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. 
Griess, R. S. 2011. Environmental enrichment improves fertility and pup survival. Tech Talk [The Newsletter for Laboratory Animal Science Technicians] 16(1), 2-3.

Historically, we have added approximately half a cup of shredded aspen bedding for nest making into each littering cage. This procedure was continued as we looked into additional environmental enrichment. There are many types of...

Gaskill, B., Winnicker, C. L., Garner, J. P. et al. 2011. The naked truth: Breeding performance in outbred and inbred strains of nude mice with and without nesting material. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 741 (Abstract #PS95).

In laboratories, mice are housed at ambient temperatures between 20 to 24 °C, which is below their lower critical temperature of 30 °C, but comfortable for human workers. Thus, mice are thermally stressed, which can...

Gaskill, B., Garner, J. P., Pritchett-Corning, K. 2011. Energy reallocation to breeding performance through improved behavioral thermoregulation. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 771 (Abstract #P120).

Mice are housed at temperatures which increase their basal metabolic rates and impose high energy demands to maintain core temperatures. Thus, energy may be reallocated from other biologic processes to increase heat production. We hypothesized...

Buck, C., Pittman, P., Coburn, A. et al. 2011. Primate foraging ice blocks: Cool treats and interactive eats. Tech Talk [The Newsletter for Laboratory Animal Science Technicians] 16(3), 2.

The [ice] blocks provide a stimulating foraging experience for the NHPs. The blocks last up to an hour fully melting; however, most NHPs have them broken apart and are eating them within 15 minutes. Some...

Brydges, N. M., Leach, M., Nicol, K. et al. 2011. Environmental enrichment induces optimistic cognitive bias in rats. Animal Behaviour 81(1), 169-175.

People's affective or emotional state can alter their cognitive processing, biasing interpretation of ambiguous stimuli. Those in a more positive state interpret such stimuli in a more optimistic manner than those in a negative state...

Breegi, S. 2011. Evaluation of nesting materials for use in nude mouse colonies. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 782 (Abstract #P171).

Nesting material has been reported to be beneficial to mice by providing environmental enrichment as well as a means of thermoregulation. Cotton nesting material has been reported to cause conjunctivitis in athymic nude mice. We...

Gaskill, B. N., Rohr, S., Lucas, J. R. et al. 2011. Working with what you've got: Changes in thermal preference and behavior in mice with or without nest material. Journal of Thermal Biology. 36(3), 193-199.

In laboratories mice are typically housed at ambient temperatures (Ta) of 20–24 °C, which are below their average preferred Ta of ≈30 °C. Adjusting laboratory Ta is not a solution because preferences differ depending on...

Swetter, B. J., Karpiak, C. P., Cannon, J. T. 2011. Separating the effects of shelter from additional cage enhancements for group-housed BALB/cJ mice. Neuroscience Letters 495(3), 205-209.

Enrichment studies with rodents have demonstrated that cage enhancements can improve animal welfare and performance on common behavioral measures, but few studies have compared more than one type of enrichment or controlled for confounds, and...

Araki, A. 2010. Using environmental enrichment to reduce fighting in mice. Tech Talk [The Newsletter for Laboratory Animal Science Technicians] 15(4), 6.

A colony of mice (base strain C57Bl6) was transferred to Oregon State University. Fighting was observed in six cages of males (2 to 5 mice per cage) at cage change, but not during daily checks...

Abou-Ismail, U. A., Burman, O. H. P., Nicol, C. J. et al. 2010. The effects of enhancing cage complexity on the behaviour and welfare of laboratory rats. Behavioural Processes 85(2), 172-180.

This experiment was carried out to investigate the long-term effects of enhancing cage complexity on behavioural measures of welfare in laboratory rats. We housed 72 rats in groups of four in either ‘enriched’ or ‘unenriched’...

Õkva, K., Nevalainen, T., Mauranen, K. et al. 2010. The effect of three different items of cage furniture on the behaviour of male C57BL/6J mice in the plus-maze test. Animal Welfare 19(4), 401-409.

The aim of this study was to assess the effects of specific regimens of enrichment on the behaviour of C57BL/6J mice in the elevated plus-maze test (EPM). A total of 192 male C57BL/6J mice were...

Waitt, C. D., Bushmitz, M., Honess, P. E. 2010. Designing environments for aged primates. Laboratory Primate Newsletter, 49(3), 5-9.

In order to prevent physical and psychological deterioration in older animals, it is important to apply the same principles of environmental enrichment and housing as are applied to younger animals. As we have discussed above...

Lozano, A., West, A., Leland, S. et al. 2010. Preventing boredom in NHPs using fleece fabric and food treats. Tech Talk [The Newsletter for Laboratory Animal Science Technicians] 15(5), page numbers missing.

Recently, I devised yet another way to use this fleece material to enhance the environments of our animals. To this end, I sought out a way to present food enrichment to our animals so that...

Veillette, M., Reebs, S. G. 2010. Preference of Syrian hamsters to nest in old versus new bedding. Applied Animal Behaviour Science 125(3-4), 189-194.

This study tested whether Syrian hamsters (Mesocricetus auratus) have an aversion to old bedding (up to 14 days) by offering them the option to nest in a new cage. A secondary goal was to assess...

Turner, P. V., Ovari, J., Pinelli, C. et al. 2010. Long-term effects of housing and enrichment on affective behavior and responsiveness of Sprague-Dawley rats. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 658-659 (Abstract #PS12).

Most rodent studies evaluate different caging paradigms over short periods of time, which may not be realistic for typical colony settings. Inappropriate housing may lead to boredom, aggression, stereotypies, and altered metabolism, which in turn...

Tilly, S.-L. C., Dallaire, J., Mason, G. J. 2010. Middle-aged mice with enrichment-resistant stereotypic behaviour show reduced motivation for enrichment. Animal Behaviour 80(3), 363-373.

For captive animals, living in barren conditions leads to stereotypic behaviour that is hard to alleviate using environmental enrichment. This resistance to enrichment is often explained via mechanisms that decouple abnormal behaviour from current welfare...

Santos, R. A., Fontes, R. S., Ong, F. M. et al. 2010. Effects of environmental enrichment and housing system on weight gain of C57BL/6 mice. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 712-713 (Abstract #P100).

Our goal was to evaluate the effect of treatment represented by enrichment with cotton balls, and the housing system, by comparing the conventional (open cage) and the ventilated cage (IVC) systems on the weight gain...

Pawlowicz, A., Demner, A., Lewis, M. H. 2010. Effects of access to voluntary wheel running on the development of stereotypy. Behavioural Processes 83(3), 242-246.

Stereotyped motor behaviors are a common consequence of environmental restriction in a wide variety of species. Although environmental enrichment has been shown to substantially reduce stereotypy levels, the various components of enrichment have not been...

Oteham, C. P. 2010. Effects of specific environmental enrichment contributing to litter size and attrition rate of TRP1/TGfβ transgenic mice in a breeding colony. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 698 (Abstract #P51).

In previous studies of environmental enrichment of mice it has been determined that certain types of mice are affected by manipulation of their living environment. Some have effects on cognitive memory and some affect the...

Newman, A. 2010. A simple improvement of rodent tunnels for environmental enrichment. Animal Technology and Welfare 9, 57-58.

We found commercially available rodent tunnels are too small in diameter when the rat reaches a size

Mikkelsen, L. F., Sørensen, D. B., Krohn, T. et al. 2010. Clinical pathology and cardiovascular parameters are not influenced by housing rats under increased environmental complexity. Animal Welfare 19(4), 449-460.

Since the release of the revised Appendix A from the Council of Europe for housing of laboratory animals there have been claims that laboratory animals should be housed under more complex conditions; known popularly as...

Li, W. J., Yu, H., Yang, J. M. et al. 2010. Anxiolytic effect of music exposure on BDNFMet/Met transgenic mice. Brain Research 1347, 71-79.

Brain-derived neurotrophic factor (BDNF) has been reported to play important roles in the modulation of anxiety, mood stabilizers, and pathophysiology of affective disorders. Recently, a single nucleotide polymorphism (SNP) in the BDNF gene (Val66Met) has...

Konkle, A. T. M., Kentner, A. C., Baker, S. L. et al. 2010. Environmental-enrichment-related variations in behavioral, biochemical, and physiologic responses of Sprague-Dawley and Long Evans rats. JAALAS 49(4), 427-436.

The behavioral, biochemical, and physiologic consequences of 6 wk of environmental enrichment were evaluated in male Long Evans and Sprague-Dawley rats and compared with those of rats in standard single-housing conditions. Standard housing provided little...

Howard, B., Nevalainen, T., Perretta, G. (ed). 2010. The COST Manual of Laboratory Animal Care and Use: Refinement, Reduction, and Research (1st Ed). CRC Press, Boca Raton, FL.

COST Action B-24 established four working groups to research and discuss issues relevant to laboratory animal science. These included the housing of animals, environmental needs, refinement of procedures, genetically modified animals, and cost-benefit analysis. Based...

Harper, V., Frey, A., Bradley, D. et al. 2010. Recognizing and addressing stereotypic behaviors. Tech Talk [The Newsletter for Laboratory Animal Science Technicians] 15(4), 2.

The combination of mouse igloos and running wheels proved to be highly effective in reducing flipping, circling, and jumping.