Eva Cepeda
Rabbits are one of the most used animals in biomedical research. Despite being social animals, they are usually kept individually in cages in the research facilities. One limitation to the group-housing is aggression when mixing strange adult animals. Some studies have shown that male urine is effective in decrease the aggressiveness between female animals. We evaluated the behavior of two groups of 4 unfamiliar adult female New Zealand White rabbits for 4 days. One group was sprayed with buck urine prior to the formation of the group, and the other group served as control. The animals were tested in a large pen with an enriched environment to facilitate social housing. The results showed no main effects of treatment on the studied behaviours (aggression, social and agonistic behavior, allogrooming and mounting). In both groups, the frequency of attacks was highest the first day and decreased considerably by day 4. Regarding social and agonistic behaviors, both increased progressively from day 1 to day 3, and decreased from day 3 to day 4. The food intake and body weight of the animals during the study was also similar between the groups. No remarkable lesions were found in any animal. The findings indicate that urine had little or no effect at reducing aggression between the animals. Nevertheless, the adaptation of the animals to the groups was easily achieved within a few days. We propose to provide a large space and an enriched environment to facilitate the socialization of unfamiliar female adult rabbits.