Movement and heart rate
response of beef heifers to the loudness and intent of human voice
J.L. Clavelle, J.M. Stookey,
J.M. Watts, L. Fritz and C.S. Waltz
University of Saskatchewan,
Saskatoon, Canada
The response of 58 yearling crossbred beef heifers (392+5.5 kg) to human vocal stimuli was studied. In Trial 1, 29 heifers were allocated to either prerecorded voices of humans intending to move cattle (Harsh; n=15), or voices intending to be neutral (Neutral; n=15). Harsh and Neutral treatments were played at the same decibel. In Trial 2, the remaining heifers were assigned to either prerecorded voices played at high decibel (Loud; dB=78; n=14) or the same recording played back at low decibel (Quiet; dB=55; n=14). Within each treatment group animals were randomly assigned to 1 of 5 voice recordings made of 5 individuals (3 women and 2 men) to avoid pseudo replication. Heifers were exposed to their designated treatments for 1 min each day for 5 consecutive days. During the treatment period, a heifer was confined in a single-animal electronic scale, directly behind and in visual contact with another heifer, not included in this experiment, to prevent a response associated with social isolation. Remote telemetry was used to record heart rate in beats per minute (HR). The behavioural response (the amount of movement) was quantified by an electronic movement measurement device (MMD). The MMD monitors changes in voltage from the load cells of the electronic scale and records a peak when a trend in voltage is reversed. The greater the number of peaks the more the animal moved during exposures. Heifers on the Harsh treatment were no different in HR and movement compared to heifers exposed to Neutral voices. In Trial 2 the Loud treatment caused a higher peak movement than the Quiet treatment (P<0.05) on day-1. No other treatment effects were observed. Heart rate and movement decreased in all treatment groups over the 5-day trial. Voice alone does not appear to be a significant cue for cattle to gauge human intent. While people may have specific intent and use voice to convey that intent it does not appear that inexperienced cattle respond differently during handling to neutral voices or harsh voices intending to move them.