Control of Reproductive Functions in Domestic Animals

247 Pages·1980·11.456 MB·English

by  Wolfgang Jöchle, Donald Ross Lamond (auth.)

Control of Reproductive Functions in Domestic Animals
Current Topics in Veterinary Medicine ond Animol Science
Volume T
other titles in this series
Volume 1
Control of Reproduction in the Cow
edited by 1. M. Sreenon
Volume 2
Patterns 01 Growth ond Developmenl in Collie
edited by H. de Boer ond J. Martin
Volume 3
Respiratory Diseoses in Collie
edited by W. B. Martin
Volume 4
Colving Problems ond Early Viobility of the Colf
edited by B. Hoffmann, I. L. Moson, ond J. Schmidt
Volume 5
The Future of Beef Production in the Europeon Community
edited by J. C. Bowmon ond P. Susmel
Volume 6
Diseoses of Collie in the Tropics: Economic ond Zoonotic Relevonce
ediled by Miodrog Ristic ond Ion Mclntyre
Controlof Reproductive Functions
in Domestic Animals
Wolfgang Jöchle
Consulting Veterinary Scientist and Theriogenologist. Denville (USA)
and
Donald Ross Larnond t
Institute of Veterinary Science. Syntex Research. Polo Alto (USA)
•
1980
Springer-Science+Business Media, BV.
Library of Congress Cataloging in Publication Data
CIP
Jăchle, Wolfgang
Control of reproductive functions in domestic ani
mals.
(Current topics in veterinary medici ne and animal
science; v. 7)
Includes index.
1. Domestic animals--Reproduction. 1. Lamond,
D. R., joint author. II. Title. III. Series.
[DNLM: 1. Breeding. 2. Reproduction Anima/s,
Domestic--Physiology. W1 CU822 v. 7 I SF105 J64c]
QP251.J63 636.08'24 80-23642
ISBN 978-90-481-8263-3 ISBN 978-94-017-1173-9 (eBook)
DOI 10.1007/978-94-017-1173-9
Copyright © 1980 by Springer Science+Business Media Dordrecht
Originally published by Martinus Nijhoff Publishers in 1980
Softcover reprint of the hardcover 1st edition 1980
AII 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 olherwise, without the prior wrilten
permission of the publisher,
Springer-Science+Business Media, B. V.
Preface
For quite some time we, the authors, feit that a and animal scientists. D. R. Lamond was one of
book of the kind presented here was needed. No their most knowledgeable, distinguished represen
comprehensive text dealing with currenttechniques tatives. He left behind the drafts of his contribu
and modern compounds useable for the control of tions; the unifying task was taken over by W. JÖchle.
reproductive functions in domestic animals existed. But D. R. Lamond's input to most of the other
The character of this book, and the presentation chapters of this book remained profound. In many
chosen of the accumulated material, emerged respects, this is a book representing for what
over theyears from ourown professional experience, D. R. Lamond has worked and stood for.
from our interaction and the cooperation between Each chapter of this book was assigned to one
us, and from our own ättempts to achieve control or two of the authors, who carried the major respon
over a wide spectrum of repraductive functions in sibility for content, format, and selection of refer
animals by reproducible techniques. ences. The final version represents also inputs
We benefited heavily from our contacts with from the other author. It was agreed thatthe authors
many of the leading scientists and research insti should not strive for completeness of details, b.ut
tutions around the world. But most importantly, for completeness of concepts. References should
three years of almost daily communications between reflect selected pertinent references and recom
us authors, assessing success and failures, new mended reviews for suggested further reading.
avenues and aspects convinced us that a book of Chapters land 111 were prepared jointly by D. R.
this kind will find its audience: with fellow scientists Lamond and W. Jöchle; Chapter 11 by W. Jöchle;
in the field of theriogenology') and in animal Chapter IV by D. R. Lamond; Chapters V, VI and
science, with scientists in ancillary fields like VII by W. Jöchle; Chapter VIII jointly by D. R. La
pharmacology and pharmacy, with students in all mond and W. Jöchle and Chapter IX by W. JÖchle.
these disciplines and even educated farm managers E. Forcielli offered his services as an editor after
of todays animals industry. Contral with its benefits D. R. Lamond's demise. His help, gratefully ac
can be achieved only by the closest possible knowledged, made it possible to finish this book,
cooperation and continuous communication be although delayed. Thanks have to go to H. Karg
tween farm management, their husbandry men, for assistance in preparing and discussing Chap
theriogenologists (veterinarians) and nutritionists ters II and IX.
(animal scientists). Writing this book would have been impossible
Our intentions to prepare such a book were met without the encouragement and cooperation given
by the publisher's commission. by Maria JÖchle.
From the beginning, the authors wanted to Comments and criticism from readers and the
present one book prepared by two or three authors. science community are expected and are welcome.
The content of the individual chapters was, as It is hoped that this book achieves what the
much as this was possible, to be presented in an authors wanted when setting out for this intellec
uniforme style. tu al adventure: to become a guidebook into the
D. R. Lamond had agreed to undertake this more important aspects and for the presently
difficult task. His untimely demise in September available or foreseeable techniques and for the
1975 caused a severe setback and was a great facts to be considered, and the methods and the
loss to the world's community of theriogenologists common pitfalls worth to be known, respectively.
Hopefully, this book will serve as a stimulant to
use appropiate techniques of control with success
') The branch of veterinary medicine which deals with
reproduction, including physiology and pathology of male and wherever their use is warranted.
female reproductive systems and the clinical practice of vete
rinary obstetrics, gynecology and andrology. W. Jöchle
5
Contents
Preface .. 5
Chapter I: lntroduction 9
1. Defi nition of the problem. 10
2. Synopsis . . . . . . . . 13
Chapter 11: Physiology of reproduction . 14
1. Hormones involved in reproduetion 14
1.1. General pri neiples of hormonal i nteraetions 14
1.2. Hormone biology, bioehemistry and assaying proeedures. 21
1.3. Hormonal i nteraetions (and speeies differenees) in male
reproduetion. . . . . . . . . . . . . . . . . . . . .. 27
1.4. Hormonal interactions (and speeies differenees) in female
reproduction. . . . . . . . . . . . . . . . . . . . .. 28
2. General reproductive physiology, and speeies peculiarities 49
2.1. Male animals. . 49
2.2. Female animals . . . . . . . . . . . 54
Chapter 111: The effects of environment on reproduction 61
1. Climate and season 65
2. Nutrition . . . . . . . . . . . . . . . 75
3. Soeial factors . . . . . . . . . . . . . 82
4. Mai ntai ni ng homeostasis under envi ronmental pressure 84
Chapter IV: The problem of determining efficacy of a compound for control
of reproductive functions. . . . . . . . . 93
1. Evaluation of a eompound for effieaey. . 93
1.1. What does the drug do to the an i mal? . 94
1.2. Is the drug safe? . . . . 97
1.3. Role in the target speeies. . . . . 98
1.4. The clinical trial. . . . . . . . . 98
2. Determination of reproductive status 101
3. I nteraetion of hormones with the ani mal-envi ronment
eomplex. . . . . . . . . . . . . . . . . . . . . . 108
Chapter V: Control of reproductive functions - methodology and com-
pounds ...... . 114
1. Methods used . . . 114
1.1. Physieal methods. 114
1.2. Sensorial methods 115
1.3. Proteetive methods . 116
1.4. Chemical methods . 116
7
2. Compounds used .... I"! 6
3. Pharmaceutical aspects . 125
4. Pharmocolog ical aspects . 127
5. Immunological aspects .. 128
Chapter VI: Control of normal reproductive funetions 132
1. Male animals . . . . . . . . 132
1.1. Control of male puberty. . . 133
1.2. Control of mature male functioll. 136
1.3. Prevention of the capabi I ity for cohab itation 137
2. Female animals . . . . . . . . . . . 137
2.1. Control of puberty in female an i mals 139
2.2. Control of mature female functions 144
2.3. PI-eg nancy . 158
2.4. Lactation . . . . . . . . . . . . . 168
Chapter VII: Control of abnormal reproduetive functions - diagnosis,
therapy, prophylaxis, management 18:5
1. Male animals 183
1.1. Puberty . 183
1.2. Matu re an i mals. 186
2. Female allimals . 187
2.1. Puberty . . . . 187
2.2. Mature animals. 190
3. Endangered gestatioil, pathologicai gestation, dystocia. 196
4. Endangered lactation. 202
Chapter VIII: Increasing litter size . 209
1. Factorslimitinglittersize. 209
1.1. Ovulation rate. . 209
1.2. Uteri ne capacity . 210
2. Management aspects of i IlCleasi ng I itter size 212
2.1. Selection . 212
2.2. Nutrition. 213
2.3. Other environmental variables and diseases 214
2.4. Hormonal support during the pre-implantation phase. 214
2.5. Parturition management strategies . . . . . 214
2.6. Increasing litter size by hormonal treatment. 216
3. The role of ova tl-ansfer i il i nueasi ng I itter size 222
Chapter IX: Environmental impact of techniques used for the control of
reproduetive funetions . . . . . 228
1. The problem of pollution ..... 228
2. Approaches to the problem of I-esidues 228
3. Methods of resi d ue determ i nations . . 229
4. Factors involved ill residue determinations. 233
5. Concluding remarks 236
Glossary . 238
Subject index 240
CHAPTER I
I ntroduction
The animal industry thrives on domestic animal shed light into the background, the prerequisites
reproduction. Control of reproductive functions, and the basis for success and the understanding
the stimulation, correCtion, restoration or inhibition of failure 0f these husbandry practices, wh ich we
of reproductive performance, embraces time now call management.
honol-ed methods, devices and techniques in As scientists interested in achieving maximum
animals - and of1ly since very recently, in man. reproductive performance under all of. the many
-Throughout the long evolution of mammals, as different conditions, and especially intensive
it is presently understood, efficiency of reproduc systems, we emphasize three themes in this book:
tive functions was an irrevocable necessity. Species
1. Identification and evaluation of those compo
survived to reproduce and, in turn, reproduced to
nents of natural or intensive animal husbandl-y
survive. Adaptation to a habitat or a way of life
systems which are important in reproductive
resulted in elimination of inefficient steps in repro
function.
ductive processes. At any point in time a frequency
2. Presentation of specialized techniques which,
distribution of the population of any species on a
when applied to the best that the system can
scale of fitness to reproduce would find distri
provide, will either lift reproductive pel-for
buted outside the norm the young and infirm,
mance to new heights, or will manipulate or
the very thin and very fat, and the diseased, to
inhibit specific traits or functions fOI" social or
gether with those who mated too soon or too late
economic benefits.
in the breeding season, or too late after reaching
3. Introduction of techniques which, when applied
puberty. Also included with those with below
to less advanced farming systems (due to eco
optimum reproductive fitness, would be animals
nomic, social 01' environmental limitations), may
wh ich were easily stressed by social contact.
increase reproductive efficiency.
For every species in its natural habitat there
developed an optimum age, size and adaptation Thus, we recognize that the new technique of
to a special season for breeding, and optimum suppression and synchronization of ovarian func
behavior patterns. Man intervened by altering the tion, of induction of multiple ovulation and hence
environment and by selecting those animals which increasing litter size, and of inducing premature
conformed to the constraints and stresses of the parturition, can be useful to the livestock industries
new environment by unimpaired, or even increased only if they interact favorably with those variables
reproductive performance, a process called do wh ich constitute the basis of good ani mal husbandry
mestication. This has resulted in a degree of for a particular environment or locality. This is
channeling of desirable genetic qualities leading most important in those situations where new
to species-Iocality specialization. The very large techniques may be used as prophylactic or thera
number of local breeds of cattle throughout the peutic tools to assure or restore fel"tility. Even in
world point to this phenomenon. There are a companion and sport animal medicine, where the
Ilumber of strains of Bovidae wh ich excel in spe emphasis is on ovarian control or l"estoration of
cific locations, and not in others. Thus, the Indian faulty reproductive functions, these aspects need
Zebu is very different from the Chianina from Italy, consideration. Control of reproduction in wildlife
the Australian Illaqarra Shorthorn, the Africander, also can succeed only when environmental COll
or the Scotch Highlander. But each is outstanding ditions are taken into consideration.
in its own locality or environmental niche. A fundamental principle throughout this book,
It has taken many centuries for man to learn the therefore, is acceptance of the fact that control of
optimum husbandry practices for his local breed. I"eproductive function for higher efficiency is
Only during the last century and a half have possible only through understanding of both the
advances in sciences concerned with the nOt-mai techniques and the compounds and the animals
and the sick animal, with genetics and environment, (or population) in which they are used. Therapeutic
9
agents helping the animal industry in the past In Chapter V, the techniques, methods and
had to be applied as prescribed or preformulated compounds used for control are presented, and their
treatments, employing fixed dosage levels, since pharmaceutical and pharmacological aspects are
they interacted with infectious invaders and para discussed.
sites, or supplemented nutritional deficiencies, Chapter VI is devoted to the techniques and
but did not, in most instances, affect directly the compounds for the contral of normal reproductive
host's system. To the contrary, the techniques functions, while Chapter VII deals with virtually the
developed for reproductive control act or interact same methodology as applied to the contral of
directly with the animal's organism. The animal abnormal repraductive functions.
industry has to accept that not all animals will In Chapter VIII, the topic of increasing litter size
respond to a given compound in a reproducible was chosen as an example for an in-depth investi
manner. galion of past misgivings, present knowledge and
In this book, the major part is devoted to the techniques and future advancements in an area
control of reproductive functions in female animals. which combines and integrates the use of many of
The male animal, as a result of decades of heavy the aspects discussed throughout the book, and
emphasis on sperm collection and preservation, which holds high expectations for the future for
has been dealt with extensively, while a condensed, researchers and husbandry-men alike.
weil researched and balanced presentation of Chapter IX takes up the enviranmental impact 01
pertinent information in the female was lacking. techniques used for the contral of repraductive
Therefore, this text does not deal with physiology, functions dealing mainly with the residue problems
biochemistry and methodology related to sperma in animal products resulting from the indiscrimi
togenesis, ejaculation, semen collection, pre nate use of compounds which are or could allegedly
servation and artificial i nsemi nation, for which be harmful to the consumer.
many good books and monographs exist. Out of the book's much broader contents, we
We have not restricted ourselves to one or the would Iike to highlight here as an introductory
other of the conditions of intensive or extensive excursion six areas of control which have received
management, or to temperate, subtropical or more public interest than others: inducing early
tropical climates. The basic principles outlined puberty in groups of animals, synchronization of
are expected to allow adaptation of new methods to ovarian function in cycling animals, induction of
any environment or locality, and, if not, to indicate more ovulations than the species is genetically
why they may not yield the expected return on capable with the aim of increasing litter size;
effort and investment. induction of parturition and use of methods of
We ho pe that this book will indicate new frontiers controlling reproductive processes for therapeutic
in addition to the important task of outlining the purposes.
present status of research and development. 1. Induction of early puberty. In the livestock
species of importance, the age of onset of puberty
(defined here as the age at which an animal is
first capable of becoming pregnant) varies widely
1. Definition of the problem enough to cause inefficiency of reproduction. The
problem is serious in the pig industry because it
is necessary to breed gilts as soon as they are
At the end of this book there is included a glossary large enough (80-90 kg) to carry a litter of econo
of terms which are either not weil known or not mic size. Usually in a population of gilts, some will
Weil understood. At this point, however, it is begin to show estrus and become pregnant at
necessary to identify those aspects of female re 80 kg while others may not have their first estrus
productive functions which we wish to emphasize. until they weigh 120 kg. It is desirable that all gilts
In Chapter II aspects of the physiological setting in a group of about the same age and weight
and in Chapter 111 those environmental influences, have their first estrus at the same time. Treatments
which form the above-mentioned animal-environ which will bring all gilts into estrus over a short
ment complex, will be discussed. Chapter IV deals period of time are required for every combination
with the formidable problem of determining efficacy of location, season, strain, and type of manage
of compounds, techniques and methods involved ment.
and developed for the control of reproductive This can be described as advancement of
functions. Its goal is the advancement of under puberty in the majority of gilts. The best time to
standing of the need to assess the status of the begin treatment is when the first pig in the group
animal or the herd in relation to its environment shows estrus.
and to adjust the selected technique for control to Growth rate and age of puberty of ewes is con
this condition for consistent results. siderably influenced by season, breed, and nutri-
10
tion, In many locations, lambs do not begin to ficial insemination programs. Recent studies show
have estrous cycles until late in the breeding sea ing that oral progestins may initiate fertile matings
son, resulting in a low pregnancy rate in the first in anestrous cows in the tropics should have
year, It would be extremely desirable for spring considerable application.
-born lambs to have fertile matings in the middle In the dairy industry, it is often desirable from a
of the next autumn breeding season. It is impracti management point of view to regulate dates of
cal and uneconomical to wait until the first lamb conception so that groups of heifers calve at
beg ins to show estrus befol-e beginning treat strategic times throughout the year. A special
ment. It is better to choose a particular date at the aspect is the use Qf progestins in individual dairy
height of the breeding season, to provide an cows, as an aid in a herd of reproductive health
adeqate growing ration and then to initiate a programs. Then the progestin is used prophylacti
treatment which will cause fertile mating in a high cally since the absence of a response at apredicted
proportion of the flock over a few days. date could lead to early discovery of functional
In today's cattle industry, the problem is not infertility problems.
as obvious as in the gilt and ewe, Rarely are heifers In the ewe, synchronization of ovarian function
mated for the first time before they are 13-16 during the breeding season is an advantage for
months of age, even though estrous cycles depend artificial insemination, and also the use of pro
ing on breed commence between 7 and 12 months. gestins with gonadotropins during anestrus can
In the annual cycle of events of a beef cow breeding be justified on economic grounds, as the demand
enterprise, it is desi rable to have the cows calve for "out-of-season" lambs is increasing. There
over a short period of time on one occassion per seems to be limited value at the present time for
year, usually in the spring. However, in dairy herds hormone use during early lactation.
and in some beef herds in favorable climatic environ In the pig industry, suppression of ovarian func
ments, it is desirable to have their heifers become tion for synchronization and artificial insemination
pregnant at certain dates during the year rather is desirable for the controlled breeding in gilts.
than wait until they reach a particular point in It is less advantageous for sows, since it is generally
their growth cycle. Especially in the latter situation inefficient to allow adult so ws to have more than
there is a need for a treatment which will advance one estrus (or estrous cycle) after weaning of the
puberty in the majority of animals, litter. A major difference between the sow on one
Two systems for very early breeding, in which hand, and the ewe and cow on the other, is that
cycle induction and control play an important role, progestin-priming appears not to be necessary in
are beyond the trial stage and are being promoted the pig but is considered to be essential for the
in the European (dual-purpose) cattle industry. other two species,
In the Heifer-for-Slaughter-Replacement Program, A useful approach to synchronization is to
dairy heifers not used for replacement are subjected induce regression of the corpus luteum thus short
to a combined estrus inductionjcontrol treatment ening the estrous cycle. Numerous compounds
at the age of 12 (to 13) months, with not more than and techniques will eliminate a corpus luteum but
two inseminations to follow, Calves are weaned a new family of naturally-occurring compounds,
after having received colostrum; those heifers, the prostaglandins (which cause immediate re
having replaced themselves, are slaughtered gression in cows between days 6-16 inclusive of
approximately two weeks later. the cycle), ofters wide practical possibilities. The
In the Early-Usage-Program, the same approach combination of both principles, the short-term use
is used in heifers earmarked for replacement. of progestins, creating an artificial corpus luteum,
Again, calves are weaned aftel' having received followed by a luteolytic prostaglandin, emerges
colostrum and lactation ceases; about two weeks as the most attractive technique for synchroni
later the heifers are put on a synchronization zation in cattle and possibly in sheep and the mare.
program for early breeding postpartum. After the This technique circumvents shortcomings both
second pregnancy the animals enter the milking methods have when employed separately.
herd. Considerable progress is being made in the mare
2. Synchronization of ovarian function. There in development of techniques for timed breeding.
exists in the animal industry a great need for a These require luteal regression and induced
progestin which economically will suppress follicle ovulation and offer hope for horse owners who
maturation and ovulation in cycling animals, and only have one or two mares and who need to use
will suppress pituitary function and prime the artificial insemination, but cannot affol-d the cost
genital tract in anestrous animals, in order to of sendi ng thei r mares to the location of the stallion.
obtain synchronization of estrus and ovulation. 3. Increasing litter size. Particularly in the cattle
In the beef industry in particular, synchronization industry, it is recognized that an extra calf per
of ovarian function would be a great help in arti- cow is of enormous economic value. In the pig
11