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. 
Córneo, E., Michels, M., Abatti, M. et al. 2022. Enriched environment causes epigenetic changes in hippocampus and improves long-term cognitive function in sepsis. Scientific Reports 12(1), 11529.

Sepsis is defined as a life-threatening organ dysfunction caused by an inappropriate host response to infection. The presence of oxidative stress and inflammatory mediators in sepsis leads to dysregulated gene expression, leading to a hyperinflammatory...

Parois, S. P., Van Der Zande, L. E., Knol, E. F. et al. 2022. A multi-suckling system combined with an enriched housing environment during the growing period promotes resilience to various challenges in pigs. Scientific Reports 12(1), 6804.

Little is known about the impact of social and environmental enrichment on improving livestock resilience, i.e. the ability to quickly recover from perturbations. We evaluated the effect of an alternative housing system (AHS) on resilience...

Archer, C., Garcia, A., Henderson, M. et al. 2022. Olfactory enrichment using a maternal pheromone improved post-weaning pig performance and behavior. Frontiers in Veterinary Science 9, 965370.

The post-weaning environment in commercial pig nursery buildings is typically devoid of both the sow and her semiochemicals. Among other factors, the loss of maternal odors may contribute to post-weaning stress. In this work, we...

Chrzanowska, A., Modlinska, K., Goncikowska, K. et al. 2022. Rat’s response to a novelty and increased complexity of the environment resulting from the introduction of movable vs. stationary objects in the free exploration test. PLOS ONE 17(12), e0279006.

Most animals, including rats, show a preference for more complex environments. This is demonstrated particularly well when complexity increases due to the addition of new elements to the environment. The aim of the study was...

Mieske, P., Hobbiesiefken, U., Fischer-Tenhagen, C. et al. 2022. Bored at home?—A systematic review on the effect of environmental enrichment on the welfare of laboratory rats and mice. Frontiers in Veterinary Science 9, 899219.

Boredom is an emotional state that occurs when an individual has nothing to do, is not interested in the surrounding, and feels dreary and in a monotony. While this condition is usually defined for humans...

Parois, S. P., Van Der Zande, L. E., Knol, E. F. et al. 2022. A multi-suckling system combined with an enriched housing environment during the growing period promotes resilience to various challenges in pigs. Scientific Reports 12(1), 6804.

Little is known about the impact of social and environmental enrichment on improving livestock resilience, i.e. the ability to quickly recover from perturbations. We evaluated the effect of an alternative housing system (AHS) on resilience...

Weir, R. 2022. The effects of various enrichment methods on the engagement nd inter-group behaviour of captive chacma baboons. Canopy 23(1), 4–6.

The goal of this study was to answer two research questions: (1) how important is it to rotate enrichment types to maintain high levels of engagement in individually-housed adult chacma baboons? and (2) which methods...

Cait, J., Cait, A., Scott, R. W. et al. 2022. Conventional laboratory housing increases morbidity and mortality in research rodents: Results of a meta-analysis. BMC Biology 20(1), 15.

Over 120 million mice and rats are used annually in research, conventionally housed in shoebox-sized cages that restrict natural behaviours (e.g. nesting and burrowing). This can reduce physical fitness, impair thermoregulation and reduce welfare (e.g...

Molina, S. J., Lietti, Á. E., Carreira Caro, C. S. et al. 2022. Effects of early noise exposure on hippocampal-dependent behaviors during adolescence in male rats: Influence of different housing conditions. Animal Cognition 25(1), 103–120.

Central nervous system (CNS) development is a very complex process that can be altered by environmental stimuli such as noise, which can generate long-term auditory and/or extra-auditory impairments. We have previously reported that early noise...

Whitbread, S. 2022. Some observations on the use of transparent barriers. RATEL (Journal of the Association of British and Irish Wild Animal Keepers) 49(3), 9-13.

What follows are some case studies in which solid but transparent barriers have been used successfully to provide a sense of security to three different mammal taxa (three-banded armadillo; Kirk’s dikdik; black rat) to reduce...

Costa, R., Carvalho, M. S. M., Brandão, J. D. P. et al. 2021. Modulatory action of environmental enrichment on hormonal and behavioral responses induced by chronic stress in rats: Hypothalamic renin-angiotensin system components. Behavioural Brain Research 397, 112928.

Environmental enrichment (EE) has been studied as a protocol that can improve brain plasticity and may protect against negative insults such as chronic stress. The aim of this study was to evaluate the effects of...

Wallgren, T., Gunnarsson, S. 2021. Effect of straw provision in racks on tail lesions, straw availability, and pen hygiene in finishing pigs. Animals 11(2), 379.

Unfulfilled exploratory behavior in pigs has been linked to tail biting, which causes reduced performance and welfare. Provision of straw can reduce tail biting, but large straw rations can cause poor hygiene in pens. This...

Pol, F., Huneau-Salaün, A., Gallien, S. et al. 2021. Compressed brown algae as a potential environmental enrichment material in growing pigs. Animals 11(2), 315.

In barren housing conditions, enrichment materials are given to pigs to improve their welfare. Here, we assessed the suitability of an algae-based cylinder as an enrichment material on the behavioral, physiological, health and productivity welfare...

Lambert, K. 2021. DIY: Ice cream cone spiced foraging cups. Laboratory Animal Science Professional 9(1) (January/February), 36.

This DIY snack is great for NHPs and can be customized in a variety of ways.

Lambert, K. 2021. DIY: Ice produce blocks. Laboratory Animal Science Professional 9(2) (March/April), 41.

This great cool-down snack is ideal for group or singly housed swine or nonhuman primates (particularly in larger pen-style housing). This item can be customized for canines as well by modifying the liquid used and/or...

Monnas, J. 2021. DIY: Creating a rat play cage. Laboratory Animal Science Professional 9(2) (March/April), 46-48.

To provide extra enrichment for our training rats (Sprague Dawley; CRL: SD), our team discussed the idea of developing a rat play cage. Animals are housed in the Comparative Bioscience Center at The Rockefeller University...

Williams, W. R. 2021. Edible nail polish as a novel enrichment strategy for single-housed nonhuman primates. Laboratory Animal Science Professional 9(2) (March/April), 50-51.

At the University of Oklahoma Health Sciences Center, NHPs may need to be singly housed for research purposes or veterinary care, and it can be challenging to keep them optimally enriched. This sometimes results in...

Guisnet, A., Maitra, M., Pradhan, S. et al. 2021. A three-dimensional habitat for C. elegans environmental enrichment. PLOS ONE 16(1), e0245139.

As we learn more about the importance of gene-environment interactions and the effects of environmental enrichment, it becomes evident that minimalistic laboratory conditions can affect gene expression patterns and behaviors of model organisms. In the...

Li, J.-Y., Kuo, T. B. J., Hung, C.-T. et al. 2021. Voluntary exercise enhances hippocampal theta rhythm and cognition in the rat. Behavioural Brain Research 399, 112916.

Regular exercise promotes learning and memory functions. Theta activity is known to relate to various cognitive functions. An increase in theta power may be related to higher cognitive functioning and learning functions. However, evidence is...

Swan, K.-M., Telkänranta, H., Munsterhjelm, C. et al. 2021. Access to chewable materials during lactation affects sow behaviour and interaction with piglets. Applied Animal Behaviour Science 234, 105174.

We investigated how providing chewable materials to piglets during the early weeks of life affect sow behaviour, sow and piglet interaction and sow health in pens with farrowing crates. We divided 59 pregnant sows into...

Aparecida Martins, R., Ribeiro Caldara, F., Crone, C. et al. 2021. Strategic use of straw as environmental enrichment for prepartum sows in farrowing crates. Applied Animal Behaviour Science 234, 105194.

Sows are highly motivated to build a nest prior to farrowing, but, given the barren environment of farrowing crates, this behaviour is limited and improperly expressed. We aimed to assess the effects of a straw...

Kauselmann, K., Krause, E. T., Glitz, B. et al. 2021. Effect of plant-based enrichment materials on exploration in rearing and fattening pigs (Sus scrofa domesticus). Applied Animal Behaviour Science 236, 105261.

When pigs cannot perform innate species-specific behaviours (e.g. rooting or chewing), behavioural disorders, like tail biting, can occur. However, it seems that various enrichment materials enhance the pigs to perform exploration behaviour and therefore can...

Fischer, M. L., Rodrigues, G. S., Aguero, W. P. et al. 2021. Refinement as ethics principle in animal research: Is it necessary to standardize the environmental enrichment in laboratory animals? Anais da Academia Brasileira de Ciências, 93(1), e20191526.

The Environmental enrichment technique, although scientifically recognized for raising the level of animal welfare, has led to the questioning of its influence on the results of experimental research. Thus, the goal is to promote reflection...

Sørensen, D., Cloutier, S., Gaskill, B. (Eds.). 2021. Animal-centric Care and Management - Enhancing Refinement in Biomedical Research. CRC Press, Boca Raton, FL.

The concept of the 3Rs (Refinement, Reduction and Replacement) has been used as a framework for improving the welfare of laboratory animals for the last half century. By establishing an animal-centric view on housing and...

Stevens, C., Hawkins, P., Smulders, T. V. et al. 2021. Report of the 2020 RSPCA/UFAW rodent and rabbit welfare meeting. Animal Technology and Welfare 20(1), 21-33.

The RSPCA/UFAW rodent and rabbit welfare group has held a one-day meeting every autumn for the last 27 years, so that its members can discuss current welfare research, exchange views on welfare issues and share...