Abstract. Two-step weaning with nose flaps is used to minimise the stress of weaning in beef calves. Farmers leave the nose flaps for 7–30 days, basing the period on practical considerations. Thus, the objective of this study was to compare the behavioural response of 6-month-old beef calves fitted with nose flaps during 7 or 21 days before permanent separation from the dam, or abruptly weaned. Angus · Hereford cow-calf pairs were assigned to: (1) calves fitted with nose flaps on Day –7 and permanently separated from their mothers on Day 0 (NF7), (2) calves fitted with nose flaps on Day –21 and permanently separated from their mothers on Day 0 (NF21), and (3) calves abruptly weaned on Day 0 (CON). Behaviours (standing, lying, walking pacing, grazing, ruminating and vocalisations) were recorded during 3 days before and 5 days after permanent separation from the dam. On Days 1–3, standing and grazing behaviours decreased, whereas walking, pacing and vocalising increased in CON calves but not in NF7 or NF21 calves. Control calves differed from NF7 and NF21 calves for all these behaviours. The two nose flap treatments differed only on Day 1, when the changes in the frequency of walking, lying and standing were smaller in NF7 than NF21 calves. In conclusion, nose flaps can be used for periods from 7 to 21 days before permanent separation from the dam, diminishing the behavioural indicators of distress provoked by weaning.
Instituto Nacional de Investigación Agropecuaria