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. 
Sokołowicz, Z., Dykiel, M., Topczewska, J. et al. 2020. The effect of the type of non-caged housing system, genotype and age on the behaviour of laying hens. Animals 10(12), 2450.

This study investigated the welfare of laying hens in different non-caged housing systems, namely a deep-litter barn system (BS), a free-range system (FRS) and an organic system (OS). The study was conducted on 270 hens...

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...

Moroki, Y. 2019. Sham dustbathing in cages by subordinate hens is increased by a partition providing isolation. Applied Animal Behaviour Science 210, 68-72.

Subordinate hens express less sham dustbathing in cages than higher ranked hens, their bouts often being disturbed by a higher ranked hen. However, seeing conspecifics seems to encourage this behaviour by hens. So to avoid...

Harris, K., New, R., Smith, P. et al. 2019. Refinement: promoting Gallus Gallus welfare in an experimental poultry unit. Animal Technology and Welfare 18(2), 137-139. (IAT Congress 2018 Poster Presentation)

The poultry team at The Pirbright Institute reviewed existing husbandry practices and trialled several refinement practices. The objective was to provide the birds used in research with an environment which enables them to express their...

Ali, A. B. A., Campbell, D. L. M., Karcher, D. M. et al. 2019. Daytime occupancy of resources and flooring types by 4 laying hen strains in a commercial-style aviary. Journal of Veterinary Behavior 31, 59-66.

In response to consumer demands and legislative measures for improving hens' welfare, many laying hen producers are replacing conventional cages with aviaries. Aviary resources, such as nest boxes, litter areas, ledges, and perches, are intended...

Cox, R. J., Nol, P., Ellis, C. K. et al. 2019. Research with agricultural animals and wildlife. ILAR Journal 60(1), 66-73.

In fiscal year 2016, agricultural animals such as swine, sheep, goats, and cattle represented 10% of the 820 812 animals used in USDA-regulated research. In addition to traditional agricultural animals, research studies using captive wildlife...

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...

Hubert, S., Al-Ajeeli, M., Bailey, C. et al. 2019. The role of housing environment and dietary protein source on the gut microbiota of chicken. Animals 9(12), 1085.

The gut microbiota of chicken has received much attention due to its importance for bird health, food safety, and performance. In the United States, the impending transition to cage-free housing environments has raised many questions...

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...

Jansson, D.S. 2018 Gaining insights into the health of non-caged layer hens. Veterinary Record 182(12), 347-349.

To prevent injuries and mortality in commercial non-caged laying hens a range of strategies should be used, including vaccination, effective biosecurity routines, optimal management and nutrition. Injurious pecking, footpad lesions, keel bone fractures, reproductive and...

Chen, S., Xiang, H., Zhu, X. et al. 2018. Free dietary choice and free-range rearing improve the product quality, gait score, and microbial richness of chickens. Animals 8(6), 84.

Poultry welfare has been extensively studied; however, there is a lack of rigorous scientific knowledge relating to the different aspects of welfare factors and how this may contribute to the production quantity and product quality...

Chuppava, B., Visscher, C., Kamphues, J. 2018. Effect of different flooring designs on the performance and foot pad health in broilers and turkeys. Animals 8(5), 70.

Litter quality has a significant influence on the performance and foot pad health in poultry. The objective of this study was to evaluate the effects of different types of flooring designs on the performance and...

Sirovnik, J., Stratmann, A., Gebhardt-Henrich, S. G. et al. 2018. Feeding from perches in an aviary system reduces aggression and mortality in laying hens. Applied Animal Behaviour Science 202, 53-62.

Some commercial aviary systems for laying hens allow birds to access feed by standing on perches instead of platforms. Despite reports that providing laying hens with perches relates to reduced aggression and cannibalism, and increased...

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...

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...

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...

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...

Edwards, G. L., Michael, J. A., Parks., A. 2018. Agricultural animals as biomedical models: Occupational health and safety considerations. ILAR Journal 59(2), 161-167.

The use of agricultural animals in biomedical research is increasing. Their overall size and metabolic rate, organ size, longer gestation period, and other physiological similarities make them good candidates for animal models of human disease...

Larsen, H., Cronin, G., Smith, C. L. et al. 2017. Behaviour of free-range laying hens in distinct outdoor environments. Animal Welfare 26(3), 255-264.

The outdoor range in free-range, egg-production systems contains features that aim to promote the performance of natural behaviours. It is unclear what features of the range laying hens prefer and how these influence hen behaviour...

Bestman, M., Verwer, C., Brenninkmeyer, C. et al. 2017. Feather-pecking and injurious pecking in organic laying hens in 107 flocks from eight European countries. Animal Welfare 26(3), 355-363.

Feather-pecking and cannibalism may reduce the potential of organic husbandry to enhance the welfare of laying hens. We report risk factors for these issues based on a large survey of 107 commercial flocks in eight...

Nordquist, R., van der Staay, F., van Eerdenburg, F. et al. 2017. Mutilating procedures, management practices, and housing conditions that may affect the welfare of farm animals: Implications for welfare research. Animals 7(2), 12.

A number of mutilating procedures, such as dehorning in cattle and goats and beak trimming in laying hens, are common in farm animal husbandry systems in an attempt to prevent or solve problems, such as...

Hunniford, M. E., Widowski, T. M. 2017. Nest alternatives: Adding a wire partition to the scratch area affects nest use and nesting behaviour of laying hens in furnished cages. Applied Animal Behaviour Science 186, 29-34.

Furnished cages (FC) are designed to accommodate highly motivated behaviour patterns like nesting; however, how hens perceive the resources provided in FCs is not fully understood. Our previous research of hens in FCs with a...

Pettersson, I. C., Weeks, C. A., Nicol, C. J. 2017. The effect of ramp provision on the accessibility of the litter in single and multi-tier laying hen housing. Applied Animal Behaviour Science 186, 35-40.

Level changes in commercial laying hen loose-housing systems may be physically difficult for birds to negotiate, preventing or limiting access to resources such as the litter area and the outdoor range, and potentially increasing injury...

Stadig, L. M., Rodenburg, T. B., Ampe, B. et al. 2017. Effect of free-range access, shelter type and weather conditions on free-range use and welfare of slow-growing broiler chickens. Applied Animal Behaviour Science 192, 15-23.

Free-range access for broiler chickens can benefit animal welfare because the birds have access to a more natural environment and more opportunities to perform natural behaviours than in indoor systems. Also, they have more space...

Rault, J.-L., Taylor, P. S. 2017. Indoor side fidelity and outdoor ranging in commercial free-range chickens in single- or double-sided sheds. Applied Animal Behaviour Science 194, 48-53.

The ranging behaviour of broiler chickens kept in free-range housing systems remains poorly understood, despite access to the outdoor range being their main feature. We investigated the impact of allowing chickens to have range access...