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. 
Robinson, L. M., Weiss, A. (Eds.) 2023. Nonhuman Primate Welfare: From History, Science, and Ethics to Practice. Springer, Cham, Switzerland. 671 p.

This volume reviews the broad topic of welfare in nonhuman primates under human care. Chapters detail the history of primates in captivity, ethical and legal issues surrounding the use of nonhuman primates as entertainment or...

Evans, L., Brooks, G. C., Anderson, M. G. et al. 2023. Environmental complexity and reduced stocking density promote positive behavioral outcomes in broiler chickens. Animals 13(13), 2074.

The objective was to evaluate the impacts of a complex environment and stocking density on Ross 708 broiler chicken behaviors. Eight pens contained either high complexity (HC) or low complexity (LC) environments, and high (HD)...

Verspeek, J., Stevens, J. M. G. 2023. Behavioral and physiological response to inequity in bonobos (Pan paniscus). American Journal of Primatology 85(1), e23455.

Inequity aversion (IA), the affective, cognitive, and behavioral response to inequitable outcomes, allows individuals to avoid exploitation and therefore stabilizes cooperation. The presence of IA varies across animal species, which has stimulated research to investigate...

Machado, M., Freitas Silveira, R. M., Machado Bittar, C. M. et al. 2023. Can the emotional state of calves be noticed by their facial expression and heart rate? Applied Animal Behaviour Science 260, 105874.

The aim of this study was to identify whether or not dairy calves change their facial expression and heart rate according to their emotional state when subjected to a stroking or umbrella stimulus. Thirty-two mixed-breed...

Hanh, H. Q., Phuong, N. T., Tien, N. D. et al. 2023. Effects of stocking density in group cages on egg production, profitability, and aggressive pecking of hens. Journal of Applied Animal Welfare Science 26(3), 374–385.

There is an increasing concern about welfare issues related to battery cages, which are commonly used in Vietnam, and requires a modified cage that improves hen welfare while retaining its economic and management advantages. We...

Mocz, F., Michel, V., Janvrot, M. et al. 2022. Positive effects of elevated platforms and straw bales on the welfare of fast-growing broiler chickens reared at two different stocking densities. Animals 12(5), 542.

In conventional rearing systems, fast-growing broiler chickens commonly experience welfare issues, such as contact dermatitis, walking difficulties or a lack of expression of species-specific behaviours. Enriching their environment may be a way to improve their...

Lambert, H., Elwin, A., D’Cruze, N. 2022. Frog in the well: A review of the scientific literature for evidence of amphibian sentience. Applied Animal Behaviour Science 247, 105559.

Millions of amphibians are traded annually around the world for the exotic pet industry. Their experience during both trade, and in captivity as pets, leads to numerous animal welfare issues. The poor welfare of many...

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...

van der Eijk, J. A. J., Gunnink, H., Melis, M. et al. 2022. Reducing stocking density benefits behaviour of fast- and slower-growing broilers. Applied Animal Behaviour Science 257, 105754.

The broiler industry has come under sustained pressure from welfare organizations to improve broiler welfare. Breed and stocking density are important factors for broiler welfare and are often specified as criteria for higher welfare systems...

Phillips, H. N., Heins, B. J. 2021. Effects of outdoor stocking density on growth, feather damage and behavior of slow-growing free-range broilers. Animals 11(3), 688.

Access to pasture is a main benefit of free-range broiler housing systems, yet the level of outdoor stocking density on broiler animal welfare remains unsettled. The growth, feather damage, pasture ranging and behaviors were assessed...

Anderson, M. G., Campbell, A. M., Crump, A. et al. 2021. Effect of environmental complexity and stocking density on fear and anxiety in broiler chickens. Animals 11(8), 2383.

Barren housing and high stocking densities may contribute to negative affective states in broiler chickens, reducing their welfare. We investigated the effects of environmental complexity and stocking density on broilers’ attention bias (measure of anxiety)...

Travain, T., Valsecchi, P. 2021. Infrared thermography in the study of animals’ emotional responses: A critical review. Animals 11(9), 2510.

Whether animals have emotions was historically a long-lasting question but, today, nobody disputes that they do. However, how to assess them and how to guarantee animals their welfare have become important research topics in the...

Forslind, S., Blokhuis, H. J., Riber, A. B. 2021. Disturbance of resting behaviour of broilers under different environmental conditions. Applied Animal Behaviour Science 242, 105425.

Resting behaviours make up a large part of the daily time budget of broilers. However, in intensive broiler production systems disruptions of resting behaviours occur, where resting individuals get disturbed by active individuals. Such interruptions...

MacLellan, A., Fureix, C., Polanco, A. et al. 2021. Can animals develop depression? An overview and assessment of “depression-like” states. Behaviour 158(14/15), 1303–1353.

Describing certain animal behaviours as 'depression-like' or 'depressive' has become common across several fields of research. These typically involve unusually low activity or unresponsiveness and/or reduced interest in pleasure (anhedonia). While the term 'depression-like' carefully...

Campbell, D. L. M., Lee, C. 2021. A perspective on strategic enrichment for brain development: Is this the key to animal happiness? Frontiers in Veterinary Science 8, 720422.

Livestock animals are sentient beings with cognitive and emotional capacities and their brain development, similar to humans and other animal species, is affected by their surrounding environmental conditions. Current intensive production systems, through the restrictions...

da Silva Medeiros Elidio, H., Coelho, J. W. R., Cavalcanti Pereira da Silva, L. C. et al. 2021. Housing density and aggression in Syrian hamsters. JAALAS 60(5), 506-509.

The Syrian hamster (Mesocricetus auratus) is a solitary and naturally territorial animal, with female hamsters being more aggressive than males. This behavior makes handling difficult because they are usually housed in groups, which can lead...

Anderson, M. G., Campbell, A. M., Crump, A. et al. 2021. Environmental complexity positively impacts affective states of broiler chickens. Scientific Reports 11(1), 16966.

Affective state can bias an animal’s judgement. Animals in positive affective states can interpret ambiguous cues more positively (“optimistically”) than animals in negative affective states. Thus, judgement bias tests can determine an animal’s affective state...

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...

Andrade, B. M.T., Freire-Filho, R., Bezerra, B. 2020. The behaviours of a female blonde capuchin (Sapajus flavius) towards her dead infant. Behaviour 157(14/15), 1231-1238.

Here we describe the behaviour of a female blonde capuchin (Sapajus flavius) towards her dead infant and discuss possible explanations linked to the anecdotal event. We conducted our study in a fragment of Atlantic forest...

Bessa Ferreira, V. H., De Paiva Fonseca, E., Chagas, Correia Santos Das, A. C. et al. 2020. Personality traits modulate stress responses after enclosure change of captive capuchin monkeys (Sapajus libidinosus). Applied Animal Behaviour Science 232, 105111.

Husbandry procedures may cause behavioral and physiological changes to animals living in captivity. However, an individual’s reaction is not uniform and may be related to different coping strategies. In this study, we analyzed whether and...

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...

Brscic, M., Dam Otten, N., Contiero, B. et al. 2019. Investigation of a standardized qualitative behaviour assessment and exploration of potential influencing factors on the emotional state of dairy calves. Animals 9(10), 757.

Assessing emotional states of dairy calves is an essential part of welfare assessment, but standardized protocols are absent. The present study aims at assessing the emotional states of dairy calves and establishing a reliable standard...

Lambert, H., Carder, G., D'Cruze, N. 2019. Given the cold shoulder: A review of the scientific literature for evidence of reptile sentience. Animals 9(10), 821.

We searched a selection of the scientific literature to document evidence for, and explorations into reptile sentience. The intention of this review was to highlight; (1) to what extent reptile capability for emotions have been...

Finkemeier, M.-A., Oesterwind, S., Nürnberg, G. et al. 2019. Assessment of personality types in Nigerian dwarf goats (Capra hircus) and cross-context correlations to behavioural and physiological responses. Applied Animal Behaviour Science 217, 28-35.

The assessment of personality in farm animals and its relation to other behavioural and physiological traits is of growing scientific and practical interest. Therefore, the aims of the present study were first to assess the...