Farmed juvenile blue foxes were housed either singly, in pairs, or in quartets at a stocking density of either 0.6 m2 or 1.2 m2 per animal. The effects of group size and space allocation on physiological, behavioural and production-related parameters were assessed. The results showed that the larger space allocation, although having only minor effects on the measured parameters, allowed the foxes to maintain their individual space even in the larger group sizes. Social tension within the groups affected the behavioural and production-related parameters to a greater extent than did space allocation. The sex-related dominance order, with males having easier access to feed than females, and females having more bite scars and higher serum cortisol levels than males, appears to be the major factor affecting the general performance of mixed-sex group-housed farmed blue foxes. These results suggest that group housing of farmed juvenile blue foxes could be considered as an alternative, socially enriched way of housing these animals.

Nowadays in Europe, farmed blue foxes are kept for most of the year in wire-mesh cages furnished with a platform for resting and observing the environment but without any opportunity for hiding from other foxes or from man. We studied the welfare effects of providing an elevated platform and two types of concealment screens in singly housed juvenile male blue foxes (n = 46) from August to December. The foxes were allocated to four experimental groups: group C had no furnishing in the cage, group P had a platform in the cage, group U had a platform and a concealment screen in the cage, and group O had a platform and a concealment screen on the outer wall of the cage. The blue foxes with platforms (groups P, U and O) spent the majority of their time on the platforms both when their cages were approached by man and as revealed by 24 h video recording. The 24 h recordings revealed that the foxes tended to avoid those locations in the cage where the screens obstructed their view (groups U and O); however, when the screens allowed the foxes to hide from an approaching man (group U), they were used for that purpose to some extent. There were no differences between the four groups in terms of growth, increase in rectal temperature after an acutely stressing situation, adrenal size, or fearfulness. The urinary cortisol: creatinine ratio showed that foxes in group U may have been less stressed than those in groups P and O in September, but no differences were observed in October. The concealment screens of group U may have improved the welfare of these blue foxes.

According to present acts and regulations, farmed foxes shall have a gnawing or other enrichment object in their cages. However, research on the welfare effects of gnawing objects has been scarce. We assessed physiology and health, that is weight development, urinary cortisol-creatinine ratio, serum cortisol level after adrenocorticotropic hormone administration, internal organ masses and incidence of gastric ulcerations as well as dental and overall oral health, in pair-housed juvenile blue foxes that were housed either with or without a possibility to interact with bones (cattle femur) during their growing season (July to December). The results show that the physiological effects of the possibility to interact with bones were either non-significant or suggested that competition for bones may jeopardize the welfare of subordinate individuals. However, the results clearly show that gnawing bones are beneficial for the dental health of farmed foxes.

The meiotic competence and meiosis resumption of Blue fox (Alopex lagopus) oocytes from anoestrous animals were followed. Oocyte–cumulus complexes (OCC) were cultured in modified TC 199 medium with or without FSH, recombinant bovine somatotrophin (bST) and okadaic acid (OA). The results showed that oocytes less than 100 μm in diameter did not achieve germinal vesicle breakdown (GFBD) by 72 h of culture, which indicates their meiotic incompetence. Oocytes larger than 100 µm in diameter underwent GVBD after 48 h of culture (27%) and reached metaphase II (MII) after 72 and 96 h (20% and 27%) in control medium. Both bST and OA accelerated resumption of meiosis (bST: 55% GVBD and 42% MII after 48 h; OA: 66% GVBD after 18 h). In contrast, FSH significantly reduced meiosis resumption (only 3% GVBD and MII after 72 h) and induced changes in the shape of cumulus granulosa (CG) cells and F-actin assembly typical for cumulus expansion. However, the innermost layers of CG cells (corona radiata) remained connected with the oocyte via gap junctions until the end of culture. Cumuli of oocytes cultured in control, bST-supplemented or OA-supplemented medium did not expand (changes in cell shape and F-actin redistribution did not occur). Moreover, especially in media with bST and OA an increased detachment and rapid disconnection of their gap junctions with the oocyte were observed. These results suggest that under in vitro conditions FSH stimulates expansion of the CG cells and the attached membrana granulosa cells but in contrast it secures heterologous gap junctions between cytoplasmic processes of the corona radiata cells and oolemma during 3 days of culture. Thus, in agreement with the in vivo situation in which Canidae oocytes are ovulated in the GV stage, the cumulus, mainly corona radiata cells, controls resumption of meiosis in Blue fox oocytes under in vitro conditions also.