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. 
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...

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...

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...

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...

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...

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...

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...

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...

Decina, C., Berke, O., van Staaveren, N. et al. 2019. An investigation of associations between management and feather damage in Canadian laying hens housed in furnished cages. Animals 9(4), 135.

Feather pecking is a continuous welfare challenge in the housing of egg-laying hens. Canada is currently making the transition from conventional cages to alternative housing systems. However, feather damage (FD) among laying hens due to...

Nie, C., Ban, L., Ning, Z. et al. 2019. Feather colour affects the aggressive behaviour of chickens with the same genotype on the dominant white (I) locus. PLOS ONE 14(5), e0215921.

Aggression in chickens is a serious economic and animal welfare issue in poultry farming. Pigmentation traits have been documented to be associated with animal behaviour. Chicken pecking behaviour has been found to be related to...

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...

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...

Mellor, E., Brilot, B., Collins, S. 2018. Abnormal repetitive behaviours in captive birds: a Tinbergian review. Applied Animal Behaviour Science. 198, 109-120.

Abnormal repetitive behaviours (ARBs) are associated with past, or present, welfare problems and are common elements of the behavioural repertoire of some captive animals, including birds. Millions of birds from hundreds of species are held...

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...

Ekesbo, I., Gunnarsson, S. 2018. Farm Animal Behaviour: Characteristics for Assessment and Welfare (2nd ed). CABI, Wallingford, UK.

Completely updated and revised, and with a new author team, this second edition of Farm Animal Behaviour continues to provide essential information on normal and stereotypic behaviors in a wide variety of farm animals to...

Marino, L. 2017. Thinking chickens: A review of cognition, emotion, and behavior in the domestic chicken. Animal Cognition 20(2), 127–147.

Domestic chickens are members of an order, Aves, which has been the focus of a revolution in our understanding of neuroanatomical, cognitive, and social complexity. At least some birds are now known to be on...

Edgar, J., Held, S., Paul, E. et al. 2015. Social buffering in a bird. Animal Behaviour 105, 11-19.

The presence of a conspecific can ameliorate an individual's stress response. This social buffering is known to be widespread in social mammals but the capacity of birds to act as social buffers has not yet...