Behaviour of growing rabbits under

various housing conditions

Zoltan Princz a, Antonella Dalle Zotte b, Istvan Radnai a,Edit Bıro-Nemeth a, Zsolt Matics a, Zsolt Gerencser a,

Istvan Nagy a, Zsolt Szendro a,*a Faculty of Animal Science, University of Kaposvar, H-7400 Kaposvar, Guba Sandor Str. 40, Hungary

b Department of Animal Science, University of Padova, Agripolis, Viale dell’Universita, 16-35020 Legnaro, Italy

Accepted 20 June 2007

Available online 1 August 2007

Abstract

The aim of this research was to assess the effects of environmental variables (group size, stocking

density, floor type, environmental enrichment) on behaviour – as a welfare indicator – of growing rabbits.

Two experiments were carried out with Pannon White rabbits. In experiment 1, 5-week-old rabbits (n = 112)

were placed in cage blocks (2 m2) with a stocking density of 16 or 12 rabbits/m2. The cages (0.5 m2) differed

in the floor type (wire or plastic net) and in the presence or absence of gnawing sticks (white locust). The

animals could move freely among the four cages through swing doors. Infrared video recording was

performed once a week, the number of rabbits in each cage was counted every half an hour (48 times/day)

during the 24 h video recording. Between ages 5 and 11 weeks the rabbits showed a preference towards the

plastic net floor (16 rabbits/m2, 62.5%; 12 rabbits/m2, 76.5%; P < 0.001). Gnawing stick application

significantly affected cage preference: 54.1% (16 rabbits/m2) or 53.1% (12 rabbits/m2) of the rabbits choose

the enriched cages (P < 0.001). In experiment 2, the 5-week-old rabbits were placed either in cages (2

rabbits/0.12 m2, n = 72) or pens (13 rabbits/0.86 m2, n = 104) with 16 rabbits/m2. The floor types were wire

or plastic net, with the presence or absence of gnawing sticks on the walls. Video recordings were made at

6.5 and 10.5 weeks of age between 11:00 a.m. and 5:00 p.m. and between 11:00 p.m. and 05:00 a.m.

Compared to cages, the rabbits housed in pens spent less time with resting (58% versus 67%) and more time

with locomotion (6.7% versus 3.8%) but the frequency of aggressive behaviour (measured by the number of

ear lesions) was also higher (0.14% versus 0.01%). In pens the application of gnawing sticks significantly

decreased the frequency of ear injuries (0.05% versus 0.22%). The floor type did not affect any behavioural

pattern (eating, drinking, movement, resting, comfort, social, investigatory) significantly. The main results

showed that growing rabbits have a preference for plastic net floor and cages provided with gnawing sticks.

www.elsevier.com/locate/applanim

Applied Animal Behaviour Science 111 (2008) 342–356

* Corresponding author. Tel.: +36 82 505800; fax: +36 28 320175.

E-mail address: pohnl@ke.hu (Z. Szendro).

0168-1591/$ – see front matter # 2007 Elsevier B.V. All rights reserved.

doi:10.1016/j.applanim.2007.06.013

The resting, locomotive and aggressive behaviour was modified by the housing system and the presence of

gnawing sticks decreased the frequency of physical injuries.

# 2007 Elsevier B.V. All rights reserved.

Keywords: Rabbit; Behaviour; Group size; Stocking density; Floor type; Gnawing stick

1. Introduction

The ancestor of the domesticated rabbit, the European wild rabbit (Oryctolagus cuniculus), is

a crepuscular animal and is mainly active during the dusk, night and dawn (Jilge, 1991). During

the night the European wild rabbit stays mostly outside of the rabbit hole. Being a prey-animal its

chances to escape from predators is higher during the night. The domesticated rabbit shows

similar behaviour if kept similarly to its ancestor. However, if the rabbits are kept in cages their

behavioural patterns change considerably primarily from the viewpoint of their activity, as

consequence of the limited available space (Lehmann, 1987; Drescher, 1992; Stauffacher, 1992;

Morisse and Maurice, 1997; Xiccato et al., 1999; Martrenchar et al., 2001).

Nowadays animal welfare raises interest world-wide. Housing the animals in large groups is

believed to be one of the most important factors of well-being. Wild rabbits live in colonies

including several adults and a lot of young rabbits together. In most intensive rabbit farms two or

three growing rabbits are housed per cage. Searching for a better housing condition fitting the

animal welfare aspects several authors compared the behaviour and production of rabbits in small

cage and pens (larger groups) (Verga et al., 2006; Jordan et al., 2006; Szendro and Luzi, 2006).

In a preference test Matics et al. (2004) demonstrated that young (3–4-week-old) rabbits like

to huddle together regardless of the cage size. Comparing the behaviour of growing rabbits in

smaller and larger groups (cage versus pen) Mirabito et al. (1999) observed that rabbits in smaller

groups spent more time resting but the frequency of locomotion, exploration and social behaviour

were higher in pens. Similar results were found by Martrenchar et al. (2001) in respect to resting,

eating and interacting socially but the locomotory and abnormal behaviours were not connected

with the housing system. In larger groups (60 rabbits) more running and hopping were observed

by Postollec et al. (2003) than in smaller group (6 or 10 animals).

In spite of the several advantages of group housing some counter-arguments can be brought

up: higher risk of infection and almost importantly the higher incidence of aggressive behaviour

with the increasing age (beginning at sexual maturity at the end of growing period). Bigler and

Oester (1996), Maertens and Van Herck (2000) and Princz et al. (2005a) reported higher

incidence of aggressive behaviour and injuries on the rabbits in larger groups. Based on these

findings Rommers and Meijerhof (1998) suggested slaughtering growing rabbits before the age

of 80 days.

The effect of stocking density on behaviour of growing rabbits was examined in some

experiments but there was a large range of group sizes.

Morisse and Maurice (1997) compared groups of 6, 7, 8 and 9 rabbits/cage (15.3, 17.8, 20.4

and 23.0 rabbits/m2) and observed that behavioural patterns of rabbits at 6 weeks were only

slightly affected by stocking density. At 10 weeks of age, social interactions, feeding and

locomotory behaviour were reduced while an increase in resting, comfort and investigatory

behaviour were noted when the stocking density was higher than 15.3 rabbits/m2. If rabbits were

housed two, three or four per cage (9.6, 14.3 or 19.2 animals/m2), the frequency of resting was

lower and of hopping was higher in groups of 2 than 3 or 4 rabbits/cage because lower number of

Z. Princz et al. / Applied Animal Behaviour Science 111 (2008) 342–356 343

animals allow higher locomotor activity (Verga et al., 2004). Mormerde (1988) found that high

density may be related to lower movement frequency.

Ferrante et al. (1997) showed a slight effect of density (12 or 16 animals/m2, 3 rabbits/cage)

on the expression of the behavioural patterns. In the study of Trocino et al. (2004) a reduction

from 16 to 12 animals/m2 had only a small effect on behaviour of growing rabbits (8 animals/

cage). The experimental results indicate that 15–16 rabbits/m2 (38–40 kg/m2 at the end

of growing period) may be considered the threshold for the compatible expression of

behaviours of caged rabbits (Trocino et al., 2004; Verga et al., 2006). In spite of this statement

more experiments are needed to examine the effect of stocking density depending on the

group size.

One of the main objections to the caged rabbit housing is the barren environment. To avoid this

problem several enrichment forms were studied with regard to productive performance, and the

behaviour and welfare of growing rabbits. One of the most common enrichments is the placement

of wooden sticks of different species, size and position in the cages.

There were only a few experiments when the gnawing stick had a significant effect on the

behavioural patterns but some more cases the same tendency was observed (Jordan et al., 2006).

Princz et al. (2005a,b) observed a decrease in aggressiveness. Jordan et al. (2003) and Luzi et al.

(2003) found reduction in bar, wire or feeder biting. The frequency of self-grooming decreased

whereas that of alo-grooming increased. In the experiment of Luzi et al. (2003) feeding and

coecotrophy increased. Verga et al. (2004) demonstrated higher frequency of hopping and

sniffing another rabbits. Some of the opposite or non-significant results could be connected with

the size of group, the species of the tree, the size of the gnawing stick and its position in the cage.

Most of the results indicated that the environmental enrichment with gnawing sticks allowed

rabbits to perform a wider range of behaviours in the ethogram (Stauffacher, 1992; Verga, 2000;

Jordan et al., 2006). The most important advantage of using wooden sticks seems to be the

reduction of aggressiveness and related injuries on the bodies of the rabbits. To get more accurate

information about the effectiveness of gnawing sticks on the behaviour and welfare of rabbits’

evaluation of more experiments is needed.

In large rabbit farms, cages are made almost exclusively from wire net. The wire net floor is

cheap, easy to clean and it also meets hygienic requirements. However, some authors consider the

wire net floors unfavourable from the animal welfare viewpoint. Drescher (1992) stated that the

rabbits could spend less time with resting on wire net compared to other floor types. Behavioural

pattern data in the experiment of Trocino et al. (2004) demonstrated that there was no difference

between floors of wire net or slats with galvanized steel bars, thus indicating a similar degree of

comfort on both type of floors. Preference tests showed that more growing rabbits choose the

plastic net but with the increasing age or/and weight they accept the wire net and plastic slat floor

as well (Matics et al., 2003).

One of the wire net alternatives is the deep litter that is often recommended for the organic

production (AIAB: www.aiab.it/home/). On deep litter, the frequency of coccidiosis increased

because the rabbits have a permanent connection with the litter. The rabbits consume the bedding

material (Dal Bosco et al., 2002) which further increases the possibility of infection and

negatively affects the rabbits’ production. Morisse et al. (1999) and Orova et al. (2004) found that

under free choice the majority of the rabbits choose wire net rather than deep litter. Thus, the

analysis of the effect of the floor types on the rabbits’ welfare is justified.

Trocino and Xiccato (2006) noted that the information gathered so far is not sufficient to

make adequate suggestions for the optimal housing conditions for growing rabbits. A similar

conclusion was expressed by the EFSA (2005). In the literature the effects of group size, floor

Z. Princz et al. / Applied Animal Behaviour Science 111 (2008) 342–356344

type and gnawing stick were mostly studied separately. In our experiment these elements of

housing conditions are examined together using preference tests and time budgets.

The objective of the present study was to examine the effects of group size (cage or pen),

stocking density, floor type (wire or plastic net) and presence or absence of environmental

enrichment (gnawing stick) on the behaviour of growing rabbits. Understanding the way housing

conditions can modify the growing rabbit’s behaviour could help us to adapt the rearing

environment in order to improve the animal welfare.

2. Materials and methods

2.1. Animals, environmental conditions and diets

Pannon White rabbits were housed in a closed climatized rabbitry at the Kaposvar University. The

lighting period was 16L/8D. The temperature of the rabbitry was constantly 18 8C. Between the ages 5–9

and 9–11 weeks the rabbits were fed ad libitum a commercial pellet (14.5% crude protein, 17.5% crude

fibre, 2.0% ether extract, 10.3 MJ DE/kg, 50 ppm tiamulin, 500 ppm oxitetracycline, 1 ppm Diclazuril; and

16.0% crude protein, 16.0% crude fibre, 3.0% ether extract and 10.6 MJ DE/kg, respectively). Water was

available ad libitum from nipple drinkers. Before weaning all rabbits were kept in the cages of does on wire

net floor.

2.2. Experiment 1 (preference test)

Five-week-old rabbits (n = 112) were housed in cage blocks having a basic area of 2 m2 with a stocking

density of 16 or 12 rabbits/m2 (2 repetitions with 32 and 24 animals, respectively). The size of each cage

within a block was 0.5 m2 and animals could move freely among the four cages through swing doors. The

cages only differed in the floor type (wire or plastic net) and in the presence or absence of environmental

enrichment (gnawing sticks) (Fig. 1). The wire net floor made from galvanized wire (2 mm in diameter) with

Z. Princz et al. / Applied Animal Behaviour Science 111 (2008) 342–356 345

Fig. 1. Design of block with four cages for preference test (experiment 1).

grid size of 10 mm � 50 mm, the width of the plastic net element was 4 mm and the parallelogram shaped

holes were 15 mm � 25 mm, in size. The 25 cm long gnawing sticks were made from fresh barked white

locust (Robinia pseudoacacia) which, after barking, were 3 cm in diameter. The gnawing sticks were placed

horizontally 15 cm above the floor on the wall of the adjacent cage-blocks. A 24 h video recording was

performed once a week using infrared cameras. On the days of recording nobody was allowed to enter the

rabbitry. Using the recordings, the number of rabbits in each cage (within the cage blocks) was counted

using a scan sampling method with a frequency of 30 min (48 times a day). The feed consumption of the four

cages in a block was measured weekly. The duration of the trial was 6 weeks (i.e. between the ages of 5–11

weeks).

2.3. Experiment 2 (behavioural patterns)

The rabbits were housed in either cages (n = 72; 2 rabbits/0.122 m2) or pens (n = 104; 13 rabbits/

0.86 m2) using the same stocking density (16 rabbits/m2). In every second cage and pen the floor was wire or

plastic net (structure of experiment 2 is given in Fig. 2). The parameters of the plastic and wire net were the

same as described in experiment 1. Every second cage and pen (with wire or plastic net floor) was enriched

with gnawing sticks made from fresh barked white locust. The length and diameter of the gnawing sticks that

were placed to the cages were 10 and 3 cm, respectively. Because a larger number of rabbits were housed in

the pens (compared to cages) the length of the gnawing sticks in the pens was 33 cm.

Using infrared cameras 24 h video recordings were performed at the ages of 6.5 and 10.5 weeks. On the

days of recording nobody entered the rabbitry avoiding any disturbance to the rabbits’ behaviour.

Recordings were made during the middle parts of the dark and light periods (11:00 a.m.–5:00 p.m.,

resting period; 11:00 p.m.–05:00 a.m., active period) and were evaluated by recording the behavioural

patterns of the rabbits with a frequency of 5 min using scan sampling methods. The examined period of the

day was chosen on the basis of our former experiment representing the period of resting and active behaviour

(Princz et al., 2005b). The behavioural patterns and their definitions are summarized in Table 1.

The productive performances were also examined but the results will be published separately.

2.4. Statistical analysis

The rabbits’ presence (in frequency, %) in the various cages and the behaviour frequencies were

evaluated by performing an analysis of variance with multiple factors. The feed consumption of the cages

was analyzed by one-factor analysis of variance. Statistical analysis was performed by means of the SPSS

11.5 software package. The ANOVA model included the following effects:

Experiment 1 : Yi j ¼ mþ Sdi þ Ft j þ Gsk þ ðSd� Fti jÞ þ ðSd� GsikÞ þ ðFt� Gs jkÞ þ ei jk

Z. Princz et al. / Applied Animal Behaviour Science 111 (2008) 342–356346

Fig. 2. Design of experiment 2 (n = number of rabbits).

where m is the general mean, Sdi the effect of the stocking density (i = 1–2), Ftj the effect of the floor type

(j = 1–2), Gsk the effect of the gnawing stick (k = 1–2) and eijk is the random error.

Experiment 2 : Yi j ¼ mþ Gi þ Ft j þ Gsk þ ðG� Fti jÞ þ ðG� GsikÞ þ ðFt� Gs jkÞ þ ei jk

where m is the general mean, Gi the effect of the group size (i = 1–2), Ftj the effect of the floor type ( j = 1–2),

Gsk the effect of the gnawing stick (k = 1–2) and eijk is the random error.

3. Results

3.1. Preference test (experiment 1)

3.1.1. Floor type

The results connected with the preference of the growing rabbits between the different floor

types are presented in Tables 2 and 3.

Throughout the entire rearing period the rabbits showed preference towards plastic net floor in

both stocking densities (Table 2). Nevertheless, increasing the stocking density resulted in an

increased proportion of rabbits found on the wire net floor (62.5% versus 76.5%, P < 0.001).

With increasing age, the rabbits’ preference towards wire net floor increased. In the group with

higher stocking density (16 rabbits/m2) the proportions of rabbits that preferred plastic net floor

decreased from 77.1 to 55.2%, while in the other group (12 rabbits/m2) it decreased from 85.8 to

Z. Princz et al. / Applied Animal Behaviour Science 111 (2008) 342–356 347

Table 1

Definition of behavioural patterns according to Gunn and Morton (1995) and Morisse and Maurice (1996)

Behavioural patterns Definition

Eat Consumption of feed from the feeder, gnawing the pellet

Drink Drinking water from nipple drinkers

Resting Sleeping, lying at any position (unsleeping, stretched), sitting

Locomotory behaviours Any voluntary change of position (treading, running, hopping, prancing)

Comfort behaviours Any behaviour form connected with the own body of the animal (washing,

licking, starching)

Social and marking behaviours The behaviour forms described at the comfort behaviours conducted on other

rabbits (marking each other with the chin)

Investigatory behaviours Behaviour forms connected to the cage or to its equipments (rubbing, licking,

gnawing, smelling, marking with the chin)

Agonistic behaviours Biting, picking, scraping, chasing other rabbits, fighting

Table 2

Rabbits’ choice (frequencies, %) between floor types, at the stocking density of 16 and 12 rabbits/m2 and in the age range

of 5–11 weeks (experiment 1)

Age (weeks) 16 rabbits/m2 12 rabbits/m2

Wire net Plastic net S.E. P-value Wire net Plastic net S.E. P-value

5.5 22.9 77.1 1.94 <0.001 14.2 85.8 2.28 <0.001

6.5 33.9 66.1 1.11 <0.001 15.2 84.8 2.32 <0.001

7.5 30.8 69.2 1.23 <0.001 22.7 77.3 1.84 <0.001

8.5 45.2 54.8 0.56 <0.001 28.0 72.0 1.57 <0.001

9.5 47.4 52.6 0.49 0.001 29.5 70.5 1.36 <0.001

10.5 44.8 55.2 0.82 <0.001 31.3 68.7 1.29 <0.001

Total 37.5 62.5 0.46 <0.001 23.5 76.5 0.74 <0.001

68.7%, from 5.5 to 10.5 weeks of age. Thus, the difference between the chosen floor types

gradually decreased between the ages of 5.5–10.5 weeks from 54.2 to 10.4% (16 rabbits/m2) and

from 71.6 to 37.4% (12 rabbits/m2), respectively.

The growing rabbits more frequently chose the plastic net than the wire net both in the active

(11:00 p.m.–05:00 a.m.) and resting (11:00 a.m.–05:00 p.m.) periods (Table 3). In the rabbit

group of higher stocking density (16 rabbits/m2) the choice between the floor types was

independent of the light and dark periods. However, in the other group (12 rabbits/m2) higher

proportion of rabbits (83.0%) were found on plastic net floor in the resting period compared to the

active period (76.3%) (P < 0.01).

Feed consumption was larger by 15.6% (P < 0.05) in the cages having plastic net floors than

wire net floors during the period after weaning (5–7 weeks of age). On the contrary, at the ages of

8–9 weeks feed consumption in cages with wire net floors was larger by 7.2% (P < 0.05).

3.1.2. Gnawing stick

The results connected to the application of gnawing sticks are provided in Tables 4 and 5.

During the whole rearing period the rabbits showed preference for cages with gnawing sticks,

independently of their stocking density (Table 4). The difference between the groups (8.2%

versus 6.2%) was significant at both stocking densities (16 and 12 rabbits/m2).

Z. Princz et al. / Applied Animal Behaviour Science 111 (2008) 342–356348

Table 3

Rabbits’ choice (frequencies, %) between floor types, at the stocking density of 16 and 12 rabbits/m2 and depending on the

part of the day (experiment 1)

Part of the day 16 rabbits/m2 12 rabbits/m2

Wire

net

Plastic

net

S.E. P-value Wire

net

Plastic

net

S.E. P-value

11:00 p.m.–05:00 a.m.; active period 37.1a 62.9b 1.05 <0.001 23.7aY 76.3bX 1.49 <0.001

05:00 a.m.–10:30 a.m. 38.8a 61.2b 0.90 <0.001 27.4a 72.6bX 1.42 <0.001

11:00 a.m.–05:00 p.m.; resting period 36.5a 63.5b 0.88 <0.001 17.0aX 83.0bY 1.65 <0.001

05:00 p.m.–10:30 p.m. 37.8a 62.2b 0.86 <0.001 25.8a 74.2bX 1.38 <0.001

Means in a row with different superscripts (a, b) were significantly different (P � 0.001). Means in a column with different

superscripts (X, Y) were significantly different (P � 0.001).

Table 4

Rabbits’ preference (frequencies, %) for the application of gnawing sticks, at 16 and 12 rabbits/m2 and in the age range of

5–11 weeks (experiment 1)

Age (weeks) 16 rabbits/m2 12 rabbits/m2

Gnawing stick P-value S.E. Gnawing stick P-value S.E.

No Yes No Yes

5.5 40.0 60.0 <0.001 1.94 52.1 47.9 0.353 2.29

6.5 43.7 56.3 <0.001 1.10 44.4 55.6 0.017 2.32

7.5 48.9 51.1 0.385 1.23 44.6 55.4 0.003 1.84

8.5 47.0 53.0 0.001 0.56 47.4 52.6 0.106 1.57

9.5 48.6 51.4 0.003 0.50 46.7 53.3 0.013 1.36

10.5 47.2 52.8 0.001 0.82 46.3 53.7 0.003 1.29

Total 45.9 54.1 <0.001 0.46 46.9 53.1 <0.001 0.74

The preference for cages provided with gnawing sticks was higher compared to the cages

without environmental enrichment both in the active and resting periods independently of the

stocking densities (Table 5). However, the part of the day significantly influenced the cage choice

(with or without gnawing sticks) of the growing rabbits. The difference between the choice of

cages with or without gnawing sticks was 12% in the active and 3.7% in the resting periods,

independently of the stocking density. In both stocking density groups a higher proportion of

rabbits (+4.1%) stayed in cages applied with gnawing sticks between 11:00 p.m. and 05:00 a.m.

than between 11:00 a.m. and 05:00 p.m.

Feed consumption (in percentage) was significantly higher in the cages applied with gnawing

sticks between weeks 5–7 (54.5%) and 9–11 (53.0%). It was similar between the ages of 7–9

weeks. The feed consumption difference between the two cage types was 4% for the whole

growing period.

3.1.3. Interactions

Stocking density � floor type significantly affected (P < 0.001) the rabbits preference (see

the last row of Table 2). The effects of stocking density � gnawing stick (P = 0.100) and the floor

type � gnawing stick were not significant (P = 0.348).

3.2. Behavioural patterns (experiment 2)

The effects of group size (cage or pen), floor type (wire or plastic net) and environmental

enrichment (gnawing sticks) on the growing rabbits’ behaviour are presented in Table 6.

Housing of growing rabbits in cages or in pens affected the majority of the behavioural

patterns. In larger groups (pen) the rabbits spent less time resting and more time with various

forms of movements. In the pens the proportion of time spent eating and drinking also increased.

The rabbits spent more time investigating the pen and each other and the occurrence of aggressive

behaviour increased.

The floor type (plastic or wire net) did not affect any behaviour form.

The environmental enrichment significantly affected only some behaviour patterns of the

growing rabbits. In cages and pens provided with gnawing sticks the rabbits spent more time with

movement than in the cages and pens without environmental enrichment. The gnawing stick

application significantly increased the comfort behaviour and decreased the aggressive

behaviour. The aggressive behaviour of the rabbits kept in pens significantly reduced with

gnawing stick application. In cages, the environmental enrichment did not decrease the

Z. Princz et al. / Applied Animal Behaviour Science 111 (2008) 342–356 349

Table 5

Rabbits’ preference (frequencies, %) for the application of gnawing sticks at 16 and 12 rabbits/m2 in relation to of the part

of the day (experiment 1)

Part of the day 16 rabbits/m2 12 rabbits/m2

Gnawing stick P-value S.E. Gnawing stick P-value S.E.

No Yes No Yes

11:00 p.m.–05:00 a.m.; active period 44.0aX 56.0bY <0.001 1.05 44.1aX 55.9bY <0.001 1.49

05:00 a.m.–10:30 a.m. 45.4a 54.6b <0.001 0.90 49.7 50.3 0.805 1.42

11:00 a.m.–05:00 p.m.; resting period 48.1aY 51.9bX 0.033 0.88 48.2aY 51.8bX 0.027 1.65

05:00 p.m.–10:30 p.m. 46.0a 54.0b <0.001 0.86 45.6a 54.4b <0.001 1.37

Means in a row with different superscripts (a, b) were significantly different (P � 0.05). Means in a column with different

superscripts (X, Y) were significantly different (P � 0.001).

aggressive behaviour significantly although its frequency was already very low without gnawing

stick application (Fig. 3).

With the increasing age the rabbits spent more time resting and less time eating, drinking,

moving, comfort, social and investigatory behaviours (Table 7). By the time they reached 10.5

weeks of age the frequency of aggressive behaviour increased.

The rabbits’ behaviour was significantly affected by the part of the day; 30.7% higher resting

was recorded between 11:00 a.m. and 05:00 p.m. (resting period in rabbits). The other

behavioural patterns showed higher frequency in the active period (11:00 p.m.–05:00 a.m.).

Eating, drinking, moving, comfort, social and investigatory behaviours were 2.4, 3.4, 4.7, 1.4, 4.4

and 2.8 times higher, respectively, in the active than in the resting period. Aggressive behaviour

was observed only during the active period (11:00 p.m.–05:00 a.m.).

4. Discussion

4.1. Floor type

The well being of the rabbits is affected by the floor type of their cage. Because the rabbits

experience a permanent connection with the cage floor, it is one of the most important factors

determining animal welfare (Verga et al., 2006; Szendro and Luzi, 2006).

Z. Princz et al. / Applied Animal Behaviour Science 111 (2008) 342–356350

Table 7

Effects of the age and the part of the day on the growing rabbits’ behaviour (experiment 2)

Behavioural patterns (%) Age (weeks) P-value Part of the day P-value S.E.

6.5 10.5 11:00 p.m.–05:00

a.m. (active)

11:00 a.m.–05:00

p.m. (resting)

Eating 12.1 9.35 <0.001 14.4 5.99 <0.001 0.21

Drinking 2.32 1.97 0.045 3.04 0.79 <0.001 0.10

Resting 53.6 65.8 <0.001 45.6 76.3 <0.001 0.53

Movement 7.19 4.48 <0.001 9.45 2.02 <0.001 0.19

Comfort behaviour 17.0 12.5 <0.001 17.4 12.1 <0.001 0.25

Social behaviour 4.56 2.95 <0.001 5.37 1.23 <0.001 0.15

Investigatory behaviour 3.21 2.73 0.363 4.61 1.57 <0.001 0.12

Aggressive behaviour 0.03 0.26 <0.001 0.20 0.00 <0.001 0.02

Table 6

Effects of group size, floor type and environmental enrichment on the growing rabbits’ behaviour (experiment 2)

Behavioural patterns (%) Group size P-value Floor type P-value Gnawing stick P-value S.E.

Cage Pen Wire

net

Plastic

net

No Yes

Eating 9.49 10.5 0.012 10.1 10.5 9.88 10.5 9.88 0.144 0.21

Drinking 1.55 2.10 <0.001 1.88 2.00 1.84 2.00 1.84 0.305 0.10

Resting 66.9 58.0 <0.001 61.0 61.4 60.5 61.4 60.5 0.304 0.53

Movement 3.79 6.71 <0.001 5.82 5.39 6.09 5.39 6.09 0.007 0.19

Comfort behaviours 14.9 14.6 0.525 14.7 14.0 15.4 14.0 15.4 0.014 0.25

Social behaviours 1.15 4.38 <0.001 3.20 3.37 3.23 3.37 3.23 0.324 0.15

Investigatory behaviours 2.21 3.53 <0.001 3.16 2.98 3.20 2.98 3.20 0.462 0.12

Aggressive behaviour 0.01 0.14 0.004 0.12 0.16 0.04 0.16 0.04 0.020 0.02

The results of our experiment are in agreement with Matics et al. (2003) in that growing

rabbits preferred plastic net compared to wire net. Matics et al. (2003) compared wire net, plastic

net, plastic slats and solid floors and found that the plastic net was chosen most frequently by the

young rabbits. By the end of the growing period the frequency of rabbits on the different floor

types was similar (except for the wet solid floor which was refused). The floor type choice of the

growing rabbits was possibly determined by the total body weight per m2 basic area. Maertens

and De Groote (1984) and Aubret and Duperray (1992) found that the production of the fattening

rabbits is determined mainly by the total body weight/m2 instead of by the stocking density. This

could be the reason that with increasing age (from 5.5 to 10.5 weeks) the difference between

proportions of rabbits on the two floor types decreased: and in the case of 16 rabbits/m2 more

rabbits stayed on wire net than with 12 rabbits/m2. These results indicate that the rabbits would

rather accept the less preferable floor type than tolerate higher stocking density.

According to the preference test the choice between the two floor types depends on the part of

the day (activity). With the stocking density of 12 rabbits/m2, during the active period more

rabbits stayed on the wire net than in the resting period. This finding shows that during resting the

rabbits tolerated the floor type less than in the active period.

Orova et al. (2004) examined the preference between deep litter and wire net. In their

experiment 85% of rabbits choose wire net independently of their age and stocking density. Thus,

it can be concluded that wire net cannot be considered as an unfavourable environment and it is

not necessarily true that this floor type violates the welfare of rabbits. In the present work the

proportion of time spent with resting and moving was the same with the plastic and wire net floor.

Trocino et al. (2004) compared the behaviour of rabbits kept in cages of wire net and wire slat.

They found that the behaviour of rabbits was not affected by the floor types and both types of floor

provided appropriate places for the growing rabbits. The results, seen as a whole, strengthen the

opinion that neither wire nor plastic net floor seems to affect the welfare of growing rabbits.

4.2. Gnawing stick

In environments of low stimuli several forms of environmental enrichment were tested to

avoid abnormal and aggressive behaviour forms. In most cases gnawing sticks were placed to the

Z. Princz et al. / Applied Animal Behaviour Science 111 (2008) 342–356 351

Fig. 3. Effect of group size and gnawing stick application on the frequency of aggressive behaviour. Differences marked

with a, b are significantly different (P � 0.05).

rabbit cages (Luzi et al., 2003; Verga et al., 2004; Princz et al., 2005a,b) and their effect on the

production and behaviour of growing rabbits was monitored.

Our experiment proved that rabbits spent more time in cages supplied with gnawing sticks and

this finding was in accordance with the observation of Luzi et al. (2003) who concluded that the

gnawing stick application had a favourable effect on the rabbits’ welfare. However, in our

experiment the difference was smaller than that found for the two floor types.

The part of the day significantly affected the cage choice by the rabbits as more rabbits choose

the cages supplied with gnawing sticks during the active period. Based on the small difference

found in this study it can be supposed that the rabbits mainly enter the cages with wooden sticks

only for gnawing then they return to their original location. During the resting period only a slight

difference was found in the cage choice.

Similar to other studies (Verga et al., 2004), gnawing stick application affected some of the

behavioural patterns. In the cages or pens enriched with gnawing sticks, the rabbits spent less

time eating. The time spent resting also decreased and the proportion of locomotion and comfort

behaviour increased. In accordance with the literature, the gnawing stick application decreased

aggressive behaviour. Verga et al. (2004) found that in cages enriched with gnawing sticks the

rabbits were more active and spent more time with investigatory behaviour and less time resting

(especially with lying) and they showed lower level of aggressiveness. This finding helps to

understand the effect of gnawing sticks on the aggressive and abnormal behaviours. Most authors

agree that in an environment enriched with gnawing sticks the rabbits exhibit abnormal (Johnson

et al., 2003; Jordan et al., 2003; Luzi et al., 2003; Verga et al., 2004) and aggressive (Princz et al.,

2005a,b, 2007) behaviour forms at lower frequencies. In natural circumstances the rabbits spend

most of the time with race-preserving (eating, drinking, reproduction and defence as attention)

activities while under farm conditions the rabbits spend less time with these activities. During the

active period the rabbits are mainly bored and if gnawing sticks are not available, they gnaw the

cage, the feeder or even each other.

This is confirmed by our recent results (Princz et al., 2006b) in which if the gnawing sticks

were made of soft trees (linden, willow) their consumption was higher compared to hard gnawing

sticks (locust) leading to the conclusion that the former can be better to use as environmental

enrichment. With an adequate gnawing stick, the level of aggressive behaviour and consequently

the resulting injuries can be reduced to a minimum.

Results of former experiments (Jordan et al., 2003; Verga et al., 2004) were not completely

concordant with the effect of gnawing sticks on the rabbits’ production. On the contrary, Princz

et al. (2005a) found higher slaughter weight, and Luzi et al. (2003) observed greater average daily

gain in groups of rabbits that had access to gnawing sticks. In case of free choice, as reported in

the present experiment, feed consumption in cages with gnawing sticks was significantly higher

between the ages of 5–7 and 9–11 weeks. The explanation for the increased consumption might

be that as the rabbits entered the cages with gnawing sticks they also consumed feed in the same

cages.

4.3. Group size

Some authors (Dal Bosco et al., 2002) recommend rearing growing rabbits in larger groups

which could be a possible alternative housing system. In this case animals move more, they can

run, hop and jump (Lehmann, 1987; Maertens and van Oeckel, 2001). On the other hand the

aggressive behaviour and injuries are more frequent. By using gnawing stick, the injuries can be

decreased (Princz et al., 2007).

Z. Princz et al. / Applied Animal Behaviour Science 111 (2008) 342–356352

Similarly to our results, Mirabito et al. (1999), Dal Bosco et al. (2002) and Postollec et al.

(2003) observed that the rabbits kept in cages spent more time resting and less time with

locomotion compared with groups of rabbits reared in pens. The lower time spent for

locomotion is connected with the cage size (Drescher, 1992; Xiccato et al., 1999; Martrenchar

et al., 2001).

Our results related to eating and drinking do not coincide with the observations of Dal Bosco

et al. (2002) who reported that the rabbits kept in cages spent more time eating and drinking.

However, they monitored the rabbits’ behaviour only during the light period (in the morning and

in the afternoon) while the frequency of eating and drinking is much higher in the dark (active)

period (Prud’hon et al., 1975).

Mirabito et al. (1999) and Dal Bosco et al. (2002) observed that the rabbits in cages showed

lower frequencies of investigatory, comfort and social behaviours than in larger groups. On the

contrary, according to Martrenchar et al. (2001), the occurrence of social behaviour was more

frequent in smaller groups. We have not found significant effects of group size on comfort

behaviours but the social and investigatory behaviours were more frequent in pens.

Age affected the aggressive behaviour. In accordance with our results, most authors

(Rommers and Meijerhof, 1998; Maertens and Van Herck, 2000; Princz et al., 2006a) found that

with ageing, aggressive behaviour and injuries could be observed more frequently. Aggressive

behaviour may have a connection with sexual maturity.

Our results are in accordance with those of several authors who found that with increasing

group size the aggressive behaviour also increases (Bigler and Oester, 1996; Princz et al.,

2005a,b, 2006a). From the behavioural point of view Drescher and Reiter (1996) established that

the group size of 16 rabbits was the most advantageous because the frequency of aggressive

behaviour (and injuries) was the lowest. Martrenchar et al. (2001) found that in the cages the ear

injuries were more frequent than in the pens, and related this phenomenon to the lack of available

space. However, Morisse and Maurice (1997) and Rommers and Meijerhof (1998) did not detect

any harmful effect of the larger group size on aggressive behaviours. Our former experiment

(Princz et al., 2006a) showed that in larger groups the percentage of aggressive rabbits remains

the same but the aggressive individuals can injure more animals.

According to the majority of the authors, in larger groups aggressive behaviour occurs more

frequently and frequency of locomotion also increases. Based on the previous findings it could be

interesting to analyze whether the increased locomotion is the consequence of the attempted

escape by individuals caused by aggression within the group.

4.4. Part of the day

In our experiment the rabbits spent more time moving, drinking and investigating both the

cage and each other during the dark (active period). Prud’hon et al. (1975) found that the major

feed and water consumption by 12-week-old rabbits occurs between 09:00 p.m. and 6:00 a.m. It

is important to point out that, similarly to observations made by Prud’hon et al. (1975) in our

experiment the rabbitry was closed at the time of recording thus the rabbits’ behaviour could not

be disturbed. The day was divided by 6 h intervals and the most characteristic active and resting

periods were compared.

Aggressive behaviour was seen only during the active period (11:00 p.m.–05:00 a.m.). This

phenomenon can explain the peaceful cohabitation of the European wild rabbit colonies. During

the day they huddle together in the rabbit hole and during this period the aggressive behaviour is

not frequent. This is necessary for the peaceful cohabitation of wild rabbits. During the active

Z. Princz et al. / Applied Animal Behaviour Science 111 (2008) 342–356 353

period the rabbits stay appropriate distances from each other but, in order to obtain territory or

food, conflicts can occur.

Hoy and Schuh (2004) observed that when 3 does were kept in 150 m2, fighting occurred at the

feeder. In the open air the rabbits have the possibility to escape. Domesticated rabbits consume

the feed too quickly, they are bored and too close to each other. Thus, from the time of sexual

maturity, aggressive behaviour becomes more and more frequent. The dominant individual

attacks the inferior ones but they do not have the possibility to escape. Our results suggest that a

gnawing stick is suitable to engage their attention.

As a result of the free choice during the active period (using a stocking density of 12 rabbits/

m2) more rabbits were found on the wire net floor than during the resting period showing that if

more space is needed then they will accept the less preferred floor types. However, during the

resting period, when less space is required they more frequently chose the preferred plastic floor.

The environmental circumstances of the previous experiments are not always specified which

makes comparison of our results with those reported in the literature more difficult. Prud’hon

et al. (1975) used ‘laboratory’ conditions. In our experiment, the rabbit house was closed on days

of recording thus human attendance did not disturb the rabbits’ behaviour. On the other hand if

the observations are carried out in an open rabbitry, the presence of the workers can modify the

daily rhythm, especially that of the morning (feeding and control of the animals).

5. Conclusions

The main results showed that growing rabbits have a preference for plastic net floor and cages/

pens provided with gnawing sticks. Moreover, the resting, locomotive and aggressive behaviours

were modified by the housing system (cage versus pen), and the presence of gnawing sticks

decreased the frequency of physical injuries.

Acknowledgements

We thank Prof. James I. McNitt for valuable comments and suggestions that improved the

manuscript.

The financial support of the GAK OMFB-01335/ALAP-00121, Hungarian-Italian Intergovern-

mental S&T Program (I-32/03) and the Oveges scholarship is gratefully acknowledged.

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