Behavioural and Physiological Characteristics of Calves Mock Fighting with a Mannequin

Abstract

The aim of this study was to clarify the behavioural and physiological characteristics of calves age 150 days, which performed mock-fighting (MF) with a mannequin. The behaviour and physiology of 6 crossbred (Japanese Black×Holstein) bull calves performing MF with a mannequin set as a substitute for human (MF group) and 4 non-performing calves (nonMF group) were compared under an ordinary rearing situation, novel situation, and stressful situation. Under the ordinary situation, there were no difference in maintenance behaviour and abnormal behaviour between groups, while the MF group performed more social behaviour than the nonMF group, especially fighting and mock-fighting behaviours with penmates (P<0.05). Under the novel environment, open-field with a mannequin (OF), the MF group walked around all over the OF, while the nonMF group avoided staying near the mannequin (P<0.001). In addition, the MF group curiously studied the mannequin more than the nonMF group, while the nonMF group investigated the wall of OF more than the MF group (P<0.05). The MF group tended to higher cardiac response (P=0.10) and lower plasma cortisol response than the nonMF group (P<0.05) in the stressful situation. The MF group had higher plasma testosterone level (P<0.05). These results suggest that the MF group and the nonMF group corresponded to the active and passive coper in the stress study, respectively.