The effect of access to a well-resourced environment on dairy calves' cognition and affective states

Calves were housed either in 1) pair housing for 22.5 h/d with 1.5 h of daily access to a well-resourced pen which included 3 other calves and physical devices (enriched calves, n=6 pairs) or 2) pair housing for 24 h/d (control calves, n=6 pairs). After 10 d of housing treatment, calves were trained to discriminate between 2 calves in a Y-maze over 20 d.

Twelve of the 24 calves tested met the learning criterion and treatment did not affect the number of sessions needed to reach the learning criterion. Calves were then subjected to a Successive Negative Contrast test during which they were trained to approach a milk reward over 3 trials/day for 3 days. On the last training day, latencies of enriched calves increased over daily trials while control calves were faster and remained relatively consistent, suggesting a greater sensitivity to reward.