Discrimination of people by dairy cows based on handling

This study examined whether dairy cows could distinguish among people based on the treatment received, whether cows used color as a cue to make this discrimination, and whether cows generalized their discrimination to other locations. Twelve cows were each repeatedly treated in a special treatment stall by two people wearing red or yellow overalls. One person always treated the cows aversively, and the other always treated them gently. The distance between each person and each cow in the home stall and in the treatment stall was scored during tests. Before treatment, the distances that cows maintained from the two people were uncorrelated, and the distances that they maintained in the treatment stall were uncorrelated with those in the home stall. Before and after treatments, the cows stood further from the handlers in the treatment stall than in the home stall, regardless of color of the overalls. Defecation and urination were more frequent during aversive treatments. After treatment, the cows stood further from the aversive handler than from the gentle handler in both stalls, and distance from the aversive handler was positively correlated with distance from the gentle handler. The cows did not discriminate when the aversive and gentle handlers wore blue overalls (as worn by the usual barn handlers), when two unfamiliar people wore the same color overalls as the handlers, or when the cows were shown photographic slides of the two handlers. In conclusion, the cows learned to discriminate among the handlers, partially based on the color of the clothes worn. This discrimination was generalized to another location.