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. 
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...

Padrell, M., Amici, F., Córdoba, M. P. et al. 2022. Cognitive enrichment in a social setting: Assessing the use of a novel food maze in sanctuary-housed chimpanzees. Primates 63(5), 509–524.

Foraging devices are effective enrichment tools for non-human primates, as they provide both cognitive and manipulative stimulation that may enhance these animals’ welfare. We assessed the behavioral effects of a novel tool-based enrichment on 14...

Butler, S. 2022. Gardening for Gorillas. Orla Kelly Publishing, Dublin, Ireland. 369 p.

During the author's 37 years as Curator of Horticulture, Dublin Zoo transformed from an almost Victorian appearance to a verdant green ark. A progressive masterplan focused on animal welfare and themed habitats reflects the spirit...

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...

Böswald, L. F., Matzek, D., Mohr, H. et al. 2022. Morphometrics of Xenopus laevis kept as laboratory animals. Animals 12(21), 2986.

Morphometric data that provide information on body conditions can be used to monitor the health and well-being of animals. In laboratory animals, they can help to evaluate the stress due to experiments or treatments, following...

Caselli, M., Messeri, P., Dessì-Fulgheri, F. et al. 2022. Enriching zoo-housed ring-tailed lemurs (Lemur catta): Assessing the influence of three types of environmental enrichment on behavior. Animals 12(20), 2836.

Environmental enrichment is a management tool used to promote positive animal welfare by stimulating species-specific behaviors and providing animals with opportunities to exert choice and control over the environment. Our study aimed to evaluate the...

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...

Dickson, E. J., Campbell, D. L. M., Lee, C. et al. 2022. Beef cattle preference and usage of environmental enrichments provided simultaneously in a pasture-based environment. Animals 12(24), 3544.

Environmental enrichment can improve livestock welfare through increasing environmental complexity to promote a greater range of natural behaviours. However, there is limited understanding of the need for and impacts of enrichments for extensively managed beef...

Edes, A. N., Zimmerman, D., Jourdan, B. et al. 2022. Value ranges and clinical comparisons of serum DHEA-S, IL-6, and TNF-α in western lowland gorillas. Animals 12(19), 2705.

Physiological data can provide valuable information about the health and welfare of animals. Unfortunately, few validated assays and a lack of information on species-typical levels of circulating biomarkers for wildlife make the measurement, interpretation, and...

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...

Reifenrath, J., Heider, M., Kempfert, M. et al. 2022. Buprenorphine in rats: Potent analgesic or trigger for fatal side effects? Acta Veterinaria Scandinavica 64(1), 37.

With ongoing animal welfare efforts, multimodal analgesia is often recommended to implement in study protocols. Buprenorphine with very potent analgesic effect is a standard opioid for the use in this context in rats. In this...

Schwarzer, A., Erhard, M., Schmidt, P. et al. 2022. Effects of stocking rate and environmental enrichment on the ontogeny of pecking behavior of laying hen pullets confined in aviary compartments during the first 4 weeks of life. Animals 12(19), 2639.

The objective of this study was to describe the ontogeny of the severe feather pecking (SFP), gentle feather pecking (GFP), aggressive pecking (AP), and enrichment pecking (EP) of non-beak-trimmed Lohmann Brown (LB)-pullets during the first...

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...

Xu, D., Shu, G., Liu, Y. et al. 2022. Farm animal enrichments improve the welfare of layer chicks and pullets: A comprehensive review. Animals 12(19), 2610.

Currently, cage housing is regarded as a global mainstream production system for laying hens. However, limited living space and confinement of birds in cages cause welfare and health problems, such as feather pecking, osteoporosis, obesity...

Yamanashi, Y., Hitoosa, K., Yoshida, N. et al. 2022. Do chimpanzees enjoy a virtual forest? A pilot investigation of the use of interactive art as a form of environmental enrichment for zoo-housed chimpanzees. American Journal of Primatology 84(10), e23343.

Environmental enrichment is essential for the well-being of zoo animals. Recent advances in sensor and video technologies may contribute to improvements in enrichment in terms of their flexibilities and time constraints. The purpose of this...

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...

Riedel, A., Rieke, L., Kemper, N. et al. 2022. A place to be? Use of winter gardens with and without automatic enrichment devices by laying hens. Applied Sciences 12(7), 3650.

Since the abolition of beak trimming in laying hens in Germany, the importance of adequate enrichment material to help reduce feather pecking and cannibalism has grown. Here we tested an automatic enrichment device dosing grain...

Kishida, T., Motokawa, Y., Yokoi, R. et al. 2022. Less invasive, simultaneous, and continuous measurements of locomotor activity and body temperature using the nano tag® small accelerometer device in cynomolgus monkeys. Journal of Pharmacological and Toxicological Methods 118, 107224.

Locomotor activity and body temperature evaluations of cynomolgus monkeys are useful to understand the effects of drugs on the central nervous system. Here, we describe a simple, inexpensive, and less invasive evaluation method using the...

Takeshita, R. S. C. 2022. Validation of an enzyme immunoassay for measurement of fecal dehydroepiandrosterone sulfate in gibbons and siamangs. Zoo Biology 41(6), 544–553.

Monitoring wildlife stress levels is essential to ensure their quality of life in captivity or in the wild. One promising method to assess the stress response is the comeasurement of glucocorticoids (GC) and dehydroepiandrosterone sulfate...

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...

Idris, M., Uddin, J., Sullivan, M. et al. 2021. Non-invasive physiological indicators of heat stress in cattle. Animals 11(1), 71.

Cattle are susceptible to heat stress, especially those kept on high levels of nutrition for the purpose of maximising growth rates, which leads to a significant heat increment in their bodies. Consequences include compromised health...

Kim, S., Hidaka, Y. 2021. Breathing pattern analysis in cattle using infrared thermography and computer vision. Animals 11(1), 207.

Breathing patterns can be considered a vital sign providing health information. Infrared thermography is used to evaluate breathing patterns because it is non-invasive. Our study used not only sequence temperature data but also RGB images...

Hirskyj-Douglas, I., Kankaanpää, V. 2021. Exploring how white-faced sakis control digital visual enrichment systems. Animals 11(2), 557.

Computer-enabled screen systems containing visual elements have long been employed with captive primates for assessing preference, reactions and for husbandry reasons. These screen systems typically play visual enrichment to primates without them choosing to trigger...