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Conference abstract - Peer-reviewed, 2004

Evaluation of the Play-Tray – an enrichment object for mice

Spangenberg Elin, Augustsson Hanna, Dahlborn Kristina


The use of environmental enrichment to improve the biological function and welfare of the animal is incorporated in the European legislation. We have developed an enrichment item for laboratory mice, the Play-Tray. The Play-Tray can be used in several existing cage types and is easy to handle, change and clean. The tray divides the back part of the cage into two levels, which increases the usability of the cage space. Previous studies have shown that mice change their preference from spending more time under the food-hopper to being more under the tray in cages equipped with the Play-Tray (1). The tray is equipped with three holes, which enables hiding and possibilities to escape and this may reduce the incidence of aggressive interactions. Aggression is a problem in male laboratory mice and this study focuses on the effect of the Play-Tray on the level of aggressive interactions and wounding. The study was performed in 190 male mice of 13 different strains. Eighty mice were purchased (at one month of age) for the study and 110 adult mice were available at the animal facility. All mice were group-housed (3-7, in Makrolon type III cages) and did not participate in any other study during the 5 weeks of this investigation. Four equally sized treatment groups of 10 cages each were created; Non-enriched control (C), Play-Tray (PT), only nesting material (hemp, “Happi-Mat”, Scanbur BK A/S, Denmark) (H), and Play-Tray and nesting material (PTH). To study the positions of the mice, the cage was divided into five zones and the number of mice in each zone was recorded three times a week. The latency to the first aggressive interaction after cage cleaning, and the number of aggressive interactions during 60 minutes after cage cleaning were recorded once a week. Aggressive interactions were recorded in 8/10 cages and on 50 % of the total observations in group C, in 10/10 cages and on 65 % of total observations in group PT, in 6/10 cages and on 45 % of total observations in group H, and in 10/10 cages and on 74 % of total observations in group PTH. There were no differences between groups in latency to the first aggressive interaction after cage cleaning. The level of fight wounds and the frequency of whisker barbering were low in all treatment groups. A significant difference in the mean number of aggressive interactions was found, where the PT group had a lower frequency compared to the PTH group (p<0.05). This was mainly due to a higher incidence of fighting among the older animals. Regardless of treatment group, the mice were more often observed in the back part of the cage. The C and H groups were more often observed under the food-hopper compared to the PT and PTH groups (p<0.001). The PT and PTH groups were seen on the Play-Tray at about 25% of the observations. In summary, the Play-Tray increases the usage of cage space, but the effects of the tray on the level of aggression are inconclusive. 1. Augustsson H, Dahlborn K. The Activity/Shelter tray – A Preliminary Report of a New Enrichment Device for Lab Mice. Abstract Scanbur Seminar, “Improving Welfare for Animals and Staff”, 15-16 March 2001, Denmark

Published in


9th FELASA Symposium

Authors' information

Swedish University of Agricultural Sciences, Department of Clinical Sciences
Swedish University of Agricultural Sciences, Department of Clinical Sciences
Augustsson, Hanna (Sassner, Hanna)
Swedish University of Agricultural Sciences, Department of Clinical Sciences

UKÄ Subject classification

Animal and Dairy Science
Veterinary Science

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