An enriched arena for lamb - anticipation behaviour before entering the arena, effects of skipping the anticipation phase and effects of being denied access to the arena

Abstract: This study aimed to investigate whether lambs show anticipatory behaviours in a holding pen prior to entering a known arena, whether the holding pen experience prior to the arena exposure affects their play expression in the arena and whether their behaviour (in home pen) is affected if arena access is denied. Twenty pair-housed male lambs (average 14 weeks old), were exposed, in chronological order, to five treatments. Holding pen treat-ment (HP-control): Each pair was led into a holding pen (2.7 m2) and remained there for 5 minutes before returning to their home pen (6 m2). Holding pen – arena treatment (HP-A): Each pair was led into a holding pen for 5 min and then was allowed access into the arena (22 m2, containing two hanging chains, one ball and one platform) for 15 min before re-turning to their home pen. Arena treatment (A): Each pair was led into the arena for 15 min before returning to their home pen (without spending time in the holding pen). HP-A(2) treatment: Same as HP-A. Home pen treatment (H): Same as HP-control but under the as-sumption that lambs anticipated arena access. Prior to HP-control, lambs were habituated to enter the holding pen. Prior to HP-A, A, HP-A(2) and H, lambs were habituated to antic-ipate entering the arena. Observations were conducted over three days for HP-control, HP-A, HP-A(2) and A treatments and one day for H treatment. Behaviours were video record-ed and analysed (Observer XT 11.5, Noldus Technology) for percentage of duration. Ex-tracted behaviour data were analysed using Wilcoxon Signed ranks test. In the holding pen, no differences were found between HP-control and HP-A for total play, exploring, walking and number of behavioural transitions. In the enriched arena, significantly higher total play was expressed in treatment A compared to treatment HP-A (P<0.05). Similarly in treatment HP-A(2) higher total play was expressed compared to treatment HP-A (P<0.05). Comparing the first with the second half of the enriched arena sessions, a higher percentage of duration for total play was found in the first part for treatment HP-A(P<0.05). No significant difference was found comparing duration of total play for the first and second half of treatment A and HP-A(2). In the home pen, lambs in H spent more time eating (P<0.01) and less time ruminating (P<0.05) and tended to lie less (P<0.1) compared to HP-control. Nevertheless holding pen exposure seems to affect when play is expressed as in treatment HP-A play was expessed more during the first part of the arena session compared to the second. No difference was found comparing the two parts for treatments A and HP-A(2). In the home pen, lambs in H were eating longer duration,ruminating shorter duration, and tended to lie and stand shorter duration (p<0.1) compared to HP-control. In conclusion, male lambs did not appear to express anticipatory behaviour before entering the play arena. Nevertheless holding pen exposure seemed to have an effect on when play was perfomed in the play arena (HP-A), and also had an effect on its total duration (A). There seemed to be no effect of holding pen exposure on when play was expressed in HP-A(2). Finally the denied access to the arena affected several behaviours as eating and ruminating that might have a connection with loss of arena access.