The horses in the treatment group spent more time engaging in physical contact with the experimenter during the motionless human test after the treatment period compared to before (p=0.05, Z=-1.96) [Figure 1]. There was no significant change in level of physical contact for the control group (p=0.11, Z=-1.58).

There was no significant difference in time spent in proximity to the unfamiliar person before and after the treatment period for either the treatment group (p=0.88, Z=-0.16) or control group (p=0.53, Z=-0.63).

Furthermore, there was no significant difference between the groups for proximity before (p=1.00, U=153) or after (p=0.50, U=132) the treatment period, or for physical contact before (p=0.27, U=186.5) or after (p=0.88, U=148) the treatment period.

Treatment horses displayed significantly fewer total stress-related behaviours after the treatment period compared to before (p=0.01, Z=-2.81) [Figure 2]. The difference was not significant for the control group (p=0.13, Z=-1.51).

There was a significant difference in the frequency of headshaking before and after the treatment period for the treatment group (p=0.03, Z=-2.20) but not for the control group (p=0.10, Z=-1.67).

There were no significant differences for the other stress-related behaviours before and after the treatment period for either group: self-grooming (treatment: p=0.18, Z=-1.34; control: p=0.32, Z=-1.00), head scratching (treatment: p=0.10; Z=-1.63; control: p=0.32; Z=-1.00), neighing (treatment: p=0.18, Z=-1.34; control: p=0.32, Z=-1.00) and pawing (treatment: p=0.32, Z=-1.00; control: p=0.66, Z=-0.45).

Furthermore, there were no significant differences in frequency of stress-related behaviours between the groups, either before or after the treatment period: self-grooming (before: p=0.73, U=142; after: p=0.99, U=152.5), head scratching (before: p=0.55, U=134; after: p=1.00, U=153), neighing (before: p=0.73, U=142.5; after: p=0.78, U=144), pawing (before: p=0.99, U=152.5; after: p=0.78, U=144.5) and headshaking (before: p=0.53, U=133.5; after: p=0.99, U=152.5). There was no significant difference between groups in the total number of stress behaviours before or after the treatment period (before: p=0.10, U=103; after: p=0.94, U=150).