Feeding
Enrichment
Rodents
Banjanin S, Barley J, Bell L, Cunneen M, Johnston I, Quintero
I, Weilemann R, Reinhardt V 2004. Environmental
enrichment for guinea pigs: A Discussion by the Laboratory Animal
Refinement & Enrichment Forum. Animal Technology and
Welfare 3, 161-163
"Autoclaved hay or straw offers optimal environmental
enrichment. This material can readily be presented in such a way
that the animals have to work for its retrieval, i.e., engage
in foraging activities."
Carder B, Berkowitz K 1970.
Rats' preference for earned in comparison with free food. Science
167, 1273-1274
"When work demands are not too high, rats prefer earned
food to free food."
Hawkins P 1999. Working together to improve rodent well-being.
Lab Animal 28(2), 30-32
Modifying food hoppers by soldering metal plates over them,
so that only 3% of the original area remains available, makes
rats work for the retrieval of their food.
Johnson SR, Patterson-Kane EG 2003. Foraging as environmental
enrichment for laboratory rats: a theoretical review. Animal
Technology and Welfare 2, 13-22
"Scattering food, giving access to whole food pellets
and providing variable food types would be basic options to start
with for making food more interesting."
Johnson SR, Patterson-Kane EG, Niel L 2004. Foraging enrichment
for laboratory rats. Animal Welfare 13, 305-312
"The limited-access hopper had a tendency to reduce food
consumption, but the time spent feeding increased. The gnawing
sticks provided the rats with the opportunity to gnawy, but did
not affect other behaviours or body weight. The foraging device
had the benefits of reducing aggression and allowing the rats
to search for and manipulate food, but resulted in significant
gains in body weight."
Leach MC, Ambrose N, Morton DB 1999. Practical rodent enrichment.
Animal Technology 50, 177-179
"We have designed and evaluated as a form of rodent enrichment
floor feeding, where in addition to the standard diet present
in the cage hopper, other food is mixed into the cage substrate.
Floor feeding appears to promote natural feeding, foraging and
exploratory behaviour without affecting body weight gain."
Neuringer AJ 1969. Animals respond for food in the presence of
free food. Science 166, 399-401
"Rats pressed a lever for food pellets while free pellets
were present. ... The act of producing food can serve as its own
motivation and, therefore, as its own reward."
Prowse L 2002. Progression of environmental enrichment at Sequani
Limited. Animal Technology and Welfare 1, 1190121
All rabbits assigned to general toxicology studies and guinea
pigs are offered hay blocks on an intermittent basis.
Scharmann W 1991. Improved housing of mice, rats and guineapigs:
a contribution to the refinement of animal experimentation. Alternatives
to Laboratory Animals [ATLA] 19, 108-114
"In our breeding colony, grains of cereals are buried
in the wood shavings when the bedding is changed. Mice, rats and
hamsters quickly learn to search for this welcome variation in
their feed."
Wrightson D, Dickson C 1999. Diet restriction through hopper design.
Animal Technology 50, 45-46
Group-housed rats were induced to 'work' for their food by
soldering metal plates over their food hoppers, so that only 3%
of the original area remains available. The animals "fed
for longer periods and rested less during the night, but there
were no adverse clinical effects and no problems with rats' muzzles,
gums, teeth or forepaws. The rats were not aggressive to one another
or to humans, and were more confident when handled. No changes
were observed in the rats' social hierarchy and there were no
increases in fighting with restricted hoppers, as up to three
rats could feed at a time. .... It was felt that this method of
food restriction was preferable to giving less food [to avoid
obesity]. ... Rather than rapidly eating a reduced ration and
feeling hungry for long periods, the rats worked harder for their
food, which enabled them to burn more calories and eat throughout
the day. This reduces the incidence of obesity and its associated
disorders and also encourages more 'natural' behaviour patterns,
both of which improve welfare."
Rabbits
Berthelsen H, Hansen LT 1999. The effect of hay on the behaviour
of caged rabbits (Oryctolagus cuniculus). Animal Welfare
8, 149-157
"When hay was available [placed on top of cage], the [single-caged]
rabbits ... performed significantly less bar gnawing and excessive
grooming" and were less restless. "This suggests that
rabbits kept in cages where hay is available are less stressed
than those kept in cages where it is not." When kept in otherwise
barren cages, rabbits interacted with the hay 16% of one-hour
observation sessions.
Brummer H 1975. Trichophagie - eine Verhaltensstörung bei
Kaninchen. Deutsche Tierärztliche Wochenschrift 82,
350-351
The provision of straw can prevent hair-pulling-and-eating.
Harris LD, Custer Lb, Soranaka ET, Burge R, Ruble GR 2001. Evaluation
of objects and food for environmental enrichment of NZW rabbits.
Contemporary Topics in Laboratory Animal Science 40(1),
27-30
"Male and female 6-week old New Zealand White rabbits
were divided into three groups: food-enriched (Bunny Stix, Bunny
Blocks, or celery), non-food enriched (Jingle Ball, Kong toy,
or Nylabone), and not enriched. ... Rabbits spent significantly
more time interacting with the Bunny Stix than any other food
item or non-food object. In addition, total activity time was
significantly greater for all rabbits enriched with food versus
any of the non-food items."
Lehmann M 1990. Beschäftigungsbedürfnis bei jungen Hauskaninchen:
Rohfaseraufnahme und Tiergerechtigkeit. Schweizer Archiv für
Tierheilkunde 132, 375-381
It was found that young rabbits have a strong preference for
hay as a medium to engage in activity.
Lidfors L 1997. Behavioural effects of environmental enrichment
for individually caged rabbits. Applied Animal Behaviour Science
52, 157-169
Hay was more effective than grass-cubes, sticks, and a box
[rat cage] in reducing behavioral disorders and giving individually
housed male rabbits something to do. The hay was placed in empty
water bottles to "make it a more lengthy task for the rabbits
to pull the straws out.
Metz JHM 1987 Behavioural problems of rabbits in cages. In Rabbit
Production Systems Including Welfare. Auxilia T (ed), 221-230.
Official Publications of the European Communities, Luxembourg,
Belgium
Group-housed rabbits interacted with hay 11% of the 24-h day.
Raje SS, Stewart KL 1997. Group
housing for male New Zealand White rabbits. Lab Animal
26(4), 36-37
To promote foraging, we scattered unscheduled treats in the
substrate materials (i.e., corn cob bedding). These treats included
dry cereal, apples, carrots, and Rabbit Stix.
Table
of Contents
Social
Enrichment
Group-Housing & Group
Formation
Rodents
Rats
Hurst JL, Barnard CJ, Nevison CM, West CD 1997. Housing and welfare
in laboratory rats: Welfare implications of isolation and social
contact among caged males. Animal Welfare 6, 327-347
Exposure to neighbours [visual contact only] reduced the aggressiveness
of singly-housed males when they were eventually introduced into
an unfamiliar group, suggesting that a degree of exposure to neighbours
may have some welfare benefits for laboratory-housed rats."
Patterson-Kane EG, Hunt M, Harper D 2002. Rats demand social contact.
Animal Welfare 11, 327-332
"Most of the rats in this experiment showed a persistent
demand for social contact but not for physical cage improvements.
These data suggest that social enrichment should be given the
highest priority as a source of environmental enrichment for laboratory
rats.
Patterson-Kane EG, van de Ven M, Ras T 2001. Enrichment of laboratory
rat caging. AALAS [American Association for Laboratory Animal
Science] 52nd National Meeting Official Program , 106 (Abstract)
"Social contact seems to be the most important enrichment.
Rats show higher demand for contact with three familiar rats,
than for larger cages or toys."
Patterson-Kane EP, Hunt M, Harper D 2004. Rat's demand for group
size. Applied Animal Welfare Science 7, 267-272
Rats had a preference for groups of 5 animals.
Mice
Barnard CJ, Hurst JL, Aldhous P 1991. Of mice and kin: The functional
significance of kin bias in social behaviour. Biological Reviews
66, 379-430
Mice tend to be intolerant of same sex partners at the time
of puberty. It is, therefore good advice to establish same sex
groups well before the onset of puberty.
Emond M, Faubert S, Perkins M 2003. Social conflict reduction
program for male mice. Contemporary Topics in Laboratory Animal
Science 42(5), 24-26
"At our Center, two observation periods were set aside
daily in order to identify, according to previously described
behaviors, dominant [aggressive] mice and separate these when
indicated. By reducing or eliminating the number of aggressive
acts between group members in the same cage, our social conflict
reduction program has led to a 57% reduction of mice being reported
for clinical signs, death, and euthanasia."
Marashi V, Barnekow A, Ossendorf E, Sachser N 2003. Effects of
different forms of environmental enrichment on behavioral, endocrinological,
and immunological parameters in male mice. Hormones and Behavior
43, 281-292
Animals were kept in groups of four males under three different
housing conditions: (A) nonstructured Makrolon type III laboratory
cages ("standard-housing" = S); (B) equivalent laboratory
cages that were enriched with a box and a scaffolding ("enriched-housing"
= E); and (C) spacious terraria that were structured richly ("super-enriched-housing"
= SE). Both forms of enrichment caused a sharp rise in aggressive
behavior, though play behavior was increased in E and SE mice,
too. "Plasma corticosterone concentrations and adrenal tyrosine
hydroxylase activities were significantly increased in male mice
kept in both forms of enriched cages. .The behavioral and endocrinological
differences were partly reflected by immunological parameters.
.. Despite the elevated levels of stress hormones under both forms
of enriched housing, the behavioral parameters also indicate positive
effects of the enrichment, especially on SE animals. Obviously,
an environmental enrichment is beneficial for male mice as long
as the spatial conditions are generous enough to allow coping
with the increased aggression brought about by the enrichment."
McGregor PK, Ayling SJ 1990. Varied cages result in more aggression
in male CFLP mice. Applied Animal Behaviour Science 26,
277-281
Male mice were introduced in unfamiliar test cages. "Adding
bricks, flowerpots and extra food and water sources halved latency
to aggression. When males were introduced to the more varied cages,
they seemed to perform more exploratory behaviour, both of the
environment and of each other, were more active generally and
appeared to more 'excitable', rushing around the cage and over
the objects. Objects close to mice are known to act as visual
landmarks for territorial boundaries and the more rapid aggression
in the varied cages may have resulted because the males were beginning
to defend territories, facilitated by the provision of landmarks.
More rapid aggression may have been caused by the provision of
resources (food and water) and objects (pots and bricks) that
are analogous to defendable resources in the wild." Obviously,
it is not a good idea to form new groups of male mice in an enriched
environment.
Peng X, Lang CM, Drozdowicz CK, Ohlsson-Wilhelm BM 1989. Effect
of cage population density on plasma corticosterone and peripheral
lymphocyte populations of laboratory mice. Laboratory Animals
23, 302-306
Groups were formed of 2, 4 or 8 animals in cages with a floor
areas of 390 cm2. "The results of this study suggest that
population density of 4 mice per cage induced minimal stress compared
to that induced by the population density of 2 or 8 mice per cage.
Since stress is known to induce alteration in a variety of biological
functions, the population density of mice per cage should be considered
in the interpretation of research data. .... There was no significant
difference of plasma corticosteroid concentration in all the 3
groups on day 14" suggesting "that social hierarchy
development might play a more important role to animal stress
than the population density in this study. It is possible that
fighting between mice within newly assigned groups was the main
cause of the elevated corticosteroid concentration."
Van Loo PLP 2001 Male Management - Coping with aggression problems
in male laboratory mice (Doctoral Thesis). Diest, Belgium:
University of Utrecht
"The purpose of this thesis was to find practical solutions
for coping with excessive aggressive behaviour in male laboratory
mice. .. The proximity of another male is preferred to individual
housing, irrespectively of dominance status, kinship or familiarity.
... Male mice of all ages tested have a preference for social
contact during rest periods. ... Nesting material was highly preferred
by mice of all ages tested. .. Transfer of nesting material reduced
post-cleaning aggression .. Moderate increase of intermale aggression
in larger cages compared to smaller cages [was observed] .. Aggression
in groups of eight animals was considerably higher than in groups
of three animals. .. Nesting material reduced aggressive behaviour,
while a shelter increased [it]."
Van Loo P 2005. Coping with aggression in group-housed male mice.
Animal Technology and Welfare 4, 84-86
"Groups of three males have been found to show the least
aggression because the dominance hierarchy is more stable than
in larger groups. Pair housing can increase aggression and is
more stressful to the subordinate because he will not receive
social comfort from a mid-ranking mouse."
Van Loo PLP, Kruitwagen CLJJ,
Van Zutphen LFM 2000. Modulation of aggression in male mice: Influence
of cage cleaning regime and scent marks. Animal Welfare
9, 281-295
"Group housing of male laboratory mice often leads to
welfare problems due to aggressive behaviour. ... Aggression peaks
after disturbances such as cage cleaning. .. Our results indicated
that neither kinship nor distribution of urine marks affected
aggression. Olfactory cues from nesting and bedding material,
however, affected aggression to a marked degree: transfer of nesting
material reduced aggression significantly, while transfer of sawdust
containing urine and faeces seemed to intensify aggression. ...
We conclude that the transfer of nesting material will reduce
aggression, or at least slow down its development, and thus aid
the reduction of social tension due to cage cleaning."
Van Loo PLP, Van Zutphen LFM, Baumans V 2003. Male management:
coping with aggression problems in male laboratory mice. Laboratory
Animals 37( ), 300-313
"We review results from the literature and our own research
with regard to coping with excessive aggressive behaviour in male
laboratory mice. Based on this review practical recommendations
concerning the housing and care of male laboratory mice are formulated.
In short, it is recommended to avoid individual housing, to transfer
odour cues from the nesting area during cage cleaning and to apply
nesting material as environmental enrichment. Furthermore, group
size should be optimized to three animals per cage."
Hamsters, guinea pigs and gerbils
Agass K, Ruffle I 2005. A refinement in guinea pig housing within
the laboratory enviroment. Animal Technology and Welfare
4, 51-52
The aggression problem in groups of males was addressed by
partitioning the large cage and dividing the group into pairs.
This considerably reduced the incidence of bullying.
Arnold CE, Estep DQ 1990. Effects
of housing on social preference and behaviour in male golden hamsters
(Mesocricetus auratus). Applied Animal Behaviour Science
27, 253-261
The hamsters showed an overall preference for being with conspecifics
and better growth when housed in same-sexed groups [of 5 males;
rather than singly], thus supporting the conclusion that hamsters
do not prefer being housed individually. " However, 40% of
the animals showed evidence of wounding.
Arnold CE, Gillaspy S 1994. Assessing laboratory life for golden
hamsters: social preference, caging selection, and human interaction.
Lab Animal 23(2), 34-37
"Female hamsters preferred social contact with other females
to solitary housing. Group-housing was associated with wounding
from fights and higher rates of obesity.. Since these animal prefer
contact with conspecifics, and since group-housed hamsters are
easier for humans to handle [less aggressive] than singly housed
hamsters, perhaps pair-housing would be a suitable alternative."
Banjanin S, Barley J, Bell L, Cunneen M, Johnston I, Quintero
I, Weilemann R, Reinhardt V 2004. Environmental
enrichment for guinea pigs: A Discussion by the Laboratory Animal
Refinement & Enrichment Forum. Animal Technology and
Welfare 3, 161-163
"In summary, social-housing is the most species-appropriate
living environment for guinea pigs. If a research protocol requires
single-caging, guinea pigs should always be able to maintain visual,
auditory and olfactory contact with other guinea pigs to buffer
the stress of social deprivation."
Fenske M 1992. Body weight and
water intake of guinea pigs: influence of single caging and an
unfamiliar new room. Journal of Experimental Animal Science
35, 71-79
"It is recommended that if guinea pigs have to be caged
singly, they should remain in their home room, for enabling them
to express their need for olfactory/auditory contact with conspecifics."
Hull EM, Kastaniotis C, L'Hommedieu G, Franz J 1976. Environmental
enrichment and crowding: Behavioral and hormonal effects. Physiology
and Behavior 17, 735-741
"Environmental enrichment and available refuge did ameliorate
the usual hormonal responses to crowding in gerbils. The enriched
environment consisted of a large central octagonal space (34cm/side,
42cm high), with a small tunnel connecting to a red Plexiglas
cubicle emerging from each of the eight sides. Rocks, sticks and
a hollow cinderblock were in the central area."
Raje SS, Stewart KL 2000. Group
housing female guinea pigs. Lab Animal 29(8), 31-32
"Group housing [female] guinea pigs can save space and
money, while improving housing standards" The authors describe
enclosure design, enrichments, and husbandry techniques that facilitate
group housing female guinea pigs As new guinea pigs are received,
we modify the enclosure. Specifically, we add a divider (wire
rack) at one end to provide vocal and visual contact without adding
animals to the established colony until a two-week acclimation
period is complete."
Sachser N, Lick C 1991. Social experience, behavior and stress
in guinea pigs. Physiology and Behavior 50, 83-90
Guinea pigs require considerable socialisation to acquire the
skills necessary to build up stable social structures. If rearing
conditions are inadequate this creates conditions of social instability
and extreme endocrine changes occur.
Stanzel K, Sachser N 1994. The ontogeny of male Guinea pigs living
under different housing conditions. Applied Animal Behaviour
Science 40, 94 (Abstract)
"From these data is was concluded that young male Guinea
pigs develop more favourably in colonies than in pairs or singly."
Rabbits
Batchelor GR 1991. Group housing on floor pens and environmental
enrichment in sandy lop rabbits. Animal Technology 42(109-120)
Species-adequate group-housing arrangements for rabbits is
described. Rabbits housed in social groups benefit both from the
company of each other and from exercise. While female rabbits
are kept in groups with direct physical contact, solitary bucks
are housed on floor pens in such a way that they can 'only' see,
touch and smell their neighbours without risk of fighting.
Cubitt S 1999. Experiences of floor housing Lop rabbits at MSD.
Animal Technology 50, 162
"Observations made during routine husbandry suggested
that the group-housed rabbits were more active, engaged in frequent
affiliative behaviour with other rabbits such as grooming, playing
and were more willing to approach the technicians. The rabbits
also seemed to make more use of the enrichment provided for them
than when single-housed.".
Gunn D, Morton DB 1994 The behaviour of single-caged and group-housed
laboratory rabbits. In Welfare and science : Proceedings of
the Fifth Federation of European Laboratory Animal Science Associations
(FELASA) Symposium. Bunyan J (ed), 80-84. Royal Society of
Medicine Press, London
Given the choice, rabbits spent an average of 79% of observed
time in close proximity with others.
Hammond K 1988. Communal housing makes for happy rabbits. Canadian
Council on Animal Care-Resource 13, 4
A plea for group-housing rather than single-housing of rabbits.
Held SDE, Turner RJ, Wootton RJ 1995. Choices of laboratory rabbits
for individual or group-housing. Applied Animal Behaviour Science
46, 81-91
Low-ranking does did not avoid living in a group [even though
they received more aggressions than high-ranking does] when given
the choice of access to a solitary pen.
Held SDE, Turner RJ, Wootton RJ 2001. The behavioural repertoire
of non-breeding group-housed female laboratory rabbits (Oryctolagus
cuniculus). Animal Welfare 10, 437-443
"Trichophagy and stereotypic behaviors observed in singly
caged rabbits were not observed in group-housed does."
Howard B, Wortley M, Kay R 1999. Rabbit enclosures - structure
and space. Animal Technology 50, 156-157
"When a screen was hung from the top of the pen near one
end, raised approximately 10 mm above the surface of the litter,
all rabbits in the pen spent much of their time in the small shielded
area. Provision of tubes within which rabbits can hide together
with the hanging screen produced an environment in which aggression
(groups of 4 or 6 [probably female] rabbits) was minimised. In
contrast, providing a shelf on which a rabbit could sit had no
effect on overall levels of aggression in the pen, although dominant
rabbits did tend to monopolise it."
Krohn TC, Ritskes-Hoitinga J, Svendsen P 1999. The effect of feeding
and housing on the behaviour of the laboratory rabbit. Laboratory
Animals 33, 101-107
"While the [individually housed] rabbits in cages spent
2-5% of the time performing abnormal behaviour like biting the
bars or scratching the bottom of the cage, these activities were
virtually absent in group-housed rabbits in floor pens."
Love JA 1994. Group Housing: Meeting the physical and social needs
of the laboratory rabbit. Laboratory Animal Science 44,
5-11
"Group housing of rabbits met the experimental and economic
limitations, and so these cannot be used to justify the continued
use of single cages for the majority of rabbits. ... Group sizes
of four to eight rabbits work well if the groups are to remain
together for long periods. ... It is highly desirable to establish
the groups when the animals are young, and certainly before they
reach puberty. ... The animals in a group should be of the same
age and sex, but it is not necessary for them to be littermates.
All female groups are best for the long-term, although groups
of castrated males will also be stable. ... The pen or bin should
be large enough to allow three hops in one direction. ... If a
wire mesh cover is used to keep the rabbits in the bin, then it
must be at least 70 cm above the floor of the bin to allow larger
rabbits to sit up on their hind legs. ... The rabbits were considered
[by animal care technicians] to be quieter and less 'stressed
out' in the pens. They were highly visible, compared with those
in the single-cage situation, and it was a pleasure to see them
interact with each other. ... If the animals have been provided
with an area to hide, they will usually dart into it. This place
should be darker than the surrounding areas, thereby providing
the animals with a sense of security. Once in the hiding place,
the animals may be picked up quietly without struggling."
Love JA 1988. Housing
for rabbits. Humane Innovations and Alternatives in Animal
Experimentation 2, 47-48
"In most laboratory situations, rabbits are kept isolated
in cages. ... We have attempted to correct this deficiency by
keeping rabbits in either large tubs which can accommodate six
or more animals or in indoor/outdoor pens. Provision has been
made in each case for a covered area under which the animals can
run when they are startled. ... The rabbits in the pens and tubs
are not as heavy as their more sedentary caged counterparts. They
run and skip and sometimes fight although we find that rabbits
which have been together from a young age fight less than the
older rabbits. .... Disease problems, other than fighting injuries,
appear to be less frequently than in the caged animals. Initial
studies suggest that hairballs are much less common in the rabbits
in tubs than those in cages. ... Tubs [lobster tubs] are cheaper
than the traditional stainless steel caging and permit greater
behavioural expression by the animals."
Love JA, Hammond K 1991. Group-housing
rabbits. Lab Animal 20(8), 37-43
The management and success of a group-housing indoor/outdoor
pen system for rabbits [mainly females] is described and discussed.
"The levels of fighting injuries was low, and considered
acceptable. ... Castrating males before reaching puberty resolved
this problem [injurious fighting among males]. ... There was no
evidence that infectious disease spread was a problem among the
group-housed rabbits. ... There were no clinical cases of trichobezoars
in the group-housed rabbits. Several factors - lack of exercise,
lack of roughage, pathologic grooming due to isolation - are implicated
in the formation of trichobezoars, and the group-housing system
took these into account. ... Group-housing rabbits requires the
ability to recognize the signs of an unwell animal. Adding treats
like hay to the diet helps, as does the weekly health check. These
checks become routine every time technicians handle the rabbits,
and do not require much time."
Podberscek AL, Blackshaw JK, Beattie AW 1991. The behaviour of
group penned and individually caged laboratory rabbits. Applied
Animal Behaviour Science 28, 353-363
"Only caged rabbits showed stereotypic behaviours and
only penned [females plus castrated males] rabbits showed aggression.
Penned [group-housed] rabbits also exhibited higher frequencies
of comfort and marking and investigatory behaviours. Penned housing
systems are more acceptable than cage systems as they allow the
rabbits to socialise and hop fully. The negative aspects of pens
are the levels of aggression and the high frequency of scratching,
sneezing and head shaking observed."
Raje SS, Stewart KL 1997. Group
housing for male New Zealand White rabbits. Lab Animal
26(4), 36-37
Establishing a group of 5 castrated male rabbits "resulted
in all but one rabbit suffering some kind of minor injury"
during a major conflict on day 6. Housing the two older animals
together as a pair and the three younger ones together as a trio,
with both groups keeping visual contact, was successful. The animals
preferred a 18" PVC pipe as hiding place. Keeping the animals
on the floor rather than in cages eliminated the problem of pododermatitis
in the two older animals.
Russert MH, Hess BH 2001. Conversion of single-housed New Zealand
white rabbits to group-housed pen. AALAS [American Association
for Laboratory Animal Science] 52nd National Meeting Official
Program , 101 (Abstract)
Ten previously single-caged individuals[probably females] were
directly introduced as a group in a pen. "Even though some
minor fighting occurred, no major injuries were incurred by any
of the rabbits. Group housing showed to be a very successful enrichment
tool for a rabbit colony and a viable alternative to single housing.
... The animals were identified with an implanted microchip that
corresponded to a cage card on the outside of the pen."
Stauffacher M 1993. Refinement bei der Haltung von Laborkaninchen.
Ein Beitrag zur Umsetzung von Tierschutzforderungen in der Praxis.
Der Tierschutzbeauftragte 2/3, 18-33
Groups are female rabbits are best formed with animals of less
than 4 months of age, ideally with animals kept together as a
group from birth. Exchange of partners of pairs should be avoided
as the introduction of a new female can lead to serious xenophobic
reactions. The cage should be large enough to allow the rabbit(s)
to stretch full length, hop some steps, have a choice for resting
and a possibility of withdrawal and avoid social contact. The
insertion of a raised area provides the caged rabbit with a choice
of resting sites, light gradients, a darkened area for withdrawal
and a stimulus for locomotor patterns.
Tamburrino PA, Michonski KJ, Cameron RA 1999. Adaptation of dog
kennels for group housing of rabbits. Abstracts of the AALAS
[American Association for Laboratory Animal Science] Meeting
, 33 (Abstract)
"An increase in rabbit census prompted conversion of dog
kennels to rabbit pens Twelve to 20 week-old female rabbits are
housed in five per group on arrival. ... Enrichment for group-housed
rabbits included food treats, toys, music, and human contact.
Each pen also contained a half of a 23-inch diameter plastic barrel
for seclusion. Twenty-three of 135 rabbits sustained minor fight
wounds ... and two sustained wounds requiring additional veterinary
care. Most of the wounds occurred during a brief interval and
were attributed to four aggressive rabbits, which underscores
timely identification of aggressors. Overall, the group-housed
rabbits are easier to restrain compared to individually-housed
rabbits. Group housing is a viable alternative to individual housing
and enhances the well-being of rabbits by allowing natural posturing
and socialization."
Turner RJ, Held SDE, Hirst JE, Billinghurst G, Wootton RJ 1997.
An immunological assessment of group-housed rabbits. Laboratory
Animals 31, 362-372
"Laboratory rabbits kept in barren 'traditional' cages
tend to develop stereotypic behaviours and bone deformation. We
have used an alternative regime, housing adult does as groups
of four or five in floor pens (2.5-3 m2) supplied with hiding
places and bedding. ... We found no evidence of immunosuppression.
... These results, together with the animals' general health and
ease of handling, lead us to conclude that group-housed does are
suitable for raising antisera and other purposes, provided that
they are adequately monitored."
Wemelsfelder F 1994. Animal
boredom - A model of chronic suffering in captive animals and
its consequences for environmental enrichment. Humane Innovations
and Alternatives in Animal Experimentation 8, 587-591
"Rabbits have been successfully housed in cages of several
square meters big, in which a nesting box and ample straw and/or
hay is provided. Because the animals create a defecation area
in one corner, the cage stays clean and the straw unsoiled for
weeks. Another successful way of achieving group housing is to
join several smaller cages into a chain of attached compartments,
into which the animals can withdraw from other animals. Straw
is provided in several, but not all compartments, since the animals
defecate in compartments without straw, no hygienic problems arise."
Whary M, Peper R, Borkowski G, Lawrence W, Ferguson F 1993. The
effects of group housing on the research use of the laboratory
rabbit. Laboratory Animals 27, 330-341
"Single and group [8 females] housed rabbits did not significantly
differ in physiological and immunological measurements, indicating
that the practical research performance (immune response, stress
level, growth rates etc.) of these rabbits was not significantly
affected by group housing compared with the more traditional single
housing."
Pair-Housing
Rodents
Heath M 1999. Preliminary behaviour data for single and pair housed
rats. Animal Technology 50, 47-48
"Singly housed rats spent most of the time in the back
of the cage, while pairs spent most time by the food hoppers.
This may have been exacerbated by the presence of humans, as pair
housed rats were more confident overall. Activity patterns were
very different between singly and pair housed rats, in term of
both the total time spent doing different things and the time
when specific activities occurred. In particular, single rats
spent far less time playing than pair housed rats."
Van Loo PLP, Baumans V 1998. Preference of subordinate male mice
for their dominant cage mates. Aktuelle Arbeiten zur artgemaessen
Tierhaltung, KTBL-Schrift 380, 45-52
Experiments that allowed subordinate male mice to choose either
a cage inhabited with a dominant partner or an empty cage have
shown that the mice preferred the proximity of the dominant male
to individual housing.
Van Loo PLP, de Groot AC, Van Zuthpen BFM, Bauman V 2001. Do male
mice prefer or avoid each other's company? Influence of hierarchy,
kinship, and familiarity. Journal of Applied Animal Welfare
Science 4, 91-103
"Experiments that allowed male mice with different histories
to choose either an inhabited or an empty cage have shown that
the mice preferred the proximity [separated by wire mesh or Perspex
wall with holes] of another male over individual housing. .. The
study concludes that separation and single housing for mice are
not attractive solutions for overcoming aggression in group-housed
male mice and that alternative approaches, such as improving the
housing conditions, should be explored as a way of tempering intermale
aggression."
Rabbits
Brooks DL, Huls W, Leamon C, Thomson J, Parker J, Twomey S 1993.
Cage enrichment for female New Zealand White rabbits. Lab Animal
22(5), 30-38
"Given a choice, [female] rabbits preferred the company
of one another."
Chu L, Garner JP, Mench JA 2004. A behavioral comparison of New
Zealand White rabbits (Oryctolagus cuniculus) housed individually
or in pairs in conventional laboratory cages. Applied Animal
Behaviour Science 85, 121-139
"We compared the behavior of female New Zealand White
rabbits (Oryctolagus cuniculus) housed either individually (N=4)
in cages measuring 61 cm×76 cm×41 cm or in non-littermate
pairs (four pairs) in double-wide cages measuring 122 cm×76
cm×41 cm. .. Over the 5 months, individually housed rabbits
showed an increase in the proportion of the total behavioral time
budget spent engaged in abnormal behaviors (digging, floor chewing,
bar biting), from 0.25 to 1.77%, while pairs remained unchanged
at 0.95% . .. Paired rabbits engaged in more locomotor behavior
(F1,6=16.49; P<0.0066) than individual rabbits (average proportions
of time budget: 2.71 and 0.70% for paired and individual rabbits,
respectively), which may be important because caged rabbits are
susceptible to osteoporosis and other bone abnormalities due to
the restricted ability to move. Time spent feeding and body weights
of dominant and subordinate rabbits in a pair did not differ,
indicating that food competition was not a problem, and paired
rabbits were often observed in physical contact (26.7% of data
records) although the size of the cages allowed physical separation.
Aggression between pairmates did not increase significantly during
the study. However, one pair did have to be separated at the end
of the study due to bite wounds from persistent aggression. Thus,
although methods for decreasing injurious aggression require further
investigation, the beneficial effects of pair housing in decreasing
abnormal behaviors and increasing locomotion suggest that pair
housing should be considered as an alternative to individual housing
for caged laboratory rabbits."
Huls WL, Brooks DL, Bean-Knudsen D 1991. Response of adult New
Zealand white rabbits to enrichment objects and pair-housing.
Laboratory Animal Science 41, 609-612
"The female pair-housed rabbits spent 88% of the observation
intervals in proximity to one another. "No aggression was
observed between the rabbits during any of the observations."
Kalagassy EB, Carbone LG, Houpt KA 1999. Effect of castration
on rabbits housed in littermate pairs. Journal of Applied Animal
Welfare Science 2, 111-121
"This study investigated the possibilities that male siblings
will remain compatible if never separated from birth and that
castration will improve compatibility." In paired animals
"there was no evidence of the stereotypies observed among
individually housed rabbits. Castrated ... littermates demonstrated
a significantly higher level of living together compatibility
than did the intact controls. All rabbits chose to rest in close
proximity or contact, although this preference was stronger in
castrated males. During puberty, intact males displayed more serious
aggression. ... Paired rabbits exhibit many postures and behaviors
that are not possible in the small, solitary cages currently listed
as minimum recommendations."
Raje SS, Stewart KL 1997. Group
housing for male New Zealand White rabbits. Lab Animal
26(4), 36-37
Establishing a group of 5 castrated male rabbits "resulted
in all but one rabbit suffering some kind of minor injury"
during a major conflict on day 6. Housing the two older animals
together as a pair and the three younger ones together as a trio,
with both groups keeping visual contact, was successful. The animals
preferred a 18" PVC pipe as hiding place. Keeping the animals
on the floor rather than in cages eliminated the problem of pododermatitis
in the two older animals.
Human
Interaction
Rodents
Arnold CE, Gillaspy S 1994. Assessing laboratory life for golden
hamsters: social preference, caging selection, and human interaction.
Lab Animal 23(2), 34-37
30 hamsters were tested at weaning. Regular handling made the
animals less defensive.
Davis H, Perusse R 1988. Human-based social interaction can reward
a rat's behavior. Animal Learning and Behavior 16, 89-92
Rats work in a Skinner box for petting by a preferred human
in the absence of reward such as food.
Davis H, Taylor A, Norris C 1997. Preference for familiar humans
by rats. Psychological Bulletin 4, 118-120
24 of the 26 subjects correctly chose the handler with whom
they had previously interacted [for 10 min]. Rats prefer contact
with an individual with whom they have safely interacted versus
a strange individual. Their preference for a familiar human remains
intact at least 5 month after the last contact.
Hirsjärvi PA, Junnila MA 1988 The effects of gentling on
open-field behaviour of rats. In New Developments in Biosciences:
Their Implications for Laboratory Animal Science. Beynen AC,
Solleveld HA (eds), 399-403. Marinus Nijhoff, Dordrecht, The Netherlands
Non-gentled rats showed higher frequencies and durations of
passive motionlessness and higher proportions of loose stools
and rigid movements during frightening situations than rats who
had been gentled for three weeks.
Lawlor MM, Wells PA, Weinberg J 1975. Deleterious effect of infantile
stimulation in the golden hamster. Experimental Brain Research
23(Supplement), 120 (Abstract)
Unlike in rats, early handling (day 1-21) makes hamsters timid
and wild when they are adults.
Meijer MK, Kramer K, Remie R, Spruijt BM, van Zutphen L. F. M.,
Baumans V 2002. Refinement of routine procedures: Can environmental
enrichment reduce the stress response of laboratory mice. Fourth
World Congress on Alternatives and Animal Use in the Life Sciences
- Program and Abstracts , 97 (Abstract)
Female mice housed in trios in enriched cages and handled daily
reacted with less anxiety to procedures than female mice housed
singly in barren cages and handled only when necessary.
Nerem RM, Levensque MJ, Cornhill JF 1980. Social environment as
a factor of diet induced atherosclerosis. Science 208,
1475-1476
Rabbits were fed a high-cholesterol diet to induce atherosclerosis.
Animals who received special attention from a person (frequent
handling, petting, playing, gentle vocalization) showed a markedly
lower incidence of atheroslerosis than subjects who received no
extra attention.
Wells PA 1985 The Influence of Early Handling on the Temporal
Sequence of Activity and Exploratory Behaviour in the Rat (Ph.D.
Thesis). London, UK: University of London, UK
Gentle handling during infancy makes rats less fearful, quasi
tame in situations in which control rats remain timidly crouched
at the back of the cage.
Würbel H 2001. Ideal homes? Housing effects on rodent brain
and behaviour. Trends in Neuroscience 24, 207-211
Pups who have been handled show reduced behavioural and endocrine
responses to stress.
Rabbits
Anderson CO, Denenberg VH, Zarrow MX 1972. Effects of handling
and social isolation upon the rabbit's behaviour. Behaviour
43, 165-175
Gentle, frequent handling of young rabbits increases general
activity while buffering emotionality.
Jezierski TA, Konecka AM 1996. Handling and rearing results in
young rabbits. Applied Animal Behaviour Science 46, 243-250
"It was concluded that the tender and frequent handling
of young rabbits not only changes their behaviour in terms of
reducing fear of humans but also positively influences growth
rate and reduces mortality rate."
Kertsen AMP, Meijsser FM, Metz JHM 1989. Effects of early handling
on later open-field behaviour in rabbits. Applied Animal Behaviour
Science 24, 157-167
Gentle, frequent handling of pre-weaned rabbits increases general
activity while buffering emotionality.
Metz JHM 1983/84. Effects of early handling in the domestic rabbit.
Applied Animal Ethology [Applied Animal Behaviour Science]
11, 86-87 (Abstract)
Rabbits handled from birth to 3 weeks of age showed a reduction
in fearfulness toward humans.
Podberscek AL, Blackshaw JK, Beattie AW 1991. The effects of repeated
handling by familiar and unfamiliar people on rabbits in individual
cages and group pens. Applied Animal Behaviour Science
28, 365-373
Rabbits of post-weaning age showed a reduction in fearfulness
towards familiar and unfamiliar people after they have repeatedly
approached and handled them.