Fig 1.
Overview of experimental design.
(A) Each day of the test and contrast phases consisted of 3 periods during which behaviours of the calves were observed: before (3 min), anticipatory (1 min) and access (30 min) periods. (B) Description of days within each phase (conditioning, test and contrast phases) and each stage of change (before change and after change).
Fig 2.
The barn contained home pens (basic or enriched) and reward pens (basic or enriched). Basic pens (2 m2 per calf) were bedded with river stones. Enriched pens (5 m2 per calf) were bedded with wood shavings and contained 3 ‘enrichment’ items: automated grooming brush, hanging manila rope, and pile of straw. All home pens contained meal, hay and water feeders. Home pens were linked with an alleyway to the reward pen during conditioning, testing and contrast phases for 30 min per day.
Table 1.
Ethogram of anticipatory behaviours of dairy calves.
Fig 3.
Behaviours expressed before and during the anticipatory periods.
Behaviours expressed before (3 min before presentation of the conditioned stimulus, light turned on) and during the anticipatory periods (1 min interval between presentation of the conditioned stimulus, and the unconditioned stimulus, access to the reward pen) for each treatment (2 x 2 factorial: basic or enriched home pen, with access to basic or enriched reward pen). Least squares means ± SE for (A) frequency of behavioural transitions (no./min), (B) duration of light and door behaviours (% of period) and (C) duration of other behaviours (% of period).
Table 2.
Behaviours expressed during the anticipatory period for each treatment.
Fig 4.
Anticipatory behaviour before and after an unexpected change in reward pen quality.
Before the change (day 13 to 15 of test phase), calves entered the reward pen expecting the original reward pen. After the change (on day 17, the first day after the change, and on subsequent days 18 to 20), calves entered the reward pen expecting the new reward pen. Calves that changed from an enriched to basic reward pen were expected to experience a reward loss, while calves that changed from a basic to enriched reward pen were expected to experience a reward gain. Least squares means ± SE of (A) frequency of behavioural transitions (no./min), (B) duration of light and door behaviours (% of period), and (C) duration of other behaviours (% of period).
Fig 5.
Latency to access the reward pen before and after an unexpected change in reward pen quality.
Before the change (day 13 to 15 of test phase), calves entered the reward pen expecting the original reward pen. After the change (on day 17, the first day after the change, and on subsequent days 18 to 20), calves entered the reward pen expecting the new reward pen. Calves that changed from an enriched to basic reward pen were expected to experience a reward loss, while calves that changed from a basic to enriched reward pen were expected to experience a reward gain. Results shown as least squares means ± SE.