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Each original is also photographed in one exposure and is included in reduced form at the back of the book. Photographs included in the original manuscript have been reproduced xerographically in this copy. Higher quality 6" x 9" black and white photographic prints are available for any photographs or illustrations appearing in this copy for an additional charge. Contact UMI directly to order. University Microfilms International A Bell & Howell Information Company 300 North Zeeb Road, Ann Arbor. Ml 48106-1346 USA 313/761-4700 800/521-0600 Order Number 9211114 Telemetric evaluation of uterine electromyographic activity and body temperature in the horse mare Cross, David Thomas, Ph.D. The Ohio State University, 1991 Copyright ©1991by Cross, David Thomas. All rights reserved. UMI 300 N. Zeeb Rd. Ann Arbor, MI 48106 TELEMETRIC EVALUATION OF UTERINE ELECTROMYOGRAPHIC ACTIVITY AND BODY TEMPERATURE IN THE HORSE MARE DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in the Graduate School of the Ohio State University By David T. Cross, B.S., M.S * * * * * The Ohio State University 1991 Dissertation Committee Approved By W.R. Threlfall R.C. Kline Adviser J.L. Pate Department of Animal/ Science J .S. Ottobre R.C. Rogers Copyright by David Thomas Cross 1991 ACKNOWLEDGMENTS I would like to thank my adviser, Dr. Walter Threlfall for his faith in me and his support throughout the course of this research. Thanks also go to Dr. Robert Kline, who not only served on my advisory committee but also gave me the opportunity to be employed as the Ohio State University horse barn manager. Special thanks to Dr. Rick Rogers for his help with the technical aspects of the research and the use of his equipment for analysis of the EMG data. I also thank Drs. Joy Pate and Joe Ottobre for serving as members of the advisory committee. Gratitude is also expressed to Dr. Dave Osgood at Mini-Mitter, Inc. for his assistance and technical advice given during the course of this research. Thanks to Jan Sally for his technical assistance and Dr. Nigel Perkins, Sue Cross, Noreen Neary and Elizabeth Berkeley for their assistance with the surgeries. Finally, gratitude is expressed to Suzanne, Matthew and Jessica who have supported me throughout eight years of graduate studies and moves to several states. Thank you. ii VITA September 6. 1953 ...........Born - Chatham, Ontario 1975 ........................ B.S., Michigan State University 1985 ........................ M.S., Michigan State University 1987 ........................ M.S., University of Wisconsin- Madison PUBLICATIONS Cross, D.T., W.R. Threlfall and R.C. Kline. 1991. Telemetric monitoring of body temperature in the horse mare. Theriogenology 36:855-861. Cross, D.T., W.R. Threlfall, R.C. Rogers and R.C. Kline. 1991. Uterine electromyographic activity in horse mares as measured by radiotelemetry. Theriogenology 35:591-601. Cross, D.T. and W.R. Threlfall. 1990. The effect of xylazine on interovulatory interval and serum progesterone concentrations in the horse mare. Theriogenology 34:461-467. Cross, D.T. and O.J. Ginther. 1988. Uterine activity in nonpregnant and early pregnant mares and jennies as determined by ultrasonography. J. Anim. Sci. 66:250-254. Bessent C.B., D.T. Cross and O.J. Ginther. 1988. Effect of exogenous estradiol 17-fi on mobility and fixation of the early equine conceptus. Anim. Reprod. Sci. 16:159-167. Cross, D.T. and O.J. Ginther. 1987. The effect of estrogen, progesterone, and prostaglandin F2a on uterine contractions in seasonally anovulatory mares. Domestic Animal Endocrinology 4:271-278. Cross, D.T. and R.J. Dunn. 1985. The incidence of multiple ovulation and twinning on a Michigan Standardbred farm. Proceedings of the Ninth Equine Nutrition and Physiology Society, East Lansing, MI pp 278-283. FIELD OF STUDY Major Field: Animal Science TABLE OF CONTENTS ACKNOWLEDGEMENTS ....................................... ii VITA .......................................................iii LIST OF FIGURES ......................................... vii INTRODUCTION ........................................... 1 CHAPTER I. LITERATURE REVIEW ............................ 3 II. UTERINE ELECTROMYOGRAPHIC ACTIVITY IN HORSE MARES AS MEASURED BY RADIOTELEMETRY ......... 41 A b s t r a c t ..................................... 41 Introduction ................................ 42 Materials and Methods ...................... 44 R e s u l t s ..................................... 51 D i s c u s s i o n................................... 52 List of References .......................... 59 III. RADIOTELEMETRIC MONITORING OF UTERINE ELECTROMYOGRAPHIC ACTIVITY DURING PARTURITION IN THE HORSE M A R E ............................ 61 A b s t r a c t ..................................... 61 Introduction ................................ 62 Materials and Methods ...................... 63 R e s u l t s ..................................... 66 D iscus s i o n................................... 69 List of References.......................... 79 IV. TELEMETRIC MONITORING OF BODY TEMPERATURE IN THE HORSE M A R E ................................ 82 A b s t r a c t .................................. 82 Introduction ................................ 83 Materials and Methods ...................... 84 R e s u l t s ..................................... 89 v Discus s i o n......................... 89 List of References .......................... 93 V. BODY TEMPERATURE FLUCTUATIONS IN THE PERIPARTURIENT HORSE MARE...................... 94 A b s t r a c t ..................................... 94 Introduction ................................ 95 Materials and Methods ...................... 96 R e s u l t s ..................................... 98 D i s c u s s i o n................................... 99 List of References.............................102 LIST OF REFERENCES ....................................... 107 vi LIST OF FIGURES PAGE Model TA10CTA-D80-L40 transmitter (Data Sciences, Inc., St Paul, MN) with the biopotential leads shielded and covered with silastic tubing. The neutral wire was connected to the shielding and used to ground the shielding to the abdominal musculature..................... 54 Diagram of the physical layout of the radiotelemetry system. The loop antennae were connected to a CTR-86 receiver located in the stall. The receiver was connected to the VRl data recorder, powered by the BCM-100. From here, data was simultaneously recorded on a VHS videocassette recorder, the physiograph and the computer. The computer was used to view frequencies in real time and selectively analyze segments of data ........ 55 Position of the transmitter and biopotential leads within the mare. The transmitter was placed lateral to the transverse abdominus muscle and medial to the last rib. The lead wires were loosely sutured in the broad ligament and the distal ends embedded into the myometrium at the base of the pregnant uterine horn. The neutral or ground wire was placed between the peritoneum and abdominal musculature ........ 56 Representative EMG recording during parturition with the mare in lateral recumbency before and immediately after delivery. Myometrial EMG activity increased during observed expulsive effort by the mare and decreased when she was observed to relax. After delivery of the fetus EMG activity decreased and settled into a rhythmic pattern. Paper speed was 60 mm/min........................................... 57 vii FIGURES PAGE 5. Effect of prostaglandin *2. on myometrial EMG activity. An increase in activity was apparent within 8 minutes of intramuscular injection of 10 mg PGF2a. Paper speed was 30 mm/min...........................................58 6. An example (10 s) of radiotelemetered myometrial EMG data. The raw data were subjected to full-wave rectification and then processed through a low pass digital linear filtering function to produce an integrated record ........ 76 7. Myometrial EMG activity during one hour periods for the 5 d prior to and following parturition. Hour 0 represents the hour ending with birth of the foal. The percentage of EMG events that were .1 to 1 s in duration were highest at hour 0 whereas the percentage of events of 1 to 10 s duration were lowest at the time of parturition.................................... 77 8. Myometrial EMG activity for one mare during the 24 h prior to and 4 h following parturition. The percentage of EMG events that were .1 to 1 s in duration peaked during the period of -1 to 0 h and the percentage of the longer duration events became minimal.............................