Submitted to: International Society of Applied Ethology
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2009
Publication Date: 7/6/2009
Citation: Lay Jr, D.C., Marchant-Forde, R.M., Janczak, A.M., Marchant Forde, J.N., Hogan, D.F. 2009. The Use of Heart Rate Variability as a Novel Method to Differentiate between Affective States. International Society of Applied Ethology. Proceedings 43rd Cong. of ISAE. Interpretive Summary:
Technical Abstract: The major goal of animal welfare scientists is to determine when animals are experiencing a state of good welfare or poor welfare. The goal of this research was to determine if measures of heart rate variability can be used to differentiate whether animals are experiencing ‘unpleasant’ versus ‘pleasant’ conditions. Nine, 4-month-old pigs were implanted with telemetric devices to collect electrocardiogram data. Data were collected while pigs were: 1) isolated for 1 hour, or 2) ‘playing’ under a water hose. Series of 512 successive inter-beat intervals (IBI) were subjected to time and frequency domain analysis. Data were analyzed using the Kruskal-Wallis test to compare data for active pigs during isolation (Active), inactive pigs during isolation (Inactive) and pigs during play (Play). Pigs were Active when they were walking, rooting, and jumping. Pigs were inactive when they remained motionless. Data for Active pigs were collected during the first 15 minutes of isolation while data for Inactive pigs were collected during the last 15 minutes of isolation. Pigs were playing when a water hose was sprayed into their pen and they exhibited animated movements and actively sought to be under the water spray. There was no difference in the ratio of low to high frequency power (P = 0.46) when comparing Active, Inactive and Play (0.18, 0.11, 0.16 ± 0.04 respectively). However, the mean IBI was less (P < 0.001) for Active pigs compared to Inactive; but not Play pigs (366.4, 499.1, 429.8 ± 11.4 ms respectively). However, the standard deviation of the IBI interval showed a different pattern with Active and Inactive pigs having a greater deviation than Play pigs (23.7, 28.4, 14.1 ± 4.1 ms respectively). These data indicate that measures of heart rate variability may prove useful to differentiate between affective states.