BACK TO QUEBEC CITY 2002 TITLES
Effects of blindfolding
on behaviour and heart rate in beef cattle during restraint
K.D. Mitchell, J.M. Stookey,
D.K. Laturnas, J.M. Watts, D.B. Haley and T. Huyde
University of Saskatchewan,
Saskatoon, Canada
Restriction of an animal's visual field by means of a blindfold or hood has been suggested for use during the handling and restraint of many wild and captive animals. However, no data has ever been presented to verify if cattle are indeed calmer during a procedure if a blindfold is used. Sixty beef heifers were randomly assigned to either visual restriction (Blindfold) or no visual restriction (Control) and tested daily during a 4 day trial to determine the effects during restraint. Heart rate (HR), measured via a telemetry system, was taken during a baseline period prior to treatment and continuously recorded during a 1 minute period of restraint, that included handling and touching the animal. Touching involved 2 people on opposite sides of the animal, simultaneously approaching the animal at 15 sec into the restraint period and grabbing the ears, poking the neck, sides and rump in a mock "ear tagging, vaccinating and prodding" procedure. Strain gauges were attached to the head gate to measure the animal's struggle during the procedure. Signals were digitized and used to determine the average and maximum exertion forces made by the heifers against the headgate during restraint. The association between treatment, sample time (day 0 - 4), animal weight and the various outcome measures were analyzed using a generalized estimating equation (GEE) method to account for the repeated measures design. Mean HR of heifers did not differ at the end of the treatment (95.04 ± 4.66 bpm ) (P=.64), but the HR tended to decrease more for blindfolded heifers compared to controls during restraint (average decrease 16.3 ± 3.2 bpm and 14 ± 2.9 bpm, respectively) (P=.10). The exertion force applied by the heifers against the headgate was lower on average (P < .05) and a lower maximum force (P < .01) for the blindfolded heifers. Heart rate and exertion forces declined over the 4 days of the trial for both treatment groups. Blindfolding cattle reduced the amount of struggle and tended to lower heart rate, a positive behavioural and physiological response. Therefore, blindfolding is recommended for use during invasive procedures that require prolonged restraint.