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. 
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...

Eusemann, B. K., Baulain, U., Schrader, L. et al. 2018. Radiographic examination of keel bone damage in living laying hens of different strains kept in two housing systems. PLOS ONE 13(5), e0194974.

A high prevalence of deviations and fractures of the keel bone is a widespread welfare problem in laying hens. The aim of this study was to experimentally investigate this multifactorial problem throughout the laying period...

Toscano, M., Booth, F., Richards, G. et al. 2018. Modeling collisions in laying hens as a tool to identify causative factors for keel bone fractures and means to reduce their occurrence and severity. PLOS ONE 13(7), e0200025.

Keel fractures represent a major productivity and welfare issue for the laying hen industry with greater than 50% of birds in recent surveys across various commercial operations and nations exhibiting some form of damage by...

Grunauer, P. P., Walguarnery, J. W. 2018. Relative response to digital tablet devices and painting as sensory enrichment in captive chimpanzees. Zoo Biology 37(4), 269–273.

Digital devices, including tablet computers and other touchscreens, can potentially serve as flexible and convenient means for providing behavioral enrichment activities to captive primates. Despite increased interest in incorporating technology into enrichment programs, no direct...

Fuller, G., Murray, A., Thueme, M. et al. 2018. Behavioral and hormonal responses to the availability of forage material in Western lowland gorillas (Gorilla gorilla gorilla). Zoo Biology 37(1), 23–34.

We investigated how forage material affects indicators of welfare in three male Western lowland gorillas (Gorilla gorilla gorilla) at the Detroit Zoo. In addition to their maintenance diet and enrichment foods, the gorillas generally received...

McConnachie, E., Smid, A. M. C., Thompson, A. J. et al. 2018. Cows are highly motivated to access a grooming substrate. Biology Letters 14(8), 20180303.

In natural environments, cattle use trees and other abrasive surfaces to scratch and groom themselves. Modern indoor dairy cattle housing systems often lack appropriate grooming substrates, restricting the animals’ ability to groom. We assessed the...

de Almeida A. C., Palme, R., Moreira, N. 2018. How environmental enrichment affects behavioral and glucocorticoid responses in captive blue-and-yellow macaws (Ara ararauna). Applied Animal Behaviour Science 201, 125-135.

Captive animals are susceptible to chronic stress due to restricted space, lack of hiding places, presence of visitors, or the lack of resources that promote physical and mental stimuli. In birds, chronic stress can promote...

Hunniford, M. E., Widowski, T. M. 2018. Curtained nests facilitate settled nesting behaviour of laying hens in furnished cages. Applied Animal Behaviour Science 202, 39-45.

Egg location can be used to determine the nests that hens prefer, but it does not indicate whether the design of that nest satisfies a hen’s nesting motivation. Hens that are satisfied with the nest...

Hunniford, M. E., Mason, G. J., Widowski, T. M. 2018. Laying hens’ preferences for nest surface type are affected by enclosure. Applied Animal Behaviour Science 201, 7-14.

The nest surfaces preferred by hens are inconsistent with those typically provided in commercial settings. However, little research has explored hens’ preferences for commercially available nest surfaces. Our objective was to compare hens’ preferences for...

Liu, K., Xin, H., Shepherd, T. et al. 2018. Perch-shape preference and perching behaviors of young laying hens. Applied Animal Behaviour Science 203, 34-41.

Provision of perches in enriched colony or cage-free hen housing facilitates birds’ ability to express natural behaviors, thus enhancing animal welfare. Although considerable research has been conducted on poultry perches, further investigation is needed of...

Jung, L., Knierim, U. 2018. Are practice recommendations for the prevention of feather pecking in laying hens in non-cage systems in line with the results of experimental and epidemiological studies? Applied Animal Behaviour Science 200, 1-12.

Feather pecking (FP) in laying hens is an important animal welfare problem in practice, despite extensive research and increasing sources of advice for farmers. We aimed to give an overview over results from experimental and...

Gebhardt-Henrich, S. G., Toscano, M. J., Würbel, H. 2018. Use of aerial perches and perches on aviary tiers by broiler breeders. Applied Animal Behaviour Science 203, 24-33.

Perching, especially during the night, is an innate behaviour of chickens and the provision of perches is mandatory for laying hens in multiple countries. We examined whether broiler breeders of the fast (Ross 308) and...

Baxter, M., Bailie, C. L., O’Connell, N. E. 2018. Evaluation of a dustbathing substrate and straw bales as environmental enrichments in commercial broiler housing. Applied Animal Behaviour Science 200, 78-85.

The use of straw bales as an environmental enrichment is common for broiler chickens in enriched housing systems, however relatively little information exists about their effectiveness in improving welfare. There has also been no widespread...

Bailie, C. L., Baxter, M., O’Connell, N. E. 2018. Exploring perch provision options for commercial broiler chickens. Applied Animal Behaviour Science 200, 114-122.

Two related experiments involving broiler chickens are presented. Experiment 1 evaluated the use of six perch types: (1) an A-frame design (incorporating a platform and ramps), (2) a ‘flat top’ ramp, (3) a curved ramp...

Ekman, L., Nyman, A.-K., Landin, H. et al. 2018. Hock lesions in dairy cows in freestall herds: A cross-sectional study of prevalence and risk factors. Acta Vererinaria Scandinavica 60(1), 47.

Hock lesions (HL) in dairy cows are a common animal welfare problem in modern dairy production with freestall housing systems, but there are no large-scale studies addressing its epidemiology in Sweden. The aims of this...

Cornelius, N., Enstam‐Jaffe, K. Minier, D. et al., 2018. Increasing captive chimpanzee (Pan troglodytes) engagement with multi-step cognitive enrichment. American Journal of Primatology 80(S1), 19 (40th Meeting of the American Society of Primatologists Scientific Program, Abstract #23).

Environmental enrichment enhances the psychological well‐being of animals and is therefore a vital part of the husbandry of captive animals. Since chimpanzees are a cognitively complex species, they may especially benefit from enrichment programs that...

Campbell, D. L. M., Horton, B. J., Hinch, G. N. 2018. Using radio-frequency identification technology to measure synchronised ranging of free-range laying hens. Animals 8(11), 210.

Free-range laying hen systems provide individuals a choice between indoor and outdoor areas where range use may be socially influenced. This study used radio-frequency identification technology to track the ranging of individually-tagged hens housed in...

Perkovic, K., Mettke-Hofmann, C. 2018. Colour polymorphic Gouldian finches avoid complex backgrounds but prefer simple camouflage colours over white backgrounds. Applied Animal Behaviour Science, 206, 102-108.

Many animals blend in well with their environment known as camouflage which is a successful predator avoidance strategy. However, captive environments often do not allow for camouflage and may result in stress and reduced welfare...

Tahamtani, F. M., Pedersen, I. J., Toinon, C. et al. 2018. Effects of environmental complexity on fearfulness and learning ability in fast growing broiler chickens. Applied Animal Behaviour Science 207, 49-56.

Increasing environmental complexity, i.e. by providing environmental enrichment, has been suggested as a way to improve broiler chicken welfare. One issue affecting broiler welfare is the level of fearfulness of the flock. Exaggerated fear responses...

Norman, K. I., Weeks, C. A., Pettersson, I. C. et al. 2018. The effect of experience of ramps at rear on the subsequent ability of layer pullets to negotiate a ramp transition. Applied Animal Behaviour Science 208, 92-99.

In commercial situations, laying hens must negotiate levels to reach resources such as food, water and litter. Providing ramps in aviary systems reduces collisions and resultant keel bone fractures in adults. We investigated whether providing...

Stachowicz, J., Gygax, L., Hillmann, E. et al. 2018. Dairy goats use outdoor runs of high quality more regardless of the quality of indoor housing. Applied Animal Behaviour Science 208, 22-30.

For dairy goats in loose housing, access to an outdoor run has potential welfare benefits as it provides additional space, enables spatial separation and may offer items representing behavioural enrichment for the goats (e.g. brush...

Maia, C. M., Volpato, G. L. 2018. Individuality matters for substrate-size preference in the Nile tilapia juveniles. Journal of Applied Animal Welfare Science 21(4), 316-324.

Preference tests have usually been used to identify nonhuman animal preferences for welfare purposes (environmental enrichment), but they are mostly at the group level—that is, group preferences for resources or environmental conditions. However, a more...

Perdue, B. M., Beran, M. J., Washburn, D. A. 2018. A computerized testing system for primates: Cognition, welfare, and the Rumbaughx. Behavioural Processes 156, 37-50.

Innovations in apparatus technology come about for a variety of reasons such as the need to use the same methodology with various species, the opportunity to present dynamic and carefully controlled stimuli, the goal 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...

Heyworth, C., Olivo, D. 2018. Environmental and psychological enrichment for NHPs reimagined and repurposed. Laboratory Animal Science Professional 5(4) (December), 39-43.

This article describes creative enrichment ideas for nonhuman primates, including celery stalks embedded with seeds; paper rolled into tubes, braided and filled with fruit and seeds; pineapple crowns loaded with treats; dry spaghetti noodles coated...