Ellen C. Jongman

Individual behavioural testing in sheep is common; however, outcomes may be misleading as they are a highly gregarious species that is usually managed in groups. We investigated whether behaviour expressed by 3–4-month-old Merino lambs (n = 220) in social isolation was related to their behaviour towards the same stimuli when three other conspecifics were present, and if measures of temperament (vocalisations and locomotory behaviours) were repeatable across both social situations. Expression of all behaviours were reduced when conspecifics were present, and vocalisations were rarely performed in social groups, suggesting that this behaviour is a response to social isolation. Similarities across the two social situations, in ranked order of how individual lambs expressed each behaviour, indicate that vigilance and attentional orienting towards a human were repeatable (p < 0.001), as was vigilance in a startle test (p < 0.05). However, no clear relationship between behaviours expressed across the two social situations was found. The results of this study suggest that testing sheep individually should be conducted with caution where the outcome is applied to animals managed in groups. Vigilance shows promise as a measure of an underlying trait that is stable across social contexts.

This study aimed to determine the effects of early-life physical and social enrichment on the ability of dairy heifers to integrate into a herd of mature cows. Fifty heifer calves were reared from the ages of 2–13 weeks in one of three treatments: (1) Hand-reared and group-housed in sheds (CC); (2) Hand-reared and group-housed at pasture (−S); or (3) Hand-reared and group-housed at pasture, with 3 non-familial dry cows per group (+S). At 23 months of age, these heifers were introduced in groups to small herds of cows (Cows) at pasture. Social interactions were recorded continuously for two 1-h periods. Feeding, ruminating and resting behaviours of all animals and walking, standing and lying behaviours of 36 heifers only (+S = 14, −S = 13, CC = 9) were recorded for 48 h after mixing. Heifers that were managed as calves according to the CC treatment delivered less agonistic behaviour to other heifers after mixing than those reared in the +S or −S treatments (p = 0.002 and p = 0.041, respectively). On Day 2, +S heifers and cows spent the lowest proportion of time feeding (p = 0.961), with −S heifers spending significantly more time feeding than cows (p = 0.046), while CC heifers spent more time feeding than both +S heifers and cows (p = 0.027 and p < 0.002, respectively). Increasing the complexity of the early-life environment, particularly socially, may aid heifers in integrating into groups of multiparous cows later in life and shape their lifelong social experiences with same-age conspecifics.