making products that could be

absorbed. Thei r compounds were ei ther too bi g (a chelate over 1,500 daltons can not be absorbed), or the

mineral was bonded to whole or partially hydrolyzed

protein (which had to be digested with subsequent release of the metal to competing reactions in the chyme

similar to those facing cations derived from any other

feedstuff).

Because of the confusion among feed companies in

trying to decide which metal proteinates were valuable

sources of the added mineral nutrition, which metal

proteinates were supported by scientific studies, and

which were "me too" products that had no support data of

their own, Albion Laboratories, Inc. applied to AAFCO

A Note to the Reader XI

for a new definition which accurately and more

completely described an amino acid chelate. Realizing the "e" word was still out of vogue among many nutritionists due to their earlier experiences with

synthetic chelates, Albion still decided to call the

products by their true name - amino acid chelates.

After several years of debate within the AAFCO

organization, a debate which was primarily fueled by companies using Albion's research to promote dissimilar

products ascribed to the proteinate definition, a new

definition was ultimately approved. The new definition

for a metal amino acid chelate rectified the looseness

of the metal proteinate definition by including absolute

requirements for molecular weights, molar ratios of

ami no ac ids to metal s, and the abso1ute presence of

chelation. The amino acid chelate definition also

disbarred the complexing of metals with protein or

peptides, both of which require further digestion before

absorption. The formation of chelates too large to be

absorbed was thus disallowed.

As defined by the American Association of Feed

Control Officials, a metal amino acid chelate is lithe

product resulting from the reaction of a metal ion from

a soluble salt with amino acids with a mole ratio of one

mole of metal to one to three (preferably two) moles of

amino acids to form coordinate covalent bonds. The

average weight of the hydrolyzed amino acids must be

approximately 150 and the resulting molecular weight of

the chelate must not exceed 800." (0

)

This book is about amino acid chelates. With few

exceptions, the research contained within it was

conducted by investigators independent of Albion

Laboratories, Inc. The organization with which each

investigator is affiliated is noted on the list of

contributors and at the beginning of each chapter.

XII A Note to the Reader

The book is divided into several sections so that

a reader, who may not wish to read the entire book, can

quickly turn to his or her own area of primary interest.

Separate sections are devoted to cattle, pigs, poultry,

horses and fish. The beginning section discusses the

fundamentals of amino acid chelation as they relate to

the various aspects of animal nutrition discussed in

each of the subsequent sections. It is strongly recommended that the reader who has primary interest in

only one species of animal still read this first section

prior to addressing the species of interest. The first

section will provide numerous basic concepts that will

enhance the reader's comprehension of the data in the

subsequent sections.

For the animal nutritionist, veterinarian, and

others whose interests range further than a si ngl e

species, reading the book in its entirety is

recommended. As noted above, it is divided into five

additional sections beyond the introductory section plus

a summary. The second sect i on deal s wi th several

aspects of dairy and beef cattle mineral nutrition.

Some topics discussed include immunity, fertility, increased mi 1k product ion, greater growth rates, and

improved feed conversions. The third section addresses

several important concepts of swine nutrition including baby pig anemia, improved reproductive capacity in older

sows, and leaner pork. Poultry is handled in the fourth

section. Topics include improvements in breeder/broiler

operations, egg production and enhanced turkey

production. The next section deals with equine nutrition as it relates to fertility and proper growth and development of the legs. The last section deals

with enhanced performance in fish and eels.

Although the data are conclusive in most cases,

the research reported in these sections is by no means

complete. In many instances the editor was faced with

A Note to the Reader XIII

making painful decisions as to whose research to

include, or not to include, in order to avoid excessive

repetition. In spite of these efforts, some repetition

was unavoidable, but hopefully not redundant.

The purpose of reporting this research in the form

of a book has been two-fold. The first is to stimulate

others to piek up the torches that have been lighted by the researchers who have contributed to this book and to

cont i nue onward from where they stopped. The second

purpose is to make the "e" word once again an acceptable

word in animal nutrition circles.

H. DeWayne Ashmead

XIV A Note to the Reader

References

1. Werner, A., "Beitrag zur Konstitution

Anaorgan ischer Verbi ndungen," Z., anorg. u. all gem.

Chern., 3:267, 1893.

2. Werner, A. and Miolati, A., Z. physik. Chern.

(Leipzig), 14:506, 1894.

3. Werner, A. and Vilmos, Z. "Beitrag zur Konstitution

Anaorganischer Verbindungen," l. anorg. u. allegem.

Chern., 21:153, 1899.

4. Werner, A., "Ueber Acetyl acetonverbi ndungen des

Platins," Ber. deut. chern. Ges., 34:2584, 1901.

5. Werner, A. , Kobaltatoms.

1911.

"ler Kenntnis des Asymmetrischen

V," Sere deut. chern Ges., 45:121,

.. 6. Werner, A., "Uber spiegelbild-isomerie bei

chromverbi ndungen. I I I," Ber. deut. chern. Ges.,

45:3065, 1912.

7. Werner, A., "lur Kenntris des Asymmetrischen

Kobaltatoms XII. Uber Optische Aktivitat bei

Koh 1enstoffrei en Verbi ndugen, II Ber. deut. chern.

Ges., 47:3087, 1914.

8. Morgan, G. and Drew, H., "Research on residual

affinity and coordination. II. Acetylacetones of

selenium and tellurium," J. Chern. Soc., 117:1456,

1920.

9. Bates, G., et li., "Facil itation of iron absorption

by ferric fructose," Am. J. Cline. Nutr., 25:983,

1972.

10. Haas, E., et li., eds., Official Publication 1989

(Atlanta: American Association of Feed Control

Officials, Inc.) 159, 1989.