View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Digital Repository @ Iowa State University Iowa State University Capstones, Theses and Graduate Theses and Dissertations Dissertations 2014 Impact of dietary fat intake on carcass iodine value and pork fat quality Trey Allen Kellner Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/etd Part of the Agriculture Commons, Animal Sciences Commons, Food Science Commons, and the Human and Clinical Nutrition Commons Recommended Citation Kellner, Trey Allen, "Impact of dietary fat intake on carcass iodine value and pork fat quality" (2014). Graduate Theses and Dissertations. 13832. https://lib.dr.iastate.edu/etd/13832 This Thesis is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Graduate Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. Impact of dietary fat intake on carcass iodine value and pork fat quality by Trey A. Kellner A Thesis submitted to the graduate faculty in partial fulfillment of the requirements for the degree of MASTERS OF SCIENCE Major: Animal Science Program of Study Committee: John F. Patience, Major Professor Kenneth J. Prusa Michael E. Spurlock Iowa State University Ames, Iowa 2014 Copyright © Trey A. Kellner, 2014. All rights reserved. ii DEDICATION To my mother and father, without giving me years of guidance and support, I would be unable to have the opportunity to publish these findings. Words cannot justify how grateful and appreciative of my upbringing I am. To my fiancée, thanks for your daily motivation and support, you truly are my balance in life. iii TABLE OF CONTENTS Page LIST OF FIGURES ................................................................................................... iv LIST OF TABLES ..................................................................................................... v ACKNOWLEDGEMENTS ....................................................................................... vii ABSTRACT………………………………. .............................................................. viii CHAPTER 1 LITERATURE REVIEW ............................................................... 1 Introduction .......................................................................................................... 1 Dietary fat metabolism ......................................................................................... 2 De novo lipogenesis ............................................................................................. 7 Lipolysis ............................................................................................................... 11 Previous research on pork fat composition .......................................................... 13 CHAPTER 2 IMPACT OF DIETARY FAT SOURCE AND CONCENTRATION, AND DAILY FATTY ACID INTAKE, ON THE COMPOSTION OF CARCASS FAT AND IODINE VALUE SAMPLED IN THREE REGIONS OF THE PORK CARCASS .............................. 19 Abstract ................................................................................................................ 19 Introduction .......................................................................................................... 20 Materials and methods ......................................................................................... 21 Results .................................................................................................................. 26 Discussion ............................................................................................................ 31 CHAPTER 3 THE IMPACT OF DIETARY FAT WITHDRAWAL ON CARCASS IODINE VALUE, BELLY CHARACTERISTICS, AND CHANGES IN BODY FAT OVER TIME ................................................................ 54 Abstract ................................................................................................................ 54 Introduction .......................................................................................................... 55 Materials and methods ......................................................................................... 56 Results .................................................................................................................. 61 Discussion ............................................................................................................ 64 CHAPTER 4 SUMMARY AND CONCLUSIONS ............................................. 78 LITERATURE CITED .............................................................................................. 80 iv LIST OF FIGURES Page Figure 2.1 Carcass iodine value averaged across three sample sites affected by linoleic acid (18:2) intake ............................................. 46 Figure 2.2 Carcass iodine value averaged across three sample sites affected by linolenic acid (18:3) intake ........................................... 47 Figure 2.3 Carcass iodine value averaged across three sample sites affected by palmitic acid (16:0) intake ............................................ 48 Figure 2.4 Carcass iodine value averaged across three sample sites affected by stearic acid (18:0) intake ............................................... 49 Figure 2.5 Carcass iodine value averaged across three sample sites affected by oleic acid (18:1) intake .................................................. 50 Figure 2.6 Carcass iodine value averaged across three sample sites affected by iodine value product (IVP) intake ................................. 51 Figure 2.7 Carcass iodine value (IV) averaged across three sample sites affected by iodine value product (IVP) ............................................ 52 Figure 2.8 Carcass iodine value (IV) averaged across three sample sites affected by treatment means of linoleic acid (18:2) intake .............. 53 v LIST OF TABLES Page Table 2.1 Ingredient composition (as-fed basis) of the experimental diets d 0 to 27 ............................................................. 36 Table 2.2 Ingredient composition (as-fed basis) of the experimental diets d 27 to 55 ........................................................... 37 Table 2.3 Effects of dietary fat source and inclusion level on growth performance and fatty acid intake ................................................. 38 Table 2.4 Effects of dietary treatment on energy intake and apparent total track digestibility of energy and dry matter ....................................... 39 Table 2.5 Effects of dietary treatment fat source and inclusion level on carcass iodine value via titration ........................................................... 40 Table 2.6 Effects of dietary fat source and inclusion level on iodine value via titration by sample site ............................................................... 41 Table 2.7 Effects of dietary fat source and inclusion level on carcass fatty acid profile measured at the jowl ....................................................... 42 Table 2.8 Effects of dietary fat source and inclusion level on belly weight, depth, and firmness .............................................................. 43 Table 2.9 Effects of dietary fat source and inclusion level on hot carcass weight and loin muscle depth .................................................. 44 Table 2.10 Effects of dietary fat source and inclusion level on back fat and fat free lean % ...................................................................... 45 Table 3.1 Ingredient composition (as-fed basis) of the experimental diets ............... 68 Table 3.2 Effects of dietary fat withdrawal and dietary fat unsaturation load on growth performance ................................................. 69 Table 3.3 Effects of dietary fat withdrawal and dietary fat unsaturation load on fatty acid intake ............................................................................. 70 Table 3.4 Effects of dietary fat withdrawal and dietary fat unsaturation load on fatty acid composition ................................................................... 71 vi Table 3.5 Effects of gender on fatty acid composition .............................................. 73 Table 3.6 Effects of dietary fat withdrawal and dietary fat unsaturation load on calculated iodine value .................................................................. 74 Table 3.7 Effects of dietary fat withdrawal and dietary fat unsaturation load on carcass IV measured via direct titration ........................................ 75 Table 3.8 Effects of dietary fat withdrawal and dietary fat unsaturation load on carcass fat and belly characteristics .............................................. 76 Table 3.9 Effects of dietary fat withdrawal and dietary fat unsaturation load on carcass characteristics ................................................................... 77 vii ACKNOWLEDGEMENTS I would like to thank John my committee chair and major professor for allowing me this life changing experience and the privilege to submit this work. Your wisdom and mentoring has and will continue to shape my future impact on my career and industry. Additionally, I would like to thank my committee members, Ken, Mike, and Tim, for their teaching and support throughout the course of this research. Next, I would also like to thank the