The response of beef cattle to noise during handling

Noise is often overlooked as a potential source of fear for cattle during h andling. Fifty-nine yearling beef heifers (362 +/- 26 kg) were used in a st udy to evaluate their behavioural and physiological response to noises duri ng a 1-min exposure. In Trial 1, 29 heifers that were naive to the treatmen ts were assigned to either prerecorded handling noise (Noise, n = 14) compo sed 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 t reatment, either the prerecorded voices of people shouting (Voice, n = 15) or recorded noise of metal-on-metal clanging (Clanging, n = 15) and again t ested for 5 consecutive days. Heifers were tested individually while they w ere constrained on an electronic scale within a chute complex. Remote telem etry was used to record heart rate (HR). The behavioural response was quant ified by an electronic movement-measuring device (MMD). The MMD monitors ch anges 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 high er HR (P < 0.01) and recorded more movement peaks (P < 0.05) during the tes ting period than heifers exposed to Silence. When the Noise treatment was s eparated into the two components and played hack in Trial 2, the sounds of humans shouting (Voice) appeared to be more alarming, based on HR and movem ent, than the sounds of metal striking metal (Clanging). Both the HR and th e number of MIMD peaks were greater for the Voice heifers (P < 0.05 and P < 0.01). Sounds were played back at equal volumes, therefore some intrinsic differences in the origin or significance of the sounds to the heifers must account for the differences in response. Heifers did show signs of habitua tion to the noises over the 5-day trials, but it is unknown if cattle would habituate to similar noises encountered during infrequent handling, as is typical with normal management procedures. By eliminating or reducing the s ounds of metal clanging and particularly the sounds of humans shouting shou ld help reduce the level of fear cattle experience during handling. (C) 199 9 Elsevier Science B.V. All rights reserved.