Table Of ContentREPRODUCTIVE, PRODUCTIVE, AND IMMUNOLOGICAL RESPONSES OF
HOLSTEIN DAIRY COWS FED DIETS VARYING IN CONCENTRATION
AND RUMINAL DEGRADABILITY OF PROTEIN AND
SUPPLEMENTED WITH RUMINALLY INERT FAT
CARLOS MIGUELjGARCIA-BOJALIL
A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL
OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT
OF THE REQUIREMENTS FOR THE DEGREE OF
DOCTOR OF PHILOSOPHY
UNIVERSITY OF FLORIDA
1993
UNIVERSITY OF FLORIDA LIBRARIES
Dedicated to
My wife Maria Elena Suarez Oporta
My daughter Carla Denisse Garcia-Bojalil
My parents, brothers, and sisters
My
family
ACKNOWLEDGMENTS
The author expresses his deepest gratitude to Dr. Charles R. Staples and
Dr. William W. Thatcher for their guidance and assistance throughout his
graduate program and for sharing their unique knowledge in this innovative
area of research. Appreciation is extended to Dr. David K. Beede, Dr. Douglas
B. Bates, and Dr. Harry S. Sitren, committee members, all of whom contributed
to the accomplishment of this goal.
Special thanks go to Dr. Jorge D. Savio, Dr. Maarten Drost, Dr. Carlos A.
Risco, and Dr. Peter J. Hansen for their assistance during the planning and
execution of the experiments as well as Dr. Peter J. Hansen, Dr. Barney Harris
Jr., Dr. Herbert H. Head, and Dr. Charles J. Wilcox for allowing the author to
benefit from their knowledge.
The author is indebted to Consejo Nacional de Ciencia y Tecnologia for
scholarship funding and to Centro de Ganaderia, Colegio de Postgraduados for
providing the means with which to further his education. Special thanks are
extended to Dr. Miguel Garcia-Winder, Dr. Ricardo Barcena Gama, Dr. Manuel
Cuca Garcia, Dr. German Mendoza, and Dr. Sergio S. Gonzalez for their
confidence in me.
III
This work would not have been completed without the technical
assistance of Paul Humphlett, Patrick Joyce, Marie Joelle Thatcher, Susan
Gottshall, Joyce Hayen, Estelle Hirchert, and Unda Hefer.
Thanks are extended to all Dairy Research Unit personnel, especially
Mary Russell, James Lindsey, Dale Hissem, Don Ferguson, Elese Griffin, David
Herbst, Frankie Love, Albert Perry, Collis Warren, Jim Hunter, and Joe and
Linda Cline for their contributions during the execution of the trials.
My learning experience would not have been complete without the
friendship and support of my fellow students, especially Eduardo Bernal, Ted
Ruiz, Bill Sanchez, Luzbel de la Sota, Miguel Campos, Carlos Becerril, Paulette
Tomlinson, Joaquin Fuentes-Pila, Brad Oldick, Dane Schoenbaum, Flavia Athie,
Irene Fiorito, and Matt Lucy.
Special thanks go to Susan Hack and Jessie Elliott for their friendship
and contribution to the final preparation of this document.
Gratitude is given to Dr. Staples, Dr. Thatcher and the Dairy Science
Department for providing financial assistance during the finalization of this
program.
iv
TABLE OF CONTENTS
1
page
ACKNOWLEDGMENTS
III
ABSTRACT
viii
CHAPTERS
INTRODUCTION
1
2 LITERATURE REVIEW 3
Description of Protein in Feedstuffs 5
Protein Digestion 6
Protein Degradability and Animal Production 9
Effect of High Protein Intake on Reproductive
Performance 14
Proposed Mechanisms of High Protein Intake on
Reproduction 31
Supplemental Fat Effect on Digestion and Production 41
Fat Supplementation and Reproductive Performance 52
3 INTAKE OF HIGH AMOUNTS OF RUMINALLY DEGRADABLE
PROTEIN ON DEVELOPMENT OF OVARIAN FOLLICLES AND
EMBRYO QUALITY OF SUPEROVULATED NONLACTATING
DAIRY COWS 64
Introduction 64
Materials and Methods 68
Experimental Animals and Dietary Treatments 68
Estrous Synchronization 70
Ultrasonography 70
Superovulation and Embryo Collection and Quality .... 72
Blood Constituents 74
Fistulated Animals 75
Statistical Analyses 75
Results and Discussion 77
V
Conclusions 116
4 EFFECT OF DIETARY PROTEIN DEGRADABILITY AND
SUPPLEMENTATION OF CALCIUM SALTS OF LONG-CHAIN
FATTY ACIDS ON PRODUCTIVE AND REPRODUCTIVE
PERFORMANCE OF LACTATING DAIRY COWS 118
Introduction 118
Materials and Methods 121
Animals and Diets 121
Prepartum 121
Postpartum 122
Blood Samples 126
Apparent Digestibility 127
Determination,of Dietary DIP Concentration 129
Reproductive Management 130
Rectal Palpation 130
Estrous Synchronization and Al 131
Reproductive Data 132
Ultrasonography 133
Health Program 134
Statistical Analyses 134
Results and Discussion 135
Diet Composition 135
Dry Matter Intake, Milk Production, and Milk
Composition 136
Total Tract Apparent Nutrient Digestibilities 148
Body Weight and Body Condition Score 153
Energy Status 156
Blood Constituents 168
Reproductive Parameters 168
Conclusions 200
5 EFFECT OF DIETARY PROTEIN DEGRADABILITY AND CALCIUM
SALTS OF LONG-CHAIN FATTY ACIDS ON BLOOD
CONSTITUENTS AND IMMUNE RESPONSE BY LACTATING
DAIRY COWS 201
Introduction 201
Materials and Methods 205
Experimental Animals 205
Delayed Hypersensitivity Test (DHT) 206
Blood Samples 206
Blood Constituents 206
VI
Support of Lymphocyte Stimulation by Serum 207
Statistical Analyses 209
Results and Discussion 209
Conclusions 231
6 SUMMARY, DISCUSSION AND CONCLUSIONS 234
REFERENCES 248
BIOGRAPHICAL SKETCH 274
Abstract of Dissertation Presented to the Graduate School of the University of
Florida in Partial Fulfillment of the Requirements for the
Degree of Doctor of Philosophy
REPRODUCTIVE, PRODUCTIVE, AND IMMUNOLOGICAL RESPONSES
OF HOLSTEIN DAIRY COWS FED DIETS VARYING IN
CONCENTRATION AND RUMINAL DEGRADABILITY OF PROTEIN
AND SUPPLEMENTED WITH RUMINALLY INERT FAT
By
Carlos Miguel Garcia-Bojalil
August 1993
Chairperson: Charles R. Staples
Major Department: Animal Science
Concentration and rumen degradability (DIP) of dietary crude protein
(CP) and fat (CaLCFA) have influenced reproductive efficiency and the immune
system of dairy cows. Experiments described herein studied interactions
between CP, DIP, and CaLCFA oh ovarian function, fertility, and productive and
immune responses of dairy cows.
Nonlactating cows were fed diets containing either 12 or 27% CP.
Plasma urea-N (PUN) was increased from 9.8 to 21.3 mg/dl by feeding 27% CP
diet. Follicular growth, response to superovulation, quality and quantity of
ova/embryos, and reproductive hormone concentrations were not altered by
feeding 27% CP diets.
Productive and reproductive performance of cows fed two dietary
concentrations of DIP (55 or 76% of CP) and CaLCFA (0 or 2.2% of DM) were
VIII
evaluated the first 16 wk postpartum. A combination of byproducts (corn gluten
meal, fish meal, blood meal, and meat and bone meal) or soybean meal and
urea were used as primary N sources for 55 and 76DIP diets, respectively.
Cows fed 76DIP diets consumed less feed the first 8 wk postpartum but more
feed thereafter. Feeding 76DIP diets increased BW loss and PUN
concentrations and decreased plasma insulin concentrations. Initiation of luteal
activity was delayed 13 d in cows fed 76DIP diets. Milk production was similar
between cows fed 0 or 2.2% CaLCFA until 3 wk postpartum at which time cows
fed 2.2% CaLCFA demonstrated greater persistency. Addition of CaLCFA
improved pregnancy 34 percentage units.
Effect of dietary concentrations of CP, DIP, and CaLCFA on blood
constituents and responsiveness of the immune system was explored. Feeding
76DIP diets decreased and CaLCFA increased platelet and white blood cell
counts. Feeding CaLCFA increased number of lymphocytes regardless of
protein degradability. Adding CaLCFA to the 55DIP diet decreased number of
neutrophils but increased numbers when added to the 76DIP diet. Skin test
thickness tended to be reduced by adding CaLCFA to the 55DIP diet but
remained unchanged when added to the 76DIP diet. Lymphocytes tended to
respond less to a mitogen when grown in media containing serum from cows
fed 76DIP diets compared with 55D1P diets.
Effects of DIP and CP on reproductive, productive, and immune system
functions of dairy cows depend upon lactational (lactating or nonlactating) and
energy status.
IX
CHAPTER
I
INTRODUCTION
Nutrient intake and body condition are known to influence reproductive
performance in a wide range of mammals. Reproduction of ruminants is
influenced by nutritional status during four phases of the life cycle. Firstly,
timing of the onset of puberty is clearly under nutritional control. Critical
minimum body weights required for ovulation or the onset of spermatogenesis
have been described. Secondly, postpubertal ovulation rate is known to be
influenced profoundly by both nutrient intake and body condition in
multiovulating species such as sheep. Thirdly, early embryonic mortality
frequently is associated with a low plane of nutrition.
For dairy cattle, plane of nutrition during lactation can have a significant
effect on timing of the onset of normal ovarian activity postpartum. Gross
dietary deficiencies of energy, protein, and some minerals and vitamins
adversely affect reproductive efficiency or viability of young cattle (Underwood,
1977; Wiltbank et al., 1964). The opposite situation may be more prevalent in
developed countries where animals are fed excessive amounts of certain
nutrients that impairs fertility. Intakes of large amounts of concentrates have
been implicated with cystic ovarian disease and increased calving intervals of
dairy cows (Morrow et al., 1969).
1
