Dairy cows' use of colour cues to discriminate between people

The role of the colour of overalls as a cue used by cows to discriminate be tween people was studied in four experiments using a total of 66 Danish Fri esian cows kept in tie-stalls. In all experiments, the average distance cow s kept from the person was calculated from 12 scores during 1 min with the person standing in front of the cow. Experiment A. The distance cows (n = 2 4) kept, from two unfamiliar people wearing red or yellow overalls, was tes ted. There was no difference in the distance the cows kept from the two peo ple and the two colours (P > 0.10). Experiment B, The distance cows (n = 18 ) kept from an unfamiliar person wearing familiar coloured overalls (blue) was compared to when the same unfamiliar person was wearing red or yellow o veralls. There was no effect due to the colour of the overalls (P > 0.10), Experiment C. Cows (n = 12) were handled repeatedly, by two handlers wearin g overalls of the same colour. Each person handled six cows gently and six cows aversively. There was no significant difference in distance kept from the gentle and the aversive handler, after 11 treatments (P > 0.10). Experi ment D. Cows (n = 12) were handled repeatedly by one person wearing either red or yellow overalls. The person wore one colour when handling the cows g ently and the other colour when the cows were handled aversively. The cows kept a longer distance when the handler wore the colour worn during the ave rsive treatment than when the handler wore the colour worn during the gentl e treatment(P < 0.01). The cows also responded according to the colour of t he clothes when worn by an unfamiliar person, although they kept a shorter distance from the unfamiliar person than to the handler. (C) 1999 Elsevier Science B.V. All rights reserved.