Hanno Würbel

• Professor at University of Bern

*Background:* Reproducibility is recognized as essential to scientific progress and integrity. Replication studies and large-scale replication projects, aiming to quantify different aspects of reproducibility, have become more common. Since no standardized approach to measuring reproducibility exists,a diverse set of metrics has emerged and a compr...

The management of an animal care and use program implies compliance with the legal requirements and observation of the societal and professional ethical concerns, both in constant evolution. This chapter answers in a practical and orderly way many questions relating to ethical and legal matters that should be considered first when setting up the pr...

Heterogeneity of study samples is ubiquitous in animal experiments. Here, we discuss the different options of how to deal with heterogeneity in the statistical analysis of a single experiment. Specifically, data from different sub-groups (e.g. sex, strain, age cohorts) may be analysed separately, heterogenization factors may be ignored and data poo...

Over the last decades, behavioural tests in animals, especially rodents, have been a standard screening method to determine the mechanisms of action and efficacy of psychopharmacological compounds. Yet, recently the reproducibility of some of these tests has been questioned. Based on a systematic review of the sensitivity of mouse behavioural tests...

Conventional housing for laboratory mice limits the expression of species-specific behaviours and restricts the control over their environment, thus failing to guarantee the animals’ welfare. To better understand the behaviour and resource use of laboratory mice, we housed mice (n=64) of two common laboratory strains (C57BL/6 and Swiss), both sexes...

Home cage aggression in group-housed male mice is a major welfare concern and may compromise animal research. Conventional cages prevent flight or retreat from sight, increasing the risk that agonistic encounters will result in injury. Moreover, depending on social rank, mice vary in their phenotype, and these effects seem highly variable and depen...

Theoretical and empirical evidence indicates that low external validity due to rigorous standardization of study populations is a cause of poor replicability in animal research. Here we report a multi-laboratory study aimed at investigating whether heterogenization of study populations by using animals from different breeding sites increases the re...

Theoretical and empirical evidence indicates that low external validity due to rigorous standardization of study populations is a cause of poor replicability in animal research. Here, we report a multi-laboratory study to test whether heterogenization of study populations by using animals from different breeders increases the replicability of resul...

An increasing number of zoos keep their animals in natural-looking enclosures, but it is often unclear whether or not the species’ behavioural and ecological needs are being adequately met. For species that suffer predation in the wild, structural enrichment in captivity can play a crucial role in connection with enclosure use. Firstly, we examined...

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Studies in mice have shown that less aversive handling methods (e.g. tunnel or cup handling) can reduce behavioural measures of anxiety in comparison to picking mice up by their tail. Despite such evidence, tail handling continues to be used routinely. Besides resistance to change accustomed procedures, this may also be due to the fact that current...

The validity of widely used rodent behavioural tests of anxiety has been questioned, as they often fail to produce consistent results across independent replicate studies. In this study, we assessed the sensitivity of common behavioural tests of anxiety in mice to detect anxiolytic effects of drugs prescribed to treat anxiety in humans. We conducte...

Anxiety disorders are among the most common mental health conditions needing new and better treatments. Research and development of anxiolytic drugs using animal models heavily rely on behavioural tests, most of which measure anxiolytic effects by increased exploratory activity in potentially threatening environments. However, interpretation of suc...

The influence of protocol standardization between laboratories on their replicability of preclinical results has not been addressed in a systematic way. While standardization is considered good research practice as a means to control for undesired external noise (i.e., highly variable results), some reports suggest that standardized protocols may l...

The phenotype of an organism results from its genotype and the influence of the environment throughout development. Even when using animals of the same genotype, independent studies may test animals of different phenotypes, resulting in poor replicability due to genotype-by-environment interactions. Thus, genetically defined strains of mice may res...

The EQIPD framework for rigor in animal experiments aims to unify current recommendations based on evidence behind their rationale and was prospectively tested for feasibility in multicenter animal experiments.

The credibility of scientific research has been seriously questioned by the widely claimed “reproducibility crisis”. In light of this crisis, there is a growing awareness that the rigorous standardisation of experimental conditions may contribute to poor reproducibility of animal studies. Instead, systematic heterogenisation has been proposed as a...

The phenotype of an organism results from its genotype and the influence of the environment throughout development. Even when using animals of the same genotype, independent studies may test animals of different phenotypes, resulting in poor replicability due to genotype-by-environment interactions. Thus, genetically defined strains of mice may res...

Facial expressions potentially serve as indicators of animal emotions if they are consistently present across situations that (likely) elicit the same emotional state. In a previous study, we used the Dog Facial Action Coding System (DogFACS) to identify facial expressions in dogs associated with conditions presumably eliciting positive anticipatio...

Animal research on anxiety and anxiety disorders relies on valid animal models of anxiety. However, the validity of widely used rodent behavioural tests of anxiety has repeatedly been questioned, as they often fail to produce consistent results across independent replicate studies using different study populations or different anxiolytic compounds....

Reproducibility in biomedical research, and more specifically in preclinical animal research, has been seriously questioned. Several cases of spectacular failures to replicate findings published in the primary scientific literature have led to a perceived reproducibility crisis. Diverse threats to reproducibility have been proposed, including lack...

The inner brow raiser is a muscle movement that increases the size of the orbital cavity, leading to the appearance of so-called 'puppy dog eyes'. In domestic dogs, this expression was suggested to be enhanced by artificial selection and to play an important role in the dog-human relationship. Production of the inner brow raiser has been shown to b...

Under the ideal free distribution (IFD), the number of organisms competing for a resource at different sites is proportional to the resource distribution among sites. The ideal free distribution of competitors in a heterogeneous environment often predicts habitat matching, where the relative number of individuals using any two patches matches the r...

Background: Social dominance status (e.g., dominant or subordinate) is often associated with individual differences in behavior and physiology but is largely neglected in experimental designs and statistical analysis plans in biomedical animal research. In fact, the extent to which social dominance status affects common experimental outcomes is vir...

“We demand rigidly defined areas of doubt and uncertainty!” —D. Adams

Broiler breeders are kept for the production of fertile eggs. They face serious welfare problems like aggressive behaviour of the males towards females during mating. Furthermore, broiler breeders are usually kept without perches which are a highly valued resource in chickens. The aim of the study was to investigate how the provision of aerial perc...

In their correspondence about our recent Perspective article (Reproducibility of animal research in light of biological variation. Nat. Rev. Neurosci. 21, 384–393 (2020)), Richter and von Kortzfleisch support our recommendations for a paradigm shift from rigorous standardization to systematic heterogenization in animal research (It is time for an e...

Poor reproducibility is considered a serious problem in laboratory animal research, with important scientific, economic, and ethical implications. One possible source of conflicting findings in laboratory animal research are environmental differences between animal facilities combined with rigorous environmental standardization within studies. Due...

Reproducible science requires transparent reporting. The ARRIVE guidelines (Animal Research: Reporting of In Vivo Experiments) were originally developed in 2010 to improve the reporting of animal research. They consist of a checklist of information to include in publications describing in vivo experiments to enable others to scrutinise the work ade...

Reproducible science requires transparent reporting. The ARRIVE guidelines (Animal Research: Reporting of In Vivo Experiments) were originally developed in 2010 to improve the reporting of animal research. They consist of a checklist of information to include in publications describing in vivo experiments to enable others to scrutinise the work ade...

Reproducible science requires transparent reporting. The ARRIVE guidelines (Animal Research: Reporting of In Vivo Experiments) were originally developed in 2010 to improve the reporting of animal research. They consist of a checklist of information to include in publications describing in vivo experiments to enable others to scrutinise the work ade...

Reproducible science requires transparent reporting. The ARRIVE guidelines (Animal Research: Reporting of In Vivo Experiments) were originally developed in 2010 to improve the reporting of animal research. They consist of a checklist of information to include in publications describing in vivo experiments to enable others to scrutinise the work ade...

Improving the reproducibility of biomedical research is a major challenge. Transparent and accurate reporting is vital to this process; it allows readers to assess the reliability of the findings and repeat or build upon the work of other researchers. The ARRIVE guidelines (Animal Research: Reporting In Vivo Experiments) were developed in 2010 to h...

Reproducible science requires transparent reporting. The ARRIVE guidelines (Animal Research: Reporting of In Vivo Experiments) were originally developed in 2010 to improve the reporting of animal research. They consist of a checklist of information to include in publications describing in vivo experiments to enable others to scrutinise the work ade...

Reproducible science requires transparent reporting. The ARRIVE guidelines (Animal Research: Reporting of In Vivo Experiments) were originally developed in 2010 to improve the reporting of animal research. They consist of a checklist of information to include in publications describing in vivo experiments to enable others to scrutinise the work ade...

Reproducible science requires transparent reporting. The ARRIVE guidelines (Animal Research: Reporting of In Vivo Experiments) were originally developed in 2010 to improve the reporting of animal research. They consist of a checklist of information to include in publications describing in vivo experiments to enable others to scrutinise the work ade...

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Context- dependent biological variation presents a unique challenge to the reproducibility of results in experimental animal research, because organisms’ responses to experimental treatments can vary with both genotype and environmental conditions. In March 2019, experts in animal biology, experimental design and statistics convened in Blonay, Swit...

Over the last two decades, awareness of the negative repercussions of flaws in the planning, conduct and reporting of preclinical research involving experimental animals has been growing. Several initiatives have set out to increase transparency and internal validity of preclinical studies, mostly publishing expert consensus and experience. While m...

Sensory Processing Sensitivity (SPS) is a personality trait in humans characterised by a tendency to process information deeply, to be easily overstimulated, and to have strong emotional responses and an enhanced sensitivity to subtle stimuli. A trait similar to SPS has recently been identified in dogs (“canine Sensory Processing Sensitivity”, cSPS...

Facial expressions are considered sensitive indicators of emotional states in humans and many animals. Identifying facial indicators of emotion is a major challenge and little systematic research has been done in non-primate species. In dogs, such research is important not only to address fundamental and applied scientific questions but also for pr...

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translate...

Social play is associated with the experience of positive emotions in higher vertebrates and may be used as a measure of animal welfare. Altering motivation to play (e.g., through short-term social isolation) can temporarily affect play levels between familiar individuals, a process which may involve emotional contagion. This study investigated how...

A tacit assumption in laboratory animal research is that animals housed within the same cage or pen are phenotypically more similar than animals from different cages or pens, due to their shared housing environment. This assumption drives experimental design, randomization schemes, and statistical analysis plans, while neglecting social context. He...

Improving the reproducibility of biomedical research is a major challenge. Transparent and accurate reporting are vital to this process; it allows readers to assess the reliability of the findings, and repeat or build upon the work of other researchers. The NC3Rs developed the ARRIVE guidelines in 2010 to help authors and journals identify the mini...

Reproducible science requires transparent reporting. The ARRIVE guidelines were originally developed in 2010 to improve the reporting of animal research. They consist of a checklist of information to include in publications describing in vivo experiments to enable others to scrutinise the work adequately, evaluate its methodological rigour, and rep...

In rabbits (Oryctolagus cuniculus L.), pododermatitis is a chronic multifactorial skin disease that appears mainly on the plantar surface of the hind legs. This presumably progressive disease can cause pain leading to poor welfare, yet the progression of this disease has not been thoroughly assessed on the level of individual animals. The aim of th...

Limited space in dairy cattle farming is associated with frequent encounters between cows, often resulting in agonistic interactions and injuries, especially in horned cows. Previous studies with dairy cows investigated space allowances in the waiting area in front of the parlour, the lying area, and the outdoor exercise area with respect to social...

Reproducibility in biomedical research, and more specifically in pre-clinical animal research, has been seriously questioned. Several cases of spectacular failures to replicate findings published in the primary scientific literature have led to a perceived reproducibility crisis. Diverse threats to reproducibility have been proposed, including lack...

Fragestellung: Ziel dieser Studie war es, den Effekt von Brustbeinfrakturen auf das individuelle Bewegungsverhalten von Legehennen in Volièrenhaltung zu untersuchen. Tiere/Material/Methoden: Hundertzwanzig Fokustiere (60 Lohmann Brown, LB & 60 Lohmann Selected Leghorn, LSL) wurden in 6 identischen, mit einem kommerziellen Volièrensystem ausgestatt...

Hormones influence the social behaviour of dogs. Castration of male dogs induces a reduction of testosterone and has been shown to affect social behaviours associated with aggression and reproduction. Changes in social behaviour could be critical in working dogs, which should be well trainable and behave reliably. It is currently unknown whether an...

The manner in which laboratory rodents are housed is driven by economics (minimal use of space and resources), ergonomics (ease of handling and visibility of animals), hygiene, and standardization (reduction of variation). This has resulted in housing conditions that lack sensory and motor stimulation and restrict the expression of species-typical...

Although up to 90% of laying hens manifest keel bone fractures, it is not known to what extent individual hens are affected. The aim of this study was to investigate the effect of keel bone fracture severity on individual productivity of laying hens. Focal hens (75 LSL, 75 LB) were housed in 10 identical pens containing a commercial aviary system (...

Objective Within the last years, there has been growing awareness of the negative repercussions of unstandardized planning, conduct and reporting of preclinical and biomedical research. Several initiatives have set the aim of increasing validity and reliability in reporting of studies and publications, and publishers have formed similar groups. Add...

In rabbits (Oryctolagus cuniculus L.), pododermatitis is a chronic multifactorial skin disease that appears mainly on the plantar surface of the hind legs. In later stages, it causes pain leading to poor welfare of affected animals. Pododermatitis is commonly observed in commercial rabbit production in breeding does housed with wire mesh flooring....

Recently, there has been a move towards positive reinforcement using food rewards in animal training. By definition, rewards function as reinforcers if they increase or maintain the frequency of behaviour that they follow. However, in operant conditioning tasks animals frequently show systematic changes in performance - in particular a reduction in...

In 2010, the NC3Rs published the Animal Research: Reporting of In Vivo Experiments (ARRIVE) guidelines to improve the reporting of animal research. Despite considerable levels of support from the scientific community, the impact on the quality of reporting in animal research publications has been limited. This position paper highlights the strategy...

Selection for hyper-prolific sows has substantially increased litter size. Consequently, the number of piglets in a litter may exceed the number of functional teats. To solve this problem, surplus piglets may be removed from the sow 2 days after birth and raised artificially. However, these piglets show increased levels of oral behaviours, such as...

The laboratory mouse is the most prevalent animal used in experimental procedures in the biomedical and behavioural sciences. Yet, many scientists fail to consider the animals’ social context. Within a cage, mice may differ in their behaviour and physiology depending on their dominance relationships. Therefore, dominance relationships may be a conf...

Judgement bias tasks are promising tools to assess emotional valence in animals, however current designs are often time-consuming and lack aspects of validity. This study aimed to establish an improved design that addresses these issues and can be used across species. Horses, rats, and mice were trained on a spatial Go/No-go task where animals coul...

Perching, especially during the night, is an innate behaviour of chickens and the provision of perches is mandatory for laying hens in multiple countries. We examined whether broiler breeders of the fast (Ross 308) and relatively slow (Sasso) growing hybrids used aerial perches (P) and perches on aviary tiers (A) during rearing and production and h...

Single-laboratory studies conducted under highly standardized conditions are the gold standard in preclinical animal research. Using simulations based on 440 preclinical studies across 13 different interventions in animal models of stroke, myocardial infarction, and breast cancer, we compared the accuracy of effect size estimates between single-lab...

Mathematica notebook with code for simulated sampling. (NB)

Mathematica code for simulated sampling. (PDF)

Data extracted from the CAMARADES database and used in this study. CAMARADES, Collaborative Approach to Meta-Analysis and Review of Animal Data from Experimental Studies. (CSV)

Supporting information, including inclusion/exclusion criteria for data sets, data set summaries, supporting discussion of the inference method, supporting data, and annotated code. (PDF)

Some commercial aviary systems for laying hens allow birds to access feed by standing on perches instead of platforms. Despite reports that providing laying hens with perches relates to reduced aggression and cannibalism, and increased prevalence of keel bone damage, the impact of feeding from perches on behaviour, health, and production has not be...

The scientific community is increasingly concerned with the proportion of published "discoveries" that are not replicated in subsequent studies. The field of rodent behavioral phenotyping was one of the first to raise this concern, and to relate it to other methodological issues: the complex interaction between genotype and environment; the definit...

We studied how space allowance affects measures of animal welfare in mice by systematically varying group size and cage type across three levels each in both males and females of two strains of mice (C57BL/6ByJ and BALB/cByJ; n = 216 cages, a total of 1152 mice). This allowed us to disentangle the effects of total floor area, group size, stocking d...

Domestic dogs (Canis familiaris) are social animals and, therefore, social interactions with conspecifics are crucial for their welfare. However, in kennelled dogs, the ability to interact with conspecifics may be limited. Swiss military dogs, for instance, are kept individually without direct contact to conspecifics. Here we asked whether short-te...

The present study investigated whether oral behaviour directed at piglets can be reduced in artificially reared piglets by providing them with sucking and massaging dummies. The artificial rearing units were equipped in a Latin square model with one of four treatments: a sucking dummy, a massaging dummy, a combined sucking-massaging dummy or no dum...

In laying hens, minimal requirements for feeder space (cm per bird) are based primarily on data from small groups of hens (n < 10) housed in battery cages. The aim of the present study was to determine the effects of feeder space on agonistic behaviour, access to the feeder, and production in laying hens housed in an aviary system. The experiment w...

Broiler breeders are commonly kept without perches, although perching has been shown to be a high-priority behavior in laying hens. We studied whether broiler breeders used elevated perches of different lengths during the night and how access to perches affected health and production. Using the Ross 308 hybrid, pens offering 4 different perch space...

Assessing emotion in animals is fundamental to the study of animal welfare with methodologies for reliable and valid assessments being highly desirable. Qualitative Behaviour Assessment (QBA) is based on the assumption that human observers are capable of integrating details of animals’ behavioural expressions using descriptors (e.g. calm, playful)...

In humans, the personality dimension ‘sensory processing sensitivity (SPS)’, also referred to as “high sensitivity”, involves deeper processing of sensory information, which can be associated with physiological and behavioral overarousal. However, it has not been studied up to now whether this dimension also exists in other species. SPS can influen...

Online survey general questions. (PDF)

Original 112 questions of the pilot study with sources. (PDF)

Dataset. (XLS)

The highly sensitive dog questionnaire (HSD-Q). (PDF)

Lab Animal is a peer-reviewed journal offering information, ideas, methods, and materials for the animal research professional

Play has been proposed as an indicator of positive emotions and welfare in higher vertebrates. This study investigated playfulness in male rats by exploring its consistency across motivational states (with/without prior short social isolation) and two age points at early and late adolescence. Twenty-four male Lister Hooded rats housed in cages of f...

Judgment bias tasks for nonhuman animals are promising tools to assess emotional valence as a measure of animal welfare. In view of establishing a valid judgment bias task for horses, the present study aimed to evaluate 2 versions (go/no-go and active choice) of an auditory judgment bias task for horses in terms of acquisition learning and discrimi...

Accumulating evidence indicates high risk of bias in preclinical animal research, questioning the scientific validity and reproducibility of published research findings. Systematic reviews found low rates of reporting of measures against risks of bias in the published literature (e.g., randomization, blinding, sample size calculation) and a correla...

Reproducibility in animal research is alarmingly low, and a lack of scientific rigor has been proposed as a major cause. Systematic reviews found low reporting rates of measures against risks of bias (e.g., randomization, blinding), and a correlation between low reporting rates and overstated treatment effects. Reporting rates of measures against b...

Distribution of internal validity score. Individual data are shown in https://figshare.com/s/bc48ed5dff9e6ebd2000 (Sample Applications). (TIFF)