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. 
Hinchcliffe, J. K., Jackson, M. G., Robinson, E. S. 2022. The use of ball pits and playpens in laboratory Lister Hooded male rats induces ultrasonic vocalisations indicating a more positive affective state and can reduce the welfare impacts of aversive procedures. Laboratory Animals 56(4), 370-379.

The advancement and quality of science rely on research that is robust and unbiased in its experimental design, execution, analysis, and reproducibility. In preclinical research, a better understanding of animal emotions and refinement of their...

Abazaris, J., Hashway, S. 2022. Vole husbandry at Colorado University Boulder. Laboratory Animal Science Professional 10(4) (July/August), 12-15.

Since they arrived at CU Boulder, we have learned a lot about the voles from the laboratory, other institutions, and our trial-and-error. We hope this information can be helpful to any considering adding voles to...

Pantophlet, J., McClusky, D. 2022. Compressed paper column housing enrichment for Naked Mole-rats. Laboratory Animal Science Professional 10(5) (September/October), 42-44.

Naked Mole-rats are relative newcomers in the research world. Due to the complexity of their natural subterranean tunneling system, it has been difficult to replicate in the laboratory environment. Housing standards often differ from the...

Ramírez-Rodríguez, G. B., Gutiérrez-Vera, B., Ortiz-López, L. et al. 2022. Environmental enrichment: Dissociated effects between physical activity and changing environmental complexity on anxiety and neurogenesis in adult male Balb/C mice. Physiology & Behavior 254, 113878.

Several factors, including environmental modifications, stimulate neuroplasticity. One type of neuroplasticity consists in the generation of new neurons in the dentate gyrus of the hippocampus. Neurogenesis is modulated by environmental enrichment (ENR, tunnels plus running...

Spitzer, H. B., Meagher, R. K., Proudfoot, K. L. 2022. The impact of providing hiding spaces to farmed animals: A scoping review. PLOS ONE 17(11), e0277665.

Many wild animals perform hiding behaviours for a variety of reasons, such as evading predators or other conspecifics. Unlike their wild counterparts, farmed animals often live in relatively barren environments without the opportunity to hide...

Kleiber, A., Le-Calvez, J. M., Kerneis, T. et al. 2022. Positive effects of bubbles as a feeding predictor on behaviour of farmed rainbow trout. Scientific Reports 12(1), 11368.

Occupational enrichment emerges as a promising strategy for improving the welfare of farmed animals. This form of enrichment aims to stimulate cognitive abilities of animals by providing them with more opportunities to interact with and...

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...

Saraiva, J. L., Rachinas-Lopes, P., Arechavala-Lopez, P. 2022. Finding the “golden stocking density”: A balance between fish welfare and farmers’ perspectives. Frontiers in Veterinary Science 9, 930221.

The effects of stocking density on fish welfare are complex and involve many interacting parameters. This complex relationship between fish welfare, stocking density and influencing factors make it challenging to define a specific optimal (“golden”)...

Wood, L. 2022. Managing long-term wellness in captive sea turtles. Animal Welfare 31(4), 423–432.

Circumstances surrounding advances in stranding response and veterinary care have created a growing need for the long-term housing of captive sea turtles. However, the difficulty in recreating natural conditions in captive settings places a responsibility...

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...

Anderson, M. G., Campbell, A. M., Kuhn, D. D. et al. 2022. Impact of environmental complexity and stocking density on affective states of rainbow trout (Oncorhynchus mykiss). Animal Cognition 25(5), 1331–1343.

Environmental condition, such as environmental complexity or stocking density, can directly or indirectly influence animal emotion and ultimately, affective state. Affective states of animals can be assessed through judgement bias tests, evaluating responses to ambiguous...

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...

Oatess, T. L., Harrison, F. E., Himmel, L. E. et al. 2021. Effects of acrylic tunnel enrichment on anxiety-like behavior, neurogenesis, and physiology of C57BL/6J mice. JAALAS 60(1), 44-53.

Environmental enrichment for mice lags behind the standard enrichment offered to other laboratory rodents due to concerns about environmental variability and, in specific contexts, aggression. Our objective in this study was to evaluate concerns that...

Schalbetter, S. M., Mueller, F. S., Scarborough, J. et al. 2021. Oral application of clozapine-N-oxide using the micropipette-guided drug administration (MDA) method in mouse DREADD systems. Lab Animal 50, 69-75.

The designer receptor exclusively activated by designer drugs (DREADD) system is one of the most widely used chemogenetic techniques to modulate the activity of cell populations in the brains of behaving animals. DREADDs are activated...

Teixeira-Santos, L., Albino-Teixeira, A., Pinho, D. 2021. An alternative method for oral drug administration by voluntary intake in male and female mice. Laboratory Animals 55(1), 76-80.

Drug administration to experimental rodents is often invasive and stressful, thus reducing animal welfare and potentially confounding experimental results. Methods of oral drug delivery in which rodents cooperate voluntarily minimize stress, pain and morbidity. We herein...

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...