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. 
Horback, K. M., Pierdon, M. K., Parsons, T. D. 2016. Behavioral preference for different enrichment objects in a commercial sow herd. Applied Animal Behaviour Science 184, 7-15.

Increased public concern about farm animal welfare is driving both legislative initiatives and market forces to change how sows are housed and managed. This study investigated the use and preference for enrichment items at a...

Nannoni, E., Sardi, L., Vitali, M. et al. 2016. Effects of different enrichment devices on some welfare indicators of post-weaned undocked piglets. Applied Animal Behaviour Science 184, 25-34.

Two experimental trials were carried out in order to test the effectiveness of different environmental enrichments in improving the welfare of weaned pigs. A total of 120 undocked piglets was used. In trial one, group...

Wallgren, T., Westing, R., Gunnarsson, S. 2016. A survey of straw use and tail biting in Swedish pig farms rearing undocked pigs. Acta Veterinaria Scandinavica 58(1), 84.

Tail biting is a common problem in intensive pig farming, affecting both welfare and production. Although routine tail docking is banned within the EU, it remains a common practice to prevent tail biting. Straw as...

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...

Crofton, E. J., Zhang, Y., Green, T. A. 2015. Inoculation stress hypothesis of environmental enrichment. Neuroscience and Biobehavioral Reviews 49, 19-31.

One hallmark of psychiatric conditions is the vast continuum of individual differences in susceptibility vs. resilience resulting from the interaction of genetic and environmental factors. The environmental enrichment paradigm is an animal model that is...

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...

Alligood, C., Leighty, K. 2015. Putting the “E” in SPIDER: Evolving trends in the evaluation of environmental enrichment efficacy in zoological settings. Animal Behavior and Cognition 2(3), 200–217.

In their seminal paper on environmental enrichment, Mellen and MacPhee (2001) proposed a set of broad goals for enrichment in zoological settings, as well as a framework for enrichment programs. Since that time, the philosophy...

Blois-Heulin, C., Rochais, C., Camus, S. et al. 2015. Animal welfare: Could adult play be a false friend? Animal Behavior and Cognition 2(2), 156–185.

There is no consensus regarding the functions of play. As play behavior is a characteristic of young stages of development, it has been suggested that the higher prevalence of adult play observed in domestic animals...

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...

Hedrick, C., Rowley, M., Lewis, S. 2014. Repurposing and recycling an institutionally retired enrichment device. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 564 (Abstract #P56).

One aspect of maintaining and updating an environmental enrichment program is regular review of enrichment devices and their current uses. The review includes maintaining an accurate inventory to reflect the animal census, evaluating species-specific use...

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...

Schimmel, A., Hlavka, R. 2014. Enhancing environmental enrichment without breaking the bank. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 562-563 (Abstract #P51).

Although our enrichment program meets all USDA, AAALAC, and IACUC standards, we wanted to do more for the animals. Due to a limited budget, we were faced with the challenge of enhancing our program without...

Schaller, T. L. 2014. A committee approach to environmental enrichment. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 534 (Abstract #PS35).

The Department of Comparative Medicine has established an enrichment program committee to provide assessment of animal enrichment. To improve the quality of this committee the members have developed and implemented an effective strategy using good...

Andersen, I. L., Vasdal, G., Pedersen, L. J. 2014. Nest building and posture changes and activity budgets of gilts housed in pens and crates. Applied Animal Behaviour Science 159, 29-33.

The aim of the present work was to study nest building, posture changes and the overall activity budget of gilts in pens vs. crates. Twenty-three HB gilts (high piglet survival day 5) and 21 LB...

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...

Hawkins, P. 2014. Results of the GR8/RSPC - A global survey on effects of enrichment on data quality. Enrichment Record 19, 5-13.

I believe that in the future, failure to provide adequate enrichment and species appropriate housing for our research subjects will be viewed upon in the same way that the absence of a suitable program of...