V01.4:351-361. Comparison of production results between blue foxes housed with and without platforms Hannu Korhonen and Paavo Niemelä Agricultural Research Centre ofFinland, Fur Farming Research Station, FIN-69100 Kannus, Finland The production results of farmed blue foxes (Alopex lagopus) housed in cages with and without resting platforms were compared. No differences in weight gain or reproductive performance were found between the groups. However, locomotor activity prior to the breeding season tended to be slightly lower in animals provided with platforms. Platform use during the period of winter fur devel- opment (Oct-Nov) varied for the different platform constructions, being highest in wooden U-type platforms placed 30 cm from the cage roof (54.1% of observations on platforms) and lowest in the corner platform type (12.6%, pcO.OOl). Use of platforms made of wire mesh (45.2%) did not differ significantly from that of the wooden U-types. Ceiling and construction material affected platform dirtiness. The proportion of clean platforms was lowest (35.7%) when the platform was 30 cm from the roof. Net platforms remained very clean throughout the study. The time required for cleaning was greatest in August, ranging from 82 seconds/platform/week for the U-30 type to 2 seconds for the net type. Fur quality (p<0.001) and clarity (p<0.001) had a significant, but negative, correlation with platform dirtiness. The condition of almost all the wooden platforms deteriorated over time due to chewing. Wire mesh platforms were not chewed on. From the farmer’s point of view, wire mesh seems to be preferable to wood as a platform material. Key words'. Farm fox, production performance, resting shelves, enrichment, welfare Introduction Unlike that of many other species of domestic animals, the design of the housing environment employed in fur-bearing animal production has not changed greatly over the years. Traditional- ly, farmed blue foxes (Alopex lagopus) have been housed in bare wire-mesh cages without any shelter other than the shed. Nestboxes have been supplied only to females during pregnancy and lactation. This housing system has proved to be economically successful. Some farmers have, however, occasionally provided seasonal or whole-year shelters such as resting platforms, sleeping ledges or nestboxes for their foxes, with variable results (Harri et al. 1992, Valtonen and Moss 1983). There is also positive, experimen- tal evidence that farmed foxes with access to whole-year shelters show a lower level of stress and fear than animals without access (Jeppesen and Pedersen 1991, 1992). © Agricultural Science in Finland Manuscript received November 1994 351 AGRICULTURAL SCIENCE IN FINLAND https://www.c-info.fi/en/info/?token=SBrMI_H-LUmdSFIE.XLtVwRXU5iDxUsik5pIOlQ.1MHOm7HfDA9Jaycs9qr_e5OE8uZNJA5HZt-0SCKiZ7dZMXnYA5YIS7gTpaX30mgkog8tsgjuWvCiI__3Sk6Ugto3bb3h8gGJQXM5Z4rtixHPRa9uMkyl24tBnRFBslg2hwoHxWa-YeMpWBrcKxDXiQta4sRktigi-cl38EmtjduAFPLxeODrcUyYYvDRuEPixrJErqx8ls8CXWRFuEtkAKBkN3q8fJ_MUi5c8FHUcnJwrzqny605wNZkuPJLwP7-Q0P10FB3YVKGLrgEcGh12b0Rb1JUFWpDJ17TUw Korhonen, H.& Niemelä, P: Comparison ofproduction results between bluefoxes housedwith and withoutplatforms The recent recommendations issued by the European Convention for animal protection in- clude the provision that for each weaned fox there should be available a secluded area which it can use for resting, observing and hiding (Eu- ropean Convention 1991). In practice, this means that each farm cage should be equipped with a resting platform or nestbox. At present, however, compliance with the recommendations is not unambiguous, first, because of the lack of com- monly accepted platform construction designs despite several studies (e.g. Harri et al. 1991, Mononen et ai. 1993, Pedersen and Jeppesen 1993, Korhonen and Niemelä 1994, Korhonen et ai. 1995) and, second, because there is evid- ence suggesting that at least some construction models may even have some negative effects on production performance. For instance, the mass and fur quality of blue foxes were poorer in an- imals having had platforms since weaning than in those raised withoutplatforms. There was also a negative correlation between fur quality and the amount of platform use (Korhonen and Niemelä 1993),In silver foxes, Harri et al. (1992) found that fur quality was adversely affected by access to whole-year shelters. Furthermore, the effect of the presence of platforms on the repro- duction performance offarm-bred foxes requires more clarification because of the controversial whelping results reported elsewhere (Konnerup- Madsen 1982, Valtonen and Moss 1983, Sönderup 1986). Thus, although there is general agreement that platforms and nestboxes can be of great importance for the welfare of farmed foxes (Braastad 1992, Bakken et al. 1994), the current recommendations of the European Con- vention need to be further investigated with re- gard to production performance. The objective of the present study was to determine whether there is a difference between the production results of farm-raised blue foxes (Alopex lagopus) housed with and those housed without resting platforms. Therefore, whelping results, locomotor activity and body weight at the breeding season, development of body weight and platform damage in the growing pe- riod, and the degree of fur defects at pelting time were compared between the experimental groups. Material and methods Platforms, animals and management The experiments were carried out at the Fur Farming Research Station of Kannus in 1993. The characteristics of the platform types used in the experiments are listed in Table 1 and sche- matic pictures are given in Fig.l. Wooden plat- forms were made of 5" board (thickness 22 mm) and wire mesh platforms of plastic-coated wire (1" x 1"). The bottoms of the V and U types were shaped like the letters V and U. The U type also had a 45 mm thin strip of wood in the middle of the bottom. The front edge of the wire mesh plat- forms was fitted with a strip of wood (22 mm x 45 mm) for better stability. The platforms were placed in cages on both sides of the aisle. Experiment 1 was carried out between Feb- ruary and July 1993 on adult blue foxes born in May 1992. Two groups were compared: (1) a control group, housed without platforms and (2) a platform group,housed with V type platforms. Both groups consisted of 60 females and 20 males. All animals of the platform group had previous platform experience of type V since their weaning (from July 1992 onwards); the controls had no previous experience. All adults were housed singly in wire-mesh cages measur- ing 107 cm wide x 120 cm long x 70 cm high. Experiment 2 was carried out between July and November on 201 juvenile blue foxes (born May 1993; age <1 year). They were housed in two-row sheds with two animals occupying one wire-mesh cage measuring 107 cm wide x 120 cm long x 70 cm high. Each animal was ear- tagged for identification. All juveniles had pre- weaning platform experience. The experimental groups were as follows: (1) U-23 platform group: U-shaped platform 23 cm from cage roof, (2) U- -30 platform group: U-shaped platform 30 cm 352 AGRICULTURAL SCIENCE IN FINLAND Vol. 4: 351-361. from cage roof, (3) Corner-23 platform group: flat bottom platform located at cage corner, 23 cm from cage roof, and (4) wire-mesh-23 plat- form group; wire-mesh platform 23 cm from cage roof (see Fig. 1). Freshly mixed fox feed manufactured by the local feed kitchen was supplied twice a day at 9 am and 1 pm from weaning to mid-September, and thereafter once a day at 1 pm. Feed portions (from 250 g in winter to 800 g/animal/day dur- ing the growing period) were adjusted accord- ing to the seasonal standards of the Finnish Fur Breeders’ Association (Berg 1986). Individual feed consumption, however, was not measured. The foxes were weighed each study month with a Lario 30 kg balance (accuracy ±2O g). Monitoring of platform use and activity Platform use was monitored with two methods: (I) continuous 24-hour recording with video camera equipment (CCD video camera 720, Bische ÜB-480 tape recorder, Koyo monitor, Bische 12-300 infrared light: 500 W) (Exp. I), and (2) daytime scanning observation made three times (8 am, 12 noon and 3 pm) each working day (Exp. 2) except Friday, when observations were made at 8 am and 12 noon only because of the shorter working day. The month was taken as the basic unit within which the platform use comparisons were made between groups. Dur- ing the scan sampling the observer walked qui- etly and slowly past the row of cages and manu- ally recorded the foxes’ location (on platforms or not) (Pedersen and Jeppesen 1993). Thus, Table 1. Characteristics of experimental platform types. V U Comer Net Experiment 12 2 2 Platform: material Wood Wood Wood Wire" location side side comer side bottom shape V U flat flat1 ' ceiling, cm‘ 23 23/30 23 23 length, cm 103 103 91 d 103 width, cm 25 30 65° 30 area, cm 2 2580 3090 2050 3090 wall height, cm 12f 12f 12s •made of plastic-coated wire, h flexible when fox on it, c distance of platform from cage roof, d hypotenuse, • the two shorter sides of a right-angled triangle, 1 at ends only, gon shorter sides only, h walls ofwire mesh cage only. Fig. 1. Schematic pictures of platform types studied. For details see Table 1 353 AGRICULTURAL SCIENCE IN FINLAND Korhonen, H. & Niemelä, P.: Comparisonofproduction results between bluefoxes housedwith and withoutplatforms when standing in front of cage N0.2 the location of the fox in cage N0.3 was recorded and so forth. If the fox fled from the observer, it’s previous location was recorded. The locomotor activity of the foxes was ana- lysed from the continuous 24-hour video cam- era observations (Korhonen and Niemelä 1993). Both the control and platform groups were re- corded for 20 days during each experimental month. Assessing fur parameters and platform conditions Urine staining and ventral fur wear were evalu- ated by two professionals at the Research Sta- tion. The evaluation scale and technique were the same as those used in our previous experi- ment (Korhonen and Niemelä 1993). The degree of ventral wear was assessed more strictly than in the normal assessment procedure used by Finnish Fur Sales Ltd. As well as furs originat- ing from the experimental platform animals, 60 pelts were evaluated from animals housed with- out platforms. These were randomly selected from farm material and were used here as con- trols (only for urine staining and ventral wear). The control animals were housed in a similar manner to the experimental animals. Commer- cial fur parameters were evaluated by Finnish Fur Sales’ professional graders (Fur Center, Van- taa). The scoring, which followed the rules of the Finnish Fur Breeders Association for experi- mental skin grading, was as follows (the lower the number, the poorer the fur quality and clari- ty and vice versa. Saga Royal, Saga etc. are the corresponding grading names used commercial- ly in Scandinavia for experimental points (Ei- narsson and Skrede 1989,Finnish Fur Sales’ auc- tion catalogue 1994)): fur quality; 10=Saga Royal, B=Saga, 6= quality class 1, 3=quality class 2 and 1= quality class 3. Clarity: 10=R+excellent, B=R good, 6=R medium, 4=OC poor, 2=OC- very poor. Clarity is an expression of the shade of the colour (Einarsson and Skrede 1989). Platform dirtiness was evaluated on a scale of 1-4, where l=clean, 2=slightly dirty, 3=mod- erately dirty, 4=very dirty (Korhonen and Niemelä 1993). Platforms were cleaned once a week. All cleaning times were recorded. The in- cidence of chewed platforms was checked at the same time. Statistical analysis Data were analysed using the SAS statistical programs (GLM procedure, NPARIWAY proce- dure). Mean differences in body weight and ac- tivity were testedby analysis of variance (ANO- VA), and the effects of advancing time by multi- variate analysis of variance (MANOVA). Differ- ences in platform use, fur defects and quality, and platform dirtiness between the groups were analysed by the Kruskal-Wallis one way analy- sis of variance and the Mann-Whitney U-test when comparing two groups. Regression analy- ses were employed to calculate the relationship between platform use and fur quality parame- ters, and between platform dirtinessand fur qual- ity parameters. Whelping results were tested between two groups using the Mann-Whitney U- test. Results Weight loss and activity during winter During the winter period from January to March (Exp. 1), the foxes spent only a short time on platforms, i.e. on average 54 ±l3 min/24 h (me- dian 18 min/24 h). Table 2 presents changes in the body weights and locomotor activities of adult blue foxes selected for breeding. No sta- tistically significant differences were found in the initial weights (Jan) between males in the control and platform groups. The trend contin- ued unchanged until breeding time in mid- March. Among females, on the other hand, the 354 AGRICULTURAL SCIENCE IN FINLAND Vol. 4: 351-361. Table 2. Body weight and locomotor activity in adult blue foxes (Exp. 1) during winter(mean ±SD). *p0.05 for each parameter (Mann-Whitney U-test). V-type platforms were used. Whelping result was calculated at age of 8 weeks (weaning). Control Platform Number of breeding females 59 60 Number of mated females 50 56 Mated, % 84.7 93.3 Barren,% 14.0 21.4 Lost their pups, % 9.3 4.5 Pups/breeding female 7.1 ±2.4 7.5 ±2.4 Pups/mated female 8.4 ±2.3 8.1 ±2.4 Pups/whelped female 9.8 ±2.2 10.3 ±2.3 the platform group than in the control group (Table 3). On the other hand, the number of barren (non-producing) females was higher in the plat- form group. The whelping result was 0.4 pups higher for animals in the platform group thanfor control animals, if calculated per female kept for breeding, but 0.3 pups lower when calculatedper mated female. However, no significant differenc- es existed in any of these reproductive parame- ters. Weight gain from weaning to pelting There were no significant differences in body weight development between groups (Exp. 2), nor did the final body weights (December 21) of the control (N=6o) and platform groups (N=2ol) differ significantly from each other (7.2 ± 0.7 kg vs. 7.2 ± 0.6 kg; mean ± SD). Because there were no differences in the platform groups, their data were pooled. Fur parameters In experiment 2, two different ceilings (platforms 23 cm and 30 cm from cage roofs) as well as wooden and plastic-coated wire mesh materials were compared to determine whether these plat- form constructions affected fur quality parame- 355 AGRICULTURAL SCIENCE IN FINLAND Korhonen, H.& Niemelä, P: Comparison ofproduction results between bluefoxeshoused with and withoutplatforms ters. Platform use during winter fur development (Oct-Nov) was of the same order of magnitude with both ceilings for the wooden U type and the net type (p>0.05) but the corner type was used significantly less compared to the others (pcO.001) (Fig. 2). The number of furs showing ventral wearranged from 9.6% (corner) to 16.0% (U-23) per group, there being no significant dif- ference between the platform groups. Ventral wear of the fur of the animals in the control group (without platforms) tended to be lower (6.6%) than that of the animals with platforms, although statistical confirmation (p<0.05) was found only in comparison with U-23 (16.0%). The number of ventrally-worn furs in the animals in the U- -30 and wire mesh groups was 12.7% and 10.0%, respectively. Urine stains were only found in the U-30 group, where 9.1% of the skins were contaminated with urine. According to the commercial evaluation scale employed by Finnish Fur Sales Ltd., the clarity and quality of furs were best in animals of the wire mesh group and poorest in the U-30 ani- mals (Table 4). The average price of pelts from the wire mesh group was FIM 40-50 higher than thatof other groups. However, the difference was not statistically significant. A weak, but statisti- cally significant, relationship was found between fur quality (Y) and individual platform use (X) during October-November, indicating that fur quality tended to be good when platform use was low and vice versa (Y=-O.OIX + 6.06; p<0.05, F=3.84, R : =0.10). A slightly stronger relation- ship was found between fur price (Y) and plat- Table 4. Characteristics of commercial pelt and fur parameters as evaluated by Finnish Fur Sales Ltd. Means with different uppercase letters (a-b) were significantly different (p<0.05) (Kruskal-Wallis test/ Mann-Whitney U-test) (Exp. 2). 23 and 30 in group names indicate the distance from cage roof in cm. All pelts were sold at the same auction (April 1994). U-23 U-30 Corner-23 Met-23 Number of pelts 50 55 46 50 Pelt length,cm 105.1 ±5.9* 105.9±5.4* 104.1 ±6.0b 108.5 ±7.1“ Clarity 6.3 ± 1.4* 5.9 ± 1,5b 6.0 ± 1,5b 6.9 ± 1.6“ Fur quality 5,6 ±2,o* 5.1 ±2.7“ 6.0 ± 2.2* 6.3±2.0b Pelt price. FIM 623 ±88“ 618 ±96“ 616 ±94“ 663 ±94“ Fig. 2. Comparison of platform use (% of observations on the platform) by blue foxes between four construction models. The groups named 23 and 30 indicate the distance from the cage roof in cm. ***p