Mississippi State University Scholars Junction Theses and Dissertations Theses and Dissertations 1-1-2011 Modifying the Double-Ovsynch Protocol to include Human Chorionic Gonadotropin to Synchronize Estrus in Dairy Cattle Joseph Andrew Binversie Follow this and additional works at: https://scholarsjunction.msstate.edu/td Recommended Citation Binversie, Joseph Andrew, "Modifying the Double-Ovsynch Protocol to include Human Chorionic Gonadotropin to Synchronize Estrus in Dairy Cattle" (2011). Theses and Dissertations. 3173. https://scholarsjunction.msstate.edu/td/3173 This Graduate Thesis - Open Access is brought to you for free and open access by the Theses and Dissertations at Scholars Junction. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of Scholars Junction. For more information, please contact [email protected]. Template Created By: Damen Peterson 2009 MODIFYING THE DOUBLE-OVSYNCH PROTOCOL TO INCLUDE HUMAN CHORIONIC GONADOTROPIN TO SYNCHRONIZE ESTRUS IN DAIRY CATTLE By Joseph Andrew Binversie A Thesis Submitted to the Faculty of Mississippi State University in Partial Fulfillment of the Requirements for the Degree of Master of Science in Animal Physiology in the Department of Animal and Dairy Sciences Mississippi State, Mississippi August 2011 Template Created By: Damen Peterson 2009 Copyright by Joseph Andrew Binversie 2011 Template Created By: Damen Peterson 2009 MODIFYING THE DOUBLE-OVSYNCH PROTOCOL TO INCLUDE HUMAN CHORIONIC GONADOTROPIN TO SYNCHRONIZE ESTRUS IN DAIRY CATTLE By Joseph Andrew Binversie Approved: __________________________________ __________________________________ Jamie E. Larson Peter L. Ryan Assistant Professor of Associate Provost for Academic Affairs Animal and Dairy Sciences Professor of Animal and Dairy Sciences (Director of Thesis) Graduate Coordinator of Animal Physiology (Committee Member) __________________________________ __________________________________ Justin D. Rhinehart George Hopper Assistant Professor of Animal Science Interim Dean The University of Tennessee College of Agriculture and Life Sciences (Committee Member) Template Created By: Damen Peterson 2009 Name: Joseph Andrew Binversie Date of Degree: August 6, 2011 Institution: Mississippi State University Major Field: Animal Physiology Major Professor: Jamie E. Larson Title of Study: MODIFYING THE DOUBLE-OVSYNCH PROTOCOL TO INCLUDE HUMAN CHORIONIC GONADOTROPIN TO SYNCHRONIZE ESTRUS IN DAIRY CATTLE Pages in Study: 82 Candidate for Degree of Master of Science The objectives of this study were to determine whether conception, ovulation rates, presynchronization rates, or follicle and CL characteristics were altered after modifying the Double-Ovsynch (DO) protocol to include human chorionic gonadotropin (hCG) compared to the conventional DO protocol in dairy heifers and lactating dairy cows. We hypothesized that replacing the first injection of gonadotropin releasing hormone (GnRH) in the DO protocol with hCG would increase the proportion of females that ovulate, thus improving the presynchronization rate leading to increased conception rates. Ovulation rates were increased in cows administered hCG compared to GnRH, but subsequent synchronization, and conception rates did not differ between treatments. A greater proportion of hCG-treated cows tended to fail to have undergone luteolysis compared to those treated with GnRH. In conclusion, no improvement in overall fertility was achieved by replacing the first injection of GnRH in the DO protocol with hCG. Key Words: Double-Ovsynch, hCG, presynchronization Template Created By: Damen Peterson 2009 DEDICATION I would like to dedicate this thesis to my wife Liz. Thank you for all of your love and support throughout my masters program at Mississippi State University. You always are able to brighten my day. ii Template Created By: Damen Peterson 2009 ACKNOWLEDGEMENTS I would first like to thank all of the graduate students that assisted me in my research project at Mississippi State University. Without your help, this research would not have been possible. A special thank you to Kenneth Graves and JB Gardner, I know having the cows and heifers up and ready every morning was a challenge at times, and I am grateful that you guys were always able to accommodate my research needs. Thank you also to David Skinner for his assistance in the breeding of the heifers and cows. Thank you to the Mississippi Agricultural and Forestry Experiment Station for the use of their facilities and animals and also to all the members in the Department of Animal and Dairy Sciences for your help and support throughout my time in Mississippi. I would also like to thank my major professor Dr. Jamie Larson for allowing me the freedom to pursue a research project in the area of estrous synchronization. I believe that you have helped me become a more independent researcher and a better statistician and writer. Thank you also to my committee members of Dr. Peter Ryan and Dr. Justin Rhinehart. I always appreciated the friendship and advisement that you both gave me. Finally, I would like to thank my family. I am very appreciative that the values of hard work and respect towards one another have helped me be the person I am today. Thank you for all of your love and support. iii Template Created By: Damen Peterson 2009 TABLE OF CONTENTS DEDICATION .................................................................................................................... ii ACKNOWLEDGEMENTS ............................................................................................... iii LIST OF TABLES ............................................................................................................. vi LIST OF FIGURES .......................................................................................................... vii CHAPTER I. INTRODUCTION ...................................................................................................1 II. LITERATURE REVIEW ........................................................................................4 Steroid Metabolism in Dairy Cattle .........................................................................4 Synchronization of the Estrous Cycle ......................................................................6 Presynchronization of the Estrous Cycle ...............................................................10 Presynchronization with PGF2α .......................................................................10 Presynchronization with CIDR devices ...........................................................11 Presynchronization with GnRH and PGF2α .....................................................13 Characteristics of Human Chorionic Gonadotropin ..............................................15 The use of hCG in Synchronization of Estrus .................................................16 The use of hCG Post-AI ...................................................................................20 The use of hCG in Resynchronization Protocols .............................................23 The use of hCG in Heifers ...............................................................................25 Summary ................................................................................................................27 References ..............................................................................................................28 III. MODIFYING THE DOUBLE-OVSYNCH PROTOCOL TO INCLUDE HUMAN CHORIONIC GONADOTROPIN TO SYNCHRONIZE ESTRUS IN DAIRY CATTLE .................................................................36 Abstract ..................................................................................................................36 Introduction ............................................................................................................37 Materials and Methods ...........................................................................................39 Herd Management Practices ............................................................................39 Experimental Design and Treatments ..............................................................40 iv Template Created By: Damen Peterson 2009 Milk Production and BCS ................................................................................42 Ovarian Measurements and Pregnancy Diagnosis ...........................................42 Blood Collection and RIA ...............................................................................43 Statistical Analyses ..........................................................................................44 Results ...................................................................................................................45 Experiment 1: Dairy Cows...............................................................................45 Ovarian Responses to hCG or GnRH during Pre-Ovsynch .......................45 Measurements at time of PGF2α of Pre-Ovsynch .......................................46 Responses to PGF2α and Day 10 Measurements ......................................47 Evaluation of Breeding-Ovsynch ...............................................................49 Experiment 2: Dairy Heifers ............................................................................50 Ovarian Responses to hCG or GnRH during Pre-Ovsynch .......................50 Responses to PGF2α and Day 10 Measurements ........................................51 Evaluation of