Refinement Database

Database on Refinement of Housing, Husbandry, Care, and Use of Animals in Research

This database, created in 2000, is updated every four months with newly published scientific articles, books, and other publications related to improving or safeguarding the welfare of animals used in research.

Tips for using the database:

  • This landing page displays all of the publications in the database.
  • Use the drop-down menus to filter these publications by Animal Type, Setting, and/or Topic.
  • Clicking on a parent category (e.g., Rodent) will include publications relating to all the items in that category (e.g., Chinchilla, Gerbil, Guinea Pig, etc.).
  • You may also add a keyword to further narrow your search.
  • Please note that at this time, only publications dated 2010 or later (with some exceptions) can be filtered by Animal Type and Topic, and only publications dated 2020 or later (with some exceptions) can be filtered by Setting. Most publications older than 2010 can only be searched by keyword. 
Lambert, H., Cornish, A., Waley, D. 2024. The value of regulating stocking densities in aquaculture must not be dismissed: A reply to Saraiva et al. 2022. Frontiers in Veterinary Science 10.

We would like to rebut the argument made by Saraiva et al. (1) in their paper “Finding the “golden stocking density”: a balance between fish welfare and farmers' perspectives,” that stocking densities should not be...

Evans, L., Brooks, G. C., Anderson, M. G. et al. 2023. Environmental complexity and reduced stocking density promote positive behavioral outcomes in broiler chickens. Animals 13(13), 2074.

The objective was to evaluate the impacts of a complex environment and stocking density on Ross 708 broiler chicken behaviors. Eight pens contained either high complexity (HC) or low complexity (LC) environments, and high (HD)...

Hube, D., Bill, J., Knop, E. S. et al. 2023. Physical injuries and hair corticosterone concentration in rabbit kits from single- and group-housed does kept on a commercial farm. Animals 13(2), 196.

In intense breeding programs, rabbits are exposed to numerous stress factors which could affect their welfare and health. It has been suggested that group housing is more comfortable for does and similar to the living...

Krunt, O., Zita, L., Kraus, A. et al. 2023. Effects of genotype and housing system on rabbit does’ aggressive behaviors and injuries in smallholding conditions. Animals 13(8), 1357.

The objective of the study was to investigate the effects of housing (deep litter + concrete floor vs. deep litter + ground soil with the possibility to dig burrows), and genotype (Mecklenburg or Hyplus) on...

Veness, A., Coyle, C., Murphy, S. et al. 2023. Minimising aggression in CD-1 and CD-1 background male mice with different enrichment types. Animal Technology and Welfare 22(1), 74–76.

Cage-mate aggression is a well-known problem that is more prevalent in certain strains of mice and is one of the most common reasons for single housing, increased stress levels, premature death and euthanasia. Numerous methods...

Watanabe, S. 2023. Infrared thermography for non-invasive measurement of social inequality aversion in rodents and potential usefulness for future animal-friendly studies. Frontiers in Behavioral Neuroscience 17, 1131427.

Infrared thermography is a method that detects thermal radiation energy and can measure the body surface temperature of animals from a distance. While rectal temperature has traditionally been used to measure animals’ core temperature, thermal...

Gauy, A. C. dos S., Bolognesi, M. C., Gonçalves-de-Freitas, E. 2023. Body tactile stimulation reduces the effects of high stocking density on the welfare of Nile tilapia (Oreochromis niloticus). Fishes 8(6), 320.

High stocking density is used in aquaculture to optimize farming. However, such strategies can stress territorial fish by increasing aggression, thus harming the fish welfare and productive performance. Here, we tested the effect of long-term...

Moëne, O. L., Larsson, M. 2023. A new tool for quantifying mouse facial expressions. ENeuro 10(2) ENEURO.0349-22.2022.

Facial expressions are an increasingly used tool to assess emotional experience and affective state during experimental procedures in animal models. Previous studies have successfully related specific facial features with different positive and negative valence situations...

Clark, F. E. 2023. In the zone: Towards a comparative study of flow state in primates. Animal Behavior and Cognition 10(1), 62–88.

Flow is an altered state of feeling ‘in the zone’ when fully absorbed in a challenge and is associated with positive affective state (feelings). Despite almost five decades of research, Flow has not yet been...

Pérez-Martín, E., Coto-Vilcapoma, A., Castilla-Silgado, J. et al. 2023. Refining stereotaxic neurosurgery techniques and welfare assessment for long-term intracerebroventricular device implantation in rodents. Animals 13(16), 2627.

Stereotaxic surgeries enable precise access to specific brain regions, being of particular interest for chronic intracerebroventricular drug delivery. However, the challenge of long-term studies at this level is to allow the implantation of drug storage...

Stevens, C., Hammonds, T., Hinchcliffe, J. et al. 2023. Report of the 2022 RSPCA/UFAW Rodent Welfare Group Meeting. Animal Technology and Welfare 22(2), 91–100.

The RSPCA/UFAW Rodent Welfare Group has held a one-day meeting every autumn for the last 29 years, so that its members can discuss current welfare research, exchange views on welfare issues and share experiences of...

Tanaka, Y., Nakata, T., Hibino, H. et al. 2023. Classification of multiple emotional states from facial expressions in head-fixed mice using a deep learning-based image analysis. PLOS ONE 18(7), e0288930.

Facial expressions are widely recognized as universal indicators of underlying internal states in most species of animals, thereby presenting as a non-invasive measure for assessing physical and mental conditions. Despite the advancement of artificial intelligence-assisted...

Mocz, F., Michel, V., Janvrot, M. et al. 2022. Positive effects of elevated platforms and straw bales on the welfare of fast-growing broiler chickens reared at two different stocking densities. Animals 12(5), 542.

In conventional rearing systems, fast-growing broiler chickens commonly experience welfare issues, such as contact dermatitis, walking difficulties or a lack of expression of species-specific behaviours. Enriching their environment may be a way to improve their...

Kitchenham, L., Nazal, B., Adcock, A. et al. 2022. Why does lifelong conventional housing reduce the sociability of female mice? Applied Animal Behaviour Science 246, 105532.

Compared to peers raised in well-resourced, 'enriched' environments (‘EE’), female laboratory mice from conventional barren cages are more aggressive to their cage-mates, and less sociable with familiar non-cage-mates (especially if these too are from conventional...

Barki, A., Cnaani, A., Biran, J. 2022. How does temperature affect aggression during and after dominance hierarchy formation in Nile tilapia? Applied Animal Behaviour Science 247, 105563.

Social animals commonly establish dominance relationships by means of aggressive interaction, leading to hierarchical stability and priority of access to limited resources by high-ranked individuals. In poikilothermic animals, temperature is a major abiotic factor influencing...

Denommé, M. R., Mason, G. J. 2022. Social buffering as a tool for improving rodent welfare. JAALAS 61(1), 5-14.

The presence of a conspecific can be calming to some species of animal during stress, a phenomenon known as social buffering. For rodents, social buffering can reduce the perception of and reaction to aversive experiences...

Orient, E., Guillén‐Salazar, F. 2022. Evaluation of social compatibility in an all‐male group of chimpanzees (Pan troglodytes) by means of social network analysis. Zoo Biology 41(1), 84-93.

The study here presented provides preliminary data regarding social compatibility of an all-male group of five chimpanzees (Pan troglodytes), assessed by means of a social network analysis (SNA). The study was conducted at the Fundació...

Knaebe, B., Weiss, C. C., Zimmermann, J. et al. 2022. The promise of behavioral tracking systems for advancing primate animal welfare. Animals 12(13), 1648.

Recent years have witnessed major advances in the ability of computerized systems to track the positions of animals as they move through large and unconstrained environments. These systems have so far been a great boon...

Fultz, A., Yanagi, A., Breaux, S. et al. 2022. Aggressive, submissive, and affiliative behavior in sanctuary chimpanzees (Pan Troglodytes) during social integration. Animals 12(18), 2421.

Chimp Haven is a sanctuary for chimpanzees being retired from biomedical research and from facilities that can no longer care for them. Chimpanzees often live in smaller groups in captive settings; however, Chimp Haven integrates...

Aldhshan, M. S., Mizuno, T. M. 2022. Effect of environmental enrichment on aggression and the expression of brain-derived neurotrophic factor transcript variants in group-housed male mice. Behavioural Brain Research 433, 113986.

Social and environmental factors influence behavior via modulation of brain physiological functions. Environmental enrichment (EE) is an animal housing technique that provides complex sensory, motor, and social stimulation, leading to modifications in the innate aggressiveness...

Lee, V. E., Arnott, G., Turner, S. P. 2022. Social behavior in farm animals: Applying fundamental theory to improve animal welfare. Frontiers in Veterinary Science 9, 932217.

A fundamental understanding of behavior is essential to improving the welfare of billions of farm animals around the world. Despite living in an environment managed by humans, farm animals are still capable of making important...

Scariot, P. P., Gobatto, C. A., Polisel, E. E. et al. 2022. Early-life mice housed in standard stocking density reduce the spontaneous physical activity and increase visceral fat deposition before reaching adulthood. Laboratory Animals 56(4), 344-355.

Laboratory rodents spend the entire day housed in standard cages that provide a restricted area for movements and might, therefore, limit physical activity. However, it has not been tested in immature rodents of ages ranging...

Houstin, A., Zitterbart, D. P., Winterl, A. et al. 2022. Biologging of emperor penguins—Attachment techniques and associated deployment performance. PLOS ONE 17(8), e0265849.

An increasing number of marine animals are equipped with biologgers, to study their physiology, behaviour and ecology, often for conservation purposes. To minimise the impacts of biologgers on the animals’ welfare, the Refinement principle from...

MacLellan, A., Nazal, B., Young et al. 2022. Waking inactivity as a welfare indicator in laboratory mice: Investigating postures, facial expressions and depression-like states. Royal Society Open Science 9(11), 221083.

Animal welfare assessment relies on valid and practical indicators of affect. In mice, the most widely used research vertebrates, lying still with eyes open, inactive-but-awake (IBA) in the home cage, has potential to be one...

Hohlbaum, K., Merle, R., Frahm, S. et al. 2022. Effects of separated pair housing of female C57BL/6JRj mice on well-being. Scientific Reports 12(1), 8819.

In laboratory animal facilities, it is a common code of practice to house female mice in groups. However, some experimental conditions require to house them individually, even though social isolation may impair their well-being. Therefore...