Effects of human handling during early rearing on the behaviour of dairy calves
We examined the effects of daily positive or negative human handling on the behaviour of Holstein-Friesian dairy calves (n = 20 calves per treatment, five calves per group). The response to humans and indicators of positive emotions were examined at four weeks of age. Calves that received
positive handling approached a familiar handler within 1 min in 50% of the handling sessions compared to 17% of the sessions for negatively handled calves but showed no difference when approaching an unfamiliar person. Calves that received positive handling showed less avoidance behaviour
in their home pen to an approaching unfamiliar person (score, positive: 3.7, negative: 2.8) but there was no treatment effect on flight distance when tested outside the home pen. Both treatment groups responded similarly to a novel object and performed the same amount of play behaviour. Calves
that received positive handling interacted more with cow brushes than calves that received negative handling (positive: 9.9%, negative: 7.9% of the total time). At three months of age, avoidance behaviour was re-tested, this time including 20 control animals of the same breed and age, reared
routinely on-farm. Controls showed more avoidance behaviour (positive: 1.5, negative: 1.0, control: 0.3) and had a greater flight distance (positive: 3.3 m, negative: 3.7 m, control: 4.9 m). The results confirm existing literature demonstrating that the quantity and quality of handling influence
the response towards humans. Little evidence was found that the type of early handling influences behaviours indicative of positive emotions.