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A behavioral comparison of New Zealand White rabbits ( Oryctolagus cuniculus) housed individually or in pairs in conventional laboratory cages
Abstract
Despite their gregarious nature, rabbits used for research are often housed individually due to concerns about aggression and disease transmission. However, conventional laboratory cages restrict movement, and rabbits housed singly in these cages often perform abnormal behaviors, an indication of compromised welfare. Pairing rabbits in double-sized cages could potentially improve welfare by providing both increased space and social stimulation. We compared the behavior of female New Zealand White rabbits (Oryctolagus cuniculus) housed either individually (N=4) in cages measuring 61cm×76cm×41cm or in non-littermate pairs (four pairs) in double-wide cages measuring 122cm×76cm×41cm. The rabbits were kept under a reversed photoperiod (lights on 22:00–12:00h). Each rabbit was observed five times per week for 5 months, using 15-min focal animal samples taken between 08:00–09:00, 12:00–13:00, and 16:00–17:00h. Data were analyzed using a repeated measures General Linear Model (GLM). 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% (treatment×time interaction, F1,24=4.60; P≤0.0422). 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.
... 27,62,89,109 Rabbits. 120,121 Pigs. 122 Rocking. ...
... Rabbits. 120,121,128 Pigs. 122* Mice. ...
... Rabbits. 120,121,128 Gerbils. 49 Sham chewing. ...
... In order to provide the highest possible standards of animal welfare, species-appropriate housing must be provided while meeting the specific goals of the researcher. Socially housed NZW rabbits engage in more active behaviors 4 , display amplified fitness and show diminished levels of gastrointestinal stasis due to increased locomotor behaviors 5 . Physical activity is particularly important for laboratory rabbits as they are prone to osteoporosis 4 when housed in a cage environment. ...
... Socially housed NZW rabbits engage in more active behaviors 4 , display amplified fitness and show diminished levels of gastrointestinal stasis due to increased locomotor behaviors 5 . Physical activity is particularly important for laboratory rabbits as they are prone to osteoporosis 4 when housed in a cage environment. In addition to the physical benefits of social housing, there is a myriad of psychological benefits. ...
... In addition to the physical benefits of social housing, there is a myriad of psychological benefits. Pair-housed NZW rabbits display increased species-specific activities 6 , receive enrichment benefits from social stimulation 4 , show increased rates of self-soothing activities 7 as well as affiliative behaviors such as allogrooming 8 and exhibit an increased ability to manage anxiety from novel stimuli, i.e. stress buffering 5 . Additionally, in comparison to socially isolated NZW rabbits, socially housed NZW rabbits did not differ in immune function 9 or antibody production 10 , however, singly housed rabbits did have higher heart rates 11 and increased white blood cell counts 10 when compared to socially housed rabbits. ...
New Zealand White (NZW) laboratory rabbits (Oryctolagus cuniculus), as well as their ancestors the European Rabbit, are a social species that exhibit numerous benefits to being housed accordingly. Although these rabbits are innately gregarious, certain behaviors can still arise when kept in captivity, which if left unchecked, can confound research results or lead to wounding, which in extreme cases can be severe. To prevent these issues, there must be a well-structured plan for the monitoring and maintenance of paired laboratory rabbits. The purpose of this protocol is to present effective procedures for establishing newly paired NZW rabbits as well as methods for successful maintenance. Multiple methods have been tested for the creation of newly paired female rabbits from the vendor, but the most efficacious technique emphasizes capitalizing on the stress bonding from transport, urine marking, pairing in a neutral cage with no forced sharing of resources and a system of monitoring and intervention. To determine the best method of housing paired rabbits in a standard caging environment, data were collected to generate a behavioral ethogram. Behaviors were then quantified as positive, neutral or negative and were tracked across the lifespan of the pair to determine which behaviors indicated pair success or failure. With the newfound knowledge of socially housed laboratory NZW rabbit behavior, enrichment intervention was applied to alleviate aggression and prevent wounding, thus resulting in a higher percentage of successful pairs. Through several years of trialing different pairing methods, the development of the ethogram and the resulting enrichment interventions, understanding of the highly complex social constructs that dominate pair housed rabbit behavior has dramatically increased and allowed for the provision of more species-specific care and increased standards of welfare. © 2018, Journal of Visualized Experiments. All rights reserved.
... a permanent marker, as done in other studies of behavior in group-housed rabbits. 5,25 The mean body weight of 41 singlehoused, age-and vendor-matched, female, New Zealand white rabbits in caging 18 in. high and providing a total of 5.44 ft 2 of floor space (Euro Rabbit Housing, Allentown Caging, Allentown, PA) at our facility was used for body weight comparison with the case study groups. ...
... The potential welfare benefits of pair-or group-housing of New Zealand white rabbits must be assessed and weighed against the potential harm associated with injurious aggression or single-housing. 5,8,21 Establishing social dominance hierarchies among rabbits in the wild and under meat production farming or laboratory conditions predictably involves age-specific, agonistic behaviors established and maintained with physical contact that produces relatively minor wounding from scratches, bites, and fur plucking to more serious injuries such as fractures, castration, and evisceration. 2,10,17,18,20,21 According to one study, aggression decreases as social dominance is established in wild does. ...
... A 5-mo investigation of paired, female New Zealand white rabbits (approximately 9 wk of age at study start) in similarly sized double-wide cages as we used in our case study, showed a reduction in stereopathies (that is, bar biting, pressing or biting of the automatic watering system, head swaying, nose rubbing, floor chewing) compared with singly caged rabbits. 5 Single-housed New Zealand white bucks and does demonstrate a broad repertoire of stereotypic behaviors, including licking, chin marking, overgrooming, bar chewing, head swaying, pawing, restlessness, and boredom behaviors, which are reduced by social housing and enrichment. 5,8,9 We observed bar chewing only once in each of our groups. ...
International animal welfare organizations and federal, regional, and institutional oversight bodies encourage social housing of gregarious species, such as New Zealand white rabbits (Oryctolagus cuniculus), to promote animal wellbeing in research, teaching, testing and farming settings. At our institution, 2 groups of female New Zealand white rabbits (approximate age, 11 wk; mean weight, 2.35 kg), compatibly paired at the vendor for 5 wk, were paired in caging or group-housed in a floor pen. The rabbits appeared compatible, demonstrating primarily affiliative behaviors throughout 6 wk of daily observations. However, occult aggression that occurred between daily observations or nocturnally resulted in skin wounding. The skin injuries, first identified during prestudy clipping of fur from the back of each rabbit 6 wk after arrival, disqualified every animal from participation in skin toxicology and muscle implantation studies. Success meeting scientific research requirements while promoting animal welfare and health when socially housing New Zealand white rabbits requires examining the behavioral repertoire of their wild counterparts, European rabbits. Factors including age, sex, and housing density influence territoriality, dominance hierarchy, social ranking, and natural, agonistic, injurious, behavioral tendencies. IACUC and other relevant oversight bodies, researchers, and animal care staff should consider this case study and the species-specific natural history of New Zealand white rabbits when assessing the harm and benefit of social housing in regard to research utility and animal welfare. Copyright 2017 by the American Association for Laboratory Animal Science.
... 15 This evidence suggests that laboratory rabbits may prefer social companionship. However, does engage in agonistic behaviors to form a social hierarchy, 9 and mixing adult does frequently results in high levels of injurious aggression. 1 Not surprisingly, subordinate does 21 and bucks 20 had higher levels of cortisol than do more dominant animals, suggesting subordinates experience some degree of chronic stress. Highranking female rabbits are more active than are low-ranking ones, suggesting that subordinate animals may be inhibited behaviorally by dominants. ...
... 24,25,37 For example, singly housed does spent more time engaged in abnormal behaviors, including sham digging, floor chewing, and bar biting, than did paired does. 9 In contrast, rabbits in pens exhibited more species-typical behaviors , including rearing, stretching, hopping, and running. 44 Another study noted that the trichophagy and stereotypic behaviors reported by others 9,17,25,55 in singly housed does did not occur in grouphoused does. ...
... 9 In contrast, rabbits in pens exhibited more species-typical behaviors , including rearing, stretching, hopping, and running. 44 Another study noted that the trichophagy and stereotypic behaviors reported by others 9,17,25,55 in singly housed does did not occur in grouphoused does. 29 In addition, single rabbits in cages reportedly develop abnormal patterns of locomotion and resting. ...
Increasing concerns regarding the wellbeing of laboratory animals have caused biomedical research stakeholders to reconsider traditional housing of laboratory species and to provide social companionship for social species. European rabbits (Oryctolagus cuniculus) are commonly individually housed in research facilities despite the occurrence of social groups in the wild. Here we review the current literature to provide a comprehensive description of the social behaviors and preferences of rabbits in the wild and in captivity. The implications of these studies regarding social housing of laboratory rabbits are discussed. © 2016 by the American Association for Laboratory Animal Science.
... For blood lactate and cortisol concentrations, data were also analysed using the same method as previously described. The effect of slaughter order on blood lactate was also measured to evaluate stress variation amongst individuals, as rabbits are known to exhibit gregarious behaviour (Chu et al., 2004). Results were considered significantly different when a P-value was lower than 0.05 and a tendency when P-value was lower than 0.10. ...
... The last rabbits in each group experienced a longer period before being handled by humans to be slaughtered, which may have contributed to the increased blood cortisol levels (Rushen et al., 1999). Moreover, rabbits are social animals that can develop physiological symptoms from stress when not in the presence of other rabbits (Held et al., 1995;Chu et al., 2004). Thus, as the rabbits were slaughtered, the remaining rabbits in the group may have experienced further stress due to the dwindling numbers, leading to increased blood cortisol levels. ...
This study aimed to characterise the physiological response of rabbits to feed withdrawal without stress caused by crating and transport to the slaughterhouse. A total of 72 recently weaned Grimaud rabbits were allocated into 12 cages, each with 6 rabbits (3 females and 3 males, to reflect commercial practices). A preslaughter feed withdrawal time (FWT) was randomly assigned to each of the 12 cages (t=0, 3, 6, 8, 10, 12, 14, 16, 18, 20, 22 or 24 h). Blood lactate and cortisol concentrations were measured at exsanguination. These observations did not indicate an elevated level of stress in the rabbits (P>0.05). The maximum Longissimus lumborum glycolytic potential was observed for rabbits that fasted for 3 and 6 h and was relatively stable from 127.78 to 139.04 μmol/g for rabbits with FWT longer than 12 h. As expected, gastrointestinal tract and stomach content weights were lower for rabbits with longer FWT (P<0.0001), while caecum weights did not (P=0.051). Rabbits with longer FWT had lower stomach pH and higher caecum pH (both P<0.0001). Metataxonomic 16S analysis revealed that FWT had a significant effect (all P<0.01) on microbiome beta diversity in faeces and caecum. The polymerase chain reaction analysis using specific primers revealed Enterobacteriaceae presence in the faeces of male rabbits only at 18 and 22 h. Our results suggest that the caecotrophic behaviour of rabbits allows them to be particularly resistant to hunger despite their small size. However, to limit Enterobacteriaceae shedding, the FWT should not exceed 18 h.
... Although rabbits live in social groups in the wild, adult domestic rabbits are commonly individually housed in intensive farming systems, even though it is known that singlehoused rabbits often perform abnormal behaviors (digging, floor chewing, bar biting), which is an indicator of compromised welfare [1][2][3]. The gregarious nature of wild rabbits ...
... For females, Whary et al. [33] suggested that their immaturity is one reason for that. Additionally, food competition should not have been a problem here [1], since there was a sufficient amount of food available and kits were still suckling. Consequently, it is more likely that cage furniture is a potential risk factor for injuries [33]. ...
Simple Summary
On commercial farms, adult female rabbits (does) are usually kept in single cages without direct contact with conspecifics other than their kits. However, wild rabbits live together in groups with several adults and their kits, and single housing of adult domestic rabbits may affect both, their own welfare and the welfare of their kits. In this study, we focused on the welfare of kits and compared three different housing systems for does and their kits: single housing of does with their respective kits; pairs of does with their kits; and groups of three does with their kits. The kits’ health and stress level were analyzed. The number of kits with skin lesions increased with increasing group size. However, when does were pair-housed, kits seemed to have fewer disease symptoms compared to the other treatments. With regard to the stress level, there was no clear result; however, kits in groups of three does did tend to have higher stress hormones in hair. We conclude that pair housing for does could be an alternative to single housing when considering the welfare of their kits. Further studies are needed to evaluate both, the effects of pair housing on kits and does.
Abstract
In intense breeding programs, rabbits are exposed to numerous stress factors which could affect their welfare and health. It has been suggested that group housing is more comfortable for does and similar to the living conditions of European wild rabbits. In this study, we compared three different housing systems—single housing; housing in pairs; and housing in groups of three does—to test whether there is a measurable impact on skin lesions, health, and hair corticosterone concentration (HCC) of their kits. The number of kits with lesions increased with the number of does kept together. The probability of kits getting injured was higher in groups of three does than in pens of single-housed does (p = 0.041). When does were pair-housed, kits seemed to have fewer disease symptoms compared to the other treatments. Concerning HCC of kits, there was no significant difference between the housing systems (p > 0.05). The mean HCC of kits was 2.94 pg/mg, while pair housing had the lowest HCC (2.59 pg/mg). This study focused on the welfare of kits from group-housed does. From this perspective, pair housing of does may be appropriate to allow social interaction between does without unduly affecting the welfare of their kits.
... Single housing deprives them of social interactions; a natural condition they demonstrably value. In fact, one study showed that rabbits in groups of two were often observed in physical contact although the size of the cage allowed bodily separation (Chu et al., 2004). In a social motivation study, rabbits worked almost as hard for limited body contact as they did for food, emphasizing the importance of social contact (Seaman et al., 2008). ...
... In a social motivation study, rabbits worked almost as hard for limited body contact as they did for food, emphasizing the importance of social contact (Seaman et al., 2008). Furthermore, stereotypies and self-destructive behaviours (bar or hair-chewing) (Gunn and Morton, 1995), limited locomotion possibilities (Chu et al., 2004) as well as frustration and boredom can result from the single housing system. Continuous group housing, however, led to agonistic interactions and lesions (Andrist et al., 2013), low productivity (Mugnai et al., 2009) and high kit mortality (Szendrő et al., 2016). ...
Although group housing of naturally social animals like rabbits (Oryctolagus cuniculus) is desirable for ethical reasons, social conflicts can significantly increase the risk for injuries as well as stress incidences and negatively affect their welfare. A common housing system in Switzerland is the "semi group-housing". Here, rabbit does are kept individually shortly before the birth of their kits until 12 days post-partum (pp) after which they are regrouped. Despite positive aspects of this housing system, like the reduction of pseudo pregnancy and crushing of kits, fights between the does often occur after the regrouping process. This study examined whether prolonged postpartum separation may reduce agonistic interactions, stress, and lesions. In total, data were collected over 5 trials on 57 Hycole breeding does. Per trial, three groups of 8 does each were artificially inseminated on day 10 pp and regrouped on either day 12, 18 or 22 pp. Non-pregnant does were replaced in every trial. Agonistic behaviour, anogenital distance, lesions and increased body temperature, as a stress indicator, were documented. The effect of the regrouping treatment on the rate of injury and agonistic interactions was different depending on the trial (lesions: interaction trial x treatment χ2 = 44.21, df = 8, P < 0.0001; agonistic interactions: interaction treatment x trial χ2 = 23.59, df = 8, P = 0.003). During winter trials (November- February), the numbers of lesions and agonistic interactions were generally lower than in the trials during summer. None of the animals with temperature transponders showed a body temperature increase after regrouping (P = 0.98), however, there was an increase after the artificial insemination (P = 0.019). The anogenital distance, measured during the artificial insemination process, was not correlated to the aggressive behaviour of does (r = 0.028; P = 0.78). These findings suggest that prolonging single housing only reduced lesions and fighting in some trials but failed to do so in others. Group composition, individuality and season are discussed as relevant factors for the extent of agonistic interactions. Against our expectations, in none of the groups a stress response after regrouping was found according to body temperature measures.
... 5 This practice is associated with abnormal behaviour in singly housed laboratory rabbits. 6 Similarly, studies indicate that pet rabbits are often housed in cages that are below the minimum space requirements for farmed or laboratory rabbits. 7 About a quarter of rabbits in a Dutch survey were strongly resistant to handling 4 and 60 per cent of rabbits are reported to struggle when handled and show fear-related aggression. ...
... Rabbit breeders were also likely to house rabbits, especially males, in single housing. Solitary housing is thought to contribute to reduced lifespan in rabbits, 4 and is associated with increased stereotypic behaviour in laboratory rabbits 6 and fearfulness in pet rabbits. 4 ...
Background
Rabbits are the third most popular pet in the UK, but little research into their welfare needs has been conducted.
Methods
A modified Delphi method was used to generate expert consensus on the most important welfare issues for rabbits in the UK. The study involved 11 experts, recruited from a range of disciplines. The experts generated an initial broad list of welfare issues via an online discussion board. Two rounds of online surveys were conducted to prioritise these issues. The final round was a workshop with a subsection of experts. The experts decided that welfare issues should be ranked considering: (1) severity, (2) duration, and (3) prevalence.
Results
Experts considered that rabbits were often kept in inadequate housing, were not handled or socialised properly, were fed inappropriate diets and owners failed to vaccinate their rabbits against preventable diseases. Rabbits were thought to experience a reduced life expectancy. Lack of owner knowledge of rabbit husbandry and behaviour and, in some cases, also lack of veterinary knowledge, contributed to poor rabbit welfare.
Conclusions
The Delphi process resulted in consensus on the most significant welfare challenges faced by rabbits and can help guide future research and education priority decisions.
... Enriching the social life of rabbits by placing at least two individuals together introduces more benefits than the use of objects to diversify the environment. This also prevents the occurrence of stereotypy as it introduces more unforeseen situations due to the presence of another individual (Chu et al., 2004). The role of environmental enrichment in captive rabbits' lives is enormous. ...
... Previous studies have also reported that the housing system (Trocino et al., 2008), the group and cage size, and the density (Chu et al., 2004;Princz et al., 2008;Buijs et al., 2011a) influence the behaviour of growing rabbits. ...
Thirty three rabbits from five litters that were weaned at the age of 5 weeks
were observed. The animals were kept in pens that were enriched with an
elevation made of bricks. In total, 150 h of observations made at feeding
time (07:30–10:00 and 18:00–20:30 LT, local time) were analysed. A
number of affiliative, exploratory, comfort, eating, resting and locomotor
behaviours were observed. Agonistic behaviour was not observed. Rabbits
showed companion and location preferences: 56 % of animals had a
preferred companion, and 84 % preferred a particular place in the pen.
Significant effects of group size and time of day on the frequency of some
forms of behaviour were found, e.g. rabbits performed comfort behaviours more
often in the morning. Sex did not influence the rabbits' behaviour.
Correlations were also found between different forms of behaviour,
e.g. animals that performed more exploratory behaviours also showed more
locomotor behaviours and affiliative interactions.
... With regards to height requirements for housing 3% of breeders housing was below laboratory requirements and 61% was below pet requirements; this limits behavioural expression, which can result in abnormal and/or stereotypic behaviour [34]. Singly housed rabbits in small pens often show limited behaviour compared to group housed rabbits [25] and have higher incidence of abnormal behaviour [35], as well as reduced locomotor and exploratory activity [34]. Reduced locomotion over a long time period results in physical malformations e.g., spinal deformity; thus causing pain and suffering, reducing the welfare of the rabbits [35]. ...
... Singly housed rabbits in small pens often show limited behaviour compared to group housed rabbits [25] and have higher incidence of abnormal behaviour [35], as well as reduced locomotor and exploratory activity [34]. Reduced locomotion over a long time period results in physical malformations e.g., spinal deformity; thus causing pain and suffering, reducing the welfare of the rabbits [35]. ...
Simple Summary
Very little is known about where our pet rabbits come from: Who the breeders are, how good/or bad the conditions are that breeding rabbits are kept in, or whether breeders are being monitored by local authorities. This study aimed to bring to light information on breeding rabbits and breeders in the UK. Several methods of data collection were used combining data from online sales adverts, with a breeder survey and a council freedom of information request. From 3446 online rabbit sale adverts we found 94.5% of adverts were from England and only 1% of breeders were licenced. Out of 33 breeders surveyed, 51.5% provided smaller housing than recommended and housed most rabbits singly, against recommendations, and males were most likely to be housed singly, in too small conditions. However, most provided toys and a diet compliant with recommended guidelines. The most commonly sold/bred rabbits were breeds with flat-faces, which can cause significant health and well-being problems. A freedom of information request sent to 10% of UK councils revealed inconsistency in licensing conditions and confusion about eligibility. Without appropriate guidelines for housing and husbandry and regulation, rabbits within the pet rabbit breeding industry are at risk of compromised welfare.
Abstract
Conditions of pet rabbit breeding colonies and breeder practices are undocumented and very little is known about the pet rabbit sales market. Here, multiple methods were employed to investigate this sector of the UK pet industry. A freedom of information request sent to 10% of councils revealed confusion and inconsistency in licensing conditions. Data from 1-month of online sale adverts (3446) identified 646 self-declared breeders, of which 1.08% were licensed. Further, despite veterinary advice to vaccinate rabbits from five weeks, only 16.7% rabbits were vaccinated and 9.2% of adult rabbits were neutered. Thirty-three breeders completed a questionnaire of which 51.5% provided smaller housing than recommended, the majority housed rabbits singly and bucks were identified as most at risk of compromised welfare. However, most breeders provided enrichment and gave a diet compliant with recommended guidelines. Mini-lops and Netherland dwarfs were the most commonly sold breeds, both of which are brachycephalic, which can compromise their health and wellbeing. From sales data extrapolation, we estimate that 254,804 rabbits are purposefully bred for the UK online pet sales market each year. This data is the first of its kind and highlights welfare concerns within the pet rabbit breeding sector, which is unregulated and difficult to access.
... Despite recommendations that rabbits should be socially housed [68,74,75], 57-58% of rabbits are kept alone in the UK [50,54]. Issues can arise from solitary housing, such as abnormal behaviors [76] and a reduced lifespan [77]. In addition, whilst there are a number of studies documenting the welfare benefits of providing rabbits with environmental enrichment such as gnawing sticks and boxes [78,79], and clear husbandry advice regarding this provision [80,81], many rabbits' behavioral needs are not met. ...
... The People's Dispensary for Sick Animals [50] reports that only 49% of rabbits get daily play with toys, 46% get play in the run, 40% get play in the garden, and 24% get opportunities for daily digging. Meeting the behavioral needs of rabbits is crucial to avoid abnormal behaviors and behavioral problems, and enhance their welfare [76,79,81]. ...
There has been a recent trend towards keeping non-traditional companion animals, also known as exotic pets. These pets include parrots, reptiles, amphibians and rabbits, as well as small species of rodent such as degus and guinea pigs. Many of these exotic pet species are not domesticated, and often have special requirements in captivity, which many owners do not have the facilities or knowledge to provide. Keeping animals in settings to which they are poorly adapted is a threat to their welfare. Additionally, owner satisfaction with the animal may be poor due to a misalignment of expectations, which further impacts on welfare, as it may lead to repeated rehoming or neglect. We investigate a range of commonly kept exotic species in terms of their suitability as companion animals from the point of view of animal welfare and owner satisfaction, and make recommendations on the suitability of various species as pets.
... 8 Pair housing of rabbits in double-sized cages can potentially improve welfare by providing both increased space and social interactions that are unpredictable and novel. 5 One potential result of this unpredictability is injurious aggression and pseudopregnancy, as described in the current report. Establishing dominance hierarchies is a normal behavior in adult female rabbits. ...
... 3 In addition, establishing social groups at weaning might reduce aggression in paired female rabbits. 5 Pseudopregnancy may resolve spontaneously but often recurs. Chronic pseudopregnancy can cause complications including endometritis, pyometra, hydrometra, and mastitis. ...
Here we describe a case of pseudopregnancy in a New Zealand White rabbit as a result of pair housing with an aggressive conspecific. Clinical signs included fur pulling and nest builDing that developed shortly after separation from the aggressor. An ovariohysterectomy was performed, and histopathologic finDings support the diagnosis of pseudopregnancy. When introducing adult female rabbits to pair housing, stable pairs may be difficult to achieve because of the dominance-associated behavior that can occur as hierarchal relationships are formed. Does that are pair-housed after puberty should be monitored for aggressive behavior.
... Rabbits have been used for decades for intensive lean meat production and also as models in biomedical research such as anti-in pairs, or in groups, on group size and stocking density, but also on the quality of the environment (Chu et al., 2004;Verga et al., 2007;Trocino et al., 2014). Physiology, health, reproduction, and production may be used to evaluate stress, but the evaluation of the ethogram represents a key welfare indicator in animals kept in intensive conditions. ...
... Previous studies have investigated the effects of housing system (Trocino et al., 2014), group size, cage size, and stocking density (Chu et al., 2004;Princz et al., 2008;Buijs et al., 2011) on the behavior of growing rabbits. However, the potential effects of changes to the composition of the social group on social interaction, aggression and injuries have been largely neglected in rabbits, except for one study which showed no effect of social group composition on behavior (Szendrö et al., 2012). ...
The objective of the study was to investigate if environmental enrichment and the composition of the social group would affect the behavior and relative brain weight of growing rabbits. Rabbits (72 males and 72 females) were assigned to cages with or without enrichment and one of three social groups (males, females, or mixed-gender). Two eucalyptus sticks suspended from the cage ceiling were provided in the enriched cages based on the results of a preliminary trial conducted on growing rabbits (n = 48) showing that pieces of wood (Eucalyptus sp, Pinus sp) or bamboo (Dendrocalamus giganteus) were preferred over PVC pipe (P < 0.05). Rabbits were exposed to the experimental conditions between six and 11 weeks of age. Behavioral activities were video recorded for 24 h, at 7, 10 and 11 weeks of age. Growth performance was recorded from 42 to 77 days of age, whereas skin wounds and brain weight were recorded at 77 days. At 70 days of age, rabbits in non-enriched cages showed a higher proportion of self-grooming (P = 0.012) than those in enriched cages. Enrichment decreased the number of social interactions among rabbits (P = 0.012), but increased aggressive behavior (P = 0.007). The number of animals showing skin wounds on day 77 was lower (P = 0.006) in enriched than in non-enriched cages. The incidence of social interactions was higher (P < 0.05) and of stereotypes was lower (P < 0.05) in mixed-gender groups than in same-sex groups. Female groups showed the lowest incidence of aggressive behavior (P < 0.05). The number of individuals with skin injuries was higher in mixed-gender groups (P < 0.05) than in female groups; male groups were intermediate. Growth performance was unaffected by enrichment or by the composition of social group. Males in enriched cages had heavier brains (P < 0.05) than those in non-enriched cages. Although aggressive behaviors were more frequent, the number of skin wounds on day 77 was lower in rabbits from enriched cages, suggesting improved welfare. Based on the increased frequency of social interactions and decreased incidence of stereotyped behavior, mixed-gender groups should be housed in collective cages from weaning up to 11 weeks of age. However, if the incidence of skin wounds is considered, only females can be housed in same-sex groups. For males, individual cages should be preferred. Whether environmental enrichment induces morphologic changes in male rabbits’ brains should be further investigated.
... Muesli and high sugar treats, including bread or breakfast cereals for humans, are not recommended due to their associations with dental disease and other illnesses [72][73][74][75]. Other environmental factors, such as a lack of enrichment and lack of conspecific companionship that can cause bar-biting [76][77][78][79] and consequent dental damage, could also be a contributing factor, so breeders should ensure that they adopt appropriate husbandry practices to promote good dental health. ...
Lop-eared and brachycephalic conformations have inconsistently been associated with dental abnormalities in pet and rescue rabbit populations. We investigated conformational risk factors for dental abnormalities in a pedigree population where conformation could be confirmed. Otoscopic oral examination was performed on breeder-volunteered pedigree rabbits at British Rabbit Council shows and studs. Multivariable models were used for risk factor analysis of 14 possible dental disease signs. In 435 rabbits examined, 68.28% showed no incisor abnormalities and 55.40% showed no cheek teeth abnormalities. Lop-eared rabbits had higher odds than erect-eared rabbits for ocular discharge (odds ratio [OR]: 4.034, p = 0.007) but not for any dental abnormalities. Erect-eared rabbits showed higher odds of reacting to incisor examination than lop-eared rabbits (OR: 1.666, p = 0.003). Brachycephaly showed no associations with dental abnormalities, whilst more dolichocephalic rabbits had increased odds of cheek teeth step or wave mouth (OR: 1.394, p = 0.004). Other conformational and signalment-related risk factor results were mixed. Brachycephaly showed no significant predisposition to dental abnormalities, and the clinical relevance of predisposition to ocular discharge in lop-eared rabbits is unclear. Conformation appears less important than husbandry factors for preventing rabbit dental disease. Generalising the results to companion rabbits is not advised due to husbandry and population differences.
... One tool to minimize this issue and enhance animal welfare is the use of environmental enrichment (Newberry, 1995;Burkhardt, 1999. Environmental enrichment can include various components, such as social interaction (Chu et al., 2004), hay (Birolo et al., 2022), grass (Lidfors, 1997;Leslie et al., 2004), wood (Huang et al., 2021b), elevated platforms (Lang and Hoy, 2011), mirrors (Elsayed et al., 2024), materials for gnawing (Zucca et al., 2012;Silva et al., 2021), hay boxes, and structural modifications of the cage (Coda et al., 2020;Van Damme et al., 2023). All these enrichments can improve rabbit welfare by allowing the expression of natural behaviors, reducing aggression, and lowering hypothalamic-pituitary-adrenal (HPA) axis activity (Kadry and Barreto, 2010;Fan et al., 2021). ...
... Additional stress arises during their use in experiments as rabbits often serve as animal models when testing new interventional treatments before clinical trials (Pánková et al. 2021;Nguyen-Thanh et al. 2022). Despite efforts to improve their living conditions, certain aspects of rearing still remain unsatisfactory for rabbits (Trocino and Xiccato 2010) that are associated with the occurrence of behavioural disorders resulting from unsuitable social situations (Chu et al. 2004) or space restrictions (Gunn and Morton 1995) or even pathological changes as detected during a postmortem veterinary inspection (Ninčáková et al. 2022). Various methods are used for the identification of rabbits reared as pets, or as laboratory or farmed animals. ...
Infrared thermography is a relatively new tool used in the evaluation of stress and health disorders in animals. This study aimed to assess changes in rabbit temperature in response to acute stress. The mean surface temperature of the inner corner of the eye was measured using a thermal camera in 12 rabbits of 3 breeds (four individuals of Mecklenburger Piebald Rabbit, Castor Rex Rabbit, and Large Light Silver Rabbit each) exposed to handling and tattooing of the ears. The mean surface temperature and the standard deviation in the inner corner of the eye in rabbits measured in their home cage was 36.75 ± 1.02 °C and was significantly lower ( P < 0.01) than that measured during subsequent handling, tattooing and restraint. It was also lower in comparison with the mean temperature measured 30 min after tattooing when the rabbits were returned to the home cage (37.78 ± 0.54 °C). The surface temperature increased ( P < 0.01) in response to handling when the rabbits were removed from the cage (38.22 ± 0.42 °C), and reached a maximum during tattooing (38.62 ± 0.52 °C). No significant difference was determined between the breeds ( P > 0.05) at any stage of measurement. Changes in the surface temperature of the inner corner of the eye in rabbits took the same course in all three studied breeds of rabbits. An increase in temperature occurred during the initial handling of rabbits unaccustomed to human handling, and this increase persisted throughout the entire period of handling associated with tattooing.
... These behaviors can be indicators of poor welfare when their frequency increases. Rabbits have been reported to exhibit various stereotypic behaviors including excessive grooming, sham chewing (chewing without anything in their mouths), bar biting, licking parts of the cage, digging against the cage, biting water nipples, sliding their noses against bars, head pressing, and running repeatedly in a specific pattern [46,121]. The results of our study revealed a decrease in sedentary behaviors, such as sitting or lying down, and stereotypical actions like gnawing within the treated groups. ...
T HE OBJECTIVE of this study was to assess the impact of incorporating different percentages (7.5% and 10%) of dried olive cake and ground date palm together with or without bentonite addition (1%) on economic efficiency, growth performance, gene expression, histopathological findings, and behavioral responses in New Zealand and V-line rabbit breeds. A total of 100 weaning rabbits, from both New Zealand and V-line breeds, were used. The groups were categorized in to five groups per breed based on the content of their feed. The inclusion of bentonite at 1% in combination with both DOC and GDP led to enhanced growth performance for both breeds. From an economic perspective, reduced costs per kilogram of feed, overall feed expenses, leading to lower total production costs. Additionally, significantly higher total return, net profit, and economic efficiency measures were specifically observed within the G10%B group. Gene expression revealed non-significant differences in the growth markers. Bentonite addition at 1% increased the expression profile of antioxidant markers. These findings were also established through the changes in histological features, including increased length of mucosal folds, villi, crypt depth in the intestine, and an enlarged hepatic lobule area in the liver. The groups that consumed treated diets displayed enhanced behavior through increased feeding and grooming activities, as well as reduced periods of inactivity. In conclusion, the inclusion of DOC and GDP together at a rate of 7.5% or 10%, along with an additional 1% bentonite in the diet of growing rabbits, has the potential to yield cost-effective production outcomes.
... Studies evaluating rabbits in research settings have demonstrated conflicting results regarding the benefits of social housing. 14,15 However, many institutions recommend attempting to at minimum pair-house rabbits to increase normal behavioral traits of the species. 16 Social behaviors of young meat rabbits were investigated in a single breeding colony. ...
... In the research community, studies on the effects and methods of pair housing on welfare comes from the laboratory animal literature focused mainly on rabbits (Chu, Garner, & Mench, 2004), rodents (Brewer, Bellinger, Joshi, & Kleven, 2014;Galef, 1999), and primates (Capitanio, Blozis, Snarr, Steward, & McCowan, 2015;Crockett, Lee, Thom, & Bentson, 2005;DiVincenti & Wyatt, 2011;Novak & Suomi, 1988). This is in-part due to Federal Animal Welfare regulations that require "specific provisions to address the social needs of nonhuman primate species known to exist in social groups in nature" (United States Department of Agriculture, 2019). ...
... This type of housing has been labelled an "especially animal-friendly" housing system (BTS, 2019). It supposedly combines the positive aspects of continuous single housing and continuous group housing, i.e. the does are undisturbed during early lactation and, from day 12 onwards, they have more space for locomotion, can interact with conspecifics and, therefore, they develop less stereotypies compared to animals in continuous single housing (Chu et al., 2004;Dal Bosco et al., 2019). Additionally, compared to continuous group housing, the rate of infanticides, litters of two does in the same nest box and pseudopregnancies are reduced in the semi-group housing system (Andrist et al., 2013;Szendrő et al., 2016). ...
The neuroendocrine regulation of rabbit maternal behaviour has been explored in detail. However, little is yet known about the hormonal regulation of aggression in concurrently pregnant-lactating does, a reproductive condition that prevails during group housing of rabbits on farms. Therefore, in this study we determined the relation between a) the levels of progesterone, testosterone, and oestradiol during lactation; b) the anogenital distance at artificial insemination; and c) the timing of grouping with the intensity of agonistic behaviour, published previously. We performed four consecutive trials, where three groups of eight does each were artificially inseminated on day 10 postpartum (pp) and grouped on either day 12, 18 or 22 pp. Using Dipetalogaster maxima, a reduviid blood-sucking bug, we collected blood samples during the pregnant-lactating phase (days 13, 15, 17, 19, 21, 23 pp) on one or two randomly chosen does per treatment group. Testosterone levels varied little across the pregnant-lactating phase, agreeing with results from pregnant-only rabbits, while progesterone levels increased from day 3 (=13 dpp) to day 7 (=17 dpp) and remained unchanged until day 13 (=23 dpp) of pregnancy. All oestradiol concentrations fell below the limit of detection. Overall, all concentrations were slightly lower in comparison to rabbit studies with pregnantonly does. The agonistic behaviour was not related to the respective hormonal concentrations at grouping. In conclusion, the time point of grouping does after artificial insemination (AI) in the semi-group housing system only had a weak influence on aggression and the hormonal profile did not indicate an optimum time for grouping.
... Electronic and physical medical records were then reviewed and scored, and data analyzed as detailed in the figure (N = 152) SAS 9.3, as required. We adopted both family-level gatekeeping tests, and a general "winnowing" strategy to avoid multiple testing (and false discovery) (Blankenberger et al., 2018;Chu et al., 2004;Parker et al., 2018). We first tested the hypothesis that medical morbidity events would differ between low-social and high-social monkeys. ...
People with autism spectrum disorder (ASD) exhibit a variety of medical morbidities at significantly higher rates than the general population. Using an established monkey model of naturally occurring low sociality, we investigated whether low‐social monkeys show an increased burden of medical morbidities compared to their high‐social counterparts. We systematically reviewed the medical records of N = 152 (n = 73 low‐social; n = 79 high‐social) rhesus macaques (Macaca mulatta) to assess the number of traumatic injury, gastrointestinal, and inflammatory events, as well as the presence of rare medical conditions. Subjects' nonsocial scores, determined by the frequency they were observed in a nonsocial state (i.e., alone), and macaque Social Responsiveness Scale‐Revised (mSRS‐R) scores were also used to test whether individual differences in social functioning were related to medical morbidity burden. Medical morbidity type significantly differed by group, such that low‐social monkeys incurred higher rates of traumatic injury compared to high‐social monkeys. Nonsocial scores and mSRS‐R scores also significantly and positively predicted traumatic injury rates, indicating that monkeys with the greatest social impairment were most impacted on this health measure. These findings from low‐social monkeys are consistent with well‐documented evidence that people with ASD incur a greater number of traumatic injuries and receive more peer bullying than their neurotypical peers, and add to growing evidence for the face validity of this primate model.
Lay Summary
People with autism exhibit multiple medical problems at higher rates than the general population. We conducted a comprehensive medical record review of monkeys that naturally exhibit differences in sociality and found that low‐social monkeys are more susceptible to traumatic injuries than high‐social monkeys. These results are consistent with reports that people with autism also incur greater traumatic injury and peer bullying and add to growing evidence for the validity of this monkey model.
... In this context, direct social interaction, or at least social non-contact enrichment, is required for animals' well-being [9]. Thus, social interactions are a prerequisite even in conventional cages [10] and are known to impact the outcomes of research experiments [4,11]. In line with this notion are behavioral studies of adult New Zealand White (NZW) rabbits. ...
Simple Summary
The group housing of animals supports species-specific behavior and avoids stress induction. Therefore, novel housing systems need to be established that provide sufficient space and meet the hygiene criteria for laboratory animals. Here, we describe the successful implementation of an improved housing system for single and group housing of laboratory rabbits under high hygiene environmental conditions. This system includes modular and mobile floor pens of different size and shape. Rabbits housed in this system showed species-specific behavior that depended on the circadian rhythm—a prerequisite for interpretable animal experiments. We propose that this housing system will be of great benefit for the well-being of laboratory rabbits used in biomedical science.
Abstract
The major responsibility of researchers and laboratory animal facilities is to ensure animal well-being during the time of acclimatization, experiments, and recovery. In this context, animal housing conditions are of utmost importance. Here, we implemented a mobile and modular floor-pen housing system for laboratory rabbits that combines rabbits’ natural behavioral requirements and the high hygiene standards needed in biomedical science. Twelve female New Zealand White (NZW) rabbits were single- or group-housed for 12 months in mobile and modular floor-pens. Their general health status was evaluated at the end of the experimental setup. Further, we performed behavioral analysis of six additional NZW females group-housed for eight weeks in pens of two different sizes. We show that our improved housing concept supported species-specific behavioral patterns. Taken together, our housing system provides an optimal setup for rabbits in animal facilities that combines strict requirements for animal experiments with animal welfare.
... Stereotypies and abnormal behaviour are indicators of reduced welfare in rabbits. These behaviours can be: head shaking, swaying, wire gnawing, wall pawing and over-grooming [9,29,34,35]. In the present study, only one farm with presence of these abnormal behaviours, 32, was found (with 13% of the animals affected). ...
Simple Summary
Animal welfare assessment protocols allow one to understand the level of welfare and to identify the main parameters to improve on farms. Accordingly, farmers have the possibility to use these tools for implementing corrective measures to improve animal welfare. This study was performed through the application of an animal welfare assessment protocol for growing-rabbits in 32 farms from Spain and Portugal. The scores obtained ranged from 44 to 82 points out of 100, depending on the farm, showing a good discriminative capacity among the 32 farms assessed. However, some key points for improving were identified in most of the farms. These points were to provide more space for the animals, improve the protocols for emergency killing due to health problems or any other cause, and to provide the farmers proper training in animal welfare.
Abstract
The objective of the present study is to present an animal welfare assessment protocol for growing-rabbits for discussion after its implementation in 32 farms from Spain and Portugal. The protocol comprises the principles of Good Feeding, Good Housing, Good Health and Appropriate Behaviour of the Welfare Quality protocols and includes 36 welfare parameters. Overall, the protocol showed a good capacity for discrimination between farms, with scores ranging 44 to 82 points. The protocol seems reliable for the assessment of animal welfare after proper training of auditors. However, for the criteria social behaviour and other behaviours, further research is needed to ascertain if the methodology and times of observation used are appropriate. Some farms had high mortality rates with a low prevalence of health problems, while others had low mortality rates with high prevalence of health problems due to different managements of culling. The protocol should be improved, to impede farms with high mortality rates but a low prevalence of health issues the day of the audit from obtaining better scores than the second type of farms, by limiting the compensation in key measures. The main points to be solved in the growing-rabbit farms were: to provide more space to the animals; register the number of animals culled accurately; change cervical dislocation for another killing method and provide the farmers training in animal welfare.
... Stereotypes and abnormal behavior are indicators of reduced welfare in rabbits. These behaviors can be head shaking, swaying, wire gnawing, wall pawing, and over-grooming (11,(40)(41)(42). In the present study, none of the animals were observed showing these behaviors. ...
Rabbits are the third species in terms of number of animals reared for meat production in the world. However, in comparison to other species, very few studies have focused on their welfare. The aim of the present study is to implement an animal welfare-assessment protocol developed through a multidimensional approach and containing a number of animal-based measures for bucks, does, and kit rabbits. Thirty Spanish farms with conventional cages in the first year of integration in an animal welfare certification scheme were visited during 2019 and audited by the same auditor. The protocol is divided into four principles and 11 criteria. The Good Feeding principle includes eight parameters (one animal-based), Good Housing includes 15 parameters (six animal-based), Good Health includes 26 parameters (16 animal-based), and Appropriate Behavior contains nine parameters (four animal-based). In general, the main problems found were the absence of platforms, low space allowance and low height of the cage, inappropriate systems for performing emergency killing, insufficient protection of does from other adjacent does when housed individually, and absence of enrichment material. To a minor degree, but also found in an important number of farms, was a lack of temperature data records, high replacement rates of does, and lack of mortality-rate data records. However, in general, most of the farms obtained a good overall score, the maximum found being 73 out of 100 points. Nevertheless, none of the farms reached an excellent score, and four farms were scored below the 55 points required in the animal welfare certification scheme. The Good Feeding principle obtained the highest score, reaching excellent in all farms, and Appropriate Behavior the lowest one, with values ranging from 21 to 41 points out of 100. The results probably show how, for years, rabbit producers have been very focused on feeding needs and very little attention has been paid to behavioral needs.
... Windschnurer et al. (2012) hingegen erkannten einen positiven Zusammenhang zwischen agonistischem Verhalten und Sicherungsverhalten. Weiterhin wird angenommen, dass mit steigender Gruppengröße die Furchtsamkeit abnehmen kann, weil mehr Tiere vorhanden sind, um potentielle Gefahren zu erkennen. Chu et al. (2004) vermuteten eine günstigere soziale Struktur in Paarhaltung anstelle von Einzelhaltung, die mehr Ruhen zulässt, da das Einzeltier nicht ständig die Umgebung sichern musste. Windschnurer et al. (2012) fanden jedoch keinen Zusammenhang zwischen Sicherungsverhalten und unterschiedlicher Gruppengröße. ...
Intensive rabbit farming in Germany is subject to the requirements of the Animal Welfare Act and since 2014 also to the special requirements of the Order on the Protection of Animals and the Keeping of Production Animals (German designation: Tierschutz-Nutztierhaltungsverordnung). Due to legally anchored minimum requirements as well as growing consumer pressure, it is necessary to develop new ways of farming for fattening rabbits and to test the systems for animal welfare. The main problems of intensive fattening rabbit housing are restrictions of species-specific locomotion and behaviour, lack of structured spaces or enrichment and high stocking densities. Two commercially applied, group housing systems were examined for different aspects of animal behaviour. In the field trial, 56 fattening rabbits per floor pen section (12.1 Animals/m²) and 52 animals per each dual purpose cage compartment (12.7 animals/m²) were put in. The behaviour of the animals was recorded at the age of 40, 54 and 75 days with infrared video cameras over 24 hours. The analysis of the pen usage was evaluated using scan sampling method, selected behaviours with behaviour sampling and continuous recording. Rabbits well used the offered elevated platforms and preferred larger platforms compared to the smaller ones. Nevertheless, only about 20% of the animals were on the elevated platforms. In addition, hayracks, gnawing blocks and gnawing sticks were installed. The fibre-rich enrichment was significantly (p < 0,05) preferred. Solitary lying without body contact with other rabbits increased with each week of fattening. Therefore the stocking density allowed the rabbits to rest without body contact even at the end of fattening, but relaxed resting positions were interrupted in 50% of observations due to a conspecific. Agonistic behaviour increased with each week of fattening. In both systems, rabbits were able to dodge effectively. Locomotion of higher intensity (including game) occurred significantly more frequently in floor pens than in the long-drawn dual purpose cage. Also the rabbit couldn’t rest at the floor as often as in the floor pen. Both systems were therefore suitable for fattening larger groups of rabbits, but from a ethological point of view, the dual purpose cage is not yet preferable to the floor pen system, as it shows restrictions in the use of space.
... The body weight did not correlate with the rank of the animals. However, as our animals were fed ad libitum, their general body condition was more equal than in their wild conspecifics, which may mask the effect (Chu et al., 2004). Additionally, the farmed does were probably more homogenous in parity and age, contrary to wild living groups, which may increase the competition and instability within groups. ...
p>Semi-group housing in breeding does has been shown to reduce production and breeding success in comparison to single-housed animals. One reason for this reduction could be stress and aggression when grouping does only 2 d after artificial insemination. The aim of this study was to test different time points of grouping on fertility of does, body weight of both kits and does, and mortality rates. Hence, does were separated and housed individually one day before giving birth to their kits. The does were then artificially inseminated on day 10 postpartum (dpp) and regrouped according to the treatment (time point) on 12 (TG12), 18 (TG18), or 22 (TG22) dpp, respectively. In total, five trials with three groups pertaining to the three treatments (eight does per treatment group) were conducted. Non-pregnant does were replaced with pregnant does before each new trial (57 different does needed). Data were analysed with (generalised) linear mixed effect models and survival analysis. There were no significant differences in fertility, body weight
or mortality of does among the treatments. The average fertility rate (number of kindling events/number of artificial inseminations×100) was low (40.92%) and seasonal effects may have partially masked treatment effects, as most trials took place during winter. Likewise, the survival rate of kits was not influenced by the treatment (survival test: χ2=2.3, df = 2, P = 0.3). Body weight of the kits was also not affected by the time point of grouping (average weight: 447.70±46.42 g (TG12), 452.20±55.30 g (TG18) and 460.06±89.23 g (TG22); P = 0.33). In conclusion, grouping does at a later time point in the reproductive cycle did not show any significant improvement in the breeding or productive success in a Swiss semi-group housing system. An elongated separation from conspecifics did not enhance the welfare of semi-group housed rabbits.</p
... hair-chew, chew or lick objects, head-sway, paw and nose slide, head-corner). Chu et al. (2004) compared the behaviour of four individually and eight paired housed laboratory rabbits from 10 to 30 weeks of age. They observed an increase (from 0.25% to 1.77%) in the proportion of time spent in abnormal behaviours (digging, floor chewing, bar biting) in the individually housed group, while such behaviours occurred in an unchanged proportion of time (0.95%) in the case of paired housed rabbits. ...
Abstract 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.
... Although, it was scientifically demonstrated that the individually housed rabbits exhibit the best live performance (Maertens and De Groote 1984) and favourable meat quality traits ) rabbit is considered a social animal (Held et al. 1995). Living in social isolation rabbits can display physiological symptoms of stress, show certain stereotypes, exhibit extreme fear towards man and new environment (Podberscek et al. 1991;Chu et al. 2004). During a long period bicellular housing was the most frequent system but recently based on the EFSA recommendation (2005) the group size of seven to nine, preferably retaining littermates in groups, would be advantageous. ...
The aim of the experiment was to study the effect of housing growing rabbits in enriched cages with small groups (eight rabbits/cage, C; n = 96; stocking density: 15 rabbits/m²) or in enriched pens with large groups (65 rabbits/pen, P; n = 130; stocking density: 15 rabbits/m²) on their growth performance and on slaughter and meat quality traits. The C rabbits showed higher final body weight (2540 vs. 2443 g, p < .01), better feed conversion ratio (5–11 weeks: 3.39 vs. 3.61, p < .05), lower mortality rate (5.2 vs. 31.5%, p < .001), and lower fecal corticosterone level (26.3 vs. 29.4 nmol/g, p < .05) compared to P rabbits. The increased possibility of physical activity of P compared to C rabbits resulted in more developed hind part of the reference carcase, thicker hind leg bones (34.8 vs. 33.4 g, p < .05), lower perirenal fat (15.1 vs. 20.8 g, p < .001) and hind leg meat lipid content (2.00 vs. 2.42%, p < .05), as well as higher haem iron content of the hind leg meat (5.29 vs. 4.22 mg/kg, p < .01). However, pen housing was detrimental for the dressing out percentage and for the hind leg meat to bones ratio. Physical meat quality traits were not affected by the housing system.
• Highlights
• Housing of growing rabbits in large cages and large pens was compared.
• Caged rabbits had better productive performance, lower mortality and stress.
• Penned rabbits resulted in lower dressing out percentage, carcase adiposity and meat lipids content.
• Most of the meat quality traits were independent of the housing system.
... The study of rabbit behaviour is necessary to understand more about the important requirements of intensive rearing housing conditions. Chu et al (2004) found that rabbits differ from other livestock with specific behaviour which assessed on the basis of the behaviour of the wild animal. ...
Nowadays, researchers and even consumers need more information on the effect of different rearing systems and seasons not only on the animal behaviour and production but also on carcass quality. Understanding more about how the rearing system and season can influence behaviour, production and carcass traits of rabbit is extremely important. This current review proposes best investigation to cover these points. In many countries like in Spain, Italy and Egypt, rabbit (Oryctolagus cuniculus) plays an important role in meat production. Rabbit rearing systems as a part of animal welfare have been the focus of scientific research in order to improve well-being for high-quality products. Rabbits have specific behavioural needs and are able to change their behaviour to adapt the changes happened in the surrounding environment. Among these changes, it was the season’s variables: high ambient temperature, humidity and ventilation that can affect the animal performance.
... In the reproduction sector, group housing in pens provides does with more space for movement than individual housing in standard cages. Moreover, does can express a wider behavioural repertoire (locomotion and social interactions), thus reducing stereotypical behaviours (Chu et al., 2004;Mugnai et al., 2009). However, continuous group housing during the reproductive cycle decreases production performance and increases aggression frequency, resulting in severe wounds that may elevate culling rates (Mirabito et al., 2005;Rommers et al., 2006;Szendrő et al., 2013Szendrő et al., , 2016a). ...
This work aimed at evaluating the effects of housing system, pen floor type, and lactation management on rabbit doe and kit performance throughout a reproductive cycle, including categorization of aggressiveness and injuries. Forty multiparous pregnant does were assigned to six experimental groups: i) individual pens with plastic floor (4 does), ii) individual pens with wire floor and plastic mats (4 does), iii) collective pens with plastic floor and fixed lactation (8 does), iv) collective pens with plastic floor and random lactation (8 does), v) collective pens with wire floor and plastic mats and fixed lactation (8 does), and vi) collective pens with wire floor and plastic mats and random lactation (8 does). In collective pens, does were kept in groups from 8 d until 2 d before kindling and from 2 d until 33 d after kindling. In the fixed group, does always nursed their own litter; in the random group, a random litter from pen-mates. Behaviours were video-recorded at 8 d before kindling (-8 d), and 2 d (+2 d) and 18 d (+18 d) after kindling. Injuries were scored at 5, 12, 19, 26, and 34 d after kindling. Bayesian inference was used to study the differences between experimental groups. During controlled lactation, doe feed intake (+17.3 g/d; ProbR = 0.84) and milk production (+11.5 g/d; ProbR = 0.83) were higher in collective pens than in individual modules, and kit weaning weight was slightly lower (-20.4 g; ProbR = 0.55). Feed intake and kit weight at weaning were lower in the fixed than in the random lactation group (ProbR = 0.61-0.89). Aggression was lower at -8 d than at +2 d (-39.1 events; ProbR = 0.98), higher at +2 d than at +18 d (+50.2 events; ProbR = 1.00), and higher in pens with plastic mats than with plastic slats (average across all observation days, -14.7 events; ProbR = 0.69). Injury rate was higher at 3 d (34%) and 10 d (47%) after does regrouped from an isolation period, compared with later time points (P < 0.05). In conclusion, aggression was high in collective pens during the short period around kindling, but doe and kit performance were not substantially affected compared with individual housing. Plastic-slatted floors reduced aggression more than plastic mats, without affecting performance. Finally, lactation method had no relevant effect. Thus, random lactation in part-time collective systems may be transferred to commercial farms without negative outcomes.
... The welfare of rabbits is typically improved if they are kept together with other rabbits. 2,21 To stress this point, explaining to clients that laboratory rabbits actively choose the company of conspecifics when given a choice [22][23][24] is helpful. The presence of a conspecific typically induces more locomotion, which can even lead to beneficial effects on bone structure 2 and possibly has prophylactic effects against urinary sludge forming uroliths. ...
Because most research on rabbit husbandry, welfare, and nutrition was performed on production animals, evidence for best practices in pet rabbits is scarce, and guidelines must be based on transfer of results, deduction, and common sense. Rabbits benefit from being kept with at least one conspecific; from large enclosures and multistory hutches; from drinking water offered ad libitum in open dish drinker systems; and from receiving hay ad libitum, with restricted amounts of fresh grass, herbs, or green leafy vegetables, and a high-fiber complete diet. Offering hay ad libitum bears several advantages and should be considered a matter of course.
... Group housing represents a stimulating form of 'enrichment'. Behavioural studies have found that pair-or group-housed rabbits spend significant amounts of their time in close proximity to others 19,20 . The quality of life of group-housed rabbits is significantly improved in comparison with singly housed animals, even for those individuals regarded as subordinate 21 . ...
... Group housing represents a stimulating form of 'enrichment'. Behavioural studies have found that pair-or group-housed rabbits spend significant amounts of their time in close proximity to others 19,20 . The quality of life of group-housed rabbits is significantly improved in comparison with singly housed animals, even for those individuals regarded as subordinate 21 . ...
... Nowadays, infrared observation techniques allow a continuous view of the animals for 24 h, without disturbing them overnight and not affecting their behaviour. Different recording frequencies and lengths have been used in behavioural rabbit research, such as one every 15 min throughout 24 h (Morisse and Maurice, 1997), one min every hour throughout 24 h (Morisse et al., 1999), 15 min at the end of the light period and at the beginning and in the middle of the dark period (Chu et al., 2004), instantaneous observations (scan sampling) at a 5 min frequency during 6 h for the light period and 6 h for the dark period (Princz et al., 2008) or 5 min in the morning and 5 min in the afternoon (Mugnai et al., 2009). However, these techniques have not been validated in farmed domestic rabbits yet. ...
p>The aim of this study was to compare the results of different simplified sampling methods for behavioural data compared to reference records of 24-h in order to assess rabbit doe behaviours at different physiological stages (gestation and lactation) in animals housed in 2 types of cages (conventional and alternative). In total, we analysed 576 h of continuous video of 12 rabbit does at the end of lactation and the same females after weaning. The behavioural observations were studied using 3 independent categories of classification (location in the cage, posture and functional behaviours). Continuous behavioural recordings of 24 h were considered as the reference method to validate another 4 data collection sampling methods by aggregated video recordings of different frequency and duration [regular short and long methods with 2.4 and 8 h of observation respectively, and irregular (more frequent during the active period) short and long methods with 6 and 8 h of observation, respectively]. The current results showed that, independently of the housing system, the best method to reduce the total observation time required to assess rabbit does’ behaviour depends on the trait studied and physiological stage of the does. In gestating does, irregular methods were not suitable to estimate behaviours of long duration such as lying, sitting, resting and grooming. However, in both physiological stages, regular methods were accurate for location behaviours, postures and functional behaviours of long duration. Instead, for the study of infrequent behaviours performed mainly during dark period, where coefficients of variation were high, the irregular long method led to the lowest mean estimation errors.</p
... This would be in line with that previously reported by Hoy and Schuh (2004). From these days on, the decrease in latency is attenuated and the level of aggressiveness maintained, but the reasons why this aggression may persist are still unknown (Chu et al., 2004). ...
p>The present work aims to define the optimal conditions to perform a resident-intruder test in individually housed breeding does as a measure of aggressiveness and describe the biological characteristics of aggressiveness in rabbit does: severity, frequency, duration and latency of aggressive events. Sixty-four nulliparous does at 90 d of age were used for this experiment, half (32 does) as residents and the rest as intruders, testing them once a week for 14 wk. The time and duration of each aggressive behaviour was recorded and analysed to assess the aforementioned measures. According to the results, and regarding the studied effects, the origin of the animals caused no effect, whereas the level of aggressiveness seemed to be clearly increased in weeks 3-7 of the experiment, when animals were 110-140 d of age. In conclusion, a resident-intruder test lasting 1 min is enough to assess individual aggressiveness in adult breeding does, the response of which evolves with age and repetition.</p
... Rabbits spend a large degree of their time in mutual grooming behaviours -as anyone who owns more than one rabbit can attest. While engaged in foraging and grooming behaviours there is less time spent engaging in destructive and abnormal behaviours (Chu et al, 2004). ...
A rabbit's need for companionship is an important element of their welfare and husbandry. Increasingly, this fact is being recognised in both the laboratory and commercial settings and legislation and guidelines have been developed to enhance a rabbits social contact with members of their own species. Sadly, the social needs of pet rabbits are often not being met by owners. This may be through lack of education on the importance of companionship to their pets or through a lack of knowledge on how to introduce members of this territorial species together. The following article discusses the importance of social housing for rabbits and ways in which introductions can be made to reduce the likelihood of fighting.
... The occurrence of the behaviors seen with both cage designs was consistent with published data. 6 When switched from one cage type to the other, 6 of the rabbits displayed some changes in behavior, but the changes Weight gain of the rabbits in group 2, which initially was housed in the shorter caging. A 2-tailed unpaired t test revealed no significant difference in weight gain in this group between the 2 cage heights. ...
The 8th edition of the Guide for the Care and Use of Laboratory Animals recommends a cage height of 16 in. for rabbits, compared with 14 in. in the previous edition. In contrast, the Animal Welfare Act Regulations prescribes a cage height of 14 in. for rabbits. A review of the literature failed to identify published data that support an advantage to rabbits having 16 in. of cage height compared with 14 or 15 in. The study described here evaluated the effect of a 3-in. difference in cage height on the health, growth, behavior, and overall wellbeing of rabbits. Groups of 10 New Zealand white rabbits were housed in cages that provided either 15 in. of interior cage height (720in2 of floor space) or 18 in. of interior height (784 in2 of floor space). The rabbits were observed during 25 periods (1 h each) over 7 wk, and various behavioral parameters were scored. In addition, rabbits were weighed weekly, and general clinical health was assessed. After 4 wk, the groups were switched to the alternate housing. No significant differences in body weight gain or behavioral parameters were detected between groups housed in cages with different heights and amounts of floor space, nor were significant behavioral differences noted in individual rabbits when moved from one cage type to the other. In addition, all rabbits remained clinically healthy throughout the study. These results demonstrate that these differences in interior cage height neither benefit nor harm rabbits. ©2016 by the American Association for Laboratory Animal Science.
Social housing of laboratory rabbits is encouraged and thought to improve animal welfare due to the social nature of this species. However, there is limited published information comparing the physiologic and cardiovascular (CV) effects of paired and single housed adult female rabbits in commonly used laboratory caging. This study describes measurement of heart rate, systolic blood pressure, activity level, body temperature and pairing methods in four female New Zealand White rabbits that were previously implanted with M10 cardiovascular telemetry devices. Data was collected in single housed rabbits having no history of social housing while they were undisturbed in the home cage, during restraint, intramuscular injections and intravenous blood collection. The same animals were then placed in compatible pairs and housed in conventional Allentown caging. As expected, we found increased activity in paired rabbits but no significant differences in body temperatures, and CV parameters in single and paired rabbits undergoing the same procedures. These data suggest that paired rabbits can be used for safety pharmacology studies with minimal impact to data, while supporting improved animal welfare.
The present paper was designated to assess the perceived frequency of problematic rabbit behavior in a sample of pet rabbit owners and to characterize this behavior. For this purpose, a questionnaire was administered to 423 rabbit owners from Spain and Latin America. The collected data was processed descriptively and using multiple correspondence analysis (MCA). Results indicated that, among the studied population, the most common behavior problems according to owners’ perception were inappropriate elimination followed by non-social fear, destructive behavior and compulsive disorders.
Rabbits generally showed more than just one behavioral problem; there seemed to be an association between non-social fear and destructive behavior as well as between owner-directed aggression and owner-directed fear. MCA indicated that the studied behavior problems were more frequent in entire females. Rabbits acquired before weaning and, to a lesser extent, between weaning and puberty were more likely to show compulsive disorders and inappropriate urine elimination. These two behavior problems seemed to be also more common in rabbits from breeders and pet stores. Such data support previous findings and provide new information in the field of epidemiology of behavioral problems in pet rabbits.
Background : For many veterinarians, focusing on rabbit behavioural issues may not seem like a top priority in their practice. However, a willingness to engage owners on this topic will significantly improve the welfare and health of the UK's third most popular mammalian pet.
Aim of the article : This article details a simple approach that can be used for the most common behavioural problems encountered in rabbits, and also suggests some tips for what to do if you are out of your depth.
In the wild, rabbits (Oryctolagus cuniculus) are social but territorial. Recent surveys suggest that over half of pet rabbits are housed singly. We aimed to compare welfare in single versus paired rabbits. We predicted singletons would show more abnormal or escape behaviour, greater stress responses to handling, and reduced body temperature (being unable to huddle with another individual when cold), but that pairs may show aggression. This study was conducted during winter at a rabbit-only rescue centre, and included 45 rabbits, comprising 15 housed singly and 15 pairs. Like most pet rabbits, they were housed either outdoors or in unheated outbuildings. Singletons were mostly in smaller enclosures than pairs. Home-pen observations (40 min) revealed bar-biting in 8/15 single rabbits compared with 0/30 of the paired ones. No other behavioural effects of social housing reached significance, and enclosure size showed no significant effects. Body temperature was significantly lower in singletons than pairs, with at least 0.5°C mean difference. On colder days, rabbits adopted compact postures more, and relaxed postures less frequently. After handling, pairs resumed normal behaviour significantly more quickly than singletons in the home-pen (3.0 [± 0.3] versus 8.3 [± 1.3] s, respectively). Aggression was never observed. The results indicate that social housing reduces bar-biting, aids thermoregulation, and may help buffer stress. Rabbit owners should be encouraged to meet the need for rabbits to be housed with an appropriate conspecific in a suitably large, sheltered enclosure.
Az európai fogyasztók egyre nagyobb hangsúlyt helyeznek az állatok jóllétére. Az elvárások megfogalmazásában jelentős szerepe van az állatvédő mozgalmaknak, amelyek egy része szakmai ismeretek, mások viszont érzelmi benyomások alapján fogalmazzák meg véleményüket. Sajnos ritkán jutnak el a kutatási eredmények a kereskedőkhöz és fogyasztókhoz, az állatvédők viszont nagyon eredményesen gyakorolnak nyomást a kereskedelemre, a politikusokra, és végül a fogyasztók választását is hatékonyan befolyásolják. Ugyanakkor az állatjólléti előírásoknak kutatási eredményeken kellene alapulniuk, valóban az állatok jóllétét kellene szolgálniuk, figyelemmel a termelőre és a fogyasztói árakra is. A nyulak védelmére vonatkozó minimális követelményekről szóló, az Európai Parlament 2017. március 14-i állásfoglalásban (2016/2077 (INI)) rámutattak arra, hogy „számos szempont mérlegelésével egyensúlyt kell tartani, figyelemmel az állatok jóllétére és egészségére, a gazdálkodók pénzügyi helyzetére és munkakörülményekre, a termelés fenntarthatóságára, a környezeti hatásra és a fogyasztóvédelmre, továbbá a fogyasztók megfizethető, jó minőségű nyúlhús iránti igényére”. A házinyulak tartásával és jóllétével kapcsolatban számos tudományos cikk, irodalmi összefoglaló és tanulmány jelent meg (EFSA, 2005; Hoy és mtsai, 2006; Trocino és Xiccato, 2006; Verga és mtsai, 2009; Szendrő és Dalle Zotte, 2011; Szendrő és McNitt, 2012; Szendrő és mtsai, 2016; Hoy és Matics, 2016; González-Mariscal és mtsai, 2017; Turner és mtsai, 2017; Szendrő és mtsai, 2019). A fogyasztók igényeinek kielégítése érdekében az Európai Unió Tanácsa (EU Tanácsa) irányelveket adott ki a tenyésztés céljából tartott állatok védelméről (Council Directive 98/58/EC of 20 July 1998), a tojótyúkok, (Council Directive 1999/74/EC of 19 July 199), a hústermelés céljából tartott csirkék (Council Directive 2007/43/EC of 28 June 2007), a borjak (Council Directive 2008/119/EC of 18 December 2008), valamint a sertések védelmére vonatkozó minimális követelményekről (Council Directive 2008/120/EC of 18 December 2008). Az EU Tanácsa azonban még nem tett közzé semmilyen előírást a tenyésztett nyulak védelméről. Jelen cikk célja, hogy tudományos eredményekre alapozva foglalja össze a házinyulak nagyüzemi tartásának minimális követelményeit. Nemcsak a követelményeket írjuk le, hanem ahol van, röviden összefoglaljuk az adott terület irodalmi eredményeit, vagyis a javaslatok magyarázatát is. A minimális követelmények „A mezőgazdasági haszonállatok tartásának állatvédelmi szabályairól” szóló 32/1999. (III. 31.) FVM rendeletre, illetve annak módosított változataira (20/2002. (III. 14.) FVM rendelet, 72/2004. (IV. 29.) FVM rendelet, 178/2009. (XII. 29.) FVM rendelet) épülnek. Ugynakkor független a sokkal szigorúbb állatkísérletekről szóló 40/2013. (II. 14.) Korm. rendelettől.
The impact of behavioural disorders on animal welfare in modern animal husbandry has been much debated. While other abnormal behaviours have been explored at length, there are a paucity of studies on tail-biting in rabbits ( Oryctolagus cuniculus ). In the present study, severe tail lesions were observed in group-reared rabbit does on a commercial rabbit farm. In the subsequent investigations, the occurrence of tail lesions in 219 rabbit does from nine batches was compared between group- or single-housing and a scoring system recording the severity of tail lesions was developed and verified. This five-grade scoring system was applied to evaluate the progression of prevalence and severity of tail lesions in 21 groups during rearing in two batches. The results revealed a significant difference in the score level between housing types with a higher prevalence of injured tails in group- (60.4%) compared to single-reared (4.0%) does. An increase in severity and frequency of tail lesions was observed in groups during the course of a rearing period. Furthermore, the established scoring system was characterised by adequate observer reliability. Overall, tail injuries occurred on a regular basis in the investigated rearing groups, indicating tail-biting to be a prevalent problem. This could be considered relevant in terms of animal welfare, both for the animal doing the biting and the individual being bitten. The findings draw attention to an inadequately described problem in rabbit husbandry. However, the search for preventive measures needs to scrutinise the role of single-housing, without failing to consider the gregarious nature of rabbits.
Rabbits are members of the class Mammalia, order Lagomorpha, and family Leporidae. Wild European rabbits live in extensive networks of interconnected burrows with multiple entry points. Rabbits are obligate herbivores. An appropriate starting point is to base pet rabbits' diet on the high‐fibre, low energy‐density herbivorous diet that they have evolved to eat. Rabbits are social animals; their motivation for companionship is almost as high as that for food. Whether human contact can be enjoyable for rabbits is unclear, although some owners report that their rabbits follow them in the garden, indicating that rabbits are choosing to spend time with a human in that context. Acute pain may prompt behaviours such as flexing their whole body, huddling tightly, and shuffling their hind legs, while reducing the occurrence of many normal behaviours. Rabbits' level of anxiety or fear, and perhaps their overall emotional state, may be indicated by their behaviour in open spaces.
Environmental enrichment is an integral part of animal care practices. Enrichment generally refers to items we provide to the animals to support their behavioral needs. It provides a way to functionally simulate the natural environment of captive animals, in an effort to increase opportunities for the expression of species-specific behaviors and decrease the occurrence of abnormal behaviors. Further, enrichment can also be a tool in the study of basic science questions, such as how environmental factors may affect disease etiology or progression. In this chapter, we discuss enrichment as both a welfare tool and as an experimental model. We will also discuss whether enrichment increases variability in research protocols, and present some practical tips on ways to implement an effective enrichment program for laboratory animals.
Beginning in 1931, an inbred rabbit colony was developed at the Phipps Institute for the Study, Treatment and Prevention of Tuberculosis at the University of Pennsylvania. This colony was used to study natural resistance to infection with tuberculosis (Robertson et al., 1966). Other inbred colonies or well-defined breeding colonies were also developed at the University of Illinois College of Medicine Center for Genetics, the Laboratories of the International Health Division of The Rockefeller Foundation, the University of Utrecht in the Netherlands, and Jackson Laboratories. These colonies were moved or closed in the years to follow. Since 1973, the U.S. Department of Agriculture has reported the total number of certain species of animals used by registered research facilities (1997). In 1973, 447,570 rabbits were used in research. There has been an overall decrease in numbers of rabbits used. This decreasing trend started in the mid-1990s. In 2010, 210,172 rabbits were used in research. Despite the overall drop in the number used in research, the rabbit is still a valuable model and tool for many disciplines.
The aim of the experiment was to study the effects of cage density (1, 3 and 5 rabbits per cage) and sex (male and female) on stress parameters of young rabbits. A total of 90 (45 male and 45 female) weaned New Zealand White rabbits aged 35 days old were used in the experiment. Rabbits were allocated as 1, 3 and 5 rabbits, in each of 5 cages, to obtain three different cage density groups: 4200, 1400 and 840 cm(2) floor area per rabbit, respectively. Mean values for total body weight gain, food intake, food:gain ratio, the plasma corticosterone level and serum levels of glucose, cholesterol and triglycerides were taken as indicators of stress. The group having 5 rabbits per cage had significantly lower total body weight gain (p<0.00 1), food intake (p<0,001) and higher food:gain ratio (p<0,01) than other groups during the experiment. The levels of plasma corticosterone and serum glucose were higher (p<0.001) in the group with 5 rabbits per cage than other groups. Values for serum levels of cholesterol and triglyceride were not affected by cage density. Gender effect was detected only in corticosterone level. Male rabbits had higher plasma corticosterone than female rabbits. The results suggest that the allocation of I or 3 rabbits per cage had no measurable adverse effects on the welfare of male and female young rabbits, whereas (at our cage densities) 5 ones.
We demonstrate that statistics textbooks differ in their prescription for the analysis of experiments that involve blocking factors. The differences in analysis may lead to differences in conclusions regarding the significance of experimental treatment effects. We outline the two approaches, discuss why they are different, and suggest when each approach may be applicable. We point out that simply following one’s textbook may not be the best course of action for any particular situation.
We demonstrate,that statistics textbooks,differ in their prescription,for the analysis of experiments,that involve,blocking,factors. The differences in analysis may,lead to differences,in conclusions,regarding,the significance,of experimental,treatment,effects. We outline the two approaches, discuss why they are different, and suggest when each approach,may,be applicable. We point out that simply,following,one’s textbook,may,not be the best course,of action for any particular situation. Key words:,blocking factors; error terms; hypothesis tests; mixed-model ANOVA; random,effects; statistical inference.
Under natural conditions, female European rabbits usually spend the whole of their life in their natal groups, establishing a network of stable relationships with their group-mates, particularly with other females. Indeed, female social interactions with groupmates are ultimately responsible for the dimension, structure, and cohesion of the group itself. Despite their importance in social organization, non-reproductive female behaviors are poorly known. This study aims to provide information on the nature and distribution of these behaviors in familiar and unfamiliar milieux. For this purpose, female rabbits unfamiliar with each other were experimentally grouped, housed in outdoor enclosures new to them, and observed as they gradually familiarized with their environment and group-mates. When females were unfamiliar with both environment and group-mates, they would often mark objects (but never conspecifics) and engage in agonistic activities, preceded by approach and olfactory investigation. Once females had become familiar with their environment and group-mates, they spent a lot of time eating and self-grooming. Marking frequency decreased, and agonistic behavior became rare and appeared no longer related to introductory behaviors, which under these conditions led to amiable interactions, such as lying side by side with group-mates or grooming them. Under both unfamiliar and familiar conditions, high-ranking females appeared more active and interactive than low-ranking ones.
The mixing of weaned pigs from different litters was observed so that the effect of a large difference in bodyweight on fighting could be examined. When 5- to 6-wk-old pigs met in pairs for 1 h, fights were longer and biting more frequent if the difference in weight between the pigs was small ( 3.0 kg). In groups of four 5- to 6-wk-old pigs taken from different litters, fighting was more prolonged during 2 h after mixing if there was little weight variation in the group (coefficient of variation ) than if there was large weight variation (coefficient of variation ). When groups of four pigs were formed by taking one large and one small pig from each of two litters, the longest duration of fighting occurred between the two large pigs. Significantly less fighting occurred between the large and small pigs and between the two smaller pigs. Subordinate pigs were less likely to retaliate against the dominant pigs if the weight difference was large. It seemed that the presence of...
Environmental enrichment is a vague concept referring to improvements to captive animal environments. Some authors have applied the term to an environmental treatment itself, without any concrete evidence that the treatment represented an improvement for the animals. Others have used the term when the main beneficiaries may have been people rather than their captive animals. The criteria used to assess enrichment have also varied according to animal use (e.g. laboratory, farm or zoo animals). In this paper, environmental enrichment is defined as an improvement in the biological functioning of captive animals resulting from modifications to their environment. Evidence of improved biological functioning could include increased lifetime reproductive success, increased inclusive fitness or a correlate of these such as improved health. However, specifying an appropriate endpoint is problematic, especially for domestic animals. Potential methods of achieving enrichment that require further investigation include presenting food in ways that stimulate foraging behaviour and dividing enclosures into different functional areas. The quality of the external environment within the animals' sensory range also deserves greater attention. A common shortcoming of attempts at environmental enrichment is the provision of toys, music or other stimuli having little functional relevance to the animals. Failure to consider the effects of developmental factors and previous experience can also produce poor results. Environmental enrichment is constrained by financial costs and time demands on caretakers, and providing live prey to enrich the environment of predators raises ethical concerns. Future research on environmental enrichment would benefit from improved knowledge of the functions of behaviour performed in captivity and more rigorous experimental design.
Repetitive 'stereotyped' behaviours are often performed by both wild and domestic rodents in small laboratory cages. In this study, a behaviour resembling a backwards somersault or backflip is described and quantified in captive roof rats (ship or black rats, Rattus rattus). Videotapes of captive-bred rat pups showed that repetitive backflipping developed rapidly after weaning. In all subjects, the behaviour was highly cyclical, with more than 90 per cent occurring during the dark phase of the light:dark cycle. Individual variability in the performance of backflipping was considerable but performance levels for each individual were consistent from day to day and at 30 and 60 days of age. Highly significant differences were found between litters (families), indicating important maternal and/or genetic effects on performance levels. Cage enrichment in the form of a wooden nest box resulted in dramatically lower rates of performance. Increased cage height resulted in delayed development of backflipping, as well as changes in the form of the behaviour. Results are consistent with the hypothesis that the development and expression of backflipping in young roof rats may be triggered by weaning and maintained by a heightened state of arousal in a relatively impoverished environment with limited opportunities for perceptual and locomotor stimulation.
Brushtail possums are generally solitary animals. They use a range of olfactory, auditory, visual, and tactile behaviour to achieve spacing between individuals and to establish dominance hierarchies. Existing descriptions of possum behaviour are either not widely available or incomplete, and the function of dominance hierarchies is unclear. Data presented here were collected incidentally during observations of captive possums to determine the effects on dominance status of suppression of reproduction for biological control. Dominant and subordinate behaviour are described and reviewed. The top‐ranking possums in dominance hierarchies were always females. Dominant possums displaced subordinates from food, water, and dens. In our captive setting, only dominant males attempted to mate with females, but dominant and subordinate females produced a similar number of pouch young. In the wild, where resources are limited, we predict that dominance behaviour should limit the frequency and success of breeding by both subordinate males and females.
1. Colonies of wild rabbits were maintained for 4 years in enclosures on old parkland on the Orielton Estate, south Pembrokeshire. One colony was confined within 1 acre, divisible into two equal half-acres A and B (the intensive enclosure), and was allowed to increase without any control. A second enclosed acre, C, the extensive enclosure, contained one buck and one or two does, their progeny being removed at weaning time. A third small enclosure, D, was built with an artificial warren faced with plate glass for observing behaviour underground. A further enclosure of 12 acres of grass and woodland harboured a small wild colony for comparative observation, but little could be observed of this colony, so well was it hidden in covert. 2. In the intensive enclosure there was an established order of dominance. One buck dominated each half-acre at first; secondary bucks had territory within that of the dominant male. Dominance was secured by constant patrol of territory, and by fighting or by aggressive display by the dominant bucks. Once the order of dominance was established the secondary individuals retired on the approach of a recognized superior within the latter's territorial range; thus fighting was generally avoided and an ordered society maintained for long periods. Dominance usually depended on seniority. Young males rarely secured a dominant position until they were 18 months old. 3. The adult female was sedentary and around her warren was centred the general activity of each group, composed of her progeny, her mate and other individuals powerful or submissive enough to retain a position in the warren. The dominant female was the mate of the dominant male, and enjoyed his protection and the security of the best position in the centre warren, in which she deposited her litter. Secondary females usually littered in stops (nursery burrows) dug in the open. 4. The doe was responsible for the major part in the digging and establishment of a warren, which developed initially from the enlargement of a nursery burrow. The buck took no part in this work, or of caring for the young. The buck tolerated young rabbits born in the warren which he occupied so long as they were being suckled by his mate, and afterwards so long as they remained submissive or retreated at his approach. Both breeding doe and buck attacked young rabbits born outside their warren, and which sought to enter. Thus the progeny of the dominant adults enjoyed a social advantage over rabbits born outside the central warren, and were more likely to succeed to dominant positions. 5. There was evidence of gregariousness in the movement of young rabbits from outside stops to the centre warren, which provided the best shelter and labyrinthine cover below ground; and in the vain attempt of the solitary buck in the extensive enclosure to penetrate into the crowded colony in the intensive enclosure. 6. The sex ratio was close to unity. There was some evidence of monogamous unions of pairs living together in established territories in the breeding season. 7. The habit of enurination is described as a release of tension, or displacement activity. 8. Live-births in the intensive enclosure, which built up from a nucleus of six pairs in the first year to twenty-four pairs in the fourth year, slowed down, as the physical and psychological stresses and tension of overcrowding and overgrazing developed, from 100% increase in the first, to 17% increase in the last breeding season. 9. The expectation of life of the marked rabbits tagged at weanling age was approximately 18 months for both does and bucks. The average age composition of the colony in the intensive enclosure showed that in spite of heavy mortality in the first year of life, rabbits under 1 year old were in excess of older rabbits at the commencement of the breeding season in December. 10. Although copulation was observed in November, no young rabbits appeared above ground before April in the intensive enclosure. It is probable that there was a high pre-natal mortality (re-absorption of embryos) due to the stresses of overpopulation. 11. Coccidiosis was the only significant identified disease, directly and indirectly causing some mortality in crowded conditions. Predation of weanlings by buzzards and feral cats caused the heaviest direct mortality in this age-group.
Bank voles were bred and lived in 4 different environments: small barren cages (SB), small enriched cages (SR), big barren cages (BB) and big enriched ones (BR). Ten different behaviours were recorded at the age of 30, 45, 60, 61, 75 and 90 days. Between day 60 and 61, within each experimental environment, the group of voles performing stereotypies (ST) and the group of those which did not (NST) were each split in two, one part being transferred to a new environment, the other remaining in the same as control. For each of the 10 behaviours, differences between the 4 environments and therein differences between the ST and the NST animals and between the age groups were analysed with a split-plot ANOVA. The results indicated that enrichment is more determinant than cage size, as more voles developed stereotypies in SB and BB than in SR and BR. Improving the environment after day 60 inhibited the stereotypies in most ST animals, while smaller and/or barren environments elicited them in very few NST. ST voles performed significantly more rearing and walking-sniffing and showed significantly less immobility than NST ones. These differences remained linked to the ST/NST status when an animal reversed it after day 60. Within different environments, some individuals are more prone to react actively to frustration, including the development of stereotypies. The performance of stereotypies is associated with a more general behavioural activation.
Levels of aggression, injuries, activity, performance and immune response were determined in 288 growing pigs in a 2×2 factorial experiment; the factors being group composition and pen size. Pigs were classified as small (SM) when allotted and then reclassified as medium (MED), large (LG) and extra-large (XL) at 3 week intervals. Static groups were initiated by 12 SM pigs and they remained together for 12 weeks. Dynamic groups consisted of three pigs of each size class. Pigs were introduced into dynamic groups as SM pigs and remained there for 12 weeks, progressing up through the size classes. At 3 week intervals the three XL pigs in dynamic groups were removed and replaced with three SM pigs. Pen sizes were 9.5 m2 and 7.6 m2. Pigs were weighed weekly and gains determined. Aggression during the 4h period after regrouping was determined by 10 min of continuous observations at 20 min intervals.
Twelve boars, three from each of four litters, were assigned at an average weight of 22.3 kg to three treatments to study effects of exercise on a treadmill on the incidence of leg weakness in terms of visual appraisal, cartilage and bone appraisal and blood serum composition. Treatments consisted of a control without enforced exercise, exercise three times/wk at a speed of 2 km/h at 0 slope (LE), and exercise at a speed of 4 km/h at 0 slope (HE). Boars were housed individually and fed a diet similar to that used in the Canadian Record of Performance for Swine program. Daily feed intake, weight gain and efficiency of feed conversion to 90 kg liveweight and average backfat and loin area at slaughter were not significantly influenced by treatment, suggesting that the degree of exercise had little influence on energy expenditure. Forelegs of non-exercised boars showed more abnormalities on visual appraisal than those of LE or HE boars and the degree of unsoundness increased from wk 6 to wk 10 for control boars, but not for LE and HE boars. When all sites were combined, there were no significant differences in mean lesion scores for joint cartilage evaluation, but there were significant differences between appraisal sites. Abnormalities of forelegs based on visual appraisal were significantly correlated with cartilage appraisal of both the proximal radius–ulna (P < 0.01) and the distal humerus (P < 0.05). Exercise had no apparent influence on bone mineralization or on the blood serum chemistry profile. The results indicate that exercise will reduce the incidence of visual abnormalities such as bow legs, flexion of the carpus and sickle leg in boars.
Behavior and average daily gain were evaluated after mixing pigs amongst litters or maintaining them as littermate groups, after weaning and initially limit or full fed. Limit fed mixed groups fought most and gained least of the treatment groups. Limit fed littermate groups fought least of the groups. Limit feeding after moving and mixing pigs amongst litters may reduce pathological conditions but was not demonstrated to reduce behavioral stress, as indicated by the expression of agonistic behavior.
It has been suggested that isolation from conspecifics may contribute to the development of abnormal behaviors that are common in captive parrots, including stereotypy, feather plucking, excessive fearfulness and aggression (e.g. [Proceedings of the European Symposium on Bird Diseases, Beerse, Belgium (1987), p. 98; Kleintierpraxis 38 (1993) 511]). Thus, we assessed the influence of isosexual pair housing on the development of these behaviors, as well as the incidence of illness and injury, in young Orange-winged Amazon parrots (Amazona amazonica). Parrots (n=21) were parent raised to 6 months of age and then housed either singly or in isosexual pairs. All cages included inanimate enrichments that were changed regularly, and all parrots were handled regularly. Behavioral activity was recorded 0,3,6,9 and 12 months after the parrots were housed in the experimental cages, and responses (e.g. willingness to approach, tolerance to touch, flight distance) to familiar and strange human handlers and to novel objects introduced into the home cage were recorded periodically. Paired parrots used their enrichments more (GLM: F1,10=13.74; P=0.004), and spent less time screaming (F1,10=4.90; P=0.051), less time preening (F1,10=5.12; P=0.047), and less time inactive (F1,10=9.24; P
Although many authors have suggested that the quality of the cage environment contributes to the development and performance of psychogenic feather picking by parrots, there is little scientific evidence for this relationship. In chickens, there is an established relationship between absence of foraging opportunity and the performance of a similar behavior, feather pecking. Thus, we assessed whether providing environmental enrichments designed to facilitate foraging behaviors would prevent or reduce the development of feather picking behavior by parrots, as evidenced by superior feather condition. Two groups of eight parrots were parent-reared to weaning and then housed singly in either enriched or unenriched cages for 48 weeks. In the enriched condition, a unique combination of one foraging and one physical enrichment was presented to each parrot weekly. In both groups, feather condition was quantified using a 10-point scale. The provision of enrichments led to an improvement in feather condition over 48 weeks in the enriched group, while feather scores in the control group decreased significantly (repeated measures GLM: F1,46=5.59; P=0.022) during this same period, indicating that feather picking behavior had developed in this group. In the second part of this study, the control group was transferred to the enriched treatment for a period of 16 weeks. During this period re-feathering occurred and feather scores improved significantly, indicating that feather picking behavior had decreased (repeated measures GLM: F1,53=35.57, P
Many studies have examined the short-term effects of inanimate environmental enrichment on the behavior of captive primates. Similarly, numerous studies have examined the behavioral effects of manipulations to the social environment. Few analyses have examined the long-term effects of inanimate environmental enrichment or compared the effects of inanimate and social enhancements. The behavior of control (n = 49) and enriched (n = 44) rhesus monkeys (Macaca mulatta) was observed from 1–4 years, as subjects spent successive years housed singly, in paris, and then in small groups. Social housing condition and/or age of subject significantly affected time spent inactive, grooming, playing, exploring, and behaving abnormally. Frequency of vocalization was similarly affected. Social housing resulted in more species-typical behavior patterns than did single caging. Subjects were more socially oriented when pair-housed than when living in small groups. Inanimate enrichment did not affect behavior over a 3 year period, although enhancements were well-used by singly-caged yearlings and pair-housed juveniles. Subjects used enrichment less frequently when housed in groups. The data suggest that the presence of a social partner(s) led to more beneficial changes in behavior than did the provision of inanimate enhancements for rhesus monkeys in the studied age range. Therefore, it is concluded that social enrichment should be provided when possible and appropriate. Efforts to enrich the inanimate environment will be most beneficial when focused on socially-restricted primates.
In group-housed female laboratory rabbits, aggression can occur during, and after, the establishment of dominance hierarchies and in association with sexual behaviours. Low-ranking animals receive more attacks than high-ranking ones. To investigate whether the low-ranking rabbits would avoid the potentially stressful group-pen in favour of a solitary compartment they were given the choice between their group-pen and a solitary pen. In Experiment 1, the solitary pen was of the same size (2.8 m2) and contents (straw, boxes, ledges) as the group-pen. Nine low-ranking and nine high-ranking rabbits from nine different groups were tested. In Experiment 2, the solitary pen was smaller (0.56 m2) and did not contain straw, boxes or ledges. Only the nine low-ranking rabbits were tested. Each rabbit was tested in 20 trials. After ten trials, the positions of the choice pens were swapped. The rabbits' choices were analysed using binomial tests and loglinear models. In Experiment 1, the low-ranking rabbits showed a preference of 1.7 to 1, the high-ranking rabbits of 1.3 to 1, for the solitary pen. Five out of the 18 tested rabbits showed a significant preference. The effect of social rank on the rabbits' choice was not significant. In Experiment 2, the low-ranking rabbits preferred the group-pen by 5.2 to 1. Eight out of the nine tested rabbits showed a significant preference. Neither the aggression levels within the groups immediately before the trials nor the long-term average aggression level seemed to affect the rabbits' choice. The outcome of the trials depended only on the solitary pen on offer.
In view of recent concerns regarding the current method of housing laboratory rabbits in the UK, the 24 h behaviour of 18 New Zealand White rabbits kept individually in standard laboratory cages (49 cm × 61 cm × 48 cm) was observed. In 24 h each rabbit was observed 288 times for 10 s and behaviour(s) was recorded using an ethogram. Results were analysed by calculating the percentage frequency of each behaviour for individual rabbits, adding these values together, and dividing by 18 to give a mean and standard error for the whole group. The most common behaviours were lie alert (23%), doze (20%), groom (10%), sleep (9%) and eat (8%). Overall, 56% of the rabbits' time was spent inactive. The level of mobility (1.2%) reflected their inability to hop normally and, in addition, they were unable to sit up, rear fully or stretch out because of spatial restriction. All rabbits showed stereotyped activities (11%) such as repetitive hair-chewing (4%), bar-chewing, head-swaying and pawing which indicated psychological problems, particularly in rabbits that were innately more active. Stereotypies and body maintenance activities were also performed at the expense of behavioural diversity. Male rabbits were significantly more likely to chin mark, while females showed a significantly higher level of hair-chewing and licking which could indicate social deprivation. In addition, this study introduces the cyclical pattern of activities throughout the day and night showing that rabbits are nocturnal. It also introduces the extent of boredom behaviours and cage frustration (stereotypies) over 24 h, providing a baseline for further research into improving the welfare of laboratory rabbits.
Eight pairs of litters were observed during Week 4, Week 7 and Week 18. One litter of each pair was kept under barren conditions and the other under enriched conditions during the whole observational period. Enriched pens were supplied with straw, logs and branches. The pigs were weaned at Week 5. Behavioural time budgets and frequencies of the elements were computed as well as an analysis of sequences. The pigs in the enriched pens spent much time in rooting, biting and chewing the provided material, while the pigs in the barren environment rooted, bit and chewed the floors and walls of the empty pen. At Week 4 the pigs in the barren environment spent 39% of all scans in manipulating the udder of the sow as compared with 22% for the pigs in the enriched pen (P < 0.01). During the whole observational period they spent on average 26% of all scans in rooting floor and walls as compared with 3% for the pigs in the enriched pens (P < 0.001). Pigs from the barren environment had higher frequencies of biting floor and walls (P < 0.001), nudging littermate (P < 0.05) and tailbiting littermate (P < 0.01). Analysis of sequences showed no direct behavioural transitions between rooting or biting/chewing material or floor and walls and manipulating littermate, but in several instances there were significant transitions between manipulating littermate and lying inactive. Enriching the environment reduced the frequency of a number of behavioural disturbances in the present study, but the presence of these activities even in the enriched pens suggests that enrichment of the pen is not a sufficient solution to these problems.
At 21 days of age, 16 pairs of male laboratory mice of the ICR strain were weaned and allocated to four treatment groups in a 2×2 factorial design matched for genetic background (litter) and body weight. Factor one was the hardness of the food pellets with a significant 2.5-fold difference between soft and hard feed. Factor two was the environment, with half of the mice being kept in barren standard cages, while the other half were additionally provided with a cardboard tube. Subjects were videotaped during the full 12-h dark period on three occasions: 3 days after weaning, when stereotypies start to develop (24 days), at an early stage of stereotypy development (34 days), and when adult with fully established stereotypies (80 days). Since feed hardness had no effect on time spent feeding, the absence of an effect of the feeding treatment on stereotypic wire-gnawing remains inconclusive with respect to the role of feeding motivation in the development of this stereotypy. The interaction between the development of feeding and wire-gnawing, respectively, does not, however, suggest a strong relationship. In contrast, enrichment significantly reduced stereotypic wire-gnawing in adults by 40% (F=4.47, df=1,26, p
Little is known about the social behaviour of young domestic rabbits, although in rabbit meat production young animals represent a large category and problems with aggressive behaviour are known to occur. Whether this behaviour is part of the normal social development of young rabbits, leading to injuries only because of lack of space or of places to hide from attacks, or whether it is a consequence of too high densities or of the food supply being concentrated in one place, is unclear. To help in answering such questions we investigated the social behaviour of young domestic rabbits during the fattening period (Days 30–125 of life) in two successive breeding groups in an enclosure (600 m2) covered with grass and bushes and with additional feeding huts provided. During 117h of observation quantitative data on 13 individuals were collected.
Certain feeding systems commonly used in practice can result in competition for food and be disadvantageous for low-ranking sows. Feeding a low density diet ad libitum should abolish competition for food and give all sows equal opportunity to obtain food. In this experiment, the consequences of the availability of food on live weight gain and feeding behaviour of sows of different social rank were investigated. Four groups of 12 multiparous sows housed in straw bedded pens were allocated to one of two feeding regimens and remained on treatment throughout gestation. Two groups were floor-fed 3.0 kg per sow of a conventional diet (13.1 MJ (DE) kg−1) once daily, the other two groups received a high-fibre diet (11.2 MJ (DE) kg−1) ad libitum. Dominance ranks were determined in a paired food competition test and from observations of social interactions in the group situation. The paired competition test indicated that the hierarchies in the four pens were almost linear. The hierarchies thus determined were a good representation of feed-related dominance hierarchies in the group situation. When sufficient social interactions were recorded in the group situation, the dominance rank determined from these was similar to the paired competition test. In the ad libitum pens insufficient interactions could be observed in a short time-span. These sows spent, on average, 1.5 h day−1 feeding. They preferred to feed singly, but low-ranking sows had to feed more often at less preferred feeding places and together with other sows. Low-ranking sows gained less weight than high-ranking sows in the floor-fed pens, but not in the ad libitum pens. By changing their feeding strategy, low-ranking sows in an ad libitum feeding system could achieve comparable intake with higher-ranking animals.
The behaviour of groups of rabbits housed in pens and individually caged rabbits was recorded and analysed. New Zealand Whites, Lop Crosses, and Dutch breeds, both female and castrated males, were observed. Locomotory behaviour accounted for 19% of penned rabbit behaviours and 23.2% of caged rabbit behaviours. Maintenance behaviours were more commonly observed in caged rabbits (44.5% of observed behaviours) than in penned rabbits (25.3%). The reverse was true for comfort behaviours (23% and 40.6%, respectively). Marking and investigatory behaviours were observed more often in penned rabbits (12.6%) than in caged rabbits (3%). Agonistic behaviours occurred only in penned rabbits (2.5% of observed behaviours) while stereotypic behaviours were only observed in caged rabbits (6.3%). Caged rabbits were commonly engaged in locomotory behaviour early and late in the day (09:00-10:00 h and 15:00-17:00 h). Resting (maintenance behaviour) and grooming (comfort behaviour) were observed more often in the middle of the day (10:00-12:00 h). Significantly (P<0.01) more scratching, head shaking, sneezing, stretching, and yawning (comfort behaviours) occurred in penned rabbits than in caged rabbits. Penned housing systems are more acceptable than caged systems but the negative aspects of pens should be addressed.
The effect of daily exercise on tied dairy cows was studied in 65 initially first and second calvers of the Swedish Red and White dual-purpose breed in a 4 year experiment, starting in July 1985. Half of the group walked outdoors for 2-3 km day(-1) from May to October and 400-800 m day(-1) from November to April. The rest of the cows were constantly tied. Health in general was significantly and positively influenced by exercise, reducing the need for veterinary treatments. Analysis over time, within lactations, showed that the difference in the number of veterinary treatments occurred entirely in Weeks 0-2 of lactation. During those weeks, non-exercised (NE) cows were more affected by calving-related diseases, mastitis and leg problems than the exercised (E) cows. The difference between groups increased with increasing lactation number. In addition, somatic cell count in the milk was higher for the NE cows in their first month of lactation. Among feeding-related diseases, the cases of bloat were notable more frequent among NE cows, whereas exercise did not influence the occurrence of clinical or subclinical ketosis. Cases of non-infectious leg and hoof disorders were also notably more frequent in the NE group, which also showed a significantly more serious score for skin lesions on the hocks, measured on one occasion. Scores for sole ulcer were significantly higher for the E cows on one occasion of four, at which there were problems with the surface of the exercise area. The causes of exclusions strengthened the differences mentioned for treatments.
Crossbred growing pigs, with an average initial weight of 29.9 kg, were housed in groups of 15 in ten experimental pens (five shapes × two sizes) to assess the importance of pen shape in the perception of space quality. Pen sizes provided 0.396 and 0.356 m2 per pig. In Experiment 1, four replications, each of a 4-week duration, were conducted comparing rectangular (length/width = 3), triangular (equilateral), square and circular pens. In Experiment 2, two replications, each of a 2-week duration, were conducted comparing altered circular (circular pen fitted with two 0.5 m interior walls) and square pens. Production parameters (Experiment 1 only), social behaviors, time budgets and space utilization were monitored for each pen of pigs.
To determine the factors that cause the development of stereotypic digging, features in the captive environment of young Mongolian gerbils, Meriones unguiculatus , were varied. It was hypothesized that stereotypic digging develops because stimuli that control digging motivation are lacking. A regulatory model of motivation was used to examine whether digging motivation is decreased by the performance of the motor pattern `digging' or by the consequences of digging. Young gerbils that could dig in a sand area developed stereotypic digging. In contrast, young gerbils that could not dig in sand but had access to an artifical burrow, which was presumed to be the consequence of digging, showed less non-stereotypic digging than gerbils from the sand treatment and did not develop stereotypic digging. Therefore, the mere perception of the stimulus `burrow' by a retreating animal decreased digging motivation. The complexity of the artifical burrow was reduced to a few elements to analyse in detail the stimuli that control digging motivation. A dark and narrow chamber at the end of a tube connected to the cage provided the stimuli that elicited retreating and prevented the development of stereotypic digging. The tube was a necessary feature: a chamber alone did not prevent the development of stereotypic digging. Such a stimulus situation seems to match the stimuli of a natural burrow which is built to buffer climatic fluctuations and to provide shelter from predators. The results show that stereotypic digging develops when a young gerbil cannot achieve a stimulus situation that is efficient in decreasing digging motivation.
The commercial breeding of rabbits in individual cages presents a number of problems with respect to animal protection legislation. These problems are first presented in an overview of the subject. Starting from the behaviour shown by domestic rabbits in a richly structured near-to-nature enclosure, a new concept for keeping breeding groups is presented. In the housing system for breeding groups (4-5 does, 1 buck, plus young until weaned) which is then developed, the main characteristics of near-to-nature surroundings required for normal behaviour are replaced by manageable artificial substitutes. The individual components of the housing system and the spatial arrangements are described and discussed. Ethological examination of group breeding has shown that this housing system is both more suitable to the requirements of the rabbits themselves and more in the interest of breeders than the present commercial cage system. However, since cages will certainly remain the most important means of housing laboratory and fattening rabbits in the medium term, the ethological requirements for keeping domestic rabbits in cages will be also be discussed.
the development and control of normal behavior, together with the processes involved in the abnormal behavior seen in some psychological conditions, suggest a number of possible mechanisms that could give rise to stereotypies [in animals], some causing the behavior pattern to be repeated even when its performance would seem inappropriate, and others causing the movements involved to be very similar from one occasion to the next / suggest that investigating the mechanisms behind stereotypies would help the construction of valid classification schemes for these behavior patterns, and increase the understanding of why stereotypies differ so much in such features as their sensitivity to environmental change and their consequences for the animal that performs them (PsycINFO Database Record (c) 2012 APA, all rights reserved)
focus . . . on the physiology of social dominance [in nonhuman primates] / dominance in a stable dominance hierarchy appears to have markedly different physiological concomitants than dominance in a primate society filled with social conflict, instability, and hierarchical reorganization / present data supporting this view, and consider the mechanisms by which physiological correlates of rank are changed so dramatically as primate societies shift between social stability and instability (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Agonistic interactions between adult domestic rabbit females were observed. Females were housed in groups of four in outdoor enclosures measuring 4 × 4 m. Agonistic patterns included aggression (AG), flight (FL), and submission (SB). Observations focused on 1) initial interactions between unfamiliar females, concomitant with the formation and establishment of a social structure (Phase 1); and 2) interactions between familiar females organized in a stable social structure (Phase 2). AG was frequent between unfamiliar females and appeared related to the acquisition of social dominance. When social organization was settled, there was a dramatic reduction in the number and frequency of aggressive behaviors. Similarly, FL was more frequent when females were unfamiliar, but it did not appear to be merely a response to AG. The decreased frequency of both AG and FL in Phase 2 was paralleled by an increased frequency of SB with respect to FL. Under stable social conditions, subordinate females frequently signalled submission to dominant counterparts. In contrast, the latter did not signal their social status with any consistent behavioral pattern. It follows that SB was not necessarily induced as the appropriate response to aggression given by dominant females. Thus, SB appeared relevant in social communication especially in structured groups, where it conveyed information on the actor's subordination and possibly inhibited the receiver's aggression. A further possibility is that it has an autonomous rather than secondary role in the maintenance of stable dominance/subordination relationships.
Certain types of inanimate environmental enrichment have been shown to positively affect the behavior of laboratory primates, as has housing them in appropriate social conditions. While social housing is generally advocated as an important environmental enhancement, few studies have attempted to measure the influence of social conditions on the effects of inanimate enrichment or to compare the relative merits of social and inanimate enhancements. In the present study, inanimate enrichment (predominately physical and feeding enhancements) resulted in increased species-typical behavior for socially restricted subjects. However, social enrichment (living in groups) appeared to be more beneficial for young rhesus monkeys, leading to increased species-typical activities and decreased abnormal activities. The behavior of one cohort of yearling rhesus monkeys (Macaca mulatta) housed in small peer groups was compared with the behavior of four yearling cohorts housed in single cages. Half the animals in each cohort received a three-phase enrichment program and the rest served as controls. Group-housed yearlings spent significantly more time feeding and exploring and significantly less time behaving abnormally, self-grooming, and drinking than did singly housed yearlings. Enriched subjects spent significantly more time playing by themselves, and significantly less time self-grooming and exploring than did controls. Among group-housed subjects only, there were no differences between enriched and control monkeys. Captive primates should be housed socially, whenever appropriate, as the first and most important step in an enrichment program, with the provision of inanimate enhancements being considerably less important. Limited resources for inanimate enrichment programs instead should be focused on those individuals who can not be housed socially. © 1996 Wiley-Liss, Inc.
This 10-year study describes a sparse population of rabbits (Oryctolagus cuniculus) living in small, semi-isolated groups on river flats with some scrub in an otherwise forested valley. The rabbits lived above ground in the scrub by day and fed in the open at night. They bred in isolated ‘stops’ dug in the shingle often far from suitable grazing for the young. Many stops collapsed, killing the young. Home ranges were recorded by radio telemetry. Bucks had larger ranges than does and spent less time in the scrub. Adults of both sexes were sedentary for life. Some bucks travelled > 500 m at night. Most ranges were too large to be defended strictly; night feeding grounds were often communal. In the evening, adult rabbits spent 44% of the time feeding and 33% inactive. Social interactions were frequent. At all seasons, in the evening most adult rabbits were seen singly or as pairs. Pairs seldom remained intact for > 12 months even when both partners were alive. The buck of the pair was usually older than the doe because bucks outlived does. The adult survival rate was about 0.80 for bucks, 0.55 for does. Four bucks lived for > 7 years. Few young survived for long after leaving the nest; many were killed by predators. Dungheaps, used for 60% of the droppings, were concentrated near the scrub where rabbits congregated in the evening. The behaviour of these rabbits differed in many ways from that of rabbits in enclosures or at higher density in the wild.
The present investigation assesses the percentage of time that rhesus monkeys (Macaca mulatta) are kept occupied by a more complex cage environment. Sixty animals were continuously exposed for at least 1.5 years to a compatible companion for social interaction, a suspended plastic pipe for perching, and a branch segment for gnawing. The behavior of the partners of each pair was recorded for 60 minutes when the animals were not distracted by human activities. Individuals spent an average of 23.5% of the time interacting with the companion, but only 10.4% with the plastic pipe and 4.8% with the branch segment. Differences were statistically significant. Females were socially more active than males. Subadult animals (3.5–4 years) used both inanimate objects significantly more than did adult animals (9–30 years). It was concluded that (1) a compatible companion, a suspended plastic pipe, and a loose branch segment remain effective stimuli for caged rhesus monkeys after more than 1 year of exposure and (2) a compatible companion is of greater stimulatory value–particularly for adults–than are inanimate objects.
The social organisation of a free-living population of wild rabbits was examined. Discrete breeding groups were recognised which consisted of individuals who shared access to underground refuges. Males attempted to maximise their access to females by a) occupying large home ranges; b) defending female access indirectly through territorial defence; c) defending female access directly within groups. Females defended nest site access within groups. Intergroup interactions between females were rare because of limited home range overlap. Interruption of female-female aggression by males was observed suggesting that conflicts of interest arose between the sexes. Adult-juvenile aggression was primarily intra-sexual; females initiated more interactions than males who adopted a protective role in some cases.
Stereotypies are repetitive, invariant behaviour patterns with no obvious goal or function. They seem to be restricted to captive animals, mentally ill or handicapped humans, and subjects given stimulant drugs. In this respect they are abnormal, although possibly the product of normal behavioural processes. Stereotypies are often associated with past or present sub-optimal aspects of the environment, and have been used as a welfare indicator. It has been hypothesized that stereotypies have beneficial consequences which reinforce their performance, although other means, such as positive feedback, may equally explain their persistence. Empirical evidence links them with lowered awareness of external events, and reduced arousal and distress. However, as most of this evidence is correlational it remains uncertain that the stereotypies are themselves the cause of coping. Furthermore, they are heterogeneous in source of origin, proximate causation and physical characteristics, and they change over time in important respects, becoming more readily elicited by a wider range of circumstances. Therefore the properties of one stereotypy are not necessarily those of another.
Former experiments have shown that social experience during nursing in either a group housing system with straw or a very spacious farrowing/nursing pen with straw, increases social skills of growing pigs considerably. Based on experiences in Taiwan, it was postulated that such skills could also be acquired in the period between being taken from flatdecks at 10 weeks of age and the age of 5 months. In an ‘arena’, copied from the one used for introducing new pigs (gilts) in a group housing system, agonistic behaviour and number and severity of lesions of the integument of 384 experimental GY x DUROC hybrid gilts were studied and compared with data of an equal number of control gilts in three different treatments (repeated once). The experimental animals were born in individual farrowing crates with slatted floors. They were weaned at 30 days and kept in flatdeck cages with two other litters, until 10 weeks. At that time they were kept in groups of eight on fully slatted floors and treated with regrouping and repenning several times until the final testing at an age of 5 months. In sequential experiments, this treatment was given twice, three times or four times and effects on social (agonistic) behaviour were studied. The control animals were born in a group farrowing house with straw, where they stayed 30 days (some days after weaning). As for the experimental pigs, two litters were grouped in flatdeck cages. At 10 weeks of age they were moved to pens with fully slatted floors, where they remained in groups of eight undisturbed until final testing at 5 months. At an age of five months, eight unfamiliar experimental animals were grouped in a so-called arena for 24 h. So were 8 control pigs in the same week. Time-lapse video observations during these 24 h (2 frames/s) revealed that the pigs were fighting for social dominance during this period. Experimental pigs that had been regrouped four times only showed 57% of bilateral agonistic actions and 82% of total fighting time, in comparison with control pigs. Three times regrouping still showed a statistically significant lower amount of fighting, but twice regrouping did not. After 24 h in the arena, the number of lesions of the integument was significantly smaller in groups that had experienced regrouping 3 or 4 times. These results proved that social experience by regrouping and repenning prepared gilts for agonistic encounters, by improving their social skills.
Applied ethology has a continuing interest in the promotion of animal welfare and the ethical treatment of animals used in research. However, in contrast to some other fields involving animal research, there are currently no guidelines written specifically for those engaged in applied ethology studies. We aim here, to provide members of the profession with a basis for structured self-evaluation of the ethical nature of their work, and to serve as inspiration for those planning research involving the use of animals. The first three sections of this document discuss the background to why ethical guidelines are needed in applied ethology studies and the relation between these guidelines and legislation. In the first section, we briefly discuss the relevant ethical principles and decision models. The main body of the guidelines then discuss how `costs' to the animals in applied ethology research can be minimised (using the principles of replacement, reduction and refinement) and `benefits' maximised. An earlier version of this manuscript was presented to the Annual General Meeting of the International Society of Applied Ethology, which accepted this as the basis of ethical review for papers presented at their International Congresses.
Out of 373 Landrace boars and gilts involved in feeding experiments, 18.2% showed severe leg weakness and 30% mild leg weakness, at 100 kg live weight. Of the boars at pig stations, 23.9% were slaughtered because of leg weakness, 75% of these being under 1 1/2 yr old. The practical significance of leg weakness is greatest in young breeding stock. High feed level in slaughter pigs resulted in poorer locomotory ability than medium feed level. Exercise resulted in pigs showing better movements. Variations of minerals and protein within limits used in practical feeding did not have any influence on the incidence of leg weakness. There was no statistically significant relationship (P>0.05) between joint lesions and locomotory ability in pigs at 100 kg live weight, although severe lesions seemed to lead to poorer mobility. The joint regions which seemed to be mainly involved in severe leg weakness in boars were the elbow and stifle joints (31.3%), the lumbar intervertebral joints (28.1%) and the hip region (15.6%). There was a significant relationship between narrow lumbar region, broad hams, large relative width between the stifle joints, and poor locomotory ability in slaughter pigs.
The experiment describes the effects of both stocking rate and group size upon agonistic behaviour in groups of ration-fed pigs. Groups of 6, 12 and 18 pigs were housed at both 0·94 and 0·56 m² per pig. The results suggested that fewer agonistic encounters occurred in the smallest groups with the greater space allowance but that there was an increase in the proportion of retaliations to threat (i.e. an increase in the intensity of aggression) in the smaller groups compared to the larger. It is suggested that the results may have been confounded by retaliatory responses arising as a result of “habituation” to social relationships and that the area available for social manoeuvring may also have been limiting.