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Dietary Factors Influencing Calcium and Phosphorus Utilization By DIETARY FACTORS INFLUENCING CALCIUM AND PHOSPHORUS UTILIZATION BY BROILER CHICKS by ANASTASSIA LIEM (Under the Direction of Gene M. Pesti) ABSTRACT Calcium and phosphorus are the most abundant minerals in the body of animals. They are macrominerals in animal nutrition, as they are required at relatively high levels. Calcium and phosphorus absorption and metabolism are influenced by many factors, such as the levels and ratio of inclusion in the diet, vitamin D3 and its derivatives, phytase, and organic acids. The effects of the above factors are investigated in four separate battery studies. Study one investigated the effects of phytase and 1α-OHD3 on Ca, P and phytate P utilization. Supplementation of 1α-OHD3 and phytase to P-deficient corn-soybean meal and corn-peanut meal based broiler diets increased P, and phytate P utilization, as indicated by an increase in bone ash, body weight gain, plasma P, phytate P and P retention, and also reduction in incidence of P-deficiency rickets. Study two investigated the effects of combinations of phytase, methionine source, and calcium or 1α-OHD3 on phosphorus utilization in broilers. Phytase, 1α-OHD3, and HMB (an organic acid) increased phytate P utilization, and the effect of each supplement often depended on the levels of other supplements and nutrients. Study three evaluated the efficacy of several 1α-OHD3 compounds as a substitute for cholecalciferol. Slope ratio analysis of data from the measurements of 16-d BWG, plasma Ca, rickets and bone ash indicated the bioavailability of the different 1α-OHD3 (except for the 5, 6 trans 1α-OHD3 which was inactive) to be 7 to 15 times more active as compared to D3. There were differences between the 1α-OHD3 compounds due to source, processing, and cis-trans isomerism. Study four investigated the effect of lithocholic acid, a bile acid which has been reported to have vitamin D activity in rats, on commercial broiler chicks. Lithocholic acid, at low levels, had some vitamin D3 activity in chicks, as indicated by increased plasma Ca and calbindin expression. It also caused severe hepatotoxicity and growth depression to chicks. INDEX WORDS: broilers, calcium, phosphorus, 1α-OHD3, vitamin D3, lithocholic acid, phytate P utilization DIETARY FACTORS INFLUENCING CALCIUM AND PHOSPHORUS UTILIZATION BY BROILER CHICKS by ANASTASSIA LIEM B. S. A. University of Georgia, 2004 M. S. University of Georgia, 2006 A Dissertation Submitted to the Graduate Faculty of The University of Georgia in Partial Fulfillment of the Requirements for the Degree DOCTOR OF PHILOSOPHY ATHENS, GEORGIA 2009 © 2009 Anastassia Liem All Rights Reserved DIETARY FACTORS INFLUENCING CALCIUM AND PHOSPHORUS UTILIZATION BY BROILER CHICKS by ANASTASSIA LIEM Major Professor: Gene M. Pesti Committee: Michael Azain Samuel E. Aggrey Robert B. Beckstead Wan-I Oliver Li Electronic Version Approved: Maureen Grasso Dean of the Graduate School The University of Georgia May 2009 DEDICATION I dedicate this dissertation to my parents for their love and support. iv ACKNOWLEDGEMENTS I would like to thank all those individuals who helped me develop academically and personally over the course of my study in University of Georgia. I thank Dr. Gene M. Pesti for his guidance and patience which allowed me to continue my study. I thank Dr. Robert Beckstead for his teaching and guidance. I am also grateful for Mrs. Fran Denman, and Elaine Foster for their guidance and friendship in the laboratory. Lastly, I would like to thank Dr. Hardy Edwards Jr. for his teaching and friendship. v TABLE OF CONTENTS Page ACKNOWLEDGEMENTS .............................................................................................................v CHAPTER 1 INTRODUCTION .........................................................................................................1 2 LITERATURE REVIEW ..............................................................................................3 3 THE EFFECT OF PHYTASE IN COMBINATIONS WITH 1α-OHD3 ADDED TO P-DEFICIENT CORN-SOYBEAN MEAL, AND CORN-PEANUT MEAL BASED BROILER DIETS .....................................................................................33 ABSTRACT ............................................................................................................34 INTRODUCTION ...................................................................................................35 MATERIALS AND METHODS ............................................................................36 RESULTS ................................................................................................................38 DISCUSSION .........................................................................................................40 REFERENCES ........................................................................................................43 TABLES AND FIGURES .......................................................................................46 4 THE EFFECT OF PHYTASE, METHIONINE SOURCE, CALCIUM, AND 1α- OHD3 ON PHYTATE PHOSPHORUS UTILIZATION IN BROILER CHICKS .55 ABSTRACT ............................................................................................................56 INTRODUCTION ...................................................................................................57 MATERIALS AND METHODS ............................................................................58 vi RESULTS ................................................................................................................60 DISCUSSION .........................................................................................................61 REFERENCES ........................................................................................................64 TABLES ..................................................................................................................68 5 THE EFFICACY OF DIFFERENT PREPARATIONS OF 1α-OHD3 DERIVATIVES ON PERFORMANCE AND CALCIUM UTILIZATION IN YOUNG BROILER CHICKS ..................................................................................................................77 ABSTRACT ............................................................................................................78 INTRODUCTION ...................................................................................................80 MATERIALS AND METHODS ............................................................................81 RESULTS ................................................................................................................83 DISCUSSION .........................................................................................................85 REFERENCES ........................................................................................................87 TABLES ..................................................................................................................89 6 EFFECTS OF LITHOCHOLIC ACID AND CHOLECALCIFEROL ON PLASMA CALCIUM AND CALBINDIN EXPRESSION IN COMMERCIAL BROILER CHICKS ..................................................................................................................98 ABSTRACT ............................................................................................................99 INTRODUCTION .................................................................................................101 MATERIALS AND METHODS ..........................................................................103 RESULTS ..............................................................................................................107 DISCUSSION .......................................................................................................109 REFERENCES ......................................................................................................111 vii TABLES ................................................................................................................113 7 GENERAL CONCLUSIONS ....................................................................................122 APPENDICES .............................................................................................................................123 A LABORATORY PROCEDURES .............................................................................124 B STATISTICAL MODELS AND ANALYSES .........................................................144 viii CHAPTER 1 INTRODUCTION Calcium and phosphorus are the most abundant minerals in the body of animals. They are also minerals required at the highest dietary levels by poultry. While the calcium requirement is easily satisfied with the supplementation of limestone, satisfying phosphorus requirement with inorganic phosphorus supplementation is relatively more costly. Plants store phosphorus in the form of myo-inositol 1,2,3,4,5,6-hexakisphosphate or phytate phosphorus (Nelson, 1968) which is mostly unavailable to monogastric animals such as birds. There are incentives to maximize the utilization of phytate P, such as possible reduction in feed inorganic phosphorus, which might result in reduction in feed cost and reduction in phosphorus content of the manure. Phytate P utilization is influenced by numerous factors, such as dietary calcium and phosphorus, phytase, vitamin D3 and its derivatives, and organic acids (Ravindran et al., 1995; Rafacz-Livingston et al., 2005; Liem et al., 2008). Calcium and phosphorus have an antagonistic relationship. Increasing dietary Ca reduced P absorption,
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