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. 
Ausderau, K. K., Colman, R. J., Kabakov, S. et al. 2023. Evaluating depression- and anxiety-like behaviors in non-human primates. Frontiers in Behavioral Neuroscience 16, 1006065.

Depression and anxiety are some of the most prevalent and debilitating mental health conditions in humans. They can present on their own or as co-morbidities with other disorders. Like humans, non-human primates (NHPs) can develop...

Baskir, E., Parsons, A., Elden, M. et al. 2023. Quantifying acute behavioral reactions of Bali mynas (Leucopsar rothschildi) to environmental and progressively challenging enrichment. Journal of Zoological and Botanical Gardens 4(1), 176–190.

Animals use specific behaviors and skills to overcome challenges and access resources. Environmental enrichment is provided to animals in human care to both promote species-appropriate behaviors and reduce undesired behaviors. Feather pecking in birds is...

van Zeeland, Y. R. A., Schoemaker, N. J., Lumeij, J. T. 2023. Contrafreeloading indicating the behavioural need to forage in healthy and feather damaging Grey parrots. Animals 13(16), 2635.

Contrafreeloading (CFL) is a concept that describes the preference of an animal to work for food even when identical food is freely available, and reflects an intrinsic motivation to engage in foraging-related activities. However, altered...

Lutz, C. K., Coleman, K., Hopper, L.M. et al. 2022. Nonhuman primate abnormal behavior: Etiology, assessment, and treatment. American Journal of Primatology 84(6), e23380.

Across captive settings, nonhuman primates may develop an array of abnormal behaviors including stereotypic and self-injurious behavior. Abnormal behavior can indicate a state of poor welfare, since it is often associated with a suboptimal environment...

Franklin, A. N., Martin, A. L., Perlman, Siti Norsyuhada Kamaluddin et al. 2022. Functional analysis and successful treatment of a captive rhesus macaque’s disruptive behavior. Journal of Applied Animal Welfare Science 25(3), 287-296.

Functional analysis (FA) is a method developed and used by behavior analysts in human clinical settings to identify possible environmental variables that reinforce undesired behavior. FA is increasingly being applied to better understand the behavior...

Laméris, D. W., Verspeek, J., Salas, M. et al. 2022. Evaluating self-directed behaviours and their association with emotional arousal across two cognitive tasks in bonobos (Pan paniscus). Animals 12(21), 3002.

Self-directed behaviours (SDBs) are widely used as markers of emotional arousal in primates, and are commonly linked to negative arousal, or are used as indicators of stress or poor welfare. However, recent studies suggest that...

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...

Schwarzer, A., Rauch, E., Bergmann, S. et al. 2022. Risk factors for the occurrence of feather pecking in non-beak-trimmed pullets and laying hens on commercial farms. Applied Sciences 12(19), 9699.

Severe feather pecking (SFP) is a behavioral disorder, for which there are multifactorial reasons. Various aspects of pullet and laying-hen husbandry—including housing conditions, management, feeding, and genetics—must be considered, to prevent negative outcomes, such as...

Petek, M.,Çavuşoğlu, E. 2021. Welfare assessment of two free-range laying hen flocks in Turkey. Journal of Applied Animal Welfare Science 24(1), 56-63.

This study aimed to determine the prevalence of keel bone deviations and feather damage of laying hens in two different free-range housing systems under commercial conditions. Both of the free-range systems had an indoor barn...

Laméris, D. W., Staes, N., Salas, M. et al. 2021. The influence of sex, rearing history, and personality on abnormal behaviour in zoo-housed bonobos (Pan paniscus). Applied Animal Behaviour Science 234, 105178.

Abnormal behaviours are often used as a welfare indicator in zoo-housed great apes. While previous studies report on the occurrence of abnormal behaviours in zoo-housed chimpanzees (Pan troglodytes), there is currently a lack of knowledge...

Novak, M. A. 2021. Self-injurious behavior in rhesus macaques: Issues and challenges. American Journal of Primatology 83(6), e23222.

Some monkeys housed in research facilities develop abnormal behavior ranging from stereotypic to the more serious condition of self-injurious behavior (SIB). We initially sought to understand how and why monkeys engaged in SIB and more...

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...

Polanco, A., McCowan, B., Niel, L. et al. 2021. Recommendations for abnormal behaviour ethograms in monkey research. Animals 11(5), 1461.

Laboratory monkey ethograms currently include subcategories of abnormal behaviours that are based on superficial morphological similarity. Yet, such ethograms may be misclassifying behaviour, with potential welfare implications as different abnormal behaviours are likely to have...

Wilson-Welder, J. H., Frank, A. T. 2021. Use of food enrichment for medication delivery in large groups of sheep. Laboratory Animal Science Professional 9(3) (May/June), 40-43.

In a 2018 AALAS webinar on Sheep and Goat Analgesia, Dr. Susie Vogel, a small ruminant expert, introduced the concept of getting sheep and goats to willingly take medication by putting it in a tasty...

Schwarzer, A., Plattner, C., Bergmann, S. et al. 2021. Feather pecking in non-beak-trimmed and beak-trimmed laying hens on commercial farms with aviaries. Animals 11(11), 3085.

Severe feather pecking (SFP) is a major animal welfare problem in layers. It results in pain and injuries in the affected animal. It was the aim of this study to gain insight into the actual...

Mellor, E. L., McDonald Kinkaid, H. K., Mendl, M. T. et al. 2021. Nature calls: Intelligence and natural foraging style predict poor welfare in captive parrots. Proceedings of the Royal Society B: Biological Sciences 288(1960), 20211952

Understanding why some species thrive in captivity, while others struggle to adjust, can suggest new ways to improve animal care. Approximately half of all Psittaciformes, a highly threatened order, live in zoos, breeding centres and...

Fangmeier, M. L., Burns, A. L., Melfi, V. A. et al. 2020. Foraging enrichment alleviates oral repetitive behaviors in captive red-tailed black cockatoos (Calyptorhynchus banksii). Zoo Biology 39(1), 3-12.

The relationship between inadequate foraging opportunities and the expression of oral repetitive behaviors has been well documented in many production animal species. However, this relationship has been less-well examined in zoo-housed animals, particularly avian species...

Fijn, L., van der Staay, F., Goerlich-Jansson, V. et al. 2020. Importance of basic research on the causes of feather pecking in relation to welfare. Animals 10(2), 213.

Feather pecking is a prominent issue in the commercial egg industry, associated with economic losses and welfare problems. A non-systematic literature search suggests that studies on feather pecking are predominantly concerned with applied research goals...

Guinebretière, M., Mika, A., Michel, V. et al. 2020. Effects of management strategies on non-beak-trimmed laying hens in furnished cages that were reared in a non-cage system. Animals 10(3), 399.

Beak trimming in laying hens limits the negative consequences of injurious pecking, but could be prohibited by future regulations. This study assessed a combination of management strategies during the rearing period (objects, perches, music, human...

Arrazola, A., Mosco, E., Widowski, T. M. et al. 2020. The effect of alternative feeding strategies during rearing on the behaviour of broiler breeder pullets. Applied Animal Behaviour Science 224, 104929.

Broiler breeders are feed-restricted during rearing to avoid the negative consequences of obesity during lay due to their genetic potential for fast growth rate. Feed restriction leads to chronic hunger, frustration and lack of satiety...

Reinhardt, V. (ed.) 2020. It’s Okay to Cry - Discussions by the Laboratory Animal Refinement & Enrichment Forum [LAREF], Volume V. Animal Welfare Institute, Washington, DC.

This is the 5th volume of selected discussions that took place on the electronic Laboratory Animal Refinement & Enrichment Forum between February 2016 and December 2019. The forum was created in October 2002; it allows...

Acharya, R., Rault, J.-L. 2020. Risk factors for feather-damaging behavior in companion parrots: A social media study. Journal of Veterinary Behavior 40, 43-49.

Studies on the etiology of behavioral problems often involve interference in the animal's routine or reliance on owners' self-reports like surveys. Gathering data from videos posted on social media, a technique coined ‘video mining’, offers...

Munari, C., Ponzio, P., Macchi, E. et al. 2020. A multifactorial evaluation of different reproductive rhythms and housing systems for improving welfare in rabbit does. Applied Animal Behaviour Science 230, 105047.

The most widespread reproductive rhythm practiced in rabbit farming is based on artificial insemination (AI) performed at around 11 days pospartum. This approach results in high production rates, but requires high yearly replacement of animals...

Jung, L., Brenninkmeyer, C., Niebuhr, K. et al. 2020. Husbandry conditions and welfare outcomes in organic egg production in eight European countries. Animals 10(11), 2102.

In the European research project HealthyHens, welfare indicators as well as husbandry and management conditions were recorded in 107 organic laying hen farms in eight countries. Farms were visited at peak and end of lay...

Schreiter, R., Damme, K., Freick, M. 2020. Edible environmental enrichments in littered housing systems: Do their effects on integument condition differ between commercial laying hen strains? Animals 10(12), 2434.

The aim of this study was to investigate the effect of additional enrichment materials (EMs; pecking stones and alfalfa bales) on the occurrence of plumage damage, skin injuries, and toe injuries, with an emphasis on...