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. 
Taylor, P. S., Hemsworth, P. H., Rault, J.-L. 2022. Environmental complexity: Additional human visual contact reduced meat chickens’ fear of humans and physical items altered pecking behavior. Animals 12(3), 310.

Increased environmental complexity can improve animal welfare, depending on the resources provided and use by the animal. We provided chickens either with physical items that posed no biosecurity risk and were inexpensive (balls, chains, perches...

Campbell, D. L. M., Belson, S., Dyall, T. R. et al. 2022. Impacts of rearing enrichments on pullets’ and free-range hens’ positive behaviors across the flock cycle. Animals 12(3), 280.

Enrichment during the indoor rearing of pullets destined for free-range systems may optimize pullet development including increasing motivated natural behaviors (termed ‘positive behaviors’) including foraging, dust bathing and chick play. Hy-Line Brown® chicks (n =...

Ratuski, A. S., Weary, D. M. 2022. Environmental enrichment for rats and mice housed in laboratories: A metareview. Animals 12(4), 414.

Environmental enrichment has been widely studied in rodents, but there is no consensus on what enrichment should look like or what it should achieve. Inconsistent use of the term “enrichment” creates challenges in drawing conclusions...

Rowe, E., Mullan, S. 2022. Advancing a “good life” for farm animals: Development of resource tier frameworks for on-farm assessment of positive welfare for beef cattle, broiler chicken and pigs. Animals 12(5), 565.

There is increasing recognition that farm animal welfare standards should ensure positive welfare, as well as prevent negative welfare. Resources that are valued by an animal and that provide opportunities to engage in motivated behaviours...

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...

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...

Sandilands, V., Baker, L., Donbavand, J. et al. 2022. Do hens use enrichments provided in free-range systems? Animals 12(8), 995.

Hens in free-range systems are given enrichments to increase foraging and limit injurious pecking, but the efficacy of enrichment types requires investigation. We studied hen behaviour and feather cover in eight commercial free-range flocks each...

Stryjek, R., Modlinska, K. 2022. Pre-exposure via wire-mesh partition reduces intraspecific aggression in male, wild-type Norway rats. Animal Welfare 31(2), 175-186.

There are instances when animals are introduced and expected to live alongside unfamiliar conspecifics within zoos, laboratories and wildlife sanctuaries. These pairings of unfamiliar animals may result in stress, trauma, or even death, in addition...

Kapusta, J., Kruczek, M., Pochroń, E. et al. 2022. Welfare of encaged rodents: Species specific behavioral reaction of voles to new enrichment items. Applied Animal Behaviour Science 246, 105522.

The enrichment of the environment of captive animals is one of the methods applied to reduce stress of the animals and to assure their proper welfare. However, placing objects in a limited space of a...

Kitchenham, L., Nazal, B., Adcock, A. et al. 2022. Why does lifelong conventional housing reduce the sociability of female mice? Applied Animal Behaviour Science 246, 105532.

Compared to peers raised in well-resourced, 'enriched' environments (‘EE’), female laboratory mice from conventional barren cages are more aggressive to their cage-mates, and less sociable with familiar non-cage-mates (especially if these too are from conventional...

Vasdal, G., Gebhardt-Henrich, S.G., Kittelsen, K.E. et al. 2022. Commercial broiler breeder pullet hens use perches but show no preference for perch type or height. Applied Animal Behaviour Science 249, 105608.

An important behavioral need for laying hens is perching, but few studies have investigated perching behavior in commercial broiler breeder pullets. The aim of this study was to investigate perching behavior throughout the pullet period...

Denommé, M. R., Mason, G. J. 2022. Social buffering as a tool for improving rodent welfare. JAALAS 61(1), 5-14.

The presence of a conspecific can be calming to some species of animal during stress, a phenomenon known as social buffering. For rodents, social buffering can reduce the perception of and reaction to aversive experiences...

Habenicht, L. M., Staley, A. W., Clancy, B. M. et al. 2022. Characterization of a jumping stereotypy in gerbils (Meriones unguiculatus) and assessment of opaque tubing enrichment on stereotypies and breeding. JAALAS 61(2), 149-158.

Mongolian gerbils can develop stereotypic behaviors, including corner digging. At our institution, gerbils also engage in repetitive corner jumping, which we sought to characterize as a potentially novel stereotypy in gerbils. We then attempted to...

Hobbiesiefken, U., Mieske, P., Lewejohann, L. et al. 2021. Evaluation of different types of enrichment - their usage and effect on home cage behavior in female mice. PLOS ONE 16(12), e0261876.

Numerous studies ascertained positive effects of enriched environments on the well-being of laboratory animals including behavioral, physiological and neurochemical parameters. Conversely, such conclusions imply impaired animal welfare and health in barren husbandry conditions. Moreover, inappropriate...

Stevens, C., Dobbinson, K., Brook, E. et al. 2022. Report of the 2021 RSPCA/UFAW Rodent Welfare Group meeting. Animal Technology and Welfare 21(2), 83-91.

The RSPCA/UFAW Rodent Welfare Group has held a one-day meeting every autumn for the last 28 years, so that its members can discuss current welfare research, exchange views on welfare issues and share experiences of...

Birolo, M., Trocino, A., Zuffellato, A. et al. 2022. Use of gnawing hay blocks: Effects on productive performance, behavior and reactivity of growing rabbits kept in parks with different sex-group compositions. Animals 12(9), 1212.

To improve animal welfare in collective park housing systems, this study assessed the effects of the provision of gnawing hay blocks and the group composition (F: females, M: males, FM: mixed sex) on performance, behavior...

Son, J., Lee, W.-D., Kim, H.-J. et al. 2022. Effect of providing environmental enrichment into aviary house on the welfare of laying hens. Animals 12(9), 1165.

This study aimed to determine the effects of providing environmental enrichment materials—pumice stone and alfalfa hay—to laying hens in the aviary system. A total of 2196 40-week-old Hy-Line Brown laying hens were randomly allotted to...

Vasdal, G., Gebhardt-Henrich, S. G., Tahamtani, F. et al. 2022. Perch use in commercial broiler breeders – Preference for perch material and effect of age. Applied Animal Behaviour Science 253, 105680.

Unlike for laying hens in most European countries, few broiler breeders have access to perches, and there is a need for more knowledge on perching behavior in broiler breeders. The aim of this study was...

Aldhshan, M. S., Mizuno, T. M. 2022. Effect of environmental enrichment on aggression and the expression of brain-derived neurotrophic factor transcript variants in group-housed male mice. Behavioural Brain Research 433, 113986.

Social and environmental factors influence behavior via modulation of brain physiological functions. Environmental enrichment (EE) is an animal housing technique that provides complex sensory, motor, and social stimulation, leading to modifications in the innate aggressiveness...

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...

Mieske, P., Hobbiesiefken, U., Fischer-Tenhagen, C. et al. 2022. Bored at home?—A systematic review on the effect of environmental enrichment on the welfare of laboratory rats and mice. Frontiers in Veterinary Science 9, 899219.

Boredom is an emotional state that occurs when an individual has nothing to do, is not interested in the surrounding, and feels dreary and in a monotony. While this condition is usually defined for humans...

Corredor, K., Marín, D. P., García, C. C. et al. 2022. Providing environmental enrichment without altering behavior in male and female Wistar rats (Rattus norvegicus). JAALAS 61(3), 234-240.

In research using animal models, subjects are commonly maintained under standard housing conditions, mainly because of the idea that enhancing welfare conditions could alter experimental data. Another common practice in many laboratories relates to the...

Hinchcliffe, J. K., Jackson, M. G., Robinson, E. S. 2022. The use of ball pits and playpens in laboratory Lister Hooded male rats induces ultrasonic vocalisations indicating a more positive affective state and can reduce the welfare impacts of aversive procedures. Laboratory Animals 56(4), 370-379.

The advancement and quality of science rely on research that is robust and unbiased in its experimental design, execution, analysis, and reproducibility. In preclinical research, a better understanding of animal emotions and refinement of their...

Abazaris, J., Hashway, S. 2022. Vole husbandry at Colorado University Boulder. Laboratory Animal Science Professional 10(4) (July/August), 12-15.

Since they arrived at CU Boulder, we have learned a lot about the voles from the laboratory, other institutions, and our trial-and-error. We hope this information can be helpful to any considering adding voles to...

Pantophlet, J., McClusky, D. 2022. Compressed paper column housing enrichment for Naked Mole-rats. Laboratory Animal Science Professional 10(5) (September/October), 42-44.

Naked Mole-rats are relative newcomers in the research world. Due to the complexity of their natural subterranean tunneling system, it has been difficult to replicate in the laboratory environment. Housing standards often differ from the...