Development of an ethogram for hutch-housed dairy calves and determination of factors influencing their behaviour

Abstract

The objectives of this study were to investigate the behaviour of hutch-housed dairy calves, develop an ethogram of general behaviour, and determine whether housing calves in different hutches, day, gender and time of day influenced the behaviour of dairy calves using the developed ethogram. Thirty-one apparently healthy Holstein Friesian calves (6 ± 1 week old) were recruited for this study. The ethogram was developed by directly observing the behaviour of ten female dairy calves housed in two group hutches for five days. Based on these observations, behaviour was then organized into three categories. The first category (I) comprised of postures, attentiveness and social interactive behaviour; the second category (II) comprised of event behaviour which were recorded each time they occurred while the last category (III) comprised of movement and activity behaviour whose duration were recorded. The ethogram was used to record the behaviour of 16 calves (4 males; 12 females) housed in groups of four using direct and video observations for two consecutive days to ascertain if there are behavioural differences between dairy calves housed in different hutches; between days and gender. Additionally, the ethogram was used to record the behaviour of an additional five dairy calves housed in a group hutch to determine the time of day effect. The behaviour of these five dairy calves were recorded hourly between the hours of 10:00 and 17:00 for two days using a combination of direct and video observations. Data were expressed as median frequency, duration or mean rank and significance was accepted at P ≤ 0.05. There were no significant differences in the behaviour of dairy calves housed in different hutches. Significant variations (P < 0.05) were observed in the response to observer, ear and mouth postures and ear flicking behaviour between the two days. Tongue position, ear flicking, tail wagging and walking behaviour were significantly higher (P < 0.05) in females than in males while body shaking and sniffing other calves were found to be significantly higher (P < 0.05) in males than in females. Time of day significantly (P < 0.05) influenced the location in the hutch, head, tail and standing posture; and the duration of standing, walking, and lying behaviour. While confirmation is needed, findings suggest the behaviour of dairy calves may be influenced by day, gender, and time of day and this should be considered when undertaking behavioural studies.