Effects of space allowance and earthen floor on welfare-related physiological and behavioural responses in male blue foxes

Abstract

Welfare-related physiological and behavioural responses were studied in farm-bred male blue foxes ( Alopex lagopus). Three different-sized cages (80-cm long [CL80], 120-cm long [CL120], and 240-cm long [CL240]; each 105-cm wide × 70-cm high) with wire-mesh floors and one enlarged cage (CL240E) with both wire-mesh floor (240-cm long × 105-cm wide × 70-cm high) and earthen floor (80-cm long × 105-cm wide × 70-cm high) were compared. N = 30 males for each group. The experiments lasted from weaning in July to pelting in December. Statistical analyses were based on the models accounting for litter as a block effect. Breaking strength of tibia was highest for foxes having access to both wire-mesh and ground floors (CL240E). Stress-induced hyperthermia was evident during capture and immobilisation. The highest rectal temperature (mean ± SEM) was found in CL240E (capture: 39.6 ± 0.09°C, restraint:40.0 ± 0.09°C) and the lowest in CL80 (capture: 39.1 ± 0.09°C, restraint: 39.7 ± 0.09°C). Likewise, capture time (median; interquartile range) in the home cage was highest in CL240E (29; 18 to 44) and lowest in CL80 (12; 9 to 14). During capture, foxes tended to withdraw to the farthest site within the cage. CL240E foxes typically showed the most fear towards human. The most confident animals were found in CL80. The cortisol:creatinine ratio (median; interquartile range) obtained from circadian urine did not reveal statistically significant differences among CL80 (3.5; 2.6 to 4.1), CL120 (2.3; 1.5 to 3.8) and CL240 (2.3, 1.5 to 3.7). The earthen flooring complicated the urine sampling and conclusions for CL240E (1.7; 1.2 to 2.2). CL240E foxes were the most active and explorative on both wire-mesh– and ground-floored open-field arenas. Altogether, 53% of furs from CL240E were classified as very dirty. Dirtiness of furs in other test groups was slight. In conclusion, the present results did not reveal an unambiguous superiority of any of the studied cage options for well-being of farmed blue foxes.