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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, Large Animal Clinical Sciences University of Saskatchewan D.B. Haley and T. Hudye Western College of Veterinary Medicine INTRODUCTION MATERIALS and METHODS (continued) Restriction of an animal’s visual field by means of a blindfold or hood has Exertion Force measurements: Strain gauges were attached to the head been suggested for use during the handling and restraint of many wild and captive gate to measure the animal’s struggle. Signals from strain gauges (Fig. 5) were animals (Fig. 1) (Fowler, 1995). digitized and used to determine the average and maximum exertion forces made by the heifers during restraint. Sample tracing 2 Max. force Stimulus strength 1.5 (volts) 1 0.5 0 -0.5 0 10 20 30 Fig.1 Examples of blindfolds and hoods used during handling and restraint in raptors, Time (seconds) domestic elk and a cat. The practice of using blindfolds on cattle is not uncommon (Ewbanks, 2000) Fig.5 Example of strain gauge signal from heifer (Fig. 2) and the use of a black box has been reported to have a calming effect on showing the maximum exertion force against cattle (Grandin, 2000), but no data has ever been presented to verify that cattle are head gate occurring at roughly 12 sec during the indeed calmer during a procedure if a blindfold is used. restraint. Statistical analysis: The association between treatment, sample time (day 0 to 4), animal weight and the various outcome measures were analyzed using a QUESTION generalized estimating equations (GEE) method to account for the repeated measures design. Variables remaining in the final multivariate model at P<0.05, Does blindfolding cattle during restraint based on the robust empirical standard errors produced by GEE analysis, were have a calming effect? considered statistically significant. Fig. 2 An example of a blindfold being used on a bovine during a RESULTS surgical procedure Mean heartrate after experimental protocol. Average difference between pre and post heart rates. 30 160 Control Control 25 Heart rate (cycles/min) 140 Blindfold (cycles / min) Blindfold Difference 120 20 100 15 80 MATERIALS and METHODS 60 10 40 5 60 beef heifers were randomly assigned to visual restriction (Blindfold) (n=30) 20 0 0 1 2 3 4 or no visual restriction (Control) (n=30) during a 4 day trial to determine the effects 1 2 3 4 Day Days during restraint (Fig. 3a and 3b). Measurements were taken each day during a Fig. 6a. Mean heart rate of blindfolded Fig. 6b. The average decrease in heart baseline period and a 1 minute period of restraint with handling/touching the and control heifers during 1 minute rate for blindfolded and control heifers animal. Touching involved 2 people on opposite sides of the animal, simultaneously approaching the animal at 15 sec into the restraint period and period of restraint (P=.64). during 1 min period of restraint (P = .10). grabbing the ear, poking the neck, side and rump in a mock “ear tagging, vaccinating and prodding” procedure. Mean force values during treatment. Maximum force values during treatment. 0.7 Control 3.5 Stimulus strength 0.6 Stimulus strength 3 Control Blindfold 0.5 Blindfold 2.5 (volts) (volts) 0.4 2 0.3 1.5 0.2 1 0.1 0.5 0 0 1 2 3 4 1 2 3 4 Day Day Fig. 7a. Mean exertion force applied Fig. 7b. Maximum force exerted against against the head gate by blindfolded and the head gate by blindfolded and control control heifers during 1 min period of heifers during 1 minute period of restraint (P<.05). restraint (P<.01). Fig. 3a. Blindfolded heifer Fig. 3b Control heifer CONCLUSIONS during restraint. during restraint. Blindfold or Touching Touching End 1) We have demonstrated that there is a positive behavioural and physiological Control starts ends response to blindfolding beef cattle during restraint. 2) Heart rate tends to decrease during restraint for blindfolded animals. A larger sample size may reveal stronger evidence for this response. 15 sec 15 sec 15 sec 3) Blindfolded animals struggle less against the head gate during restraint compared to controls. Pre-Touch Touch Post-Touch 4) We recommend cattle be blindfolded for invasive procedures that require prolonged restraint. Pre Heart Post Heart Rate Rate ACKNOWLEDGEMENTS Funding for this research was provided by the Interprovincial Summer Student Fig. 4. Heart rate was measured via telemetry system during times indicated above. Research Project Fund and the Saskatchewan Agricultural Development Strategic Fund.
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