The effect of breed, time spent with dam and late pregnancy induction of parturition on behavioural development in dairy calves.

Three experiments examined the impact of breed, time spent with dam (TWD), gender, and late pregnancy induction of parturition and caesarean on the behavioural and heart rate responses of dairy calves at 2 and 6 weeks of age to Open field, Novel object and Startle tests and a Learning task. In Experiment 1 with male Jersey, Friesian and Friesian x Angus calves, there were some significant breed effects on responses to the Open field and the Novel object tests; Jersey calves appeared more curious and less fearful than Friesian x Angus calves. In Experiment 2, in which male and female Friesian calves were removed from their dams either between 0 and 12h or 12 and 24h after birth, there were no significant effects of gender or TWD. In Experiment 3, which studied the effect of induction of parturition using a long-acting glucocorticoid combined with short-acting progesterone 10 days prior to due calving date, there were no significant effects of late pregnancy induction of parturition. Across all three experiments, age at testing was the main factor influencing the responses of the calves. However, a number of interactions suggest that gender, time spent with dam and late pregnancy induction of parturition modified some of the responses to the tests as the calves developed.