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. 
Reese, L., Ladwig-Wiegard, M., von Fersen, L. et al. 2020. Deflighting zoo birds and its welfare considerations. Animal Welfare 29(1), 69-80.

For over a century, the practice of deflighting has taken place in zoological collections in order to ensure birds remain in open-topped enclosures. Over time, efforts have been made to improve or develop new (surgical)...

Armstrong, E. A., Rufener, C., Toscano, M. J. et al. 2020. Keel bone fractures induce a depressive-like state in laying hens. Scientific Reports 10(1), 3007.

In commercial flocks of laying hens, keel bone fractures (KBFs) are prevalent and associated with behavioural indicators of pain. However, whether their impact is severe enough to induce a depressive-like state of chronic stress is...

Rogers, L., Sales, E., Shamsi, S. et al. 2020. Aggressive encounters lead to negative affective state in fish. PLOS ONE 15(4), e0231330.

Animals show various behavioural, neural and physiological changes in response to losing aggressive encounters. Here, we investigated affective state, which are emotion-like processes influenced by positive or negative experiences, in a territorial fish following aggressive...

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...

Thoré, E. S. J., Brendonck, L., Pinceel, T. 2020. Conspecific density and environmental complexity impact behaviour of turquoise killifish (Nothobranchius furzeri). Fish Biology 97(5), 1448–1461.

Fish models are essential for research in many biological and medical disciplines. With a typical lifespan of only 6 months, the turquoise killifish (Nothobranchius furzeri) was recently established as a time- and cost-efficient model to...

McMahon, S. A., Wigham, E. 2020. ‘All Ears’: A questionnaire of 1516 owner perceptions of the mental abilities of pet rabbits, subsequent resource provision, and the effect on welfare. Animals 10(10), 1730.

Pet rabbit welfare is a hidden crisis: Inappropriately housed, fed, and not routinely provided healthcare—rabbits can often suffer painful conditions and shortened lifespans. This study provides novel understanding of owners’ perceptions of rabbits’ mental capabilities...

Nawroth, C., Gygax, L. 2020. The legislative, ethical, and conceptual importance of replicability in farm animal welfare science. agriRxiv 2020, 20203211980.

In this commentary, we discuss three replicability issues that are specifically relevant to research regarding farm animal welfare: (1) Legislative action, and its potential economic consequences, should derive from robust and replicable research to benefit...

Pedersen, I. J., Forkman, B. 2019. Improving leg health in broiler chickens: A systematic review of the effect of environmental enrichment. Animal Welfare 28(2), 215-230.

Leg problems are highly prevalent in modern broiler production and provision of environmental enrichment could be a strategy to improve leg health. Different types of environmental enrichment have undergone evaluation. Our objective was to conduct...

Fife-Cook, I., Franks, B. 2019. Positive welfare for fishes: Rationale and areas for future study. Fishes 4(2), 31.

Traditional animal welfare paradigms have focused on maintaining physical health and mitigating negative impacts to wellbeing. Recently, however, the field has increasingly recognized the importance of positive welfare (i.e., mental and physical states that exceed...

Baker, S. W., Tucci, E. R., Felt, S. A. et al. 2019. A bird's-eye view of regulatory, animal care, and training considerations regarding avian flight research. Comparative Medicine 69(3), 169–178.

A thorough understanding of how animals fly is a central goal of many scientific disciplines. Birds are a commonly used model organism for flight research. The success of this model requires studying healthy and naturally...

Zaytseva, A. S., Volodin, I. A., Ilchenko, O. G. et al. 2019. Ultrasonic vocalization of pup and adult fat-tailed gerbils (Pachyuromys duprasi). PLOS ONE 14(7), e0219749.

Ultrasonic vocalizations (USVs) of laboratory rodents indicate animal emotional arousal and may serve as models of human disorders. We analysed spectrographically USV calls of pup and adult fat-tailed gerbils Pachyuromys duprasi during 420-s tests, including...

Ross, M., Garland, A., Harlander-Matauschek, A. et al. 2019. Welfare-improving enrichments greatly reduce hens' startle responses, despite little change in judgment bias. Scientific Reports 9, 11881.

Responses to ambiguous and aversive stimuli (e.g. via tests of judgment bias and measures of startle amplitude) can indicate mammals’ affective states. We hypothesised that such findings generalize to birds, and that these two responses...

Jung, L., Knierim, U. 2019. Differences between feather pecking and non-feather pecking laying hen flocks regarding their compliance with recommendations for the prevention of feather pecking – A matched concurrent case-control design. Applied Animal Behaviour Science 219, 104839.

Feather pecking (FP) is a multifactorial problem in all housing systems. Using a case-control design we wanted to determine a set of variables which may be decisive for a flock to become case or control...

Sanchez-Casanova, R., Sarmiento-Franco, L., Segura-Correa, J. et al. 2019. Effects of outdoor access and indoor stocking density on behaviour and stress in broilers in the subhumid tropics. Animals 9(12), 1016.

Studies investigating the welfare of commercial-line broiler chickens raised in houses with outdoor access in the tropics are scarce, and none have investigated whether responses vary according to indoor conditions. Hence, we assessed the effects...

Colby, L. A., Nowland, M. H., Kennedy, L. H. 2019. Clinical Laboratory Animal Medicine: An Introduction (5th ed). Wiley-Blackwell, Ames, IA.

The revised fifth edition of Clinical Laboratory Animal Medicine: An Introduction is an accessible guide to basic information for conducting animal research safely and responsibly. It includes a review of the unique anatomic and physiologic...

McMillan, F. D. (ed). 2019. Mental Health and Well-being in Animals (2nd ed). CABI, Wallingford, UK.

This second edition is fully revised, expanded, and comprehensively updated with the most current knowledge about the full array of mental health issues seen in animals. Written by key opinion leaders, internationally-recognized experts and specialists...

Machado, M., Oliveira da Silva, I. J. 2019. Does farm animals experience emotions and feelings? Journal of Animal Behaviour and Biometeorology 7(4), 170-175.

In recent years, there has been a great increase in the interest of "emotion" and how it can be studied and translated from animals. Emotions arise when the brain receives an external stimulus, while the...

Špinka, M. 2019. Animal agency, animal awareness and animal welfare. Animal Welfare 28(1), 11–20.

In nature, animals need to actively engage with the environment in order to prosper in survival and reproduction. Hence, agency is a central adaptive characteristic of animal life. In this paper, I propose that from...

Riddle, E. R., Ali, A. B. A., Campbell, D. L. M. et al. 2018. Space use by 4 strains of laying hens to perch, wing flap, dust bathe, stand and lie down. PLOS ONE 13(1), e0190532.

The laying hen industry is implementing aviary systems intended to improve welfare by providing hens with more space and resources to perform species-specific behaviors. To date, limited research has examined spatial requirements of various strains...

Carter, E. 2018. Updated Code of Practice for the welfare of meat chickens and meat breeding chickens in England. Animal Welfare 27(2), 181-185.

Much of the content in the 2018 Code is similar to that found in previous guidance documents: the 2002 Code of Practice for the Welfare of Meat Chickens and Meat Breeding Chickens, and the 2011...

Paul, E. S., Edgar, J. L., Caplen, G. et al. 2018. Examining affective structure in chickens: valence, intensity, persistence and generalization measured using a Conditioned Place Preference Test. Applied Animal Behaviour Science 207, 39-48.

When measuring animals’ valenced behavioural responses to stimuli, the Conditioned Place Preference (CPP) test goes a step further than many approach-based and avoidance-based tests by establishing whether a learned preference for, or aversion to, the...

Bertin, A., Cornilleau, F., Lemarchand, J. et al. 2018. Are there facial indicators of positive emotions in birds? A first exploration in Japanese quail. Behavioural Processes 157, 470-473.

The positive aspect of emotions, like pleasure, remains overlooked in birds. Our aim was to contribute to the exploration of facial indicators of positive emotions. To observe contrasting emotional expressions, we used two lines of...

Zepp, M., Louton, H., Erhard, M. et al. 2018. The influence of stocking density and enrichment on the occurrence of feather pecking and aggressive pecking behavior in laying hen chicks. Journal of Veterinary Behavior 24, 9-18.

The housing conditions and environments experienced during the rearing period can influence the development of feather pecking in chickens during this time and in the subsequent laying period. The aim of this study was to...

Vargas-Galicia, A. J., Sosa-Montes, E. Rodríguez-Ortega, L. T. et al. 2017. Effect of litter material and stocking density on bone and tendon strength, and productive performance in broilers. Canadian Journal of Animal Science 97(4), 673-682.

Litter material and stocking density were evaluated on welfare-related variables and productive performance in broilers. Male chicks (n = 744, “Ross 308” strain) were raised on either tezontle (TEZ) or wood shavings (WS) litter, with...

Yin, L., Yang, H., Xu, L. et al. 2017. Feather performance, walking ability, and behavioral changes of geese in response to different stocking densities. Applied Animal Behaviour Science 196, 108-112.

In recent decades, goose production has become more specialized and widespread, and rearing geese in plastic wire-floor pens is common in China. This type of rearing pattern is more productive than other rearing patterns since...