The UFAW 3Rs Liaison Group Research Studentship
Shirley Seaman, University of Edinburgh
Development of laboratory rabbit housing: meeting animal and industry needs
The first 3Rs Liaison Group Studentship to be awarded was in 1999 to Ms Shirley Seaman. Ms Seaman was interested in refining the housing of laboratory rabbits and carried out her project at Edinburgh University, under the supervision of Dr Natalie Waran, Dr Mike Appleby and Dr Rick D’Eath.
In the year 2000, approximately 39,700 scientific procedures were carried out on laboratory rabbits, this equates to around 1.5% of the 2.71 million procedures started that year. Where rabbits are used in research, it is important to refine their care where possible to improve welfare and the Home Office recommends that female rabbits should, wherever practicable, be housed in groups to satisfy their need for social contact. However, for experimental reasons, this is not always possible and rabbits may be housed singly. Where rabbits are housed singly, they have been found to perform stereotypic behaviours, such as bar-biting and fur pulling which can either lead to or be a result of poor welfare.
Ms Seaman was interested in assessing whether providing caged rabbits with minimal tactile and visual contact with conspecific rabbits in adjacent cages may be beneficial to welfare, and also the motivation of caged rabbits to gain access to a platform (rabbits housed in cages without a platform/bolt-hole have been found to be more restless and more easily affected by their environment than rabbits housed with a platform).
To investigate social contact and platform use, Shirley carried out a number of short and long-term motivational tests on singly and socially (pair) housed rabbits. In the short-term motivational tests to assess social contact, rabbits were given the opportunity to push through a weighted push-door in a runway (see Figure 1) to gain access to 1 minute of visual and minimal tactile contact through a mesh panel with an unfamiliar rabbit, a familiar rabbit, or nothing (control). The weight on the door was increased in stages to determine the maximum weights the rabbits would push through – it is thought that the greater an animal will ‘work’ to gain access to a resource, the more important that resource is to that animal.
Figure 1: Experimental apparatus (2.75m long, 0.4m wide, 0.6m high)
For the long-term motivational test, rabbits were housed in plus-shaped sets of apparatus for the duration of the experiment (Figure 2). The ‘arms’ of the plus were termed resource cages and the central area was termed the home cage. Four resources were available in the resource cages: food, social contact through a mesh panel, a cage platform and an empty space. Food and an empty space were expected to be of high and low value respectively; the importance of social contact and a platform could therefore be compared to the importance of these resources. Each resource cage could only be entered through a one-way weighted push-door. Weights were increased every two days. The maximum weights pushed through for each resource were recorded, as were the number of times rabbits entered each resource cage at each weight and the total and mean duration of visits to each resource cage.
Figure 2: One of the four plus-shaped sets of apparatus showing the resource available in each resource cage
Additionally, the cage environment of ten socially (pair) caged and eleven singly caged rabbits was manipulated to investigate how platform use was affected by social stimuli from conspecifics. Singly caged rabbits were housed both with and without a platform, and both with and without visual and minimal tactile contact with the rabbit in the adjacent cage (through a mesh panel). Socially caged rabbits were housed in their pairs, next to their cage-mate and next to an unfamiliar rabbit, both with and without visual and minimal tactile contact.
Ms Seaman found that both singly and socially housed rabbits worked to gain visual and minimal tactile contact with both a familiar and unfamiliar conspecific. Singly housed rabbits pushed through heavier weights than the socially housed rabbits, suggesting that singly housed rabbits were more motivated for contact than previously socially housed rabbits.
Olfactory cues were found to be important during the short-term test on singly housed rabbits - several of the rabbits did not push through the push-door in the control when there was no rabbit at the end of the runway. However, when further trials were carried out with an unfamiliar rabbit at the end of the runway, these rabbits pushed through the push-door again. This suggests that if rabbits can smell and hear other rabbits, they are motivated to gain visual and minimal tactile contact with them. Olfactory cues were also found to be important in the experiment with the socially housed rabbits. When the previously pair housed rabbits were housed in olfactory contact with their cage-mate they were less motivated to gain visual and minimal tactile contact than they were when they were housed out of olfactory contact. This suggests that olfactory contact with a familiar rabbit is important, and it may at least partly compensate for the lack of visual and minimal tactile contact.
During the long-term motivational test, food and social contact were found to be of equal importance. Rabbits were highly motivated to gain limited social contact with a conspecific. The rabbits made frequent short visits to the food and social contact cages and continued to make frequent visits as the weight on the doors increased. The rabbits did not alter their visits to make fewer longer visits to the social contact cage as the work effort to gain contact increased indicating that it was the frequency of visits to the social contact cage that was important, rather than the total duration of time spent in close proximity to another rabbit.
In the social contact cage, rabbits spent over a third of their time out of direct visual contact with the other rabbit suggesting that whilst rabbits are motivated to be in close proximity to another rabbit, they do not necessarily want to be in direct visual contact all the time. In the platform cage the rabbits spent almost all of their time in front of the platform, rather than on or under it, showing that rabbits were motivated to be in close proximity to the platform.
Shirley concluded that laboratory rabbits are motivated to gain visual and minimal tactile contact with conspecifics and that social contact was found to be of equal importance to food. Therefore, where it is not possible to house female rabbits in groups, providing limited social contact is likely to be beneficial. Rabbits were also found to be motivated for a cage platform, although it appeared to be proximity to a bolt-hole that was most important.
Dr Seaman gained her PhD in 2002.
Published papers arising from Shirley’s work supported by UFAW:
Seaman SC, Waran NK, Mason G & D'Eath RB. 2008. Animal economics: assessing the motivation of female laboratory rabbits to reach a platform, social contact and food. Animal Behaviour. 75(1): 31-42. http://dx.doi.org/10.1016/j.anbehav.2006.09.031.
