Effects of access to extra cage constructions including a swimming opportunity on the development of stereotypic behaviour in singly housed juvenile farmed mink (Neovison vison)

The aim of the study was to find out whether an access to extra cage constructions including either a 1801 pool (SP group) or a pool-sized extra cage (0.61 m(2)) (EC group) would slow down the development of stereotypic behaviour in singly housed farmed mink (Neovison vison). Mink housed in traditional mink cages (TC group) served as controls. The results show that stereotypic behaviour increased in all groups with advancing autumn, the increase being the greatest in TC group. Pair-wise comparisons between the groups showed that the occurrence of stereotypic behaviour was significantly lower in SP group than in IC group from November onwards (November-December: 1.4 +/- 0.6-2.2 +/- 0.6% vs. 6.0 +/- 1.7-7.8 +/- 1.3% of observations spent in stereotypic behaviour, respectively). Furthermore, the SP mink spent significantly less of their active time in stereotypic behaviour than the TC mink from November onwards (November-December: 6.2 +/- 2.4-10.3 +/- 2.8% vs. 21.4 +/- 5.5-29.2 +/- 4.3% of active time spent in stereotypic behaviour, respectively). The mink that had an access to an extra cage of the similar size as the pool were intermediate in their level of stereotypic behaviour (November-December: 2.6 +/- 0.9-4.7 +/- 1.1% of observations spent in stereotypic behaviour) and the percentage of active time spent in stereotypic behaviour (November-December: 10.1 +/- 13.5-17.6 +/- 3.9%). The amount of stereotypic behaviour of the EC mink did not differ significantly from the amount of stereotypic behaviour of either the TC or SP mink. In conclusion, the present results show that extra cage constructions including a swimming opportunity slow down the development of stereotypic behaviour in singly housed farmed mink. (C) 2011 Elsevier B.V. All rights reserved.