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Fur-chewing and other abnormal repetitive behaviors in chinchillas (Chinchilla lanigera), under commercial fur-farming conditions
Abstract
Fur chewing is a behavioral disorder frequently reported in chinchillas kept for fur-farming purposes. Rodents kept in barren cages usually develop some form of abnormal repetitive behavior, which can indicate a past or present welfare problem. Fur chewing may not be the only form of abnormal repetitive behavior present but is the one reported because of its direct repercussion on fur production. The aim ofthis study was to describe the frequency of occurrence of fur chewing and the distribution of time dedicated to it in chinchillas diagnosed as presenting this behavior. A secondary aim was to determine the presentation of other abnormal repetitive behaviors. Ten chinchillas, 5 fur chewers and 5 controls, were video recorded for 24hours with an infrared camera. Behavioral analysis was done with The Observer XT from Noldus (The Netherlands). Focal sampling and continual recording were used, the 24-hour time budget was calculated, and abnormal repetitive behaviors were analyzed in terms of time dedication and frequency of presentation. A paired t test was used to compare differences in the amount of nocturnal versus daytime abnormal behavior. When normality was not met, a 2-sample t test and randomization test were used to compare data between treatments. No differences were observed between the time budgets of fur-chewing and control chinchillas, and all individuals exhibited more than one abnormal repetitive behavior. The amount of time devoted to abnormal repetitive behaviors was significantly higher during night in both groups and reached its lowest level between 13:00 and 17:00hours. Fur chewing is not the only abnormal repetitive behavior developed by chinchillas in fur-farming systems, although it is the only one reported by the producer. The presence of bar chewing, cage scratching, and backflipping should also be welfare concerns. The higher presentation of abnormal repetitive behaviors at night may be associated with the lack of recognition by the producer, especially because these abnormal behaviors do not result in direct product loss as does fur chewing.
... They are also used as indicators for poor welfare scores when present (16)(17)(18). Overgrooming is currently described as an indicator of poor welfare especially in species whose allocate a significant part of time-budget to grooming (13,19). In chinchillas, for example, fur chewing is classified as ARB and is linked with inappropriate and restrictive environmental conditions (19). ...
... Overgrooming is currently described as an indicator of poor welfare especially in species whose allocate a significant part of time-budget to grooming (13,19). In chinchillas, for example, fur chewing is classified as ARB and is linked with inappropriate and restrictive environmental conditions (19). Grooming represents 4% of the daily activity budget of cats, i.e., 8% of non-sleeping or resting time (20), which is a high proportion of their timebudget. ...
... Besides, the impact on both the owners and the animal quality of life can lead to euthanasia. 1 1 1 2 1 2 2 2 2 2 0 2 2 19 2 1 0 2 1 2 2 2 2 1 1 2 2 18 3 1 1 1 0 1 2 2 2 0 0 1 2 13 4 1 1 0 0 2 2 2 2 2 2 2 1 17 5 1 0 0 1 0 2 2 2 1 2 0 1 12 6 1 0 0 1 2 1 2 2 2 1 2 2 16 7 1 0 2 0 0 2 2 2 2 0 2 2 15 8 1 0 0 1 0 2 2 2 2 0 2 2 14 9 1 1 2 0 2 1 2 2 2 1 1 2 17 10 1 0 2 0 2 2 2 2 0 2 1 2 16 11 1 0 2 0 2 2 2 2 1 1 1 2 16 12 1 1 2 1 2 0 2 2 0 2 1 1 15 13 1 1 2 0 2 2 2 2 2 0 2 2 The organization and the regulation of grooming in cats is thought to be under the control of a central mechanism (20). In other species, it has been shown that this control could be deregulated by poor welfare (19) and leads to abnormal repetitive behaviors like fur chewing (19). In internal medicine, it is now well recognized that stress induced by environment has a strong influence in the aetiopathogenesis of idiopathic cystitis (33). ...
Feline idiopathic head-and-neck dermatitis—also named feline idiopathic ulcerative dermatitis (IUD)—is considered as a rare skin disease of unknown origin. It is usually associated with a crusted, non-healing, self-induced ulcer occurring most commonly on the dorsal or lateral neck or between the scapula where self-grooming by scratching occurs. Usually, IUD is diagnosed after exclusion of other causes of pruritus. In feline medicine, self-induced alopecia is recognized as a behavioral disorder (abnormal repetitive behavior) due to excessive licking, which is an amplification of a normal maintenance behavior. Such repetitive behaviors, like self-induced alopecia or self-induced wounds, are named stereotypies and considered as indicators of poor welfare. The objectives of our study were to determine, first, if the repetitive behavior associated with self-induced wounds was related to a poor welfare, and, second, if improving the welfare in the cat’s environment would lead to healing, thanks to environmental enrichment. We recruited 13 cats diagnosed with IUD by a dermatologist. These cats were referred to a behaviorist for welfare evaluation. A welfare score was attributed using a new 21-point welfare scale. The median score of the 13 IUD cats was 16, while the median score of 35 healthy cats was 7 (significant difference, p < 0.001). Major modifications of the cat’s environment and the human–cat relationship were then recommended for IUD cats. Within 15 days after environment modifications, ulcerative lesions were healed and welfare scores improved significantly (median score of 6, significantly different from the score before environmental modifications), being similar to healthy cats (no significant differences). Only one cat was treated with a psychotropic drug, owners being reluctant to improve environmental modifications. These results suggest that feline IUD is a behavioral disorder indicative of poor welfare and that it requires management by behavior specialists, proposing environmental modifications. We hence propose to rename this affection to “behavioral ulcerative dermatitis,” given that welfare scores were significantly different from healthy cats, and that environmental modifications modified welfare scores and lead to successful healing in all cases.
... (Fig. 1). According to Franchi et al. [2016] the maximum intensity of such type of behaviour in chinchillas occurs at night. The animals devoted the smallest amount of time to fur chewing between 1.00 p.m. and 5.00 p.m. Simultaneously the authors observed that fur chewing is not the only anomalous behaviour in chinchillas, but it is the most frequently reported one, for commercial reasons, by fur farmers. ...
... The animals devoted the smallest amount of time to fur chewing between 1.00 p.m. and 5.00 p.m. Simultaneously the authors observed that fur chewing is not the only anomalous behaviour in chinchillas, but it is the most frequently reported one, for commercial reasons, by fur farmers. Equally often chinchillas bit cage bars; the highest intensity of this type of behaviour was also observed during night time [Franchi et al. 2016]. The analysis of data comprised in Fig. 2 showed interrelation between most of the studied features. ...
The aim of the study was to define the extent of occurrence of stereotypic compulsive behaviour in chinchillas (biting the cage, licking the paws, fur chewing, aimless running around the cage) depending on the displayed character type (temperament). Thirty chinchillas were assigned to three character type (temperament) groups on the basis of a behavioural test. The conclusion of the analysis was that the chinchillas not displaying any signs of fear or hyper-excitability spent the least time on stereotypic compulsive behaviour. More timid individuals most frequently displayed oral compulsion such as paw licking or fur chewing, whereas hyperactive ones most frequently were observed to aimlessly run around the cage. It was concluded that the animal's disposition significantly influenced the amount of time spent on repetitive stereotypic behaviour (P ≤ 0.01), and also that the time of day significantly influenced the frequency of chinchillas biting cage bars (P ≤ 0.05). It was observed that chinchillas in group III manifested the analysed behaviour mainly during the night time, in the remaining two groups the intensity of studied traits was more diversified during both day and night. Additionally, a positive correlation was found between most analysed behaviours.
... Stress can promote repetitive behaviors [78]. Fur biting, which is sometimes interpreted as repetitive behavior, may also be caused or enhanced by stress [7,9,11]. However, as fur biting may not always occur in the presence of caretakers, it might be under-reported, which could explain the lack of a significant association. ...
For pet chinchillas, limited data are available on husbandry and the human–animal relationship despite their impact on health, behavior, and welfare. We conducted an online survey with pet chinchilla caretakers (n = 336), targeting husbandry practices, health, behavioral indicators of welfare, and human–chinchilla relationships. We further investigated associations between caretakers’ perceptions of stress in their chinchillas and emotional closeness to their animals. Basic needs such as keeping with conspecifics, constant access to water and hay, or offering dust baths were mostly fulfilled. Potential welfare issues included individual keeping (14.3%), undersized cages/enclosures (reported by 27.6% of the Austrian respondents), and suffering from a disease (14.7%). Behavioral indicators of good welfare, such as playing and cuddling with conspecifics, were observed several times per day by 40.9% and 87.9% of the respondents, respectively. Repetitive and unwanted behaviors were less common (fur biting, for instance, occurred ‘never’ in 82.9%). Caretakers rated their animals as generally more stressed if the animal was ill and more often showed fearful behavior toward them. Caretakers feeling closer to their animals spent more time engaging with them. Correct identification of this kind of association could be used as guidance for recommendations to improve chinchilla welfare at home and in the veterinary setting.
... Stereotypical behaviour, an indicator of poor environmental conditions, has been observed in farmed mink (pacing, somersaults, circular movements of the head (Hansen et al., 2010)), blue foxes (pacing, tail-chasing, cage-biting, tail biting (Korhonen et al., 2001)), chinchillas (furchewing bar chewing, cage scratching, and backflipping (Franchi et al., 2016)), raccoon dogs (pacing, scratching at cage, head twirling, and biting or licking the cage (Koistinen et al., 2018)) and rabbits (biting bars and smelling bars (Mugnai et al., 2009) and repetitive hair-chewing, barchewing, head-swaying, and pawing (Gunn and Morton, 1995)). In rabbits, the motivation for and expression of these stereotypical behaviours may be reduced by group housing, although this can lead to agonistic behaviour (Mugnai et al., 2009), so their welfare might be jeopardised in group housing too. ...
... Crowley-Koch and Van Houten (2013) described a variety of technological solutions aimed at facilitating the collection of data via direct observation, including video-synced software applications and internetbased applications. Software, such as The Observer XT (Noldus Information Technology, 2019), has been used widely in studies involving systematic observation in the areas of animal learning and experimental psychology (e.g., Franchi et al., 2016), organizational and consumer behavior (e.g., Allen et al., 2015), clinical interaction in psychotherapy (e.g., Pardo-Cebrian et al., 2021;Virues-Ortega et al., 2011), intervention studies in children and adults with and without developmental and intellectual disability (Hutman et al., 2012;Meirsschaut et al., 2011;Mossman, 2011;Naber et al., 2008), and studies in dementia (Moyle et al., 2014), among numerous other applications. These studies show the range of applications of such systems, and they have all consistently reported high levels of interobserver agreement for computer-aided observations. ...
Computer-aided behavior observation is gradually supplanting paper-and-pencil approaches to behavior observation, but there is a dearth of evidence on the relative accuracy of paper-and-pencil versus computer-aided behavior observation formats in the literature. The current study evaluated the accuracy resulting from paper-and-pencil observation and from two computer-aided behavior observation methods: The Observer XT® desktop software and the Big Eye Observer® smartphone application. Twelve postgraduate students without behavior observation experience underwent a behavior observation training protocol. As part of a multi-element design, participants recorded 60 real clinical sessions randomly assigned to one of the three observation methods. All three methods produced high levels of accuracy (paper-and-pencil, .88 ± .01; The Observer XT, .84 ± .01; Big Eye Observer, .84 ± .01). A mixed linear model analysis indicated that paper-and-pencil observation produced marginally superior accuracy values, whereas the accuracy produced by The Observer XT and Big Eye Observer did not differ. The analysis suggests that accuracy of recording was mediated by the number of recordable events in the observation videos. The implications of these findings for research and practice are discussed.
... Small mammals may be presented to practitioners for traumatic wounds or dermatopathies caused by self-mutilation. 2 ARBs may not always be easily identified at home, particularly in nocturnal small mammals where ARBs occur more often at night, during their peak of activity. 20 Therefore, a detailed history and/or videos recorded at home are important to detect these behaviors. Owners also may not seek advice from veterinarians when noticing ARB in their pet, unless physical consequences are already present, as reported in avian medicine. ...
Self-mutilation and abnormal repetitive behaviors in small mammals are challenging conditions for veterinary practitioners. The etiology may be difficult to identify, and the treatment is often unrewarding unless the specific underlying cause can be found. Reinforcement of the abnormal behavior may also complicate the treatment. However, medical causes, including painful conditions, should be investigated thoroughly. Owing to the small blood volume of many small exotic mammals and the associated risk of hypovolemia in case of hemorrhage, an hospitalization with potent multimodal analgesia and physical barriers to prevent self-mutilation is often warranted. Psychogenic drugs may be useful in some cases.
... Fur chewing is an abnormal, repetitive, excessive grooming behavior reported in captive chinchillas. 4,25,26 The underlying etiology remains elusive; however, evidence supports stress as a cause of this compulsive behavior. The most severely affected fur-chewing female chinchillas demonstrated an elevated mean concentration of cortisol metabolites in the urine. ...
Chinchillas have been used mostly as fur animals and as animal models for human ontological diseases and only recently have been recognized as excellent, long-lived, and robust pet rodents. This review aims to provide updated information on emerging disease conditions in pet chinchillas, such as Streptococcus equi subsp zooepidemicus and Pseudomonas aeruginosa. Furthermore, this review article provides updated information on previously documented disorders, such as urolithiasis and middle ear disease, in chinchillas. This article is intended to serve as a complement to the current veterinary reference literature and to provide valuable and clinically relevant information for veterinarians treating chinchillas.
... A widely studied behavior in the chinchilla fur industry, due to its important economic impact, is fur-chewing. This repetitive abnormal behavior performed by chinchillas kept in captivity has been studied due to its negative physiological and productive consequences [10]. Stereotypes are defined as a behavioral disorder, where the behavioral patterns are invariant and repetitive, with no obvious aim or function [11]. ...
Simple Summary
Many chinchillas kept in captivity develop fur-chewing. This behavior does not only affect fur price, but most importantly it can be the result of an animal welfare problem. The causes of this behavior are not well understood and a genetic component could exist. This is why the aim of this study was to determine the genetic component and the effect of this behavior on fur price. The data from a commercial fur-farm was used, it included information on 10,196 chinchillas recorded between 1990 and 2011. The heritability of the behavior and its effect on fur price were determined. The results show a significant genetic variation in fur-chewing with an estimated heritability of 0.16. At the same time, the behavior had an important negative effect on fur price. The selection and management practices used in fur-farming should be improved in order to decrease the incidence of this behavior.
Abstract
Fur-chewing is a common behavioral disorder developed by chinchillas kept in confinement that can indicate a past or present welfare problem. It also has a negative productive impact associated. The aim of this study was to determine the genetic component of fur-chewing, and the effect of this undesired behavior on fur price in a commercial fur-farming system of chinchillas (Chinchilla lanigera). The data for the analysis was derived from a commercial population of 10,196 chinchillas, recorded between the years 1990 and 2011. For determining differences in fur price according to presence of fur-chewing behavior, analysis of variance (ANOVA) was used, considering 3007 animals. For estimation of variance components of fur-chewing a sire-dam threshold (probit) mixed model was used, using data of 9, 033 individuals, and then heritability on the underlying liability scale was calculated. The analysis revealed a significant negative impact on fur price from fur-chewing chinchillas (p-value < 0.05). In addition, the study showed that fur-chewing presents significant genetic variation, with an estimated heritability of 0.16. The presentation of fur-chewing should be taken into account when selecting broodstock in these systems, in order to reduce the number of affected individuals.
... Według Franchi i wsp. (8), maksymalne nasilenie tego rodzaju zachowań u szynszyli pojawia się w nocy. Najmniej czasu na wygryzanie futra zwierzęta te poświęcają między godziną 13 a 17. ...
Fur animals kept indoors, due to partial limitation of their natural behavior, are more likely to develop behavioral disorders. This is due to negative emotions associated with inability to satisfy certain needs or achieve a particular purpose, which leads to frustration or deprivation in animals. This condition can lead to the emergence of compulsive behaviors, which are often a form of coping with stress. Compulsive behaviors in fur animals are usually stereotypical: animals walk along the cage, catch their own tail, gnaw fur (trichotilomanie), or bite the trellis or the claws. The environmental factors resulting from the maintenance conditions and social relations of the animals in the group play an important role in the emergence of this type of behavior. Another factor that is equally important in causing compulsive behavior is mental strain resulting from disease..
... For example, in Mexico since the Department of Ethology at UNAM was opened in 1993, many zoological parks became interested in doing research on animal behaviour in order to set up programmes to improve environmental enrichment practices and linking animal behaviour studies to conservation efforts, such is the case of the Mexican wolf (Canis lupus baiyeli) (Pifarré et al., 2012). In the case of alternative production systems with native species an example is the study of repetitive behaviours and fur chewing in chinchillas (Chinchilla lanigera) kept in fur-farming systems (Franchi et al., 2016). Other examples include South American camelids, crocodiles, iguanas, deer, capybara, among many others. ...
Latin America is a diverse region of the world that is destined to play a major role in food production. This region also has a growing urban population with increasing numbers of companion animals, and major issues related to biological diversity, sustainable livestock production, and wildlife and ecosystems conservation. Considering these issues the role of applied ethology has been increasingly important in multiple areas. Although there are courses given in many countries of the region, scientific research is limited to a few groups. Still, networking and collaboration within the region has been quite strong. Some examples of this include the numerous training courses at different levels in the region and participation in international research projects. There has been an active, although fluctuating, involvement of the region in ISAE meetings, usually increasing in years when the annual ISAE conference has been hosted in Latin America. Three ISAE conferences have been held in the region, two in Brazil (2000 and 2013) and one in Mexico (2007). The World Organisation for Animal Health (OIE) agenda on animal welfare has become a good opportunity to promote research on applied ethology in the region and will be a useful tool to strengthen networking and promote collaborative research. It is important to raise awareness among decision makers and intergovernmental organisations of the work that the ISAE is doing and of the role of ethology in science-based policies. Animal behaviour studies will be a necessary tool for the development of efficient policies and legislation.
В пушном звероводстве при клеточном содержании длиннохвостых шиншлл важным критерием здоровья животных являются уровень адаптационных возможностей организма. Систематическая неадекватность условий клеточного содержания приводит в пушном звероводстве к появлению стрессовых состояний, в том числе к проявлению у шиншилл признаков синдрома самовыкусывание волоса (стрижки), как одного из вариантов синдрома гиперкортицизма. Цель исследования – изучение влияния питьевой воды, обогащённой молекулярным водородом, на гематологические показатели у малой длиннохвостой шиншиллы в возрасте 2, 4 и 6 мес. Через 2-3 месяца ог начала использования питьевой воды, обогащённой молекулярным водородом, у молодняка шиншилл наблюдаются сдвиги в показателях общего (клинического) анализа и биохимичческого состава крови: повышается количество лимфоцитов (Р˂0,05) и эозинофилов (Р˂0,05), снижаются уровни биллирубина (Р˂0,001), активности АСТ (Р˂0,05) и АЛТ (Р˂0,05), триглициридов (Р˂0,05), холестерина (Р˂0,05), мочевины (Р˂0,05) а креатинина (Р˂0,05) Снижение уровней билирубина и АСТ указывает на улучшение функций печени и уменьшение нагрузки на нее. Снижение уровня триглицеридов и холестерина указывает на улучшение липидного обмена; уменьшение содержания мочевины и креатинина свидетельствует об улучшении функций почек. Заключили, что использование питьевой воды, обогащйннойя молекулярным водородом, оказывает благоприятное воздействие на общее физиологическое состояние, в том числе на статус иммунной системы и здоровья животных.
In fur farming, with cage keeping of the long-tailed chinchillas, an important criterion for animal health is the level of the body's adaptive capabilities. Systematic inadequacy of cage keeping conditions leads to stress conditions in fur farming, including the manifestation of signs of hair-biting syndrome (haircutting) in chinchillas, as one of the variants of hypercorticism syndrome. The purpose of the study is to study the effect of drinking water enriched with molecular hydrogen on hematological parameters in small long-tailed chinchillas aged 2, 4 and 6 months. After 2-3 months of using drinking water enriched with molecular hydrogen, the significant shifts in blood composition indicators were observed; there was an increase in the number of lymphocytes (P<0.05) and eosinophils (P<0.05) and a decrease in the levels of bilirubin (P<0.001), AST activity (P<0.05) and ALT (P<0.05), triglycerides (P<0.05), cholesterol (P<0.05), urea (P<0.05) and creatinine (P<0.05) A decrease in bilirubin and AST levels indicates improved liver function and a decrease in the load on it. A decrease in triglyceride and cholesterol levels indicates improved lipid metabolism; a decrease in urea and creatinine levels indicates improved kidney function. Concluded that the use of drinking water enriched with molecular hydrogen has a beneficial effect on the general physiological state, including the status of the immune system and health of animals.
Dans l’espèce féline, face à des lésions cutanées auto-induites, le praticien doit désormais inclure une origine comportementale. Certains signes cliniques et un questionnaire sur le bien-être du chat peuvent permettre d’orienter le diagnostic vers cette cause. La prise en charge nécessite alors une modification importante de l’environnement du chat. Les données scientifiques en éthologie doivent orienter cette thérapie pour un bien-être préservé et une guérison définitive.
В пушном звероводстве важным критерием здоровья животных являются уровень их адаптационных возможностей,в том числек появлению стрессовых состояний.Цедь данной работы - исследование показателей состава крови и антиоксиданого статуса у малой длиннохвостой шиншиллы при проявлении «стрижки» (самопроизвольного выкусывания) мехового покрова, как одного из вариантов синдрома гиперкортицизма в условиях клеточного содржания. Три группы самцов Chinchilla lanigera двухмесячного возраста (n=5) со средней живой массой 270 г были сформированы методом парных аналогов и рассажены в индивидуальные клетки; I группа (контроль) не имевшая признаков «стрижки», получала основной рацион (ОР) и чистую питьевую воду; II группа, с проявлением синдрома «стижки», ОР и чистую питьевую воду; III группа, с синдромом «стрижки» - ОР и воду, обогащённую молекулярным водородом. При исследовании клеточного состава крови выявлено, что во II группе возросло против контроля количество лейкоцитов (P<0.05), эритроцитов и уровня гемоглобина(P<0.05). В III группе количество лейкоцитов, эритроцитов и гемоглобина уменьшилось по сравнению со II группой (P<0.05). В сыворотке крови во II группе отмечено увеличение против контроля уровней мочевины, общего биллирубина, активности аспартатаминотрансферазы, аланинаминотрансферазы и щелочной фосфатазы на фоне снижения содержания креатинина и показателей антиоксидантной защиты. В III группе снижены по сравнению со II группой количество продуктов перекисного окисления липидов, активность аланинаминотрансферазы, щелочной фосфатазы и уровень общего биллирубина. Заключили, что использование питьевой воды, обогащённой молекулярным водородом, удучшаетпоказатели состава крови и антиоксидатного статуса у длиннохвостой шиншиллыс синдромом сечения меха в условиях клеточного содержания.
In fur farming, an important criterion for the health of animals is the level of their adaptive capabilities, including the emergence of stressful conditions. The aim of this work was to study hematological parameters and antioxidant status in the small long-tailed chinchilla during the manifestation of “haircut” (HC, spontaneous fur chewing)under conditions of cage keeping. Three groups of animals were formed by the method of paired analogues (n=5) and placed in individual cages; group I (control), which had no signs of HC, was fed the basic diet (BD) and clean drinking water; group II, with signs of HC,BD plus clean drinking water; Group III with signs of HC, BD and water enriched with molecular hydrogen. When studying the cellular composition of the blood, it has been revealed that in group II the number of leukocytes (P<0.05), erythrocytes and hemoglobin level (P<0.05) increased compared to controls. In group III, the number of leukocytes, erythrocytes and hemoglobin decreased compared to group II (P<0.05). When analyzing biochemical data, changes were observed in group II, with a marked increase compared to control in the amount of urea, total bilirubin, activity of aspartate aminotransferase, alanine aminotransferase and alkaline phosphatas and decreased level of creatinine. In group III, an activity of alanine aminotransferase, alkaline phosphatase and total bilirubinlevel weredecreased compared to group II. In group II, the amount of lipid peroxidation products was increased versus control and the indicators of antioxidant protection was decreased. In group III, the amount of peroxidation products was lower than in group II. Concluded that the use of drinking water enriched with molecular hydrogen ameliorates hematological parametersand antioxidant statusinsmall long-tailed chinchilla whith fur cutting syndrome under conditions of cage keeping.
This article reviews the most common dermatologic conditions of the pet rodent population, including the prevalence, clinical signs, diagnosis, and treatment recommendations.
It was found that the inclusion of water enriched with molecular hydrogen into the diet of a long-tailed chinchilla changed the fur quality indicators. In animals of the experimental group, the guard and downy hairs were thinner than in the control group. The length of downy hair in the experimental group was higher, the number of hairs in the follicle in the chinchillas of the experimental group was greater than in the control group, besides, the hair was stronger and softer. The animals of the experimental group showed less tendency to gnaw out fur. When considering the data on the chemical composition, it was found that in the dry matter of the hair of the animals of the experimental group, there were less organic substances, and there were more minerals in comparison with the animals of the control group.
Fur-chewing is a common problem in chinchilla (Chinchilla lanigera). It may affect the welfare of animals due to heat loss, thereby possibly impacting food and water intake to maintain body temperature. In this context, infrared thermography seems to be a suitable method of measuring heat emissions from the surface of objects.
Sexually mature male domestic chinchillas were divided into two groups: “non-fur chewers”, exhibiting normal behaviour (n = 25), and “fur chewers” displaying fur-chewing behaviour (n = 23). Food and water intake (mean ± SD) measured in the control animals amounted to 20.7 ± 4.52 g and 15.9 ± 3.45 mL, while in fur-chewing chinchillas were 25% and 33% higher, respectively. Metabolic energy intake, were calculated 2.2 and 2.8 W for the control and fur-chewing animals, respectively. Heat flux through chewed areas was 6.06 mW cm-2, which is 2.8 times higher than through undamaged chinchilla fur. To sum up, thermal imagingexplicitly shows that fur-chewing causes increased heat loss. Disturbances in the maintenance of thermal homeostasis may be an additional factor that reduces the welfare of these animals.
One of the most serious problems in the chinchilla industry is 'fur-chewing', when the chinchilla bites off areas of its own or some other animal's fur. The condition generally develops in both genders at the age of 6-8 months. In chinchilla farms in Croatia an incidence of 15-20% has been observed. A pathomorphological, microbiological and parasitological investigation was conducted on eleven 6- to 11-month-old chinchillas of both sexes with clinical symptoms of 'fur-chewing' and three chinchillas without such signs. Histopathology of the adrenal glands and of the chewed skin revealed changes typical of Cushing's syndrome in 'fur-chewed' chinchillas, such as hyperkeratinisation of the epidermis, epidermal atrophy, pronounced follicular and sebaceous gland atrophy, hyperkeratinisation of the follicles with comedo formations and the presence of calcium salts in subcutis.
Traditionally farmed silver fox cubs are raised after weaning either in pairs or singly in a traditional fox cage (1.2 m2). However, this way of housing foxes has been criticised because the foxes may have limited chance to exercise and to show social behaviour. Therefore, the aim of the present study was to evaluate the effects of different social and spatial conditions on the welfare of silver fox cubs. The cubs were housed singly, in pairs or in quartets with space allocation of either 0.6 or 1.2 m2 per animal. Behavioural, physiological and production-related welfare parameters were assessed. The results revealed that space allocation had only minor effects on the measured welfare related parameters. With regard to social conditions, the results showed that the possibility for social behaviour is important for the welfare of young cubs. However, the welfare of the cubs may be jeopardised if they are kept in quartets beyond their natural dispersal time. Therefore, the welfare of silver fox cubs could be enhanced by allowing the cubs to enjoy of social companionship during the first months of their lives and by separating them into pairs in later autumn.
The present study examined daytime behavior patterns of 19 captive tigers (Panthera tigris tigris) housed in Nandankanan Zoological Park, Odisha, India. Behavioral observations of 1254 hours were analyzed for target behaviors using instantaneous sampling and 1-minute sample periods. We found that these captive tigers spent about 23% of the daytime exhibiting stereotypic behavior, that is, pacing, with a biphasic peak at 10:00 to 11:00 am and 16:00 to 17:00 pm. The incidence of stereotypic pacing behavior appears high, warranting further investigation of the cause of this stereotypic behavior and whether an effect of behavioral enrichment is required for a better understanding of welfare implications on the animals.
The aim of the study was to assess the extent of fur chewing problems on chinchilla farms. The research was based on a 20-question survey addressed to breeders. A total of 47 anonymous questionnaires were answered. Results showed that the problem of fur chewing was found in as many as 85% of the farms but the proportion of affected animals was usually low (mean±SE: 3.5±0.55%). To determine the relationship between herd size and the extent of the problem, the Pearson’s correlation coefficient was calculated to be r = -0.315 (P≤0.05), possibly indicating the problem to be more severe on smaller farms. No correlation was found between fur chewing and the type of fodder (pellets from different producers), temperature, humidity, type of cage equipment or frequency of dust baths. Moreover, the level of fur-biting animals kept on a deep-litter floor was estimated at 1.7% while the level of those kept on a wire floor and in a mixed system was 2.8-times higher (P≤0.05). The fact that 37.5% of the respondents perceived the predisposition to fur chewing to be hereditary was an important observation suggesting a direction for further research. A considerable proportion of those surveyed (37.5%) also pointed to a greater excitability among fur chewers. To sum up, results of the present study revealed that keeping animals on litter reduces the incidence of fur chewing. Breeders’ observations also suggest that fur biting may be determined genetically and/or connected with impulsive-compulsive disorders; however, more detailed studies are necessary to confirm these hypotheses.
Based on the content of feces, we studied the food habits of the endangered rodent Chinchilla lanigera. On a seasonal basis, during two years of contrasting rain levels (1992 = 242 mm; 1993 = 123 mm), we collected chinchilla feces from El Cuyano ravine, adjacent to the Chinchilla National Reserve in north central Chile (31° 29′ 10.8″ S, 71° 03′ 43.9″ W). The main plant species eaten was the perennial graminoid Nassella chilensis. Chinchillas showed a broader trophic niche during the rainy year, than during the dry year, consuming 55.5 and 40.7% of the 38 and 27 plants available, respectively. Within the wet year the diet differed less between winter and summer (Horn similarity index R0= 0.58) than within the dry year (R0= 0.83). Between years, the diet differed more during winters (R0= 0.20) than during summers (R0= 0.52). Chinchillas are folivorous, using a feeding pattern of a generalist species. The opportunistic feeding behavior of chinchillas may be an adaptation to the harsh conditions and high variability in food availability triggered by fluctuations in rainfall among years in the arid north central Chile.
The WelFur project aims at the development of on-farm welfare assessment protocols for farmed foxes (the blue fox [Vulpes lagopus], the silver fox [Vulpes vulpes]) and mink (Neovison vison). The WelFur protocols are based on Welfare Quality® (WQ) principles and criteria. Here, we describe the WelFur protocols after two years of developmental work. Reviews for each of the 12 WQ welfare criteria were written for foxes and mink to identify the welfare measures that have been used in scientific studies. The reviews formed the basis for potential measures to be included in the WelFur protocols. All measures were evaluated for their validity, reliability and feasibility. At present, we have identified 15 fox and 9 mink animal-based (or outcome-based) welfare measures, and 11 and 13 input-based (resource-based or management-based) measures. For both foxes and mink, each of the four WQ principles is judged by at least one criterion, and seven out of the 12 criteria include animal-based measures. The protocols will be piloted in 2012. Using the WQ project and protocols as a model has been a fruitful approach in developing the WelFur protocols. The effects of the WelFur protocols will provide benchmarks from which the welfare of animals on European fur farms can be assessed.
We have until now in the majority of this monograph considered the behaviour of beef cattle in as natural a situation as possible: out all year and raising their own calves. In modern farming, however, there is a tendency to intensify animal husbandry which usually entails housing the animals and, in beef production, introducing the intensive feed-lot and barley beef systems. The freedom of the cattle is therefore restricted to a greater or lesser extent by management conditions. In some systems, particularly in Europe, the animals are yoked for the majority of their lives and have almost no freedom to do anything except lie down, eat and drink, but even then they tend to form some relationships with their fellows. In other systems they are loose-housed and are physically able to behave much as normal.
This book is comprised of 11 chapters generally discussing different perspectives of stereotypic behaviour in man and animals. The chapters are divided into 3 parts (normal animal and abnormal environment, stereotypic behaviours as pathologies and treating stereotypic behaviours). The first chapter reviews the extent and nature of research into stereotypic behaviour. Chapters 2-4 (part I) focus on the ethological perspective. Behaviour is discussed, including stereotypies, in terms of its motivated basis (stereotyping subjects are normal animals responding in species-typical ways to an abnormal environment). Chapters 5-8 (part II) emphasize clinical psychology, psychiatry and neuroscience. Three assumptions are presented: stereotypies of focus are the products of dysfunction (animal is abnormal); fullest understanding of stereotypies will come from investigating the neurophysiological mechanisms involved; and processes involved at this level have great cross-species generality. Part III (chapter 9 and 10) illustrates how stereotypies can be tackled and reduced by those concerned about their unaesthetic appearance and/or welfare implications. Chapter 11 provides a synthesis of the book and future research and suggestions on how terminology can be improved.
Improving the home cages of laboratory mice by environmental enrichment has been widely used to reduce cage stereotypies and anxiety-related behaviour in behavioural tests. However, enrichment studies differ substantially in type, complexity and variation of enrichments. Therefore, it is unclear whether success depends on specific enrichment items, environmental complexity, or novelty associated with enrichment. The aim of this study was therefore to dissociate the effects of environmental complexity and novelty on stereotypy development and compare these effects with the provision of nesting material alone. Thus, 54 freshly weaned male ICR (CD-1) mice were pairwise allocated to standard laboratory cages enriched in three different ways (n=18 per group). Treatment 1 consisted of cotton wool as nesting material. Treatments 2 and 3 were structurally more complex, including a shelter and a climbing structure as additional resources. To render complexity and novelty independent of the specific enrichment items, three shelters (cardboard house, plastic tunnel, red plastic house) and three climbing structures (ladder, rope, wooden bars) were used to create nine different combinations of enrichment. In treatment 2 (complexity), each pair of mice was assigned to a different combination that remained constant throughout 9 weeks, whereas in treatment 3 (novelty), each pair of mice was exposed to all 9 combinations in turn by changing them weekly in a pseudorandom order. After 9 weeks, stereotypic behaviour in the home cage was assessed from video recordings, and anxiety-related behaviour was assessed in two behavioural tests (elevated zero-maze, open-field). However, no significant differences in stereotypy scores and no consistent differences in anxiety-related behaviours were found between the three groups. These findings indicate that within standard laboratory cages neither complexity nor novelty of simple enrichments have additional effects on stereotypic and anxiety-related behaviour beyond those of adequate nesting material.
The ontogeny of two stereotypic patterns, wire-gnawing and jumping, was studied in 24 laboratory mice: six males and six females each of two closely related outbred strains, kept under standard housing conditions, a conventional albino strain (ICR) and a nude, athymic mutant (ICR nu; hereafter: NU). All 24 individuals developed wire-gnawing after weaning at 20 d of age. In ICR one female and in NU five males and three females additionally developed jumping. ICR developed wire-gnawing between the age of 20 and 30 d, in NU jumping started at the age of 20 d, but intense jumping and wire-gnawing comparable to that of ICR did not develop in NU before the age of 40–50 d. Within each strain there was no significant difference between males and females with respect to the development of stereotypic behaviour. By contrast, ICR showed significantly more wire-gnawing but less jumping than NU.
Stereotypy level increased with age up to a mean of 10.7 % of total activity in ICR and up to 7.4 % in NU at 100 d of age. However, there was huge inter- and intra-individual variability with respect to all parameters assessed in this study, i.e. total duration, number of bouts and bout length of the two stereotyped patterns.
Wire-gnawing developed from outside-directed explorative climbing at the cage lid, whereas the source behaviour pattern (Mason 1991 a, Anim. Behav. 41, 1015–1037) of jumping was outside-directed explorative rearing at the cage wall. At 20 d of age, before the onset of stereotypy development, ICR showed significantly more climbing but less rearing than NU. Physical retardation of NU at weaning may account for decreased climbing ability during early ontogeny, and hence for the retarded development of wire-gnawing. The difference in early experience with either of the two patterns rather than genetic effects may be responsible for the qualitative difference between the strains with respect to the form of later stereotypy.
Weaving is a common locomotor stereotypy in horses, which has been shown to be reduced by the presence of a mirror in the stable; however, it remains unclear whether this effect is due to the reflected image of a horse or some other property associated with the introduction of a mirror. To investigate this further, the response of six known weaving horses to each of three different types of poster was recorded. The poster images consisted of a life-size image of a horse's face (true image), a version of the same image cut into 54 squares, which were then randomly rearranged (pixilated image) and a blank (white image) display of the same size as the other posters. Four observation periods were included in each of the two days of observation per treatment condition: 08:00–08:30h, 10:00–10:30h, 12:00–12:30h and 16:00–17:00h. The first observation period was followed by the provision of concentrate feed and forage, the second observation period by exercise, the third by further forage and the fourth by concentrate feed and forage. The horses’ activities and positions in the box were scanned at 1min intervals and the number of observations registering each activity and position was calculated as a percentage of the total number of observations for each observation period.Weaving was significantly less when the horses were provided with the image of a horse's face (mean percentage of observations±S.E.M.; 5.56±1.57), compared to both the pixilated (14.85±3.06) and white (20.52±4.12) images. Nodding was significantly less when provided with the true image of a horse (0.45±0.15) compared to the pixilated image (2.15±0.67). The pattern of weaving throughout the day differed from that of nodding, and together these results suggest that the two behaviours are not analogous. The presence of the image of the horse's face was associated with a significant increase in alertness (F112,2=11.31, p
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
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.
The Behaviour of Horses in Relation to Management and Training is a unique and important work, being a fascinating mixture of scientific fact and original thinking which will stimulate all horse owners to look more closely into patterns of behaviour resulting in a greatly improved understanding of equine species. The book covers: * Feeding behaviour and digestion * How horses learn * Behavioural problems * Horse welfare * Horse language * Visual communication * Sex, maturity and the foal * Horse society
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.
We estimate that stereotypies are currently displayed by over 85 million farm, laboratory and zoo animals worldwide. This paper investigates their reliability as welfare indicators, by surveying studies relating stereotypy to other welfare measures and by analysing the mechanisms underlying this behaviour. Where data exist, most (approximately 68%) situations that cause/increase stereotypies also decrease welfare. Stereotypy-eliciting situations are thus likely to be poor for welfare, although exceptions exist. Within such an environment, however, most (approximately 60%) accounts link individual stereotypy performance with improved welfare (cf approximately 20% linking it with reduced welfare). Thus, in a sub-optimal environment, non-stereotyping or low-stereotyping individuals could well have the poorest welfare, although again exceptions exist. Examining the mechanisms underlying stereotypy performance, we discuss four processes that could account for these complex links between stereotypy and welfare. Beneficial consequences from performing the specific source-behaviour of the stereotypy ('do-it-yourself enrichment'), or arising from repetition per se ('mantra effects'), may ameliorate welfare in poor environments. In addition, stereotypies that have become centrally controlled (habit-like), or that arise from autistic-like changes in the control of all behaviour (perseveration), are likely to be unreliable indicators of current state because they can be elicited by, or persist in, circumstances that improve welfare. To refine the role of stereotypy in welfare assessment, we suggest the collection of specific additional data to reveal when any of these four processes is acting. Until such research increases our understanding, stereotypies should always be taken seriously as a warning sign of potential suffering, but never used as the sole index of welfare; non-stereotyping or low-stereotyping individuals should not be overlooked or assumed to be faring well; simple measures of frequency should not be used to compare stereotypies that differ in age, form, or the biological or experiential characteristics of the performing animal; enrichments that do not immediately reduce stereotypies should not be assumed failures with respect to welfare; and finally, stereotypies should not be reduced by means other than tackling their underlying motivations.
Chinchilla lanigera intensive breeding programmes are affected by an abnormal repetitive behaviour called 'fur-chewing', yet the aetiology is still unknown and little scientific work has been published on this condition. Recent studies have supported the idea that fur-chewing is a stress-related behaviour. In the present study, we used a questionnaire survey in order to: 1) describe general aspects on the epidemiology of fur-chewing in Argentinian farms, and 2) identify which management and/or environmental factors within the breeding facilities may be influencing the occurrence of fur-chewing. The survey consisted of 28 questions focused on farm characteristics, environmental variables and husbandry routines, and was distributed to Argentinian chinchilla farmers. All quantitative variables were tested in a multiple logistic regression model. The mean incidence of fur-chewing was 4.32 ± 0.37% (n = 107 farms). Variables negatively related to fur-chewing were the breeder experience in the activity, the total volume of the facility, and the number of wood shaving changes per week. Positive relationships were found for space index, number of rooms in the facility and presence of different rooms for fur production and reproduction. Other tendencies suggested that farms with the presence of external sound disturbance nearby had higher incidence levels. Also, we detected a tendency towards lower numbers of affected animals with an increment in the provision of dusting baths per week. Finally, results suggested a female prevalence in the development of the behaviour.
Abstract— Three conditions affecting the skin and fur of Chinchilla lanigera, and the pockets of the breeders of these animals, namely fur-slip, fur fungus, and fur-chewing are considered. The aetiology, pathology, clinical picture, and treatment of all three are discussed in detail and the picture of recent research into the causation and treatment of fur-chewing presented.
Traditionally farmed silver fox cubs are raised after weaning either in pairs or singly in a traditional fox cage (1.2 m 2). However, this way of housing foxes has been criticised because the foxes may have limited chance to exercise and to show social behaviour. Therefore, the aim of the present study was to evaluate the effects of different social and spatial conditions on the welfare of silver fox cubs. The cubs were housed singly, in pairs or in quartets with space allocation of either 0.6 or 1.2 m 2 per animal. Behavioural, physiological and production-related welfare parameters were assessed. The results revealed that space allocation had only minor effects on the measured welfare related param-eters. With regard to social conditions, the results showed that the possibility for social behaviour is important for the welfare of young cubs. However, the welfare of the cubs may be jeopardised if they are kept in quartets beyond their natural dispersal time. Therefore, the welfare of silver fox cubs could be enhanced by allowing the cubs to enjoy of social companionship during the first months of their lives and by separating them into pairs in later autumn.
Due to its complexity, in combination with a lack of scientific reports, fur-chewing became one of the most challenging behavioral problems common to captive chinchillas. In the last years, the hypothesis that fur-chewing is an abnormal repetitive behavior and that stress plays a role in its development and performance has arisen. Here, we investigated whether a relationship existed between the expression and intensity of fur-chewing behavior, elevated urinary cortisol excretion and anxiety-related behaviors. Specifically, we evaluated the following parameters in behaviorally normal and fur-chewing animals of both sexes: (1) mean concentrations of urinary cortisol metabolites and (2) anxiety-like behavior in an elevated plus-maze test. Urinary cortisol metabolites were higher only in females that expressed the most severe form of the fur-chewing behavior (P≤0.05). Likewise, only fur-chewing females exhibited increased (P≤0.05) anxiety-like behaviors associated with the elevated plus-maze test. Overall, these data provided additional evidence to support the concept that fur-chewing is a manifestation of physiological stress in chinchilla, and that a female sex bias exists in the development of this abnormal behavior.
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.
Artificial weaning in laboratory mice elicits increased levels of exploratory and escape behaviour. Under barren housing conditions patterns of exploration and escape subsequently develop into stereotypic behaviour. Weaning weight in wild house mice,Mus musculus domesticus, is known to affect offspring fitness, thus reduced weaning weight represents a risk to fitness. In male ICR-mice,Mus musculus, precocious weaning 3 days prior to standard weaning age tended to decrease growth rate in the long term, and differences in weaning weight of mice weaned at the standard age persisted into adulthood. Both plasma corticosterone levels 48 h after weaning and adult stereotypy levels were higher in precociously weaned mice, but also in animals weaned at the usual age but at a low weight. These results suggest that potential costs in terms of fitness may affect stress levels at the onset of stereotypy development and predispose ICR-mice to perform stereotypies at a high level when adult.
Stereotypies are repetitive, unvarying, apparently purposeless behavioural patterns. They develop in animals kept in barren environments and are highly prevalent in laboratory mice (Mus musculus), yet their underlying mechanisms have remained elusive. In humans, stereotypies are associated with several psychiatric disorders and are thought to reflect dysfunction of inhibition of motor programs mediated by the corticostriatal circuitry, resulting in recurrent perseveration (=inappropriate repetition of behavioural responses). Several studies in captive animals of different species have reported a correlation between stereotypy performance and perseverative behaviour, indicating a similar dysfunction. To examine whether stereotypies in mice correlate with recurrent perseveration and whether they are causally related, we raised 40 female ICR CD-1 mice in either barren or enriched cages from three to either six or 16 weeks of age (2 × 2 factorial design) and assessed stereotypic behaviour in the home cage and recurrent perseveration on a two-choice guessing task. Enrichment significantly reduced stereotypic behaviour both at six and 16 weeks of age and recurrent perseveration increased with age. Although enriched housing reduced the number of repetitions in the guessing task significantly, there was no clear evidence for an effect on recurrent perseveration, and recurrent perseveration did not correlate positively with stereotypy level. These findings indicate either that this test did not measure recurrent perseveration or that cage stereotypies in these mice do not reflect behavioural disinhibition as measured by recurrent perseveration.
Female mink pups were weaned at 6, 8 or 10 weeks of age and subjected to two different housing conditions. They were either kept together with a single male sibling in traditional mink cages (30x45x90 cm) or housed socially with all litter-mates in an alternative system consisting of three adjoining traditional cages (90x45x90 cm). All cages were supplied with nest boxes. At 5 months of age, the siblings were removed leaving the females socially isolated in the two different cage systems. Females' stereotypies were quantified by repeated scanning observations under the social housing conditions immediately before removal of the siblings, and again at the age of 7 and 9 months, when the animals had stayed solitary in the two systems for 2 and 4 months. Solitary females showed significantly more stereotypies than females under social housing conditions in both cage systems. Stereotypies were more frequent in the smaller traditional cages. Stereotypies declined from 7 to 9 months of age among solitary animals in traditional cages but not in alternative cages. Early-weaned solitary females in traditional cages showed more stereotypies than later-weaned animals, but only when measured at the age of 7 months. It is suggested that early weaning, individual housing and small cages promote the development of stereotypies in farmed mink. The influence of early weaning on stereotypies seems to decline with age, while effects related to individual housing and small cages appear to be more persistent.
Normal behavior plays a key role in facilitating homeostasis, especially by allowing the animal to control and modify its environment. Captive environments may interfere with these behavioral responses, and the resulting stress may alter many physiological parameters. Abnormal behaviors indicate that an animal is unable to adjust behaviorally to the captive environment and, hence, may be expressing abnormal physiology. Therefore, captive environments may affect the following aspects of an experiment: validity, by introducing abnormal animals into experiments; reliability, by increasing interindividual variation through the introduction of such individuals; and replicability, by altering the number and type of such individuals between laboratories. Thus, far from increasing variability, enrichment may actually improve validity, reliability, and replicability by reducing the number of abnormal animals introduced into experiments. In this article, the specific example of abnormal repetitive behaviors (ARBs) is explored. ARBs in captive animals appear to involve the same mechanisms as ARBs in human psychiatry, which reflect underlying abnormalities of brain function. ARBs are also correlated with a wide range of behavioral changes that affect experimental outcomes. Thus, ARBs in laboratory animals may compromise validity, reliability, and replicability, especially in behavioral experiments; and enrichments that prevent ARB may enhance validity, reliability, and replicability. Although many links in this argument have been tested experimentally, key issues still remain in the interpretation of these data. In particular, it is currently unclear (1) whether or not the differences in brain function seen in animals performing ARB are abnormal, (2) which common behavioral paradigms are affected by ARB, and (3) whether enrichment does indeed improve the quality of behavioral data. Ongoing and future work addressing these issues is outlined.
Horses displaying an oral stereotypy were tested on an instrumental choice paradigm to examine differences in learning from non-stereotypic counterparts. Stereotypic horses are known to have dysfunction of the dorsomedial striatum, and lesion studies have shown that this region may mediate response-outcome learning. The paradigm was specifically applied in order to examine learning that requires maintenance of response-outcome judgements. The non-stereotypic horses learned, over three sessions, to choose a more immediate reinforcer, whereas the stereotypic horses failed to do so. This suggests an initial behavioural correlate for dorsomedial striatum dysregulation in the stereotypy phenotype.
La chinchilla, su crianza en todos los climas
- J Grau
Grau, J., 1986. La chinchilla, su crianza en todos los climas, 3era edición. El Ateneo,
Buenos Aires, Argentina.
Ethological examination of breeding chinchillas
- Lanski
Lanski, J., Sepesi, E., 1996. Ethological examination of breeding chinchillas. Scientifur
20, 35e41.
Standard-haltung für labormäuse—probleme und lösungsansätze
- Würbel
Würbel, H., Stauffacher, M. 1994. Standard-Haltung für labormäuse -problema und
373
lösungsansätze. Tierlaboratorium. 17, 109-118.