Abstract:
Proc. Aust. Soc. Anim. Prod. I996 Vol. 21 THE USE OF PULSE RATE MEASURED BY TELEMETRY AS AN INDICATOR OF OXYGEN CONSUMPTION IN CATTLE J.B. GAUGHANA, I.J. BRUCEB, D.M. KEENANA, B.A. YOUNGA, T.L. MADERC and W. JABBOORI * Dept of Animal Production, The University of Queensland, Gatton, Qld 4343 * Faculty of Business, The University of Queensland, Gatton, Qld 4343 'Dept of Animal Science, University of Nebraska, Lincoln, Nebraska, U.S.A. A Much of the research on energy metabolism and metabolic rate in cattle has been conducted with animals restrained in metabolism cages or respiration chambers because measurement under field conditions is difficult. Furthermore, the act of collecting data from restrained cattle may alter their physiological state (Hahn et al. 1990). This study was undertaken to explore the relationship in cattle between pulse rate (measured by telemetry) and oxygen consumption when pulse rate was increased by exogenous adrenalin to simulate different levels of sympathetic stimulation. Six 18 month old Hereford heifers were used. All heifers had been implanted with a pulse rate telemetry probe (Model HR 400 Telonics, Mesa, Arizona) 8 months prior to the study. A low quality roughage diet was available ad libitum except during the 12 hours prior to adrenalin treatment when all feed was removed. Water was available continuously. The adrenalin treatments were an intra muscular injection of sterile water (0), 2 mg adrenalin (2) or 4 mg adrenalin (4). All 6 heifers were subjected to all treatments. A randomised complete block design was used where the animals were blocks and 48 hours elapsed between treatment applications for each animal. Pulse rate was measured and recorded on a data logger every 2 seconds for 15 minutes following the injections. Rate of oxygen consumption was measured concurrently (15 minute periods) using a face mask and an open circuit respiratory analyser (Brosh et al. 1994). The results for pulse rate and oxygen consumption are shown in Table 1. Table 1. Means (k SEM) for pulse rate (PR) and rate of following exogenous adrenalin treatment owwn consumption W) over a 15 BROSH, A., BENEKE, G., FENNELL, S., WRIGHT, D., AHARONI, Y. and YOUNG, B.A. (1994). Proc. Sot. Nut. Physiol. 3: 3 12. HAHN, G.L., EIGENBERG, R.A., NIENABER, J.A. and LITTLEDIKE, E.T. (1990). J. Anim. Sci. 68: 2658-65. RICHARDS, J.I. and LAWRENCE, P.R. (1984). J. Anim. Sci., Camb. 102: 71 l-7. WEBSTER, A.J.F. (1967). Br. J. Nutr. 21: 769-85. 387
