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. 
Campo, J. L., Gil, M. G., Dávila, S. G. 2005. Effects of specific noise and music stimuli on stress and fear levels of laying hens of several breeds. Applied Animal Behaviour Science 91(1-2), 75-84.

The results of the present study indicate that specific noise stimulus (90 dB versus 65 dB) causes stress and fear in laying hens and specific classical music stimulus (75 dB versus 65 dB) has a...

Benefiel, A. C., Dong, W. K., Greenough, W. T. 2005. Mandatory enriched housing of laboratory animals: The need for evidence-based evaluation. ILAR Journal 46(2), 95-105.

Environmental enrichment for laboratory animals has come to be viewed as a potential method for improving animal well-being in addition to its original sense as a paradigm for learning how experience molds the brain. It...

Bayne, K. 2005. Potential for unintended consequences of environmental enrihment for laboratory animals and research results. ILAR Journal 46(2), 129-139.

Many aspects of the research animal's housing environment are controlled for quality and/or standardization. Of recent interest is the potential for environmental enrichment to have unexpected consequences such as unintended harm to the animal, or...

Baumans, V. 2005. Environmental enrichment for laboratory rodents and rabbits: Requirements of rodents, rabbits, and research. ILAR Journal 46(2), 162-170.

Environmental conditions such as housing and husbandry have a major impact on the laboratory animal throughout its life and will thereby influence the outcome of animal experiments. However, housing systems for laboratory animals have often...

Sherwin, C. M. 2004. E2 = 3R + 2Q: Calculating species-appropriate environmental enrichment. Proceedings of the International Congress of the International Society for Applied Ethology, 132 (Abstract).

Species appropriate environmental enrichment should be provided to improve both animal welfare and the quality of research data. For research animals, species-appropriate Environmental Enrichment (E2) can be considered as a function of the 3 Rs...

Key, D. 2004. Environmental enrichment options for laboratory rats and mice. Lab Animal 33(2), 39-44.

Environmental enrichment is the alteration of animals' microenvironment to provide them with the opportunity to perfrom species-specific behaviors that we perceive as positive, while reducing abnormal behaviors. [p. 39] Several interesting products are now available...

Applebee, K. A. 2002. Rodent environmental enrichment - animal welfare or human feel-good factor. Animal Technology and Welfare 1(2), 65-69.

This article discusses environmental enrichment for rodents, mainly mice and rats housed in conventional caging, in U.K. research facilities. Environmental enrichment should allow and encourage animals to perform normal behavioural patterns. Cage furniture cannot be...

Morris, T., Goulet, S., Morton, D. 2002. The International Symposium on Regulatory Testing and Animal Welfare: Recommendations on best scientific practices for animal care and regulatory toxicology. ILAR Journal 43(Supplement), S123-S125.

The key conclusion from the group's initial discussions was that enough information was now available to make robust recommendations for animal care best practices. Implementation, not information, is therefore the critical issue [p.123]... Well-implemented enrichment...

Olsson, I. A. S., Dahlborn, K. 2002. Improving housing conditions for laboratory mice: A review of 'environmental enrichment'. Laboratory Animals 36, 243-270.

We have reviewed 40 studies carried out between 1987 and 2000, in which preferences as well as the effect of housing modifications have been studied. Mice will work for access to nesting material and make...

Guittin, P., Decelle, T. 2002. Future improvements and implementation of animal care practices within the animal testing regulatory environment. ILAR Journal 43(Supplement), S80-S84.

The enrichment of the animals' environment will not likely affect the interpretation of the results, particularly if adequate controls are used. Appropriate enrichment methods can be chosen to be compatible with the aims of the...

Fernández-Teruel, A., Giménez-Llort, L., Escorihuela, R. M. et al. 2002. Early-life handling stimulation and environmental enrichment: Are some of their effects mediated by similar neural mechanisms? Pharmacology Biochemistry and Behavior 73(1), 233-245.

Neonatal (early) handling (EH) and environmental enrichment (EE) of laboratory rodents have been the two most commonly used methods of providing supplementary environmental stimulation in order to study behavioral and neurobiological plasticity. A large body...

Fillman-Holliday, D., Landi, M. S. 2002. Animal care best practices for regulatory testing. ILAR Journal 43(Supplement), S49-S58.

General discussion of environmental enrichment. Many laboratory animal species, especially dogs and nonhuman primates, lose interest and stop using a particular device after exposure to it for some time (authors' experiences). It is best to...

Sambrook, T. D., Buchanan-Smith, H. M. 1997. Control and complexity in novel object enrichment. Animal Welfare 6(3), 207-216.

We discuss the properties of controllability and complexity in novel object enrichment, their definition and present a critique of previous work related to them.

Pecenko, N. 1997. Visitors as an environmental enrichment. In: Proceedings on the International Conference on Environmental Enrichment. Holst, B. (ed), 325-33. Copenhagen Zoo, Frederiksberg, DK.

Because of the influence in behaviour, we can say that visitors are a kind of environmental enrichment. .... Sometimes visitors have a negative effect (increase of aggressive behaviour, begging for food) and in some cases...

Dahlborn, K., van Gils, B. A. A., van de Weerd, H. A. et al. 1996. Evaluation of long-term environmental enrichment in the mouse. Scandinavian Journal of Laboratory Animal Science 23(Supplement 1), 97-106. (Conference Paper)

It appears that mice who were enriched with both objects [nest box and plastic tube] and nesting material were more active, and spent less time on feeding and drinking, and they weight less compared to...

Burghardt, G. M., Ward, B., Rosscoe, R. 1996. Problem of reptile play: Environmental enrichment and play behavior in a captive Nile soft‐shelled turtle, Trionyx triunguis. Zoo Biology 15(3), 223-238.

Giving captive animals the opportunity to interact with objects in a “playful” manner is often considered a method of environmental enrichment. However, the occurrence of play in nonavian reptiles is controversial and poorly documented. Similarly...

Sherwin, C. M. 1995. Environmental enrichment for laying hens - Spherical objects in the feed trough. Animal Welfare 4, 41-51.

Brightly coloured spherical objects [balls 4-9 cm in diameter] placed in the feed trough are considered to be a promising method of successful environmental enrichment [simulating ground-litter] for caged laying hens. There was no indication...

Chamove, A. S. 1989. Environmental enrichment: A review. Animal Technology 40(3), 155-178.

The aims of this contribution are to look at three areas which are addressed by enrichment studies, within the context of a review: (1) the problems produced by spatial restriction, (2) the goals of enrichment...

Beaver, B. V. 1989. Environmental enrichment for laboratory animals. ILAR Journal 31(2), 5-13.

A review of enrichment studies.

Boyd, J. 1988. Mice. Humane Innovations and Alternatives in Animal Experimentation 2, 49-50.

Description of an ingenious, simple method to minimize odor, provide species-appropriate nesting opportunities and to facilitate cleaning.

Jones, R. B., Harvey, S., Hughes, B. O. et al. 1980. Growth and the plasma concentrations of growth hormone and prolactin in chicks: Effects of 'environmental enrichment', sex and strain. British Poultry Science 21(6), 457-462.

The enriched boxes were similar to the bare ones but also contained the following objects: two large red rubbing bungs, a golf ball, a bottle top, two coloured table tennis balls hanging from the cage...

Gutwein, B. M., Fishbein, W. 1980. Paradoxical sleep and memory (I): Selective alterations following enriched and impoverished environmental rearing. Brain Research Bulletin 5(1), 9-12.

Mice were reared in either enriched (EE), social control, (SE), or impoverished (IE) environments for 30 days. Environmental enrichment results in a significant and selective increase in paradoxical sleep (PS, or REM sleep) and also...