Beteenderesponser hos farmuppfödda minkar (Mustela vison) hållna i stora och berikade burar

Abstract: The standard housing of farmed mink provides little opportunities for them to behave naturally and abnormal behaviours such as stereotypic behaviour and tail biting may occur. To prevent abnormal behaviours animals in captivity are often provided with different kinds of enrichments. The aim of this study was to investigate what kind of enrichment farmed mink use when they have several kinds to choose from and to observe if abnormal behaviours can be decreased with a larger cage and a more multifaceted environment. Totally 20 silver blue, 10 months old female mink were kept in traditional cages (80x30x40 cm) for 7 days and in larger cages (195x80x40 cm) with several types of enrichments for 7 days. The enrichments were wire net- and wooden shelves, wire net- and plastic cylinders, water bath, plastic ropes, branches, straw and tennis balls. One-zero scan sampling on behaviour and choice of place were performed during 3 hours and 20 minutes prior to feeding during 7 days per treatment in April 2004. A range of behaviours were recorded: normal active behaviour, interactions with enrichments, inactive behaviour, stereotypies, tail biting and choice of place. The results showed that when female mink were kept in large enriched cages they spent 22,3% of their active time in contact with different enrichments. They interacted with the water bath 10,4%, shelves 4,8%, cylinders 3,2%, plastic rope 2,1%, tennis balls 1,2%, straw 0,3% and branches 0,3% of their active time. When kept in large enriched cages the mink performed the same types of stereotypies as when kept in traditional cages, but the frequency of stereotyped behaviour decreased when kept in large enriched cages (p< 0,05, median value traditional cage = 0 and large enriched cage = 37, Mc Nemar Chi-2 test). When kept in traditional cages mink also performed additional types of stereotypies. No differences were found in stereotypic behaviours between mink first kept in traditional cages or first kept in large enriched cages (n. s., Wilcoxon Matched Pair Test). No differences in total active time between the treatments were found (n. s., Wilcoxon Matched Pair Test), but when mink were kept in traditional cages 10% of their active time was spent performing stereotypic behaviour compared with 1,4 % in large enriched cages (p< 0,05, Wilcoxon Matched Pair Test). Mink's spent equal time inactive in both treatments (n. s., Wilcoxon Matched Pair Test). Two individuals performed tail biting when they were kept in traditional cages. No tail biting was preformed when they were kept in large enriched cages. In conclusion this study shows that female mink utilized the enrichments frequently and decreased their stereotypic behaviour pattern considerably when housed temporary in large and enriched cages. They also performed more normal active behaviour suggesting better coping potentials and implying improved animal welfare in an enriched cage system. 6