Use of Water for Swimming and its Relationship to Temperature and Other Factors in Farm Mink (Mustela vison)

An investigation into swimming behaviour and its relationship to outdoor temperature was conducted in 40 ranch mink. Two different cage sizes were used and all animals had access to a basin filled with water 15 cm deep. During the years 1994-1998, water loss from the basin and temperatures at a nearby weather station were recorded once a week. In the last year 11 mink were video-recorded for 24 h. Using the monthly average daily water loss as an indicator, swimming activity showed a clear annual variation over 4 years and was positively correlated with average monthly temperature. With regard to swimming activity, a large individual variation existed: average water loss varied from 10 ml to nearly 4 litres per day, with those in large cage units having the greatest water loss. The video-recordings confirmed this variation: the number of swims ranged from zero to 177 during 24 h and there was an indication of more swimming bouts in the mink in the large cage units. The duration of swims varied from 2 to 55 s per bout. The relationship between swimming and general activity is discussed, along with the importance of water for swimming as a means of thermoregulation.     

The Effect of Cage Environment and Ad Libitum Feeding on the Circadian Rhythm,Behaviour and Feed Intake of Farm Mink

Abstract

The effect of cage size and nest box environment on circadian rhythm and on stereotyped and non-stereotyped activities was measured for 66 farmed female mink fed ad libitum. The behaviour of the animals was recorded over 24 h on video in the months of September and October. Weight and feed consumption were measured for the 66 females and the 66 male mink placed with the females. The experiment included three cage sizes (0.10, 0.27 and 1.10 m²) and cages with and without nest boxes. In the cages with nest boxes the use of wire netting cylinders and shelves was evaluated.

Farm mink, fed ad libitum, had their primary activity period from 04:00 to 10:00 h. There was no food anticipatory activity, but the actual feeding at noon caused an interruption of the animals' resting period. Mink in cages without nest boxes performed more stereotyped behaviour than mink with nest boxes. There was no effect of cage size on the measured behavioural elements. Mink were passive for more than 70% of the day and night and preferred to rest together. Apart from resting in the nest box, mink preferred to rest on shelves above floor level. Lacking the possibility of using a nest box and performance of stereotyped behaviour increase the feed intake of farm mink. A large variation between animals, having a significant effect on all the measured behavioural elements, indicates different coping patterns and/or stress sensitivity.     

Effects of Family Housing on Behaviour,Plasma Cortisol and Performance in Adult Female Mink (Mustela vison)

Various behavioural, physiological and production-related parameters were examined in 200 adult female pastel and pearl mink either family housed in three-room cages with no weaning or housed singly in one-room cages after normal weaning procedures. Scanning observations of behaviour and use of the cages were performed in the nursing period and several parameters related to reproduction were registered. The adult female mink were weighed when kits were 16 weeks old (September) and again at pelting time (November). Blood samples were collected from all adult female mink in September at which time the teat condition and fur damage were evaluated. After pelting, bite marks on the leather side of the skin were counted, fur damage was graded after severity and the fur size was measured. Some positive consequences of being family housed were revealed. The familyhoused adult female mink showed a lower level of stereotypes and a higher level of defensiveness and curiosity than the adult female mink in one-room cages during the nursing period. In September and November, family-housed adult females were heavier than singly housed adult females. However, most of the physiological or production-related parameters pointed in a negative direction for familyhoused adult female mink. Reproductive success was somewhat reduced, although not significantly. Plasma cortisol levels were elevated in September, indicating higher levels of stress in these females. They showed a generally poor teat condition in September, with a high proportion of swollen or bitten teats. A high proportion of these adult females showed fur damage in both September and November, and a high number of bite marks was found on the leather side of the skins of these females, indicating that family housing had a high cost for the adult female mink. In conclusion, there seem to be some benefits, at least on the behavioural level, in keeping adult female mink in three-room cages during the nursing period, but both physiological and production-related parameters indicated that the welfare of the adult female mink was threatened if she was continuously cohoused with her litter past the normal age of weaning.     

Selection of group size by individual laying hens

1. In a multi‐choice test, with unfamiliar cagemates and group sizes of up to 6, the attraction of a cage was inversely proportional to the number of hens it contained, empty cages being chosen most often. This trend was modified but not abolished by the previous experience of being reared in pens in large groups.

2. In a factorially‐designed test all hens spent the greater part of their time in large rather than small cages; hens reared singly chose empty cages rather than cages occupied by one other unfamiliar bird, whereas group‐reared hens selected the occupied cages.

3. In two‐choice tests, a familiar group of 3 hens was strongly preferred to a strange group of the same size; the familiar group was also preferred to an empty cage, but less strongly so.     

Behavior, physiology, performance and physical condition of layers in conventional and large furnished cages in a hot environment

The aim of the present study was to compare old layers' level of welfare and performance between conventional and large furnished cages under hot environmental conditions. At the age of 80 weeks, 104 Boris Brown layers were divided into two groups: 12 conventional cages (two hens/cage) and four large furnished cages (20 hens/cage, 240 cm wide × 62 cm deep). The room temperature was set to fluctuate between 25 and 33°C in a day. The hens' behavior, immune response, performance and physical condition were measured. Aggression and moving were more frequent in furnished than in conventional cages (P < 0.05 for both items). Egg production (P < 0.05), egg mass (P < 0.05) and feed conversion ratio (P < 0.01) were better in conventional cages than in furnished cages. No significant differences were found in the birds' immune responses or physical condition between the cage designs. In conclusion, under a hot environment, the performance of old layers in large furnished cages was lower compared with that in small conventional cages, which might be due to their greater aggressive interactions. However, it was not evident that welfare level was lower in large furnished cages compared with conventional cages. Hereafter, additional studies about large furnished cages using young layers over a long term should be performed.     

Effect of Inside-cage and Outside-cage Environment on Behaviour Test Performance of Blue Foxes (Alopex lagopus)

Abstract

In-cage reaction tests, the open field test and daily activity in the home cage were used to assess the effect of the internal design and location of cages on the behaviour of juvenile blue foxes (Alopex lagopus) during the growing season. The inclusion of nest boxes or resting platforms affected the behaviour of farmed blue foxes, but to a lesser extent than did the location of the animal in the cage row, i.e. the environment outside the cage itself. This study demonstrated that the actual environment in which the farm foxes live may be far larger than the cage interior itself, and that attempts to improve housing design should take into consideration the environment outside the cage to a greater extent than has heretofore been the case.     

Food transit time,nutrient digestibility and nitrogen retention in farmed and feral American mink (Neovison vison) – a comparative analysis

The aim of this study was to determine whether farming leads to changes in gastrointestinal function and nitrogen metabolism in farmed mink (FA), as compared with their wild‐living counterparts. Three digestibility and balance trials were carried out. Experiment I was performed in May, and experiments II and III were conducted in September 2011. Farmed mink with the standard coat colour were purchased from a production farm in south‐eastern Poland. Feral mink were harvested using cages in the hunting grounds of the Polish Hunting Association, Branch in Olsztyn. The experimental materials comprised of the following: trial I – adult males (eight animals per group), trial II – young females (six animals per group), trial III–young animals (five males and five females per group). Food transit time was measured during digestibility trials, on 10 consecutive days. The coefficients of nutrient and energy digestibility and daily nitrogen balance values were compared between groups in each experiment. It was found that farming contributed to changes in gastrointestinal function and nitrogen metabolism in mink. Farmed animals were characterized by a longer bowel transit time, a tendency towards higher nutrient digestibility and higher nitrogen retention, which resulted from selection for higher productivity.     

Age‐dependent baseline values of faecal cortisol metabolites in the American mink (Neovison vison) under semi‐natural housing conditions

The welfare of an animal is ensured if it is able to fully satisfy its essential species‐typical needs in all functional aspects of behaviour. In mink, stereotypies and apathy, internal and/or external injuries as well as increased susceptibility to disease have been known to occur as a result of chronic stress. The non‐invasive method of analysing faecal cortisol metabolites (FCM) allows conclusions to be drawn about the stress level in the respective housing system. The objective of this study is to find out how the cortisol metabolites content in the faecal changes with increasing age of the mink under semi‐natural housing conditions. Thus, 40 American mink (Neovison vison) were housed in two outdoor enclosures imitating natural conditions. Throughout the entire study (13th to 32nd week of life), faecal samples were collected to measure cortisol metabolites. No differences in FCM concentrations between the two outdoor enclosures were found. In the young mink lower, less fluctuating FCM levels were found than in older animals. After the first faecal collection in the 13th/14th week of life, the level of metabolites decreased slightly (p = 0.032; 17th/18th week). From the 22nd/23rd week onwards until the 30th/31st week, shortly before the animals were pelted, continuously increasing concentrations were then measured. Increasing FCM levels with advancing age of the animals are probably attributable to the onset of sexual maturity and/or the respective season. This has to be taken into account in future studies using this method for assessing welfare and when comparing different mink housing systems.     

Comparison of Pseudomonas aeruginosa isolates from mink by serotyping and pulsed-field gel electrophoresis

Isolates of Pseudomonas aeruginosa from clinical infections in mink were subjected to serotyping and pulsed-field gel electrophoresis (PFGE) using SpeI. A total of 212 isolates of P. aeruginosa from the year 1998 to 2001 were included in this study: 168 isolates from mink obtained from 74 farm outbreaks of haemorrhagic pneumonia. Isolates from mink were separated into 34 distinct clones by PFGE subtyping. All isolates from mink infected during the same farm outbreak were identical, except in one case where two different strains were isolated from mink obtained from the same farm outbreak. P. aeruginosa of specific PFGE types were found to cause clusters of outbreaks on several farms within a few weeks of each other. However, PFGE types of strains causing clusters of farm outbreaks changed from year to year. These results suggest that some outbreaks of haemorrhagic pneumonia are caused by pathogenic strains of P. aeruginosa spread between farms and animals either mechanically, or through feed or water from a common source, rather than by random nosocomial infections with strains from the farm environment.     

Genetic parameters and effect of selection for body weight in lines of mink (Neovison vison) on ad libitum and restricted feeding

Abstract

Selection was performed for high November weight on ad libitum (AL) and restricted feeding (RF) in mink in two generations. A farm fed line (FF) was maintained as a control. The estimates of heritability for November weight were large (0.62, 0.52, and 0.73 in males and 0.68, 0.51, and 0.60 in females in the FF-, AL-, and RF-line). The results indicate that selection on AL feeding increased appetite and thereby improved feed conversion ratio while selection on RF improved feed utilization. Furthermore, the results suggest that selection for August weight produces lean mink while selection for November weight produces fat mink.     

Effects of single caging and cage size on behavior and stress level of domestic neutered cats housed in an animal shelter

Cats need a minimum amount of space even in animal shelters. In this study the effects of single caging and cage size on the behavior and stress level of domestic cats were investigated. Six neutered cats (2–15 years old) that had been housed in a group for at least 7 months were moved to three kinds of single cages (small, medium and large) by rotation on a Latin square design. They experienced each cage size for 6 days. Cats could use vertical dimensions when housed in a group room and the large cage. Behavioral observation was conducted for 3 h in the evening, and stress levels were assessed by urine cortisol‐to‐creatinine ratios. The amounts (estimated proportions) of time spent in locomotion and social/solitary play were lower even in large cages than in group housing (both P < 0.05). Conversely, the amount of time spent resting tended to increase when housed singly (P = 0.104). The urine cortisol‐to‐creatinine ratios of singly housed cats tended to be higher than that of group‐housed cats (P = 0.086). The results indicate that cats become less active when they are housed singly in cages regardless of the cage size. Cats seem to feel no undue stress even in small cages if the stay is short.     

Performance of Four Hybrids of Laying Hens in Modified and Conventional Cages

Abstract

In two trials, production, feed consumption, mortality, egg quality and birds' live weight of a total of 2877 caged laying hens of four hybrids, Dekalb XL, Lohmann Selected Leghorn (LSL) and Shaver 288 in Trial 1 and ISA Brown and LSL in Trial 2, were studied during full production cycles. The cage designs were Get-away cages (GA) with 15 hens per cage, a special version of the “Edinburgh modified cage” called “Modified and enriched cage” (ME) with 4 ISA or 5 Leghorn hens per cage, conventional cages of metal (CO) with 4 hens per cage and conventional cages of plastic (PL) with 3 hens per cage. GA and ME included nests, perches and sandbaths. LSL produced significantly better than the other hybrids. Shaver had a significantly lower live weight than Dekalb and LSL, while ISA was significantly heavier than LSL. Production in ME was similar to that in conventional cages and, in Trial 2, birds in ME, CO and PL produced significantly better than those in GA. The highest mortality was registered in GA, where in Trial 2 it was significantly higher than in ME. GA gave a significantly higher and CO a lower proportion of cracked eggs than ME and PL. In both trials ME gave significantly lower proportions of dirty eggs than GA and in Trial 2, the lowest. Few differences between the systems were registered regarding interior egg quality. It was concluded that ME is better for production, mortality and management than GA but similar to conventional cages.     

Farming minks--possibilities for more adequate husbandry within the current circumstances

The keeping of minks in farms is widely disputed. As the present article illustrates, improvement in the management of farm minks can be achieved with relatively little effort. By implementing connecting openings between regular cages the area for living can easily be enlarged, moreover the structure of the cages will be improved. This resides in minks living in groups intensifying their social contacts. Analyses by "Het Spelderholt", Praktijkonderzoek Pluimverhouderij, Beekbergen, Netherlands show that behavioural problems can be significantly reduced by raising minks in adequate groups. Also the interior design and structure of cages is of equivalent importance reducing the occurrence of behavioural problems. The importance of an access to a water basin however has still to be investigated. One striking aspect on the subject of hygiene that has to be pointed out is the regular removal of faeces.     

Cage size and flooring preferences in litter‐reared and cage‐reared hens

1. Pullets (Ross Rangers) reared commercially either in cages or on deep litter were tested for their responses to small (0.38 × 0.43 m) and large (0.76 x 0.86 m) cages with wire floors and to small and large cages with litter floors.

2. When tested at 29 weeks of age, the birds' responses were significantly affected both by cage size (large preferred to small) and by flooring (litter preferred to wire).

3. No difference in cage preference was apparent between cage‐reared and litter‐reared birds either when they were first tested at 17 weeks or when they were re‐tested at 29 weeks. Birds do not have to be reared on litter in order to be attracted by it.     

An outbreak of toxoplasmosis in farmed mink (Mustela vison S.).

A large Wisconsin mink (Mustela vison) farm experienced an outbreak of toxoplasmosis in the spring of 1999 following an outbreak of canine distemper during the previous fall. Major clinical signs for pregnant females included reduced feed consumption, abortions, and stillborn kits; kits < or =3 weeks old experienced ataxia and mortality. Of 7,800 females, 1,976 (26%) lost their entire litter either from abortion or neonatal mortality. Kit mortality from 7 days to 3 weeks of age was 3,300, and overall kit mortality attributed to the toxoplasmosis outbreak was 10,408. Six neonatal mink kits, 12 3-week-old kits, and 2 adult female mink were submitted to the University of Minnesota Veterinary Diagnostic Laboratory for diagnostic workup. Gross postmortem lesions were limited to empty stomachs (12 of 12 kits) and pale livers (4 of 12 kits) for the 3-week-old kits. Major microscopic lesions included interstitial pneumonia, encephalitis, encephalomalacia, and myocarditis. Toxoplasmosis was diagnosed by microscopic lesions, microscopic lesion distribution, and the detection of Toxoplasma gondii tachyzoites by immunohistochemistry. This is the first detailed report of an outbreak of toxoplasmosis in mink in the United States.     

育成期不同饲养方式对水貂配种行为和配种进度的影响

观察并研究了水貂育成期不同饲养方式,即断奶后一直双层单笼单养和单层单笼多养(3~4只)对水貂配种行为变化和配种进度的影响。结果表明:育成期单笼多养的水貂的初配率和复配率均显著高于单笼单养的水貂(P<0.05)。说明水貂饲养环境的改变直接影响水貂的繁殖情况,单笼多养饲养方式代替传统的单笼单养饲养方式,显著提高水貂的配种进度及水貂的配种率,水貂育成期单笼多养饲养方式具有较大的推广应用前景。     

Behavior, performance and physical condition of laying hens in conventional and small furnished cages

The aim of the present study was to compare the welfare level and performance of laying hens between conventional and small furnished cages. At the age of 54 weeks, 120 White Leghorn layers were divided into four groups: four (C4) or six hens/cage in conventional cages and four or six (F6) hens/cage in furnished cages. Their behavior, number of steps taken, performance and physical condition were measured. Sham dust‐bathing was greater in conventional cages than in furnished cages (P = 0.05) and dust‐bathing, litter scratching and litter pecking were also observed in furnished cages. Other comfort behavior, moving and number of steps taken were more frequent in the four‐hen cages than in the six‐hen cages (P < 0.01, P < 0.001, P < 0.001, respectively). Though egg production and egg mass in C4 and F6 were lower than in the other groups, no significant differences were found in the other production measurements. Bodyweight gain was larger in the four‐hen cages than the six‐hen cages (P < 0.01). In conclusion, behavior was not restricted in the furnished cages, but activity and bodyweight gain were affected by group size (density) rather than cage design. Hereafter, the studies on suitable density in each cage design, using young layers, are required.     

Effect of Feed Structure on Performance and Welfare in Laying Hens Housed in Conventional and Furnished Cages

A small-scale experiment was conducted to examine layers' selection pattern of whole wheat (WW), protein concentrate (PC) and coarse shell meal (SM) throughout the light day. Consumption of all feed components increased prior to darkness. However, an interaction between SM and the other feed components was found (P<0.05), caused by a greater increase in SM consumption prior to darkness than WW and PC. This interaction is probably related to the requirement for calcium for eggshell formation. Energy (WW)/ Protein (PC) consumption ratio did not vary throughout the light day. In a large-scale experiment, a diet with 40% whole wheat incorporated into 3 mm pellets was compared with a complete diet, also as 3 mm pellets, but containing no whole wheat. Coarse shell meal was added in the feed trough for the experimental diet. These diets were examined in conventional 3-hens cages and two furnished cage systems. The hybrids LSL and Shaver 2000 were used. A tendency towards a lower (P=0.07) feed conversion ratio (FCR) was found in the experimental diet relative to the control diet. This may be a result of a better plumage condition for birds fed the experimental diet. Weight of gizzard and gizzard contents was higher among birds on the experimental diet. Self-selection of shell meal did not affect eggshell strength and legbone strength. Birds housed in furnished cages with 16 birds per cage unit showed higher (P<0.05) feed consumption than birds housed in furnished cages with 8 hens per cage and birds housed in conventional 3-hens cages. Egg production was similar in all cage systems, except for a tendency for lower (P=0.06) egg production in the 8-hens cages in the second half of the experiment period. Plumage condition was generally poorer (P<0.05) in the furnished cages than in the conventional 3-hens cages. Fewer comb lesions were found among birds in furnished cages, which may indicate less aggression in layers housed in furnished cages compared with conventional barren 3-hens hen cages.     

Testing the protective effectiveness of vaccines against infection with Pseudomonas aeruginosa in mink (Lutreola vison)

Infections by Pseudomonas aeruginosa have caused losses on mink farms in recent years, particularly with a clinical manifestation of haemorrhagic pneumonia. This paper includes the first results of the practical use of the Czechoslovak soluble monovaccine of polyvalent action in the treatment of mink infected by Pseudomonas aeruginosa. The action of the vaccine is based on the protective effect of Original Endotoxin Protein (OEP), antigen common to all species of the genus Pseudomonas. After due testing, the vaccine was given to mink. Doses of 50, 200 and 500 micrograms, and in another series 50 and 200 micrograms of the vaccine were tested in subcutaneous administration at 0.2 ml volume in a 7-day interval. No adverse side-effects and reactions were observed in the animals. A protective action was demonstrated, resulting in a higher number of reared mink in comparison with the control groups. After vaccination, titres ranging from 2 to 160 were determined by the indirect haemagglutination method and from 320 to 164,000 by the RIA method. In 1984 the vaccine was used for practical treatment on a mink farm with the stock exposed to Pseudomonas aeruginosa infection (5551 mink were treated). In the vaccinated group losses amounted to 3.1% whereas in the control group the mortality level was above 17%. Vaccination was demonstrated to have a favourable effect and the vaccine was then preventively used on the same farm in the subsequent year; the treatment of 29,350 mink had the required protective effect.     

Effect of Perches at Different Positions in Conventional Cages for Laying Hens of Two Different Strains

Production, health and behaviour were studied in 648 White Leghorn hens of two strains, LSL and Shaver 288, housed in three-tier battery cages (four hens per cage, 600 cm2 per hen) with three treatments; two with a perch fitted across the cage, 17 (PB) or 24 cm (PC) from the back of the cage, respectively, and control cages without perch (NP). Introducing a perch did not significantly affect production, but PC gave more dirty eggs, and both PC and PB tended to give more cracked eggs. The perch caused inferior keel bone condition and hygiene of the cage floor and a stronger tibia. LSL hens showed higher production, better feed conversion ratio, fewer cracked eggs, better keel bone health and shorter claws than Shavers. Use of the perch averaged 25 and 90% during day and night, respectively. The perch did not significantly affect other behaviours. There were significant interactions between strain and cage design regarding laying percentage, egg weight, cracked eggs, live weight, foot- and perch hygiene, keel bone condition and toe pad hyperkeratosis.