Preliminary results: effectiveness of cage enrichment for reducing aggressive behavior in group-housed unfamiliar breeding does

Society increasingly expects social farm animals, including rabbits, to be housed in group. Maternal protective behavior, however, induces aggressive behavior and skin lesions when breeding does are grouped. This study aimed to evaluate the effectiveness of cage elements for reducing the frequency and intensity of aggressive behavior in group-housed does. Eighty does with their 22 days old kits were allocated to 20 group-pens (1x2 m with a 0.30x2 m raised platform) so that each pen housed four unacquainted does and their litters for a period of 10 days (until weaning). Pens were subjected to one of the following treatments: small pressed alfalfa blocks as distraction material (A), three wooden panels attached underneath the platforms, visually separating the pen into four areas (P), both alfalfa and wooden panels (AP), or no extra elements (controls, C). This experiment was replicated for three reproduction cycles ensuring that each doe and pen never received the same treatment. Skin lesions were scored one, three, six, eight and ten days after grouping with a tagged visual analogue scale. For ethical reasons, sick, severely injured or overly aggressive animals were removed from the experiment. Activity detectors were implemented using computer vision techniques and calibrated to rate rabbit activity continuously throughout the entire experiment. Detectors were set to specifi cally detect agonistic behavior on a subset of three pens per treatment and cycle. One day after grouping, 67% of the does and 13% of the kits acquired new injuries. This prevalence increased to respectively 82% and 33% after ten days in group. Neither the severity nor the number of injuries were affected by treatment but both were highest on the sixth day for the does (P<0.001) and on the tenth day for the kits (P<0.001). Activity showed an interaction effect between treatment and day in group (P<0.001). During the fi rst three days, activity was highest in C and lowest in AP (P<0.01). Compared with C, activity was lowest in AP on the sixth day (P=0.03). Between the fi rst and second day, activity decreased signifi cantly in all treatments (P<0.001) further decreasing on the third day except in AP. Although treatment did not signifi cantly affect the number or severity of skin lesions, providing cage elements reduced activity during the fi rst days after grouping. Ongoing imaging analysis will document activity levels for the remaining pens, and the full dataset will be used for elucidating links between activity, agonistic behavior and skin lesions.