Heat stress alters animal physiology and post-absorptive

263 Pages·2016·2.82 MB·English

Iowa State University Capstones, Theses and
Graduate Theses and Dissertations
Dissertations
2014
Heat stress alters animal physiology and post-
absorptive metabolism during pre- and postnatal
development
Jay Steven Johnson
Iowa State University
Follow this and additional works at:https://lib.dr.iastate.edu/etd
Part of theAgriculture Commons,Animal Sciences Commons,Human and Clinical Nutrition
Commons, and thePhysiology Commons
Recommended Citation
Johnson, Jay Steven, "Heat stress alters animal physiology and post-absorptive metabolism during pre- and postnatal development"
(2014).Graduate Theses and Dissertations. 13982.
https://lib.dr.iastate.edu/etd/13982
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Heat stress alters animal physiology and post-absorptive metabolism during
pre- and postnatal development

by

Jay Steven Johnson

A dissertation submitted to the graduate faculty in partial fulfillment of the requirements
for the degree of
DOCTOR OF PHILOSOPHY

Major: Nutritional Sciences

Program of Study Committee:
Lance H. Baumgard, Major Professor
Donald C. Beitz
John F. Patience
Jason W. Ross
Hongwei Xin

Iowa State University

Ames, Iowa

2014

Copyright © Jay Steven Johnson, 2014. All rights reserved.
ii
TABLE OF CONTENTS

LIST OF TABLES............................................................................................................ vi
LIST OF FIGURES.......................................................................................................... ix
LIST OF ABBREVIATIONS......................................................................................... xiii
ACKNOWLEDGEMENTS............................................................................................. xv
ABSTRACT.................................................................................................................... xvi

CHAPTER I. LITERATURE REVIEW............................................................................ 1

Introduction......................................................................................................... 1
Global Impact of Heat Stress.............................................................................. 2
Climate Change....................................................................................... 2
Economic and Food Security Impacts of Heat Stress............................. 2
Heat-Related Illnesses in Humans and Animals..................................... 3
Management Strategies to Reduce Heat Load........................................ 4
Nutritional Strategies to Reduce Heat Load........................................... 5
Direct and Indirect Effects of Heat Stress.............................................. 7
Thermoregulatory Response to Heat Stress....................................................... 9
Thermoregulation................................................................................... 9
Conductive Exchange................................................................. 10
Convective Exchange................................................................. 11
Radiative Exchange.................................................................... 12
Evaporation............................................................................................. 13
Respiration.............................................................................................. 14
Feed Intake.................................................................................................. 15
Van’t Hoff Arrhenius Equation and the Q Effect................................. 16
10
Adaptation and Acclimation................................................................... 17
Nutrient Metabolism and Partitioning................................................................ 18
Carbohydrates......................................................................................... 19
Digestion and Absorption........................................................... 19
Synthesis and Oxidation............................................................. 20
Heat Stress and Carbohydrate Metabolism............................................ 21
Protein..................................................................................................... 24
Digestion and Absorption........................................................... 24
Synthesis and Degradation.......................................................... 25
Heat Stress and Protein Metabolism....................................................... 28
Lipid........................................................................................................ 30
Digestion and Absorption........................................................... 30
Synthesis and Oxidation............................................................. 31
Heat Stress and Lipid Metabolism.......................................................... 33
Bioenergetics........................................................................................... 35
Porcine Tissue Accretion ....................................................................... 36
Prenatal Insults.................................................................................................... 37
Epigenetics.............................................................................................. 38
Maternal Heat Stress............................................................................... 39
iii
Maternal Nutrient Restriction................................................................. 41
Elevated Maternal Glucocorticoids......................................................... 43
Summary............................................................................................................. 45
Literature cited.................................................................................................... 47

CHAPTER II: EFFECTS OF MAMMALIAN IN UTERO HEAT STRESS ON
ADOLESCENT BODY TEMPERATURE...................................................................... 66

Abstract........................................................................................................................... 66
Introduction..................................................................................................................... 67
Materials and Methods.................................................................................................... 68
Gestational Environments................................................................................... 68
Adolescent Environments................................................................................... 69
Statistics.............................................................................................................. 70
Results............................................................................................................................. 71
Thermal Indices................................................................................................... 71
Regression Analysis............................................................................................ 72
Growth Parameters.............................................................................................. 72
Discussion....................................................................................................................... 73
Conclusion...................................................................................................................... 77
References....................................................................................................................... 79

CHAPTER III: IN UTERO HEAT STRESS INCREASES POSTNATAL CORE
BODY TEMPERATURE IN PIGS.................................................................................. 88

Abstract............................................................................................................................. 88
Introduction....................................................................................................................... 89
Materials and Methods...................................................................................................... 90
In utero environments........................................................................................... 90
Postnatal environments......................................................................................... 91
Blood sampling and analysis................................................................................ 93
Statistics................................................................................................................ 94
Results............................................................................................................................... 97
Thermal indices..................................................................................................... 97
Core temperature....................................................................................... 97
Respiration rate......................................................................................... 98
Skin temperature....................................................................................... 98
Growth parameters................................................................................................ 99
Blood parameters.................................................................................................. 99
Discussion....................................................................................................................... 100
Perspectives and significance......................................................................................... 105
References....................................................................................................................... 107
iv
CHAPTER IV: EFFECTS OF IN UTERO HEAT STRESS AND CORE BODY
TEMPERATURE ON TISSUE ACCRETION DURING THE GROWING
PHASE (30 TO 60 KG) IN PIGS................................................................................... 120

Abstract........................................................................................................................... 120
Introduction..................................................................................................................... 121
Materials and Methods.................................................................................................... 122
In utero environments......................................................................................... 122
Postnatal environments....................................................................................... 123
Blood sampling and analysis.............................................................................. 124
Serial slaughter and sub-sample analysis............................................................ 125
Statistical analysis............................................................................................... 127
Results............................................................................................................................. 128
Thermal indices.................................................................................................. 128
Growth performance........................................................................................... 128
Organ and carcass weight................................................................................... 129
Tissue composition and accretion....................................................................... 129
Blood analysis..................................................................................................... 129
Discussion....................................................................................................................... 130
Conclusion...................................................................................................................... 136
References....................................................................................................................... 137

CHAPTER V: IN UTERO HEAT STRESS ALTERS BODY COMPOSITION
DURING THE EARLY FINISHING PHASE (60 TO 80 KG) IN PIGS....................... 152

Abstract........................................................................................................................... 152
Introduction..................................................................................................................... 153
Materials and Methods.................................................................................................... 155
In utero environments......................................................................................... 155
Postnatal environments....................................................................................... 155
Blood sampling and analysis.............................................................................. 157
Serial slaughter and sub-sample analysis............................................................ 158
Statistical analysis............................................................................................... 159
Results............................................................................................................................. 160
Thermal indices................................................................................................... 160
Growth performance........................................................................................... 160
Organ and carcass weight................................................................................... 161
Tissue composition and accretion....................................................................... 162
Blood analysis..................................................................................................... 162
Discussion....................................................................................................................... 163
Conclusion...................................................................................................................... 169
References....................................................................................................................... 171
v
CHAPTER VI: THE IMPACT OF IN UTERO HEAT STRESS AND NUTRIENT
RESTRICTION ON PROGENY BODY COMPOSITION........................................... 186

Abstract........................................................................................................................... 186
Introduction..................................................................................................................... 187
Materials and Methods.................................................................................................... 189
Maternal environment......................................................................................... 189
Postnatal environment......................................................................................... 190
Tissue collection................................................................................................. 191
Histology............................................................................................................. 191
Statistics.............................................................................................................. 191
Results............................................................................................................................. 192
Maternal phase.................................................................................................... 192
Thermal indices....................................................................................... 192
Growth variables..................................................................................... 192
Offspring variables.............................................................................................. 193
Growth.................................................................................................... 193
Tissue composition and accretion........................................................... 193
Organ and tissue weights........................................................................ 194
Histology................................................................................................. 195
Discussion....................................................................................................................... 195
Perspectives and significance......................................................................................... 199
References....................................................................................................................... 202

CHAPTER VII: SUMMARY......................................................................................... 218

APPENDIX..................................................................................................................... 223
vi
LIST OF TABLES

Table 1.1: Symptoms of heat-related illnesses from mild (1) to severe (5)...................... 4

Table 1.2: Euthermic rectal temperature (T ) of multiple species.................................. 10
re

Table 1.3: The impact of heat stress (HS) on dry matter intake (DMI) of
various species.................................................................................................................. 16

Table 1.4: Glucose transporters and their function......................................................... 20

Table 1.5: The impact of heat stress on parameters of carbohydrate metabolism.......... 23

Table 1.6: The impact of heat stress on blood biomarkers of proteolysis...................... 29

Table 1.7: The impact of heat stress on biomarkers of lipid metabolism....................... 34

Table 1.8: The impact of in utero heat stress on postnatal phenotypes.......................... 41

Table 1.9: Phenotypic consequences of maternal nutrient restriction exposure
during early, mid, and late gestation................................................................................. 42

Table 1.10: The impact of in utero glucocorticoids on postnatal phenotypes................ 45

Table 2.1: Effects of gestational and adolescent thermal environments on body
temperature indices in growing pigs................................................................................. 83

Table 2.2: Effects of gestational and adolescent thermal environments on
production parameters in growing pigs............................................................................. 84

Table 3.1: Effects of in utero heat stress on core body temperature in growing pigs... 112

Table 3.2: Effects of in utero heat stress on thermoregulation parameters in
growing pigs.................................................................................................................... 113

Table 3.3: Effects of in utero heat stress on growth parameters in growing
pigs.................................................................................................................................. 114

Table 3.4: Effects of postnatal heat stress on bioenergetic parameters in growing
pigs.................................................................................................................................. 115

Table 4.1: Ingredients and chemical composition of diet for growing pigs (as-fed
basis)............................................................................................................................... 144

Table 4.2: Effect of in utero and postnatal environment on growth parameters
in growing pigs............................................................................................................... 145
vii
Table 4.3: Effect of in utero and postnatal environment on carcass and organ
weights of growing pigs.................................................................................................. 146

Table 4.4: Effect of in utero and postnatal environment on tissue accretion in
growing pigs.................................................................................................................... 147

Table 4.5: Effect of in utero and postnatal environment on blood parameters in
growing pigs.................................................................................................................... 148

Table 5.1: Ingredients and chemical composition of diet for growing pigs (as-fed
basis)............................................................................................................................... 179

Table 5.2: Effect of in utero and postnatal environment on growth parameters in
growing pigs.................................................................................................................... 180

Table 5.3: Effect of in utero and postnatal environment on carcass and organ
weights of growing pigs.................................................................................................. 181

Table 5.4: Effect of in utero and postnatal environment on carcass composition
and tissue accretion in growing pigs............................................................................... 182

Table 5.5: Effect of in utero and postnatal environments on blood parameters in
growing pigs.................................................................................................................... 183

Table 6.1: Effect of environmental treatment on maternal variables............................ 208

Table 6.2: Effect of in utero environment on rat offspring growth.............................. 209

Table 6.3: Effect of in utero environment on postnatal body composition in rat
offspring.......................................................................................................................... 210

Table 6.4: Effect of in utero environment on postnatal tissue accretion in rat
offspring.......................................................................................................................... 211

Table 6.5: Effect of in utero environment on postnatal carcass components in rat
offspring.......................................................................................................................... 212

Table 7.1: The biological consequences of heat stress.................................................. 222

Table A-3.1. Ingredients and chemical composition of diet for growing pigs
(as-fed basis)................................................................................................................... 223

Table A-3.2: Effects of in utero heat stress on bioenergetic parameters in pigs........... 224

Table A-6.1. Relevant nutrient content of Harlan 2018 rodent diet (as-fed basis)........ 225
viii
Table A-6.2: Effect of in utero environment on bioenergetic variables of fasted
rats.................................................................................................................................. 226
ix
LIST OF FIGURES

Figure 1.1: Protein turnover............................................................................................ 28

Figure 1.2: Lipogenesis................................................................................................... 32

Figure 1.3: Schematic of energy utilization.................................................................... 36

Figure 2.1: Effects of gestational and adolescent thermal environments on the
temporal changes in respiration rate, rectal temperature (T ), and T averaged by
re re
gestational and adolescent environment in growing pigs................................................. 85

Figure 2.2: Effects of gestational and adolescent thermal environments on the
temporal changes in ear skin temperature, shoulder skin temperature, rump skin
temperature and tail skin temperature in growing pigs................................................... 86

Figure 2.3: Linear regression (y = mx +b) of respiration rate as a function of rectal
temperature for gestational thermal neutral and gestational heat stress exposed pigs,
regardless of adolescent environment............................................................................. 87

Figure 3.1: Ambient temperature (T ) by day of study................................................. 116
a

Figure 3.2: Effects of in utero environment on the temporal changes in core body
temperature (T ) averaged by in utero treatment and day of study in growing
core
pigs.................................................................................................................................. 117

Figure 3.3: Linear regression (y = mx + b) of core temperature (T ) as a function
core
of hour (0800-1500h)...................................................................................................... 118

Figure 3.4: Effects of in utero environment on the temporal changes in feed
intake (kg) averaged by in utero treatment and day of study in growing pigs............... 119

Figure 4.1: Effects of in utero and postnatal thermal environments on (A) respiration
rate (RR), and (B) rectal temperature (T ) averaged by in utero and postnatal
re
environment in growing pigs.......................................................................................... 149

Figure 4.2: Effect of postnatal thermal environments on protein accretion (g/d) and
adipose accretion (g/d) in growing pigs.......................................................................... 150

Figure 4.3: Linear regression (y = mx + b) of (A) average daily gain (ADG) as
a function of feed intake (FI), (B) protein accretion (g/d) as a function of
FI, (C) adipose accretion (g/d) as a function of FI, and (D) the ratio of
adipose to protein accretion/d as a function of FI........................................................... 151