The effect of different degrees of ‘positive’ human–animal interaction during rearing on the welfare and subsequent production of commercial dairy heifers

Abstract A 3-year study tested the hypotheses that brushing each heifer for 5 min per week in the weeks preceding calving (long term positive treatment: PT) while the heifers were unrestrained, is sufficient to improve subsequent parlour behaviour and production, and this could be influenced by the extent of the PT. Four intakes of commercial dairy heifers (total n148) managed under typical UK conditions were divided into treatment (T) and control (C) groups. The PT for the four treatment groups comprised of brushing each heifer for 5 min per week in the weeks preceding calving for either 30 min, 65, 155 or 245 in total for the different groups (equating to 6, 13, 31 and 49 weeks before calving). In the first 4 weeks after calving T heifers had 19% faster milk letdown ( P r 2  = 0.071, P P P  = 0.017) compared to their respective C. The T heifers who had received 155 min of PT during rearing displayed violent kicks 74% less than their C ( P P