To go or not to go? Assessing anticipation for outdoor access in dairy cows.
Résumé
Regular outdoor access may enrich movement-restricted cows’ lives, but how they perceive it is unclear. Measures of cognitive processes, such as anticipation, can provide information on animal emotions. Our study aimed to characterize the anticipatory behaviors of cows living in restricted movement environments when an outing experience is provided as enrichment. In 2 independently analyzed trials, 32 tie-stall-housed lactating cows were blocked by parity and DIM and divided into 2 groups. Control cows (C; n = 8 in winter (W) and summer (S)) remained inside for the duration of the experiment, and outdoor cows (O; n = 8 in W and S) were provided with 5 d/week of outdoor access for 8 weeks. The outdoor areas combined different durations of outing (1 vs 2 h) and area sizes (20, 40, 60 and 80 m2). Exit cues, such as route
preparation and halter placement in front of the outdoor cows, were set 20 min before the cows had outdoor access, and video recordings were taken during this period. The number of behavioral and ear position transitions were recorded and analyzed with 2 mixed models:1) to compare C vs. O cows with treatment, day, and their interaction as fixed effects, and cow nested within block as random effect; and 2) to test the influence of duration, area size, their interaction, and day as fixed effects, and cow nested within block as random effect. For W and S, no significant differences were found for anticipatory behaviors between C and O cows, nor for different durations and area sizes (overall mean ± SD: behavioral transitions: C: 23.9 ± 22.5, O: 20.9 ± 20.4; ear position transitions: C: 71.3 ± 22.5, O: 79.6 ± 20.4). Investigation of other behaviors before the exit (e.g., exploration, trampling, or lying) and having targeted observation periods (e.g., the first 5 min after setting exit cues) could allow for a more detailed study of the animal’s behavioral expression during anticipation. Combined with other indicators such as motivation, it would provide a basis for assessing emotional states in animals.