Abstract
Noise is often overlooked as a potential source of fear for cattle during handling. Fifty-nine yearling beef heifers (362±26 kg) were used in a study to evaluate their behavioural and physiological response to noises during a 1-min exposure. In Trial 1, 29 heifers that were naive to the treatments were assigned to either prerecorded handling noise (Noise, n=14) composed of humans shouting and metal clanging or no prerecorded noise (Silence, n=15) and tested daily for 5 consecutive days. In Trial 2, the remaining 30 naive heifers were assigned to one of the two components of the Noise treatment, either the prerecorded voices of people shouting (Voice, n=15) or recorded noise of metal-on-metal clanging (Clanging, n=15) and again tested for 5 consecutive days. Heifers were tested individually while they were constrained on an electronic scale within a chute complex. Remote telemetry was used to record heart rate (HR). The behavioural response was quantified by an electronic movement-measuring 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. Heifers exposed to Noise had higher HR (P