Frequency Of Stereotypies Research Articles

Effects of Multistrain Probiotic Supplementation on Sows' Emotional and Cognitive States and Progeny Welfare.

The intensification of production systems has resulted in detrimental effects on sow welfare, which can have an adverse influence on their offspring. Considering the relevance of the microbiota-gut-brain axis, probiotics can mitigate such impacts. To investigate the effects of the dietary inclusion of probiotics on the welfare of sows and piglets, 147 multiparous sows were randomly assigned to two groups: a control group or a group supplemented with a multistrain probiotic from the beginning of pregnancy to the end of lactation. The human-animal relationship (HAR), stereotypic behavior, position changes, salivary cortisol, and plasma serotonin levels were assessed in the sows. The piglets' back test behavior and organ weight were analyzed. The probiotic-supplemented sows exhibited a better HAR index (p = 0.017), which indicated reduced aversion towards humans. The frequency of stereotypies was not influenced by the treatments. However, the supplemented sows spent more time standing (p = 0.054) and less time lying down (p = 0.008). The cortisol level of the supplemented sows was 50% lower (p = 0.047) and the serotonin levels were 11% higher (p = 0.034) than control animals. The multistrain piglets were more passive and less resistant (p = 0.076) in the back test. The organ weights were not influenced by treatments. In conclusion, the sows supplemented with probiotics showed less fear and more motivation indicators, while their piglets showed less aggression behaviors.

Relationship between hand stereotypies and purposeful hand use and factors causing skin injuries and joint contractures in individuals with Rett syndrome

BackgroundSkin injuries and joint contractures in the upper limbs are observed in approximately 50 % of individuals with Rett syndrome, respectively. AimsTo investigate the relationship between stereotypic hand movements and purposeful hand skills, items related to these, and factors that cause upper extremity skin injuries and joint contractures in individuals with Rett syndrome. Study designWe conducted a cross-sectional observational study in 2020 with families belonging to either of the two largest Rett syndrome organizations in Japan. SubjectsIn 2020, we sent a questionnaire to 194 Japanese families. Outcome measuresWe used descriptive statistics to indicate frequency in each question. We analysed the association between hand stereotypies and purposeful hand use, their associations with each questionnaire item, and the relationship between the occurrence of skin injuries and joint contractures. ResultsWe acquired information from 72 cases. We found correlations between stereotypy frequency with reaching and between purposeful hand use with intellectual development grade and hand function. Hand and finger skin injuries and elbow and finger joint contractures were associated with wringing/washing, grasping, locomotion, reaching, and intellectual development grade. We identified cut-off points for the occurrence of elbow and finger joint contractures of 10 years 6 months, ability to roll over, finger feeds only, and understanding of simple words. ConclusionsDirect interventions can reduce hand stereotypies and increase purposeful hand use, while related items can be addressed with indirect interventions. Evaluations of factors that cause skin injuries and joint contractures can prevent their occurrence.

Colombian Creole Horse: Frequency of oral and motor stereotypies.

Background and Aim:The current stable housing of Colombian Creole Horses severely restricts the animals’ locomotion and natural behaviors. In addition, their feed consists of a combination of high-energy concentrates with considerably little forage which potentially leads to locomotor or oral stereotypies. This study aimed to report the frequency of locomotor and oral stereotypies in Colombian Creole Horses in Girardota (Antioquia, Colombia) and associated risk factors.Materials and Methods:A prospective cross-sectional study was conducted from 2019 to 2020, in which 102 stabled horses aged 28 months and older participated. A questionnaire was developed to collect information on the horses’ daily barn routines. The horses were observed twice a day for 2 h for 3 consecutive days to record information related to stereotypy behaviors. The Fisher’s exact test and the Mann–Whitney U test were utilized for data analyses. Associations were considered statistically significant at p<0.05.Results:Among the horses evaluated, 32.35% presented at least one stereotyped behavior. The most common was crib-biting (i.e., cribbing), with 17.65% exhibiting this behavior. Age, weight, gender, type of feeding, visual contact between horses, and natural lighting were all associated with oral stereotypies. Crib-biting was most common in young horses (U=1.36, p≤0.05), wind-sucking was more common in lighter weight animals (U=1.45, p=0.01), and lip-smacking was more common in stallions (χ2=9.10, p≤0.01). It is noteworthy that their feeding diet included bran, molasses, and gopher. Horses that did not have visual contact with other horses and those that did not have natural lighting were associated with pica (χ2=9.52, p≤0.02; χ2=3.72, p≤0.05; and χ2=3.72, p≤0.05, respectively). Of locomotor stereotypies, kicking the wall was significant in young animals (U=1.54, p=0.03) and walking in circles in lactating mares (χ2=13.20, p≤0.02).Conclusion:Housing conditions in this study were found to have several risk factors affecting horses that exhibit stereotypic behaviors, and all these factors resulted in a higher frequency of stereotypies. Establishing risk factors for the presentation of abnormal behaviors allows for the implementation of better management practices in the production systems of the Creole Colombian Horse and will help improve their overall welfare.

Review of Temporary Crating of Farrowing and Lactating Sows.

Temporary crating (TC) provides lactating sows with the opportunity to move more freely after crate opening a few days after parturition. The aim of this paper was to evaluate whether TC gives overall welfare improvement when compared to permanent crating or free farrowing. This review shows that when pens with TC allow the sows to turn during the majority of time in the farrowing unit, it is the pen design and period of confinement in a crate within it that influence the extent to which different functional and motivated behaviors can be fulfilled. This review also indicates that there are at least short-term benefits to sows when confinement is reduced, as shown by reported increases in motivated behaviors such as exploration and interactions with piglets when not permanently crated. It remains unclear whether there are any longer-term beneficial effects (until or beyond weaning) due to the paucity of studies. Furthermore, it is uncertain whether the observed short-term benefits translate to other welfare indicators. Research findings indicate no reduction in the frequency of stereotypies or body lesions and do not provide a clear answer regarding sow stress response when released from confinement. Compared to free farrowing, TC appears beneficial for reducing piglet mortality. The impact of the time of onset of TC on the farrowing process and piglet mortality have been inconsistent. While confinement before farrowing prevents nest building behavior, consequences of this for sow physiology have been ambiguous. Confining the sow briefly after farrowing may be the best compromise, allowing the sow to perform motivated nest-building behavior, but the risks of crushing during the unconfined farrowing period may increase. Subsequent crate reopening seems to increase piglet mortality but only if done earlier than 3–5 days after farrowing. The review also provides methodological considerations, a proposal for consistent and accurate terminology when describing systems and highlights gaps of knowledge. In conclusion, TC is a step forward to better pig welfare compared to the farrowing crate, as it allows some freedom of movement for sows without impairing piglet welfare. However, more comprehensive research is needed to draw sound conclusions as to whether TC is a viable transition from permanent crating to free farrowing.

Cognitive, Behavioral, and Sensory Profile of Pallister-Killian Syndrome: A Prospective Study of 22 Individuals.

Background: Developmental delay and intellectual disability are two pivotal elements of the phenotype of Pallister–Killian Syndrome (PKS). Our study aims to define the cognitive, adaptive, behavioral, and sensory profile of these patients and to evaluate possible correlations between the different aspects investigated and with the main clinical and demographic variables. Methods: Individuals of any age with genetically confirmed PKS were recruited. Those ≤ 42 months were administered the Bayley Scales of Infant and Toddler Development Third Edition (Bayley-III), and those > 42 months the Vineland Adaptive Behavior Scales—Second Edition (Vineland-II). Stereotyped behaviors (Stereotypy Severity Scale, SSS) and aggressive behaviors (Behavior Problems Inventory—Short Version, BPIs) were assessed in all subjects > 1 year; sensory profile (Child Sensory Profile 2, C-SP2) in all aged 2–18 years. Results: Twenty-two subjects were enrolled (11 F/11 M; age 9 months to 28 years). All subjects ≤ 42 months had psychomotor developmental delay. Of the subjects > 42 months, 15 had low IQ deviation, and 1 in the normal range. Stereotypies were frequent (median SSS-total score 25/68). Lower Vineland-II values corresponded to greater intensity and frequency of stereotypies (p = 0.004 and p = 0.003), and self-injurious behaviors (p = 0.002 and p = 0.002). Patients with severe low vision had greater interference of stereotypies (p = 0.027), and frequency and severity of aggressive behaviors (p = 0.026; p = 0.032). The C-SP2, while not homogeneous across subjects, showed prevalence of low registration and sensory seeking profiles and hypersensitivity to tactile and auditory stimuli. Lower Vineland-II scores correlated with higher Registration scores (p = 0.041), while stereotypies were more frequent and severe in case of high auditory sensitivity (p = 0.019; p = 0.007). Finally, greater sleep impairment correlated with stereotypies and self-injurious behaviors, and lower Vineland-II scores. Conclusions: The present study provides a further step in the investigation of the etiopathogenesis of the syndrome. Furthermore, these aspects could guide rehabilitation therapy through the identification of targeted protocols.

An Observational Study of the Behaviour of Captive Rehabilitant Sun Bears (Helarctos malayanus)

ABSTRACT Rehabilitant Malayan sun bears often remain in captivity for long periods of time and may experience significant welfare challenges including disability and persistent lip lesions. This study aimed to investigate whether short-term observations of behavior such as oral stereotypies are useful as noninvasive indicators of lip lesion pain, and whether behavior differs between able-bodied and disabled bears. Observations were collected from 21 captive, rehabilitant Malayan sun bears, of both sexes, a range of ages, and with lip lesions ranging in severity. Some also had disabilities. Oral stereotypy frequency was unrelated to lip lesion severity (p > 0.05), and no relationships with other behaviors were found; however, visual disabilities had significant effects on behavior. For example, visually disabled bears walked more than able-bodied bears (p = 0.003) or those with physical disabilities (p = 0.01). Further research on the feeding behavior of bears suffering from lip lesions may elucidate other potential behavioral indicators of pain. Researching effects of visual disabilities in bears with a larger sample size is also recommended to determine generalizable impacts in affected individuals and resulting welfare implications.

Stereotypic Behavior in Sows Is Related to Emotionality Changes in the Offspring.

Some effects of expressing stereotypic behavior have not yet been elucidated. During gestation, the environment has the potential to interfere with offspring development and to have prenatal or longer-term consequences. We tested the hypothesis that the occurrence of stereotypic behavior during gestation could affect the phenotype of the offspring. Twenty-eight pregnant sows were studied by comparing two groups differing in the amount of stereotypy shown. We analyzed emotionality in the offspring from sows showing high or low stereotypy frequency using the open field and novel object tests. In the open field test, piglets from sows with a high rate of stereotypies walked more in central sectors (p < 0.0001) and lateral sectors (p = 0.04) than piglets from sows with a low rate of stereotypies. In the novel object test, the offspring from low stereotypy sows vocalized more (p = 0.008). We demonstrate for the first time that the stereotypic behavior by the mother during gestation changes the phenotype of the offspring, in particular, their emotionality.

Happiness is positive welfare in brown capuchins (Sapajus apella)

Questionnaires that allow people who are familiar with individual animals to rate the welfare of these animals are an underutilised tool. We designed a 12-item welfare questionnaire and tested its reliability and associations with subjective well-being (SWB), locomotor stereotypy, and personality traits. The welfare questionnaire included questions relating to physical health, stress and coping, satisfaction with social relationships, psychological stimulation, and the display of positive and negative welfare indicators. We collected ratings of 66 brown capuchins (Sapajus apella) living in three facilities. Each capuchin was rated on the welfare questionnaire by an average of 2.8 raters. The interrater reliability of the welfare questionnaire items ranged from ICC(3,k) 0.51 to 0.86. A principal components analysis indicated that the 12 welfare items loaded onto one component. We repeated this process with the welfare and four items used to measure subjective well-being and found all the items were defined by a single component (welfareSWB). We then conducted three sets of analyses, one predicting the welfare component, one predicting the SWB component, and predicting the welfareSWB component. The independent variables were frequency of locomotor stereotypy, personality, age, and sex; facility was included as a random effect. In models including stereotypy, age, and sex we found frequency of stereotypy to be significantly associated with all three predicted components (ps<0.01). After controlling for stereotypy (b=−0.25, p=0.17), age (b=−0.54, p=0.01), and sex (b=−0.32, p=0.07), the personality traits of Sociability (b=1.02, p<0.001), Assertiveness, (b=0.63, p<0.001), and Attentiveness (b=0.54, p=0.01) were associated with higher scores on the joint welfareSWB component; Neuroticism was negatively associated with welfare SWB (b=−0.60, p=0.01). Our results suggest that welfare questionnaires is a useful, reliable, and valid tool for primate welfare assessment.

Motor stereotypies in fragile X syndrome

The purpose of this study was to quantify the type and frequency of stereotypies in fragile X syndrome and to determine the relationship of observed stereotypies with gender, level of cognitive function, and parent-reported scores for repetitive behaviors. Subjects with fragile X syndrome were videotaped during the administration of a standardized conversation task, a standardized narrative task, and sitting alone. Two individuals rated the stereotypies on the videotapes (10 min each) using the stereotyped behavior scale. Intelligence quotient scores were collected and parents/guardians completed the Vineland adaptive behavior scale and the aberrant behavior checklist – community edition. Thirty-eight subjects were tested (mean age 17.1 ± 7.1 yr). The mean total of stereotypies was 11 ± 11.7 movements in 10 min and the mean stereotyped behavior scale score was 5.8 ± 5.5. The most common type of movement was rubbing him/herself, followed by body movement and repetitive movement. There were correlations between the stereotyped behavior scale score and intelligence quotient ( P = 0.0006), the aberrant behavior checklist total score ( P = 0.01), and the stereotypy subscore ( P = 0.0007). Stereotypies are common in fragile X syndrome and more frequent in individuals with lower intelligence quotients and more severe behavior. The stereotyped behavior scale measure correlated with parent completed checklists, but showed poor to moderate reliability for measurement of stereotypies by a single rater and test retest in fragile X syndrome.

Stereotypic behaviors in degenerative dementias

Stereotypies are simple or complex involuntary/unvoluntary behaviors, common in fronto-temporal dementia (FTD), but not studied in other types of degenerative dementias. The aim was to investigate stereotypy frequency and type in patients with FTD, Alzheimer's disease (AD), progressive supranuclear palsy (PSP) and Parkinson's disease with dementia (PDD) in a multicenter observational study; and to investigate the relation of stereotypies to cognitive, behavioral and motor impairment. One hundred fifty-five consecutive outpatients (45 AD, 40 FTD, 35 PSP and 35 PDD) were studied in four hospitals in northern Italy. Stereotypies were examined by the five-domain Stereotypy Rating Inventory. Cognition was examined by the Mini Mental State and Frontal Assessment Battery, neuropsychiatric symptoms by the Neuropsychiatric Inventory, and motor impairment and invalidity by the Unified Parkinson's Disease Rating Scale part III, and activities of daily living. Stereotypies were present in all groups. FTD and PDD had the greatest frequency of one-domain stereotypies; FTD also had the greatest frequency of two-or-more domain stereotypies; movement stereotypies were the most common stereotypies in all groups. AD patients had fewer stereotypies than the other groups. Stereotypies are not exclusive to FTD, but are also fairly common in PSP and PDD, though less so in AD. Stereotypies may be underpinned by dysfunctional striato-frontal circuits, known to be damaged in PSP and PDD, as well as FTD.

Salivary biomarkers of HPA axis and autonomic activity in adults with intellectual disability with and without stereotyped and self-injurious behavior disorders

Salivary levels of biomarkers for the hypothalamic–pituitary–adrenal axis (HPA; cortisol) and sympatho-adreno-medullary system (SAM; α-amylase) were measured in 51 adults (57% male) with neurodevelopmental disorders associated with intellectual disability (i.e., mental retardation) and chronic self-injurious behavior (SIB) and compared with matched controls without SIB. Cortisol levels differed significantly (p < 0.01) between the SIB and control group (SIB > control). Within-group analyses showed significant differences (p < 0.05) in levels of salivary α-amylase between individuals with SIB and those with SIB meeting criteria for stereotyped movement disorder (SMD; SIB + SMD > SIB). Salivary α-amylase was significantly correlated with frequency of stereotypy among the SIB group (r = 0.36, p < 0.05). These preliminary findings warrant further exploration into the role of the SAM system in the pathophysiology of SIB and related repetitive behaviors among individuals with neurodevelopmental disorders associated with intellectual disability.

Comparing the Neuropsychiatric Profile of Patients with Alzheimer Disease Who Present Spared versus Impaired Executive Functioning

Background. A “dysexecutive” group of patients with Alzheimer disease (AD) has been previously identified, and these patients have been found to present higher frequency of psychiatric symptoms and more pronounced functional impact. This study aimed at evaluating the frequency of neuropsychiatric symptoms in patients with early AD who present with impaired executive functioning. Methods. Thirty patients with early AD diagnosis were divided into a spared (SEF) and an impaired (IEF) executive functioning group according to their performance scores on neuropsychological tests. Their closest relatives or caregivers completed the Cambridge behavioral inventory (CBI), which assesses behavioral symptoms grouped into 13 categories. Results. A significant difference was exclusively found between SEF and IEF in terms of the frequency of stereotypies and repetitive motor behavior (U = 60.5, P = .024). Conclusions. The presence of stereotypies could be associated with a dysexecutive profile in AD patients. These results shed light on the role of frontal circuitry in the expression of motor symptoms in AD and prompt for further research that will contribute to the differential diagnosis both of different subtypes of AD and other types of dementia.

Indirect basal ganglia pathway mediation of repetitive behavior: Attenuation by adenosine receptor agonists

Repetitive behaviors are diagnostic for autism and common in related neurodevelopmental disorders. Despite their clinical importance, underlying mechanisms associated with the expression of these behaviors remain poorly understood. Our lab has previously shown that the rates of spontaneous stereotypy in deer mice (Peromyscus maniculatus) were negatively correlated with enkephalin content, a marker of striatopallidal but not striatonigral neurons. To investigate further the role of the indirect basal ganglia pathway, we examined neuronal activation of the subthalamic nucleus (STN) using cytochrome oxidase (CO) histochemistry in high- and low-stereotypy mice. CO activity in STN was significantly lower in high-stereotypy mice and negatively correlated with the frequency of stereotypy. In addition, exposure to environmental enrichment, which attenuated stereotypy, normalized the activity of STN. Co-administration of the adenosine A2A receptor agonist CGS21680 and the A1 receptor agonist CPA attenuated stereotypy dose-dependently. The significant reduction associated with the lowest dose of the drug combination tested was due to its effects on mice with lower baseline levels of stereotypy. Higher doses of the drug combination were required to show robust behavioral effects, and presumably requisite activation of the indirect pathway, in high-stereotypy mice. These findings support that decreased indirect pathway activity is linked to the expression of high levels of stereotypy in deer mice and that striatal A1 and A2A receptors may provide promising therapeutic targets for the treatment of repetitive behaviors in neurodevelopmental disorders.

Lack of effect of anticonvulsant topiramate on methamphetamine-induced stereotypy and rewarding property in mice

The effects of topiramate, a structurally novel anticonvulsant, on the methamphetamine (METH)-induced expression of stereotypy and conditioned place preference (CPP) in male ICR mice were investigated. After a single administration of METH (10 mg/kg, i.p.), mice showed stereotyped behaviors with a plateau level 25 min after drug challenge. Pretreatment with topiramate (1, 10, and 100 mg/kg, i.p.) 30 min prior to METH challenge had no effect on the expression frequency of stereotypy, compared with saline challenge. No differential effects of topiramate on METH-induced stereotyped behavior (that is, head-bobbing, circling, continuous sniffing, nail and/or wood-chip biting, and vigorous and compulsive grooming) were observed. In saline-challenged groups, the doses of topiramate examined did not induce any stereotyped behaviors. Although mice showed a significant CPP for METH (0.5 mg/kg, i.p.), pretreatment with subchronic topiramate did not affect the magnitude of CPP. Locomotor activity was not affected by the doses of topiramate tested. Conditioned rewarding or aversive effects of topiramate were not observed as indexed by the place preference procedure. These results suggested the lack of effect of topiramate on METH-induced stereotypy and rewarding property in mice.

Selection against stereotypic behaviour may have contradictory consequences for the welfare of farm mink ( Mustela vison)

The present study aimed to examine if divergent selection for stereotypic behaviour in mink influences the welfare of the animals. Two breeding lines were used, a high stereotyping line (HSL, N = 139) and a low stereotyping line (LSL, N = 132). Their welfare was assessed on the basis of adrenocortical activity (faecal cortisol metabolites, FCM), confident versus fearful temperament, growth and reproduction. The results showed that the LSL performed less stereotypic behaviour and were less active than the HSL. Furthermore, the results demonstrated that: (1) the LSL had lower concentrations of FCM, indicative of better welfare; (2) there was no clear difference in temperament between the lines, however, within the HSL a positive correlation was found between the frequency of stereotypy and the frequency of confident temperament; (3) there was no difference in reproduction; (4) there was no failure to grow in any line, but on average the body weight in the LSL was higher than that in the HSL. The correlation between stereotypy and confidence in the present study supports earlier findings showing a higher proportion of fearful animals in groups of low stereotyping mink. So, although the selection against stereotypic behaviour clearly reduced the FCM it may have contradictory consequences for the welfare of the mink.

Stereotypy and perseverative responding in caged bears: further data and analyses

Stereotypies are common in captive animals; yet, their underlying mechanisms are poorly understood. One hypothesis [Garner, J.P., 1999. The aetiology of stereotypy in caged animals. Ph.D. Thesis. University of Oxford, UK] proposes them to be symptoms of altered behavioural organisation (behavioural disinhibition) mediated by striatal dysfunction, and thus, fundamentally analogous to the repetitive behaviours associated with human pathologies such as schizophrenia and autism, or induced in animals by stimulant drugs and striatal lesions. Consistent with this, we previously showed stereotypy frequency to be positively correlated with inappropriate responding during the extinction phase of learning, a measure of ‘perseveration’ consistent with striatal dysfunction, in caged bears [Vickery, S.S., Mason, G.J., 2003. Behavioral persistence in captive bears: implications for reintroduction. Ursus 14, 35–43]. Here, adding new data, we strengthen this finding and look for further evidence of striatal involvement. Twenty-one bears of two species (Asiatic black bears ( Ursus thibetanus) and Malayan sun bears ( Helarctos malayanus)) were taught a simple food rewarded spatial discrimination task. Home cage stereotypy levels ranged between 1 and 45% of all observations (S.E. = 2.75), and high and low stereotypy bears did not differ in the ease with which they learnt the task. However, when responses were no longer rewarded (i.e. food rewards were withheld), as predicted, the most stereotypic animals took the longest to extinguish responding. Contrary to some previous studies, however, further evidence of striatal involvement was limited: behavioural switching rates were not related to stereotypy frequency or to perseveration, and levels of normal activity were only weakly related to perseveration (a trend), leaving the mechanism underlying the relationship between stereotypy and perseveration in these animals unclear. Alternative non-striatal explanations include natural individual variation in habit-formation, general behavioural persistence or compulsiveness and these possibilities require further investigation.

Behaviour of mink kits and dams (Mustela vison) in the lactation period

This study describes the development of the behaviour of mink kits and dams from the fourth to the eighth respectively seventh week after delivery. The study is based on scan observations of 72 mink dams and their kits at a conventional Danish mink farm. The kits started eating when they were about 30 d old. Drinking started almost 2 wk later. During these 2 wk there was a peak in the licking of saliva from the dam and of the inter-litter agonistic behaviour. A causal relationship between experienced thirst and agonistic behaviour is suggested. The kits’ sucking declined to only 5% of the time budget in the seventh week and the stereotypy frequency of the dams increased to about 4% of the time budget. It is suggested that some dams are frustrated by the forced cohabitation with their nutritionally independent kits already in the seventh week and that this should be taken into account when deciding time of weaning. Key words: Animal welfare, behaviour, mink dam, mink kit, Mustela vison, weaning

Striatal opioid peptide content in an animal model of spontaneous stereotypic behavior

Stereotypic behaviors are associated with a broad spectrum of developmental, psychiatric, and genetic disorders. Several lines of evidence indicate that these abnormal repetitive behaviors may be expressed as a consequence of imbalanced activity along the direct and indirect processing pathways of the basal ganglia. Because the activity of these two pathways is modulated, in part, by the neuropeptides dynorphin and enkephalin, we sought to determine whether spontaneous and persistent stereotypy is associated with alterations in striatal neuropeptide content. Specifically, the present study employed radioimmunoassay to measure dynorphin-A and leu-enkephalin content in the dorsolateral striatum of deer mice exhibiting different levels of spontaneous stereotypic jumping. The results indicate significantly decreased leu-enkephalin content and significantly increased dynorphin/enkephalin content ratios in high-stereotypy mice relative to low-stereotypy mice. Moreover, analyses revealed a significant negative correlation between striatal enkephalin content and frequency of stereotypy as well as a significant positive correlation between the dynorphin/enkephalin content ratio and frequency of stereotypy in these mice. These data are consistent with the hypothesis that spontaneous stereotypic behavior is expressed as a consequence of relative hyperactivity along cortico-basal ganglia-cortical feedback circuits involving the direct (facilitative) pathway, but suggest that primary perturbations to the indirect (inhibitory) pathway give rise to such imbalanced activity.

Effects of group housing systems on behaviour and production performance in farmed juvenile mink (Mustela vison)

Juvenile mink were kept in two different group housing systems and their behaviour and physiology compared to that of juvenile mink kept traditionally in pairs. One group housing system was made by adjoining three traditional cages (row system) and the other by stacking a slightly smaller cage on top of a traditional cage (stacked system). Frequent scan sampling observations on behaviour and choice of stay were performed during 3 months on a focal female mink in each system. The occurrence and severity of damages to the fur was registered as well as morbidity and mortality in each system. The data showed that the frequency of stereotypies, auto-grooming and play did not differ significantly between systems. But the stacked system deviated significantly from both the traditional and row system in a number of occasions. There was a higher frequency of surveillance ( P<0.01), exploration ( P<0.01) and agonistic behaviour ( P<0.05) and a lower frequency of sleeping ( P<0.05) and eating/drinking ( P<0.05) in the stacked system. Morbidity and mortality was significantly higher in both group housing systems (9–11%), compared to the traditional system (0%). Group housing of juvenile mink, as practised in this experiment, could not be recommended from a welfare point of view. If group housing of mink, despite these findings, gets widely adopted, it is crucial that further research continues in order to find the appropriate stocking density, no. of feeding places and nest boxes, and optimal group composition acquired to obtain a good and acceptable welfare level in all individuals in the group.

Effects of group housing systems on behaviour and production performance in farmed juvenile mink (Mustela vison)

Juvenile mink were kept in two different group housing systems and their behaviour and physiology compared to that of juvenile mink kept traditionally in pairs. One group housing system was made by adjoining three traditional cages (row system) and the other by stacking a slightly smaller cage on top of a traditional cage (stacked system). Frequent scan sampling observations on behaviour and choice of stay were performed during 3 months on a focal female mink in each system. The occurrence and severity of damages to the fur was registered as well as morbidity and mortality in each system. The data showed that the frequency of stereotypies, auto-grooming and play did not differ significantly between systems. But the stacked system deviated significantly from both the traditional and row system in a number of occasions. There was a higher frequency of surveillance (P<0.01), exploration (P<0.01) and agonistic behaviour (P<0.05) and a lower frequency of sleeping (P<0.05) and eating/drinking (P<0.05) in the stacked system. Morbidity and mortality was significantly higher in both group housing systems (9–11%), compared to the traditional system (0%). Group housing of juvenile mink, as practised in this experiment, could not be recommended from a welfare point of view. If group housing of mink, despite these findings, gets widely adopted, it is crucial that further research continues in order to find the appropriate stocking density, no. of feeding places and nest boxes, and optimal group composition acquired to obtain a good and acceptable welfare level in all individuals in the group.