influence of the nutritional status of piglets on their ability to perform appropriate dietary selection

192 Pages·2014·1.15 MB·English

INFLUENCE OF THE NUTRITIONAL STATUS
OF PIGLETS ON THEIR ABILITY TO PERFORM
APPROPRIATE DIETARY SELECTION
PATTERNS AFTER WEANING
TESI DOCTORAL PRESENTADA PER:
Sergio A. Guzmán Pino
SOTA LA DIRECCIÓ DE LES DOCTORES:
José Francisco Pérez Hernández i David Solà Oriol
PER ACCEDIR AL GRAU DE DOCTOR DINS EL PROGRAMA DE
DOCTORAT EN PRODUCCIÓ ANIMAL DEL DEPARTAMENT DE
CIÈNCIA ANIMAL I DELS ALIMENTS
BELLATERRA, 2014

El Dr. José Francisco Pérez Hernández i el Dr. David Solà Oriol, ambdues del
Departament de Ciència Animal i dels Aliments de la Facultat de Veterinària de la Universitat
Autònoma de Barcelona,

Certifiquen:

Que la memòria titulada “Influence of the nutritional status of piglets on their ability to
perform appropriate dietary selection patterns after weaning”, presentada per Sergio A.
Guzmán Pino amb la finalitat d’optar al grau de Doctor, ha estat realitzada sota la seva
direcció i, considerant-la acabada, autoritzen la seva presentació perquè sigui jutjada per la
comissió corresponent.

I perquè consti als efectes oportuns, signen la present a Bellaterra, 28 de Juliol de 2014.

Dr. José Francisco Pérez Hernández Dr. David Solà Oriol

This study was supported by the Spanish Government (Ministerio de Ciencia e Innovación,
Project PET2008_0002). The author was granted with a “Becas Chile” research fellowship
from the Chilean Government (Programa Formación de Capital Humano Avanzado,
CONICYT) to pursue doctoral studies at Universitat Autònoma de Barcelona.

Contents
Summary/Resumen ..................................................................................................................... i
General introduction ................................................................................................................. vii
1. Literature review .................................................................................................................... 1
1.1. Introduction: preference, appetence and palatability .......................................................... 3
1.2. Regulation of feed intake in pigs ......................................................................................... 6
1.2.1. Sensorial perception of feed ......................................................................................... 7
1.2.1.1. Olfaction ................................................................................................................ 7
1.2.1.2. Somatosensing ....................................................................................................... 8
1.2.1.3. Taste ....................................................................................................................... 9
1.2.2. Post-ingestive effects .................................................................................................. 14
1.2.3. Metabolic and hormonal homeostasis ........................................................................ 16
1.2.4. Central regulation of feed intake ................................................................................ 19
1.2.5. Theories of control of feed intake and diet selection .................................................. 20
1.3. Gustatory preferences and aversions in pigs ..................................................................... 22
1.3.1. Sugars/carbohydrates .................................................................................................. 22
1.3.2. Amino acids/proteins .................................................................................................. 24
1.3.3. Lipids/fats ................................................................................................................... 28
1.3.4. Minerals and acids ...................................................................................................... 29
1.3.5. Anti-nutritional factors, drugs and toxins ................................................................... 30
1.4. Learning and diet selection in pigs .................................................................................... 31
1.5. Summary and implications ................................................................................................ 34
2. Hypothesis and objectives .................................................................................................... 37
3. Chapter 1 Dietary energy density affects the preference for protein or carbohydrate
solutions and piglet performance after weaning ...................................................................... 41
3.1. Abstract ............................................................................................................................. 43
3.2. Introduction ....................................................................................................................... 44
3.3. Materials and methods ...................................................................................................... 44
3.3.1. Diets and feeding ........................................................................................................ 44
3.3.2. Animals, facilities and experimental design ............................................................... 45
3.3.3. Calculations and statistical analysis ........................................................................... 46
3.4. Results ............................................................................................................................... 46
3.5. Discussion ......................................................................................................................... 48
4. Chapter 2 Influence of the protein status of piglets on their ability to select and prefer
protein sources .......................................................................................................................... 49
4.1. Abstract ............................................................................................................................. 51
4.2. Introduction ....................................................................................................................... 52
4.3. Material and methods ........................................................................................................ 53
4.3.1. Animals and housing .................................................................................................. 53
4.3.2. Experimental diets and feeding .................................................................................. 54
4.3.3. Experimental designs .................................................................................................. 56
4.3.3.1. Preference of piglets for protein sources in a protein-deficiency status
(Experiment 1) .................................................................................................................. 56
4.3.3.2. The value of associative learning on diet selection of piglets in a protein-
deficiency status (Experiment 2) ...................................................................................... 57
4.3.4. Calculations and statistical analysis ........................................................................... 59
4.4. Results ............................................................................................................................... 60
4.4.1. Feed intake and growth performance of piglets ......................................................... 60
4.4.2. Experiment 1............................................................................................................... 61
4.4.2.1. Choice test ............................................................................................................ 61
4.4.2.2. First contact of piglets .......................................................................................... 62
4.4.3. Experiment 2............................................................................................................... 63
4.4.3.1. Choice test ............................................................................................................ 63
4.4.3.2. One-pan test ......................................................................................................... 65
4.5. Discussion ......................................................................................................................... 66
4.6. Conclusion ......................................................................................................................... 70
5. Chapter 3 Effect of a long-term exposure to carbohydrate and artificial sweetener solutions
on the preference, appetence, feed intake and growth performance of post-weaned piglets ... 71
5.1. Abstract ............................................................................................................................. 73
5.2. Introduction ....................................................................................................................... 74
5.3. Material and methods ........................................................................................................ 76
5.3.1. Animals, diets and housing ......................................................................................... 76
5.3.2. Experimental designs .................................................................................................. 78
5.3.2.1. Experiments 1, 2 and 3: Long-term solution exposure in piglets ........................ 78
5.3.2.2. Experiment 4: Piglets preference for carbohydrate or artificial sweeteners
solutions ............................................................................................................................ 80
5.3.3. Calculations and statistical analysis ........................................................................... 81
5.4. Results ............................................................................................................................... 82
5.4.1. Experiments 1, 2 and 3 ............................................................................................... 82
5.4.1.1. Ad libitum solution exposure ............................................................................... 82
5.4.1.2. Initial and final choice test ................................................................................... 85
5.4.1.3. One-pan test ......................................................................................................... 88
5.4.2. Experiment 4............................................................................................................... 89
5.5. Discussion ......................................................................................................................... 90
5.6. Conclusion ......................................................................................................................... 96
6. Chapter 4 Influence of dietary electrolyte balance on feed preference and appetence, and
growth performance of post-weaned piglets ............................................................................ 97
6.1. Abstract ............................................................................................................................. 99
6.2. Introduction ..................................................................................................................... 100
6.3. Materials and methods .................................................................................................... 100
6.3.1. Animals and housing ................................................................................................ 101
6.3.2. Experimental diets and feeding ................................................................................ 101
6.3.3. Experimental designs ................................................................................................ 104
6.3.4. Calculations and statistical analysis ......................................................................... 105
6.4. Results ............................................................................................................................. 106
6.5. Discussion ....................................................................................................................... 111
7. General discussion .............................................................................................................. 117
7.1. The response of the animals to a protein-deficiency condition ....................................... 120
7.2. Protein deficiency by a free-availability of highly-hedonic solutions ............................ 123
7.3. An integration of the protein deficiency and the dietary selection based on the framework
of minimal total discomfort .................................................................................................... 125
7.4. An imbalance in the acid-base homeostasis .................................................................... 129
7.5. The importance of learning in the ability of piglets to perform an appropriate dietary
selection pattern ...................................................................................................................... 131
8. Conclusions ........................................................................................................................ 135
9. References .......................................................................................................................... 139
10. Annexes ............................................................................................................................ 153
10.1. Annex 1 ......................................................................................................................... 155
10.2. Author education and training ....................................................................................... 159
10.3. List of publications ........................................................................................................ 163