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. 
Wang, C., Yang, C., Zeng, Y. et al. 2023. GnRH-immunocastration: An alternative method for male animal surgical castration. Frontiers in Veterinary Science 10.
Sweet, R., Cheyne, S. 2023. Hierarchical position of individual captive western lowland gorillas Gorilla gorilla gorilla and its impact on neighbour associations and behaviour. Journal of Zoo and Aquarium Research 11(2), 259–266.

This study investigated the social relationships observed within a captive breeding group of western lowland gorillas Gorilla gorilla gorilla at a European Association of Zoos and Aquaria (EAZA) accredited facility: Blackpool Zoo, UK. Gorillas are...

Baker, P. E., Nicol, C. J., Weeks, C. A. 2022. The effect of hard pecking enrichment during rear on feather cover, feather pecking behaviour and beak length in beak-trimmed and intact-beak laying hen pullets. Animals 12(6), 674.

Injurious pecking, commonly controlled by beak trimming (BT), is a widespread issue in laying hens associated with thwarted foraging. This controlled study compared the effect in intact and beak-trimmed pullets of providing pecking pans to...

Orient, E., Guillén‐Salazar, F. 2022. Evaluation of social compatibility in an all‐male group of chimpanzees (Pan troglodytes) by means of social network analysis. Zoo Biology 41(1), 84-93.

The study here presented provides preliminary data regarding social compatibility of an all-male group of five chimpanzees (Pan troglodytes), assessed by means of a social network analysis (SNA). The study was conducted at the Fundació...

Knaebe, B., Weiss, C. C., Zimmermann, J. et al. 2022. The promise of behavioral tracking systems for advancing primate animal welfare. Animals 12(13), 1648.

Recent years have witnessed major advances in the ability of computerized systems to track the positions of animals as they move through large and unconstrained environments. These systems have so far been a great boon...

Fultz, A., Yanagi, A., Breaux, S. et al. 2022. Aggressive, submissive, and affiliative behavior in sanctuary chimpanzees (Pan Troglodytes) during social integration. Animals 12(18), 2421.

Chimp Haven is a sanctuary for chimpanzees being retired from biomedical research and from facilities that can no longer care for them. Chimpanzees often live in smaller groups in captive settings; however, Chimp Haven integrates...

Lee, V. E., Arnott, G., Turner, S. P. 2022. Social behavior in farm animals: Applying fundamental theory to improve animal welfare. Frontiers in Veterinary Science 9, 932217.

A fundamental understanding of behavior is essential to improving the welfare of billions of farm animals around the world. Despite living in an environment managed by humans, farm animals are still capable of making important...

Escribano, D., Doldán-Martelli, V., Cronin, K. A. et al. 2022. Chimpanzees organize their social relationships like humans. Scientific Reports 12(1), 16641.

Human relationships are structured in a set of layers, ordered from higher (intimate relationships) to lower (acquaintances) emotional and cognitive intensity. This structure arises from the limits of our cognitive capacity and the different amounts...

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...

Funkhouser, J. A., Mayhew, J. A., Mulcahy, J. et al. 2021. Human caregivers are integrated social partners for captive chimpanzees. Primates 62(2), 297–309.

In a captive environment, it is challenging to ensure the highest level of social and psychological well-being for species with naturally complex social organizations and structures. There is a growing need to meet the social...

Tahamtani, F. M., Herskin, M. S., Foldager, L. et al. 2021. Assessment of mobility and pain in broiler chickens with identifiable gait defects. Applied Animal Behaviour Science 234, 105183.

Gait defects, assessed as gait score (GS), is a common welfare problem in broiler chicken production. The aim of this study was to examine whether birds with GS2 experience pain and poor locomotor ability compared...

Leeds, A., Boyer, D., Ross, S. R. et al. 2021. Patterns of wounding in mixed-sex social groups of western lowland gorillas (Gorilla gorilla gorilla). Applied Animal Behaviour Science 236, 105226.

Long-term, multi-institutional assessments have become a reliable tool for evaluating patterns of wounding in zoo-living primates, with results informing on best practices for species-specific care protocols and population management strategies. For western lowland gorillas (Gorilla...

Kittelsen, K. E., Gretarsson, P., Jensen, P. et al. 2021. Keel bone fractures are more prevalent in White Leghorn hens than in Red Jungle fowl hens—A pilot study. PLOS ONE 16(7), e0255234.

Fractures and deviations to the keel bone are common in commercial laying hens, with reported variations in occurrence across strains and breeds. The aetiology is not fully understood, however, modern genetics and selection for efficient...

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...

Gartland, K. N., Carrigan, J., White, F. J. 2021. Preliminary relationship between overnight separation and wounding in bachelor groups of western lowland gorillas (Gorilla gorilla gorilla). Applied Animal Behaviour Science 241, 105388.

Despite no significant difference in wounding between bachelor and mixed-sex groups of western lowland gorillas (Gorilla gorilla gorilla) in zoological settings, anecdotal concerns around the frequency and severity of wounding in bachelor groups have perpetuated...

Pfoh, R., Tiddi, B., Di Bitetti, M. S. et al. 2021. Grooming site preferences in black capuchin monkeys: Hygienic vs. social functions revisited. American Journal of Primatology 83(12), e23336.

When primates groom each other, they tend to concentrate on those parts of the body they cannot efficiently self-groom (i.e., not visually accessible), and prefer to intensify grooming in areas with high hair density, thus...

Crailsheim, D., Stüger, H., P., Kalcher-Sommersguter, E. et al. 2020. Early life experience and alterations of group composition shape the social grooming networks of former pet and entertainment chimpanzees (Pan troglodytes). PLOS ONE 15(1), e0226947.

The long-term effects of early life adversities on social capacities have been documented in humans and wild-caught former laboratory chimpanzees (Pan troglodytes). However, former pet and entertainment chimpanzees have received little attention to date. This...

Piller, A., Bergmann, S., Schwarzer, A. et al. 2020. Validation of histological and visual scoring systems for foot-pad dermatitis in broiler chickens. Animal Welfare 29(2), 185-196.

In this study, an appropriate visual scoring system for foot-pad dermatitis was validated, considering the histologically measured depth of the inflammation zone and the histopathological grade (no lesion, mild lesion, ulcer). The aim being to...

Jones, P., Tahamtani, F., Pedersen, I. et al. 2020. The productivity and financial impacts of eight types of environmental enrichment for broiler chickens. Animals 10(3), 378.

Reduced mobility in broilers can contribute to leg health problems. Environmental enrichment has been suggested as one approach to combat this through stimulating increased physical activity. Past studies have tested the effect of environmental enrichments...

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...

Baker, S. L., Robison, C. I., Karcher, D. M. et al. 2020. Keel impacts and associated behaviors in laying hens. Applied Animal Behaviour Science 222, 104886.

Factors contributing to the development of keel bone damage are not well understood. This study aimed to identify behaviors and cage structures associated with acceleration events experienced by individual hens at their keels as the...

Thøfner, I., Hougen, H. P., Villa, C. et al. 2020. Pathological characterization of keel bone fractures in laying hens does not support external trauma as the underlying cause. PLOS ONE 15(3), e0229735.

Keel bone fractures in laying hens have been described with increasing prevalence from several countries over the last twenty years and are considered one of the greatest welfare problems to the layer industry. In Denmark...

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...

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...

Allanic, M., Hayashi, M., Matsuzawa, T., 2020. Investigating the function of mutual grooming in captive bonobos (Pan paniscus) and Chimpanzees (Pan troglodytes). Folia Primatologica 91, 481-494.

Social grooming is often exchanged between individuals in many primate species. Rates of bidirectional (or simultaneous mutual) grooming vary across primate species, and its function is not yet fully understood. For example, mutual grooming is...