The development of behaviour patterns and temperament in dairy heifers.

Observations were carried out on a group of twenty autumn born Friesian heifer calves from birth until calving at about 25 months of age. During rearing they experienced several rearing conditions; (I) Calf house, where from 48 hrs of age they were individually penned. (II) Group housed Indoors. At weaning they were housed in pens in groups of 10-20 animals and fed hay or silage ad libitum plus some concentrate food. (III) Grazing out doors (HGI) from spring to autumn in groups of 15-30 animals and moved to fresh pastures at about 2 week intervals. (IV) Housed indoors in large groups of 70-80 animals in a yard with access to covered or indoor cubicles, and fed silage ad lib. During this period they were artificially inseminated. (V) Second grazing period. In the following spring they were kept in large groups for grazing. Focal animal sampling to allow sequence analysis of behaviour was performed and a time base was used to estimate time budgets. In addition the temperament of each animal was assessed by recording its reaction to being touched. The development of behaviour was strongly influenced by changes between rearing conditions but generally stabilized rapidly within a particular husbandry condition. The time spent resting was greater when the animals were in the fields than indoors. Ruminating increased over the first 20 weeks and then stabilized. In the calf house the time spent in investigation increased up to 4-5 weeks and then decreased while the frequency of investigation increased. Grooming generally decreased over the study period. In the calf house calf licking increased but after grouping this decreased and rubbing of the body increased. Social encounters tended to decrease with age. The development of temperament as defined later in the text here appears to be determined at an early age and to be stable thereafter. Sequence analysis showed that behavioural sequences became shorter and less variable in content and that as the animal matured fewer behavioural activities were associated in any sequence and that these showed an increase in their degree of association.