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. 
Bulens, A., Biesemans, C., Van Beirendonck, S. et al. 2016. The effect of a straw dispenser on behavior and lesions in weanling pigs. Journal of Veterinary Behavior 12, 49-53.

Slatted floors and liquid manure–handling systems in intensive housing systems preclude the use of large straw quantities as enrichment material for pigs. Consequently, there is a need for alternative enrichment strategies, for example, by using...

Jensen, M. B., Herskin, M. S., Forkman, B. et al. 2015. Effect of increasing amounts of straw on pigs' explorative behaviour. Applied Animal Behaviour Science 171, 58-63.

According to European legislation, pigs must have permanent access to sufficient quantity of material to enable manipulation activities. However, few studies have quantified how much straw is needed to fulfil the requirements of growing pigs...

Westin, R., Hultgren, J., Algers, B. 2015. Strategic use of straw increases nest building in loose housed farrowing sows. Applied Animal Behaviour Science 166, 63-70.

In spite of domestication, sows are still genetically programmed to perform nesting behaviour close to farrowing. In order to facilitate nest building, a method for a strategic use of large quantities of straw has been...

Martin, J. E., Ison, S. H., Baxter, E. M. 2015. The influence of neonatal environment on piglet play behaviour and post-weaning social and cognitive development. Applied Animal Behaviour Science 163, 69-79.

Research has shown that the domestic pig is highly playful throughout its development and that play is an important aspect of social and cognitive development. Therefore, the neonatal environment is fundamental to successful stimulation of...

Cornale, P., Macchi, E., Miretti, S. et al. 2015. Effects of stocking density and environmental enrichment on behavior and fecal corticosteroid levels of pigs under commercial farm conditions. Journal of Veterinary Behavior 10(6), 569-576.

In intensive pig farming of Western and Southern Europe, welfare concerns are still often related to barren environments and crowded conditions. Pig producers need to balance the requirements to improve welfare conditions at farm with...

Verdon, M., Hansen, C. F., Rault, J. L. et al. 2015. Effects of group housing on sow welfare: a review. Journal of Animal Science 93(5), 1999-2017.

Factors that have been shown to impact the welfare of group-housed sows are discussed in this review. Floor space allowance markedly affects sow welfare. In addition to quantity of floor space, the quality of space...

Bayne, K. A., Beaver, B. V., Mench, J. A. et al. 2015. Laboratory animal behavior. In: Laboratory Animal Medicine, 3rd edition. Fox, J. G., Anderson, L., Otto, G., et al. (eds). Elsevier, Inc., Amsterdam, NL. pp. 1617-1651.

The study of laboratory animal behavior has increased steadily over the last decade, with expanding emphasis on a variety of commonly used species. In the United States, this trend was initially focused on species for...

Ferreira Vasconcelos, E. K., da Silva Borges, L., Lopes da Silva, Â. et al. 2015. Behavior of pigs in the growth phase raised in an enriched environment. Journal of Animal Behaviour and Biometeorology 3(4), 120-123.

In this study we aimed to evaluate the behavior of pigs raised in an enriched environment. 12 male piglets, hybrids between 35 and 105 days of age were used. We assessed the behavioral variables: sleeping...

Washburn, D. 2015. The four Cs of psychological wellbeing: Lessons from three decades of computer-based environmental enrichment. Animal Behavior and Cognition 2(3), 218–232.

Three decades ago, the Animal Welfare Act was amended to require researchers to provide environments that promoted the psychological, as well as the physical, wellbeing of nonhuman primates maintained for research purposes. We developed a...

Perret, A., Henry, L., Coulon, M. et al. 2015. Social visual contact, a primary “drive” for social animals? Animal Cognition 18(3), 657–666.

Social animals are always searching for conspecifics, thereby expressing a genuine “social need”. This need is illustrated by the fact that social isolation can induce isolation syndromes that can be attenuated by devices such as...

Pedersen, L. J., Herskin, M.S., Forkman, B. et al. 2014. How much is enough? The amount of straw necessary to satisfy pigs' need to perform exploratory behaviour. Applied Animal Behaviour Science 160, 46-55.

Since 10 years, EU-legislation states that "pigs must have permanent access to sufficient quantity of material to enable proper investigation and manipulation activities." While much research has focused on which materials enable proper investigation and...

Monts de Oca, N., Diaz, L., McMahen, D. et al. 2014. The use of lean management principles to enhance a nonhuman primate environmental enrichment program. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 580-581. (Abstract #P122).

Sewage back-up and overflows in the rooms of our primate facility initiated an analysis of the factors contributing to the clogging of the drains. An investigation reviewing the materials responsible for the clogging of the...

Rose, A. M., Ferrecchia, C. E., Van Andel, R. 2014. Developing an enrichment plan for water-regulated nonhuman primates. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 565 (Abstract #P60).

Environmental enrichment for nonhuman primates is an essential requirement in laboratory animal research. The Animal Welfare Regulations and the Guide for the Care and Use of Laboratory Animals state that the facility’s enrichment program must...

Willey, S. 2014. Nonhuman primate enrichment room planning, design, and use. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 539 (Abstract #PS52).

Princeton University continually makes efforts to improve and enhance the quality of life of our NHPs used in research. A part of this effort is to continue to improve our environmental enrichment program, promoting the...

Qi, K., De-mi, S., Chuan, Q. 2014. Current understanding and use of environmental enrichment in China. Enrichment Record 20, 8-11.

In practice, consideration is given to providing most of the species used in research,testing and education withsome level of environmental enrichment. However, although the current level of awareness and understanding about the benefits of environmental...

Telkanranta, H., Bracke, M. B. M., Valros, A. 2014. Fresh wood reduces tail and ear biting and increases exploratory behaviour in finishing pigs. Applied Animal Behaviour Science 161, 51-59.

Chewing and rooting are high behavioural priorities in pigs. Lack of suitable materials can lead to abnormal behaviours such as tail and ear biting. In commercial farming, slatted floors limit the use of straw, and...

Croney, C. 2014. Let's stay together: Implications of social housing for laboratory pig welfare and management. Enrichment Record 19, 14-19.

Appropriately accommodating the pig's normal social behavior is an essential step in protecting its well-being in managed environments. Doing so is particularly important in laboratory settings in which distress due to social isolation and other...

Callan, T. 2014. Primates Presents. Enrichment Record 18, 5-6.

In the world of enrichment, ideas can be limitless. Sometimes, you just have to think outside the box... or in this case, "inside the box"! Who doesn't love a present with the colorful exterior and...

Alworth, L. C., Buerkle, S. C. 2013. The effects of music on animal physiology, behavior and welfare. Lab Animal 42(2), 54-61.

Physiological and psychological effects of listening to music have been documented in humans. The changes in physiology, cognition and brain chemistry and morphology induced by music have been studied in animal models, providing evidence that...

Reinhardt, V. (ed.) 2013. Compassion Makes a Difference - Discussions by the Laboratory Animal Refinement & Enrichment Forum [LAREF], Volume III. Animal Welfare Institute, Washington, DC.

This is the third volume of discussions that took place on the Laboratory Animal Refinement & Enrichment Forum (LAREF). This forum is dedicated to the exchange of personal experiences of refining the conditions under which...

Pierre, P. J., Torres, N. A., Rosga, M. D. et al. 2013. Colony-wide assessment of the foraging devices: Refinement of delivery practices, cost and the caloric content delivered via foraging devices. American Journal of Primatology 75(S1), 82. (36th Meeting of the American Society of Primatologists Scientific Program, Abstract #163)

Foraging opportunities are a key component of enrichment in captive nonhuman primates (NHP) providing manipulative opportunities in which animals can engage in species-typical behaviors. Recent studies suggest captive NHP populations have increased body weight over...

DeBoer, S. P., Garner, J. P., Lay Jr, D. C. et al. 2013. Does the presence of a human affect the preference of enrichment items in young, isolated pigs? Applied Animal Behaviour Science 143(2-4), 96-103.

Pigs may be housed individually in both production and research settings. Gregarious by nature, pigs kept in isolation may show behavioural and physiological signs of stress. In this study we investigated the preference of individually...

Hrapkiewicz, K., Colby, L. A., Denison, P. 2013. Clinical Laboratory Animal Medicine: An Introduction (4th Ed). Wiley-Blackwell, Ames, IA.

Clinical Laboratory Animal Medicine: An Introduction, Fourth Edition offers a user-friendly guide to the unique anatomy and physiology, care, common diseases, and treatment of small mammals and nonhuman primates. Carefully designed for ease of use...

Hoffman, H. 2013. Ice cube treats for swine. Enrichment Record 16, 23-24.

The frozen Veggie Bite ice cube treat is hung inside the swine chain-link type enclosure with a Carabineer hook. ... Because swine avoid objects that are contaminated with feces, suspending this enrichment treat encourages more...

Gehlot, P. 2013. Enrichment of Göttingen Minipigs: Models of human hepatocellular carcinoma. Newsletter Ellegaard 40, 4-5.

Social or pair-housing is our main form of swine enrichment. The minipigs are group-housed in stalls that have sliding divider doors/panel which allow separation of animals for feeding and study procedures, as needed. Ideally, enrichment...