Behavioural responses of dairy cows toward novel stimuli presented in the home environment

Abstract

Several tests of behavioural and physiological responses toward novel stimuli are used in the study of stress and adaptability in cattle. The majority of them, however, are characterised by a relatively high degree of situational novelty and stimulus complexity. In the present experiment we examined behavioural responses of dairy cows toward novel stimuli presented in the home environment with minimal situational novelty, and investigated whether any consistency could be found across responses toward different novel stimuli. Four different stimuli were presented: usual food (30 min provision of 8 kg total mixed ration); novel food (30 min provision of 5 kg of carrots); novel object (30 min exposure to a white plastic container) and an unfamiliar person (5 min exposure to person dressed in hooded white overall). Sixteen Danish Friesian cows kept in tie-stalls were used, and one stimulus presented each day in a balanced order according to a Latin Square design. The presentations of novel food or a novel object resulted in several comparable variables, and a comparison of the responses showed that the novel food induced increased duration and frequency of sniffing ( P < 0.05 for both), increased self-grooming ( P < 0.01) as well as a longer duration of standing ( P < 0.05) compared with the novel object. Responses toward the unfamiliar person could only be compared with responses toward the other novel stimuli for three variables. Here, the unfamiliar person induced a higher frequency of sniffing than the novel object ( P < 0.01). These results suggest that dairy cows show increased behavioural responses characterised by increased exploration, arousal as well as behavioural conflict when exposed to novel food or an unfamiliar person compared with a novel object. Correlations between responses toward the different novel stimuli were low and non-significant. Thus, no evidence for consistent inter-test responses across the novel stimuli presented in the home environment were found.