Handling effects on body weight and behaviour of group-housed male rabbits in a laboratory setting

Welfare of domestic birds and rabbits transported in containers

This opinion, produced upon a request from the European Commission, focuses on transport of domestic birds and rabbits in containers (e.g. any crate, box, receptacle or other rigid structure used for the transport of animals, but not the means of transport itself). It describes and assesses current transport practices in the EU, based on data from literature, Member States and expert opinion. The species and categories of domestic birds assessed were mainly chickens for meat (broilers), end-of-lay hens and day-old chicks. They included to a lesser extent pullets, turkeys, ducks, geese, quails and game birds, due to limited scientific evidence. The opinion focuses on road transport to slaughterhouses or to production sites. For day-old chicks, air transport is also addressed. The relevant stages of transport considered are preparation, loading, journey, arrival and uncrating. Welfare consequences associated with current transport practices were identified for each stage. For loading and uncrating, the highly relevant welfare consequences identified are handling stress, injuries, restriction of movement and sensory overstimulation. For the journey and arrival, injuries, restriction of movement, sensory overstimulation, motion stress, heat stress, cold stress, prolonged hunger and prolonged thirst are identified as highly relevant. For each welfare consequence, animal-based measures (ABMs) and hazards were identified and assessed, and both preventive and corrective or mitigative measures proposed. Recommendations on quantitative criteria to prevent or mitigate welfare consequences are provided for microclimatic conditions, space allowances and journey times for all categories of animals, where scientific evidence and expert opinion support such outcomes.

Use of Gnawing Hay Blocks: Effects on Productive Performance, Behavior and Reactivity of Growing Rabbits Kept in Parks with Different Sex-Group Compositions

To improve animal welfare in collective park housing systems, this study assessed the effects of the provision of gnawing hay blocks and the group composition (F: females, M: males, FM: mixed sex) on performance, behavior, and reactivity of 288 growing rabbits reared in 18 parks (16 rabbits/park) from 31 to 73 days of age. The presence of gnawing blocks inside the feeding area of the parks scarcely affected performance and budget time, but decreased the time spent in the resting area compared to parks without blocks (p < 0.001); it increased the time spent moving during the open field test (p < 0.05) and the rate of rabbits that approached the object in the novel-object test (p < 0.05). As for sex-group composition, the feed conversion ratio was lower in parks F and FM than in park M (p < 0.05). During the open-field test, FM rabbits spent more time moving (p < 0.05), whereas M rabbits displayed self-grooming for a longer time (p < 0.01). Results related to production, behavior, and reactivity indicate the provision of gnawing blocks for welfare improvement, but do not support the change from current mixed-sex to single-sex rearing.

Effect of access to outdoor grazing and stocking density on space and pasture use, behaviour, reactivity, and growth traits of weaned rabbits

In a context of evolving concern over housing conditions of farmed rabbits, we developed a housing system that allows access to an outdoor area. The aim was to study the health status, growth and behaviour of rabbits raised at two stocking densities with access to a paddock, or not. We distributed 299 weaned rabbits in four groups (YH: 100, NH: 99, YL: 50 and NL: 50) using a 2 × 2 factorial design including access (Y: yes) or not (N: not) to a 23 m² paddock and the indoor stocking density (H, high: 17 or L, low: 9 rabbits/m²). We measured the growth and health status of each animal weekly for 42 days (from 31 to 73 days of age) and performed reactivity tests to a new environment, a human and new object. We also assessed the rabbits' behaviour at days 26 and 40 by doing a visual scan of each animal at regular time intervals. Our results showed that stocking density had no effect on mortality, but mortality tended to increase with outdoor access from 3.0% to 7.0% (P < 0.10). Although the stocking density had no effect on average daily gain, it was higher in rabbits in the N group than in the Y group (+3.6 g/day; P < 0.05). Rabbits entered the paddocks for the first time in less time at the beginning of the trial (50 s at day 3 vs 10 min at day 31; P < 0.001). The proportion of rabbits outside after 20 min of the new environment test was higher among rabbits in the L group than in the H group (+24% points at day 3 and +11% points at day 20; P < 0.001). Regardless of the stocking density, more rabbits in the N group touched the experimenter's hand (16% vs 27%; P < 0.05) and the new object (34% vs 20%; P < 0.05) than rabbits in the Y group. Inactivity was more frequent in rabbits inside the pens than in the paddocks (70.0% vs 34.2% at days 26 and 40; P < 0.05). Locomotion was more frequent in the paddocks than in the indoor pens (20.0% vs 7.2% at days 26 and 40; P < 0.05). The stocking density did not affect the behavioural traits measured. In conclusion, providing rabbits access to a paddock could allow them to fulfil some natural behaviours but slightly reduced their growth.

Development of the Bristol Rabbit Pain Scale (BRPS): A multidimensional composite pain scale specific to rabbits (Oryctolagus cuniculus)

A species-specific composite pain scale is a prerequisite for adequate pain assessment. The aim of this study was to develop a multidimensional pain scale specific to rabbits (Oryctolagus cuniculus) called the Bristol Rabbit Pain Scale (BRPS). The scale was developed over five phases using a unique combination of methods: focus groups and behavioural observation. The first two phases aimed at identifying descriptors to describe a rabbit in pain, and then reducing their number, both using focus groups. A total of 72 pain descriptors were grouped under six categories (Demeanour, Posture, Facial expression, Attention to the painful area, Audible and Other) and 'No pain' descriptors were added. The third phase aimed to confirm, through video observation of rabbits, the categories and descriptors previously described, to reject those terms that were ambiguous, and identify any new descriptors that had not been included in the previous list of descriptors. This led to the rejection of the categories Audible and Attention to the painful area and of 34 descriptors. Seven new descriptors were identified. The last two phases constructed the final format of the BRPS by refining the categories, ranking the descriptors on an ordinal scale and testing the internal reliability of the scale using Cronbach's alpha test. This led to a composite pain scale of six categories (Demeanour, Posture, Locomotion, Ears, Eyes and Grooming) with four intensities of pain (0, 1, 2, and 3), a total score of 0-18, and a high Cronbach's alpha coefficient (alpha = 0.843). This BRPS fills an important gap in the field of rabbit medicine and has the potential to improve the assessment and management of pain in rabbits providing veterinary professionals with a novel multidimensional pain assessment tool. Further studies will investigate the clinical utility, validity and reliability of the BRPS.

Stunning methods and slaughter of rabbits for human consumption

This opinion on the killing of rabbits for human consumption (‘slaughtering’) responds to two mandates: one from the European Parliament (EP) and the other from the European Commission. The opinion describes stunning methods for rabbits known to the experts in the EFSA working group, which can be used in commercial practice, and which are sufficiently described in scientific and technical literature for the development of an opinion. These are electrical stunning, mechanical stunning with a penetrative and non‐penetrative captive bolt and gas stunning. The latter method is not allowed in the EU anymore following Council Regulation (EC) No 1099/2009, but may still be practiced elsewhere in the world. Related hazards and welfare consequences are also evaluated. To monitor stunning effectiveness as requested by the EP mandate, the opinion suggests the use of indicators for the state of consciousness, selected on the basis of their sensitivity, specificity and ease of use. Similarly, it suggests indicators to confirm animals are dead before dressing. For the European Commission mandate, slaughter processes were assessed from the arrival of rabbits in containers until their death, and grouped in three main phases: pre‐stunning (including arrival, unloading of containers from the truck, lairage, handling/removing of rabbits from containers), stunning (including restraint) and bleeding (including bleeding following stunning and bleeding during slaughter without stunning). Ten welfare consequences resulting from the hazards that rabbits can be exposed to during slaughter are identified: consciousness, animal not dead, thermal stress (heat or cold stress), prolonged thirst, prolonged hunger, restriction of movements, pain, fear, distress and respiratory distress. Welfare consequences and relevant animal‐based measures (indicators) are described. Outcome tables linking hazards, welfare consequences, indicators, origins, preventive and corrective measures are developed for each process. Mitigation measures to minimise welfare consequences are also proposed.

Scientific opinion concerning the killing of rabbits for purposes other than slaughter

Rabbits of different ages may have to be killed on-farm for purposes other than slaughter (where slaughter is defined as killing for human consumption) either individually or on a large scale (e.g. for production reasons or for disease control). The purpose of this opinion was to assess the risks associated to the on-farm killing of rabbits. The processes during on-farm killing that were assessed included handling, stunning and/or killing methods (including restraint). The latter were grouped into four categories: electrical methods, mechanical methods, controlled atmosphere method and lethal injection. In total, 14 hazards were identified and characterised, most of these related to stunning and/or killing. The staff was identified as the origin for all hazards, either due to lack of the appropriate skill sets needed to perform tasks or due to fatigue. Possible corrective and preventive measures were assessed: measures to correct hazards were identified for five hazards and the staff was shown to have a crucial role in prevention. Five welfare consequences of the welfare hazards to which rabbits can be exposed to during on-farm killing were identified: not being dead, consciousness, pain, fear and distress. Welfare consequences and relevant animal-based measures were described. Outcome tables linking hazards, welfare consequences, animal-based measures, origins, preventive and corrective measures were developed for each process. Mitigation measures to minimise welfare consequences are proposed.

Health and welfare of rabbits farmed in different production systems

The AGRI committee of the European Parliament requested EFSA to assess the welfare of rabbits farmed in different production systems, including organic production, and to update its 2005 scientific opinion about the health and welfare of rabbits kept for meat production. Considering reproducing does, kits and growing rabbits, this scientific opinion focusses on six different housing systems, namely conventional cages, structurally enriched cages, elevated pens, floor pens, outdoor/partially outdoor systems and organic systems. To compare the level of welfare in the different housing systems and rabbit categories, welfare impact scores for 20 welfare consequences identified from the literature were calculated, taking their occurrence, duration and severity into account. Based on the overall welfare impact score (sum of scores for the single welfare consequences), obtained via a 2‐step expert knowledge elicitation process, the welfare of reproducing does is likely (certainty 66–90%) to be lower in conventional cages compared to the five other housing systems. In addition, it is likely to extremely likely (certainty 66–99%) that the welfare of kits is lower in outdoor systems compared to the other systems and that the welfare is higher in elevated pens than in the other systems. Finally, it is likely to extremely likely (certainty 66–99%) that the welfare of growing rabbits is lower in conventional cages compared to the other systems and that the welfare is higher in elevated pens than in the other systems. Ranking of the welfare consequences allowed an analysis of the main welfare consequences within each system and rabbit category. It was concluded that for reproducing does, as well as growing rabbits, welfare consequences related to behavioural restrictions were more prominent in conventional cages, elevated pens and enriched cages, whereas those related to health problems were more important in floor pens, outdoor and organic systems. Housing in organic rabbit farming is diverse, which can result in different welfare consequences, but the overall welfare impact scores suggest that welfare in organic systems is generally good.

Long-lasting behavioral and neuroendocrine changes provoked in rabbits by cancelling a single nursing bout in early lactation

To restore estrus in lactating doe rabbits, nursing was prevented on lactation day 10 and allowed again from day 12 onward. This "biostimulation" procedure, used to accelerate reproduction, allows kit survival despite a 48 hr fast. Yet, the consequences of "biostimulation" on their psychobiological and neuroendocrine development are largely unknown. Therefore, we determined, in adult males and females, tested in the morning or afternoon: corticosteroid secretion (baseline and reactive), sexual behavior, and responses in six tests measuring stress/anxiety. The latter were not affected by maternal deprivation or time of testing in either sex. The lordosis quotient was reduced in deprived does (relative to controls), an effect eliminated when only non-kins (of both groups) were compared. Deprived males showed altered sexual behavior, evidenced by a large number of mounts not culminating in ejaculation. Corticosterone and cortisol secretion increased (relative to baseline) following i.m. saline in all groups, but the magnitude of the response was affected by maternal deprivation, time of day, and sex. Results indicate that particular behaviors and reactivity to stress have different thresholds regarding the effects of mother-litter separation in early lactation.

Behaviour and reactivity of growing rabbits housed in collective pens: Effects of floor type and stocking density at different ages

At 33 d of age, 376 crossbred rabbits of both genders were housed in sex-mixed groups in 16 open-top collective pens (1.68 m²) in a factorial arrangement, with 2 types of flooring (wooden slats <em>vs.</em> plastic grid, W <em>vs.</em> P) and 2 stocking densities (12 <em>vs.</em> 16 animals/m²). Behavioural recordings (time budget), reactivity towards unknown humans (tonic immobility and human approach tests) and environment (open-field and novel object tests) and hair and faeces sampling for corticosterone analysis were performed during the 8^th wk of age and at a pre-slaughter age (during the 11-12^th wk of age). The effects of age and gender were also taken into account. Rabbits housed in W pens rested more in the crouched position (41.4 <em>vs.</em> 35.5% of the observed time) (<em>P</em>&lt;0.001) and showed lower allogrooming (<em>P</em>=0.05), running (<em>P</em>&lt;0.01) and biting pen elements (<em>P</em>=0.01) than those housed in P pens. The percentage of rabbits that interacted with humans during the human approach test (24.0 <em>vs.</em> 48.1% of rabbits in the pen; <em>P</em>&lt;0.01) and number of rabbit-object contacts during the novel object test (on av. 50.4 <em>vs.</em> 87.2; <em>P</em>&lt;0.001) were lower for rabbits in W pens compared to those in P pens. During the open-field test, the percentage of rabbits that spontaneously entered the arena was lower for rabbits from W pens than for those from P pens (60.0 <em>vs.</em> 72.5%; <em>P</em>&lt;0.05). Finally, the hair corticosterone level was higher in the former than in the latter rabbits (on av. 14.0 <em>vs.</em> 12.5 ng/g; <em>P</em>&lt;0.05). As the stocking density increased, only the time spent resting increased (66.7 to 69.1% observed time; <em>P</em>&lt;0.01), and the percentage of rabbits that spontaneously entered the arena during the open-field test decreased (73.8 to 58.8%; <em>P</em>&lt;0.01). When age increased, the rabbits were less active at the reactivity tests and interacted less with an unknown object or person. Differences according to gender were weak. In conclusion, the wooden slatted floor challenged the welfare of growing rabbits as it constrained their movement, conditioned their reactivity towards a new environment, and increased their stress level, whereas the increase in stocking density did not impair rabbit welfare.

Appropriate handling of pet rabbits: a literature review

Many rabbits show fear behaviours when lifted off the ground. Estimates from owner surveys suggest that around 60% of pet rabbits struggle when lifted and fear-related aggression is common. This article integrates information from both laboratory and pet rabbit studies to formulate a list of recommendations for appropriate handling of rabbits. Reduction of the frequency of the stressor can be achieved by educating owners on alternative management practices to reduce the need to carry their rabbits. However, in some situations, it is unavoidable that a rabbit is lifted. Amelioration of the stress in these instances can be achieved by a 2 pronged strategy. First, the population of rabbits can be made more resilient to infrequent stressors by selectively breeding for confident rabbits and by better socialisation of unweaned kits, and, where possible, training of individual animals to permit handling. Secondly, any unavoidable lifting can be made less stressful by educating veterinary staff in appropriate methods of holding rabbits during both consultations and inpatient care. Better understanding of appropriate interactions with rabbits will improve welfare.

Promoting positive states: the effect of early human handling on play and exploratory behaviour in pigs

It is known that tactile stimulation (TS) during ontogeny modifies brain plasticity and enhances the motor and cognitive skills. Our hypothesis was that early handling including TS would increase play and exploratory behaviour in commercial pigs under standardized test conditions. Piglets from 13 litters were subjected to three handling treatments from 5 to 35 days of age: all the piglets were handled (H), none of the piglets were handled (NH) or half of the piglets in the litter were handled (50/50). At 42 days of age, the pigs' behaviour was observed in pairs in a novel pen with a 'toy' (tug rope). The main results were that more locomotor play was performed by pigs from litters where all or half of them had been handled, whereas social exploratory behaviour was more pronounced in pigs from litters where half of them had been handled. Although behaviour was affected by the interaction of treatment with sex or with weight category, we propose that the handling procedure does seem to have acted to increase locomotor skills and that handling half of the piglets in the litter may have triggered a series of socio-emotional interactions that were beneficial for the whole group.

Effects of Transfer from Breeding to Research Facility on the Welfare of Rats

Simple Summary

This study measured effects of transfer on body temperature, stress hormone levels, body weight, behavior and water and food intake in rats. Environmental temperature strongly affected body temperature of rats and needs to be controlled. Male rats need to habituate for at least one week, females for two weeks after transfer.

Abstract

Transfer from the breeding facility to a research facility is a stressful event for laboratory animals. Heat stress has been reported to constitute one of the major concerns during transport of animals. This study measured ambient and body temperature, corticosterone and glucose levels, body weight, behavior and water and food intake before, during and after transfer in Wistar rats. Decreased body weight, water and food intake were observed on the day of transfer in rats. Environmental temperature strongly affected body temperature of rats and needs to be controlled. Male rats need to habituate for at least one week, females for two weeks after transfer.

Housing of growing rabbits in individual, bicellular and collective cages: fear level and behavioural patterns

During growth (27 to 75 days of age), a total of 384 rabbits were kept in 72 individual cages, 48 bicellular cages (2 rabbits/cage) and 24 collective cages (9 rabbits/cage). To evaluate the effects of the housing system on the fear level and behavioural patterns of rabbits at the two ages (39 to 45 days and 66 to 73 days), a tonic immobility test and an open-field test were conducted and their behaviour was video recorded. In the tonic immobility test, the number of attempts to induce immobility (1.38) was lower, and the duration of immobility (47.8 s) was higher (0.05 < P < 0.01) in the rabbits housed in individual cages than in those kept in bicellular (1.72 attempts and 25.0 s of immobility) and collective cages (1.99 attempts and 25.0 s of immobility). During the open-field test, the rabbits from individual and bicellular cages showed higher latency (38.8 and 40.3 v. 27.0 s), a lower number of total (73.3 and 81.7 v. 91.9) and central displacements (3.6 and 2.8 v. 5.4) and a shorter running time (11.8 and 13.6 s v. 17.7 s) and the time biting the pen (5.5 and 9.1 s v. 28.2 s) compared with the rabbits kept in collective cages (0.05 < P < 0.001). During the 24-h video recording, the rabbits in individual and bicellular cages spent less time allogrooming (0.34% and 0.19% v. 1.44%), moving (0.74% and 0.60% v. 1.32%) and running (0.08% and 0.03% v. 0.21%) than the rabbits in the collective cages (0.01 < P < 0.001). The lowest numbers of alerts and hops were observed in the rabbits kept in bicellular cages. With increasing age, a lower number of rabbits were sensitive to the immobility test and more rabbits entered the pen spontaneously during the open-field test (P < 0.001). In conclusion, the rabbits in individual cages exhibited the highest fear level and incomplete behavioural patterns; the rabbits housed in collective cages showed the lowest fear levels and had the possibility of expressing a wider range of behaviour; and the rabbits in bicellular cages exhibited an inconsistent pattern of fear in the tonic immobility and open-field tests. Probably, these rabbits were in a less stressful condition compared with animals in individual cages because social contacts were allowed, even if freedom of movement was more limited.